An electrocoagulation treatment process was developed for treatment and upgrade of petroleum refinery effluent （wastewater）, instead of the conventional methods, which can consume higher amounts of chemicals and pro...An electrocoagulation treatment process was developed for treatment and upgrade of petroleum refinery effluent （wastewater）, instead of the conventional methods, which can consume higher amounts of chemicals and produce larger amounts of sludge. The effect of the operation parameters, such as current density, initial pH, anode material, anode dissolution, energy consumption and electrolysis time, on treatment efficiency was investigated. The experimental results showed that the effluent can be effectively treated under optimal conditions. Fourier transform infrared （FTIR） analysis of the effluent, and scanning electron microscopy （SEM） coupled with energy dispersive analysis of X-rays （EDAX） of the sludge produced, revealed that the unwanted pollutants can be eliminated. The electrocoagulation treatment process was assessed by using the removal efficiency of chemical oxygen demand （COD）, total suspended solids （TSS）, and the general physicochemical characteristics of wastewater, and the results showed that the electrocoagulation is an efficient process for recycling of petroleum wastewater; it is faster and provides better quality of treated water than the conventional methods.展开更多
Petroleum and Natural Gas still represent a considerable share in terms of energy consumption in the current global matrix, so that its exploration/exploitation is present in the market and driving activities in locat...Petroleum and Natural Gas still represent a considerable share in terms of energy consumption in the current global matrix, so that its exploration/exploitation is present in the market and driving activities in locations of specific complexities, as the ones along unconventional hydrocarbon resources from the Brazilian pre-salt. The daily cost of well drilling under harsh conditions can exceed US $1 million a day, turning any type of downtime or necessary maintenance during the activities to be very costly, moment in which processes optimization starts to be a key factor in costs reduction. Thus, new technologies and methods in terms of automating and optimizing the processes may be of great advantages, having its impact in total related project costs. In this context, the goal of this research is to allow a computation tool supporting achieving a more efficient drilling process, by means of drilling mechanics parameters choosiness aiming rate of penetration (ROP) maximization and mechanic specific energy (MSE) minimization. Conceptually, driven by the pre-operational drilling test curve trends, the proposed system allows it to be performed with less human influences and being updateable automatically, allowing more precision and time reduction by selecting optimum parameters. A Web Operating System (Web OS) was designed and implemented, running in online servers, granting accessibility to it with any device that has a browser and internet connection. It allows processing the drilling parameters supplied and feed into it, issuing outcomes with optimum values in a faster and precise way, allowing reducing operating time.展开更多
1.Introduction Climate change mitigation pathways aimed at limiting global anthropogenic carbon dioxide(CO_(2))emissions while striving to constrain the global temperature increase to below 2℃—as outlined by the Int...1.Introduction Climate change mitigation pathways aimed at limiting global anthropogenic carbon dioxide(CO_(2))emissions while striving to constrain the global temperature increase to below 2℃—as outlined by the Intergovernmental Panel on Climate Change(IPCC)—consistently predict the widespread implementation of CO_(2)geological storage on a global scale.展开更多
Morphology and growth rate of carbon dioxide hydrate on the interface between liquid carbon dioxide and humic acid solutions were studied in this work.It was found that after the growth of the hydrate film at the inte...Morphology and growth rate of carbon dioxide hydrate on the interface between liquid carbon dioxide and humic acid solutions were studied in this work.It was found that after the growth of the hydrate film at the interface,further growth of hydrate due to the suction of water in the capillary system formed between the wall of the cuvette and the end boundary of the hydrate layer occurs.Most probably,substantial effects on the formation of this capillary system may be caused by variations in reactor wall properties,for example,hydrophobic-hydrophilic balance,roughness,etc.We found,that the rate of CO_(2) hydrate film growth on the surface of the humic acid aqueous solution is 4-fold to lower in comparison with the growth rate on the surface of pure water.We suppose that this is caused by the adsorption of humic acid associates on the surface of hydrate particles and,as a consequence,by the deceleration of the diffusion of dissolved carbon dioxide to the growing hydrate particle.展开更多
This study investigates the mineralogy and mineral-chemistry of a newly discovered Au-Ag-Bi-Te mineralization at the Aydindere Fe-Cu skarn deposit,within the Pontides Tectonic Unit,northeastern Turkey.The mineralizati...This study investigates the mineralogy and mineral-chemistry of a newly discovered Au-Ag-Bi-Te mineralization at the Aydindere Fe-Cu skarn deposit,within the Pontides Tectonic Unit,northeastern Turkey.The mineralization is developed in the skarn zone at the contact between Upper Cretaceous andesite-pyroclastic rocks and a Paleocene–Eocene I-type granitoid.The principal ore minerals of the Aydindere Fe-Cu deposit are oxides(magnetite),sulfides(pyrite-chalcopyritegalena-sphalerite),tellurides/sulfotellurides(tetradymite,hessite),sulfosalts(wittichenite,emplectite,aikinite) and native gold-electrum.Skarn minerals include anhydrous phases(garnet) formed in a prograde stage and hydrous phases(amphibole,epidote,chlorite),which were formed in a retrograde stage in association with quartz,adularia,apatite and late calcite.Sulfides,tellurides and sulfosalts are introduced during the retrograde stage.The Au-Ag-Bi-Te mineralization was detected for the first time within the western ore body of the Aydindere deposit,and occurs in calcite-bearing sulfide bodies that cut magnetite-garnet-amphibole-epidote skarns with magnetite ores of different grade,including massive magnetite.Chlorite geothermometry indicates formation of the Au-Ag-BiTe mineralization at temperatures between 300 and 250 ℃,during the retrograde skarn evolution.Assuming the temperature is ~275 ℃,logfS_(2) =-10.5 to-13,logfO_(2) =-37 to-33,and logf Te2 values range from approximately-12 to-8.5 were estimated.The available mineralogical and geological data(presences of magnetite,oxidized-type tellurides/sulfotellurides,and andraditic garnets,and absence of pyrrhotite and arsenopyrite) suggest that Aydindere is an oxidized Au-bearing skarn deposit.The discovery of Au-Ag-Bi-Te mineralization at Aydindere increases its productivity and requires more detailed exploration in the deposit for precious(Au,Ag) and critical(Bi,Te) metals.展开更多
The utilization of liquefied petroleum gas (LPG) as an alternative automobile fuel in Nigeria was studied, focusing on varying different blend ratios of propane and butane as an alternative fuel in a single-cylinder, ...The utilization of liquefied petroleum gas (LPG) as an alternative automobile fuel in Nigeria was studied, focusing on varying different blend ratios of propane and butane as an alternative fuel in a single-cylinder, four-stroke, and spark ignition (SI) engine. Ricardo WAVE, 1-Dimensional engine simulator was used to model the internal combustion engine where the different blend ratios of propane and butane (P100, P90B10, P80B20, P70B30, P60B40 and P50B50) were tested and compared with a gasoline engine operating under same conditions. From the simulation results for the different LPG blends, there was no significant difference in the engine performance and emissions, but when compared with pure gasoline, it was observed that the LPG showed improved engine performance and lower emissions. The engine power output in using the blends was 25% higher compared to using gasoline;CO emission was 50% less, UHC was 20% less while NO<sub>x</sub> at low speed was significantly lower.展开更多
In the design of building structures,joint efforts must be decided to resolve the depth of competent layers across the intended site to safeguard the durability of civil engineering structures and to avert the disastr...In the design of building structures,joint efforts must be decided to resolve the depth of competent layers across the intended site to safeguard the durability of civil engineering structures and to avert the disastrous consequences of structural failure and collapse.In this study,an integrated methodology that employed DC resistivity tomography involving 2-D and 3-D techniques and geotechnical-soil analysis was used to evaluate subsoil conditions for engineering site investigation at Okerenkoko primary school,in the Warri-southwest area of Delta State,to adduce the phenomena responsible for the visible cracks/structural failure observed in the buildings.The results obtained brought to light the geological structure beneath the subsurface,which consists of four geoelectric layers identified as topsoil,dry/lithified upper sandy layer,wet sand(water-saturated)and peat/clay/sandy clayey soil(highly water-saturated).The deeply-seated peat/clay materials(ρ≤20Ωm)were delineated in the study area to the depths of 17.1 m and 19.8 m from 2-D and 3-D tomography respectively.3-D images presented as horizontal depth slices revealed the dominance of very low resistivity materials i.e.peat/clay/sandy clay within the fourth,fifth and sixth layers at depths ranging from 8.68-12.5 m,12.5-16.9 m and 16.9-21.9 m respectively.The dominance of mechanically unstable peat/clay/sandy clay layers beneath the subsurface,which are highly mobile in response to volumetric changes,is responsible for the noticeable cracks/failure detected on structures within the study site.These observations were validated by a geotechnical test of soil samples in the study area.Atterberg’s limits of the samples revealed plasticity indices of zero.Thus,the soil samples within the depth analyzed were representatives of sandy soil that does not possess any plasticity.The methods justifiably provided relevant information on the subsurface geology beneath the study site and should be appropriated as major tools for engineering site assessment/geotechnical projects.展开更多
Fluid imbibition from hydraulic fractures into shale formations is mainly affected by a combination of capillary forces and viscous resistance,both of which are closely related to the pore geometry.This study establis...Fluid imbibition from hydraulic fractures into shale formations is mainly affected by a combination of capillary forces and viscous resistance,both of which are closely related to the pore geometry.This study established five self-imbibition models with idealized pore structures and conducted a comparative analysis of these models.These models include circular,square,and equilateral triangular capillaries;a triangular star-shaped cross-section formed by three tangent spherical particles;and a traditional porous medium representation method.All these models are derived based on Newton’s second law,where capillary pressure is described by the Young-Laplace equation and viscous resistance is characterized by the Hagen-Poiret equation and Darcy’s law.All derived models predict that the fluid imbibition distance is proportional to the square root of time,in accordance with the classical Lucas-Washburn law.However,different pore structures exhibit significantly different characteristic imbibition rates.Compared to the single pore model,the conventional Darcy’s law-based model for porous media predicts significantly lower imbibition rates,which is consistent with the relatively slower uptake rates in actual shale nanoscale pore networks.These findings emphasize the important role played by pore geometry in fluid imbibition dynamics and further point to the need for optimizing pore structure to extend fluid imbibition duration in shale reservoirs in practical operations.展开更多
Renewable energy technologies, while often labeled as clean or net-zero alternatives to fossil fuels, involve substantial use of critical minerals in products like electric vehicles, solar panels, wind turbines, and b...Renewable energy technologies, while often labeled as clean or net-zero alternatives to fossil fuels, involve substantial use of critical minerals in products like electric vehicles, solar panels, wind turbines, and battery storage systems. This aspect is frequently underappreciated, yet studies indicate it could be a significant area of environmental impact. For instance, research has shown that a typical electric vehicle needs around six times the mineral resources of a conventional vehicle, while an onshore wind turbine requires nine times the mineral input compared to a gas power plant of similar capacity. This paper seeks to analyze the environmental effects linked to the critical minerals required by certain renewable energy technologies. The study begins with an estimation of the future megawatt capacities for each type of renewable technology. Next, it calculates the specific mineral quantities necessary for each model, followed by an assessment of the environmental repercussions tied to their extraction and processing. The results highlight the unique environmental challenges posed by the rising demand for minerals in solar and wind energy systems, taking into account various adoption scenarios.展开更多
Shale gas,a type of unconventional natural gas found within shale formations,has emerged as a significant source of energy globally.The West Bokaro Basin,part of the Damodar Valley,is known for its rich coal deposits ...Shale gas,a type of unconventional natural gas found within shale formations,has emerged as a significant source of energy globally.The West Bokaro Basin,part of the Damodar Valley,is known for its rich coal deposits and complex geological history.The basin's stratigraphy includes significant coal-bearing formations interbedded with shales,which may be potential sources of shale gas.The key formations in the basin include the Barakar Formation,which is the primary coal-bearing unit,and the Raniganj Formation,which contains substantial shale intervals.These formations exhibit varying thicknesses,organic content,thermal maturity,and mechanical strength,all of which are critical factors influencing shale gas potential.The assessment of shale gas potential in the West Bokaro Basin involves evaluating the organic richness,thermal maturity,pore characteristics,geochemistry,and mineralogy of the shale formations.Apart from organic richness and thermal maturity,the shale formations must be friable,as they generally lack natural permeability.This study aims to present a comprehensive analysis of the prospects of shale gas in the West Bokaro Basin based on the organic petrography,geochemistry,mineralogical study,Fourier Transform Infrared Spectroscopy(FTIR)analysis,and low-pressure N_(2) adsorption analysis.The dark color,greasy touch,and high total organic carbon(TOC)content(5.88%-22.84%)provided an initial clue for the shale's potential as a source rock.Results from organic petrographic analysis suggest that these shales contain kerogen type Ⅲ,which is a known indicator of gas-prone zones.The random vitrinite reflectance(R_(o),0.80%-0.91%)and the temperature of maximum pyrolysis yield(Tmax,434-448℃)indicate that the organic matter has attained the sufficient thermal maturity required for the generation of hydrocarbons.FTIR and X-ray diffraction(XRD)analyses identified inorganic entities and high quartz content in the shale samples,confirming their friability.The brittleness index(BI)calculated using X-ray fluorescence(XRF)data showed BI values above 0.48,indicating that the shales are brittle,which is advantageous for hydraulic fracturing.The high quartz content in the shale might act as a natural proppant,enhancing gas extraction efficiency.These findings suggest that the West Bokaro shales hold promise for economically viable shale gas production.展开更多
Hydraulic fracturing is a commonly used stimulation technique for production optimization in various geological formations such as tight sandstone,shale,coal bed methane,and heat extraction in geothermal reservoirs.Br...Hydraulic fracturing is a commonly used stimulation technique for production optimization in various geological formations such as tight sandstone,shale,coal bed methane,and heat extraction in geothermal reservoirs.Breakdown pressure is a vital component in hydraulic fracture job design,which is affected by various parameters including rock strength and depth.Various methods including modelling and experimental approaches exist to quantify the breakdown pressure.There have been many strategies to reduce this pressure for efficient and economical hydraulic fracture jobs,especially when this pressure exceeds pump capacity.This study provides a detailed review of breakdown pressure in terms of fundamentals,influencing factors,and estimation approaches.In addition,different strategies are also presented to reduce the breakdown pressure along with cost analysis.Lastly,research gaps pertinent to this area are highlighted for emphasis in future research.Specifically,it has been found that high breakdown pressure is associated with challenges,but there are no comprehensive techniques and strategies to lower this pressure in formations with very high in situ stress profiles or complicated tectonic settings.Developing such methods is important to minimize operational failures,lower costs and reduce the environmental risks during reservoir exploitation.This study reviews the fundamentals,influencing factors,and estimation methods of breakdown pressure and provides a deep understanding of the strategies for its reduction.The study also presents the cost analyses,and highlights research gaps for future investigation.展开更多
The preservation of the integrity of CO_(2) injection wells holds immense significance for the efficacy of Carbon Capture and Storage (CCS) projects.This is attributable to the fact that a wellbore exhibiting robust m...The preservation of the integrity of CO_(2) injection wells holds immense significance for the efficacy of Carbon Capture and Storage (CCS) projects.This is attributable to the fact that a wellbore exhibiting robust mechanical and flow integrity substantially diminishes the likelihood of CO_(2) leakage into the overlying aquifer or release to the atmosphere,thereby curtailing associated risks.Given the potential hazards and repercussions stemming from the failure of CO_(2) injection wells,encompassing environmental catastrophes,financial implications,and health risks,it is imperative to earnestly address these challenges through adept management and monitoring protocols.This study aims to advance the current understanding and enhance the management of wellbore integrity issues in CO_(2) injection wells.Accordingly,this review paper undertakes a thorough exploration of the primary factors influencing wellbore integrity in CO_(2) injection wells.Furthermore,it delineates a pressing necessity for more exhaustive investigations regarding the influence of CO_(2) injection rate,CO_(2) purity,and wellbore geometry on wellbore integrity.展开更多
Shale formations have recently gained plenty of attention owing to their large amounts of reserves.Horizontal drilling and hydraulic fracturing are the proposed approaches for the development of shale formations.The e...Shale formations have recently gained plenty of attention owing to their large amounts of reserves.Horizontal drilling and hydraulic fracturing are the proposed approaches for the development of shale formations.The extended information of the mechanical properties of shale formation is crucial for designing a successful hydraulic fracturing operation.On the other hand,the mechanical properties of such organic-rich formations are greatly affected by the mechanical characteristics of the present kerogen(organic matter),which dramatically changes during the maturation process.In this study,a Qingshankou shale sample containing kerogen type I is mechanically investigated at different maturity levels using the grid nanoindentation approach.To this end,the original immature sample is artificially matured during hydrous(HP)and anhydrous(AHP)pyrolysis.More than 930 nanoindentation tests were performed on grids of 9×8 on the surface of 13 samples with different maturities.The test results showed that the presence of water during pyrolysis can significantly affect the shale sample's mechanical characteristics.In higher temperatures and higher levels of maturity,the role of water becomes more pronounced.During hydrous pyrolysis,kerogen produces larger amounts of oil and bitumen,which become progressively porous.While the original sample showed a Young's modulus value of more than 48 GPa,and it fluctuated between approximately 19 and 32 GPa during the HP scenario and between 17 and 34 GPa during the AHP process.In terms of hardness,the original sample exhibited an initial value of about 1.1 GPa and more mature samples reflected hardness values in the range of approximately 0.3 and 0.97 GPa in both scenarios.According to the trends of mechanical properties during maturation,mechanical properties decreased at the initial stage of maturation and remained relatively constant during the oil window.Then,another decline was detected at the wet-gas window's closure.In the dry-gas window,HP and AHP scenarios exhibited different behaviors mainly due to the chemical structure of the kerogen residue.展开更多
Understanding the active tectonic processes in the Nandakini Watershed is imperative for evaluating geological hazards and seismic risks,as well as for informing land-use planning and natural resource management strat...Understanding the active tectonic processes in the Nandakini Watershed is imperative for evaluating geological hazards and seismic risks,as well as for informing land-use planning and natural resource management strategies in the region.Tectonic geomorphology serves as a vital tool for characterizing recent tectonic movements.This research employs GIS techniques to elucidate tectonic activity and its influence on drainage patterns in the Nandakini Watershed,utilizing morphometric parameters derived from SRTM DEM data.Morphometric indices are employed to assess the tectonic movement within drainage basins,capturing both areal and linear factors such as drainage density,texture,circulatory and bifurcation ratios,and stream length ratios.The linear and areal morphometric indices are categorized into three classes representing varying degrees of active tectonic activity.These classifications are then utilized to compute the relative active tectonic index(IRAT).In addition,geomorphic parameters include hypsometric integral,stream length-gradient index,normalized steepness index,chi gradient index,and swath profiles.The majority of the studied region is in an extremely high to moderately active tectonic zone.Large-scale faults and thrusts within the basins are closely correlated with these zones that have been identified.The integrated methodology of GIS-based morphometric analysis and geomorphic study enables the identification of deformed landforms associated with ongoing tectonic activity.Furthermore,these results offer valuable insights for informing watershed management strategies and promoting sustainable land use planning initiatives.展开更多
An important challenge in ensuring the long-term effectiveness of geological nuclear waste disposal is predicting the transportation of decay heat and gases released from nuclear waste canisters.In this study,thermo-h...An important challenge in ensuring the long-term effectiveness of geological nuclear waste disposal is predicting the transportation of decay heat and gases released from nuclear waste canisters.In this study,thermo-hydromechanical(THM)coupled simulations were conducted using the TOUGH + FLAC3D simulator to predict the THM behaviors of a generic nuclear waste repository over 100,000 years following closure.The designed engineered barrier system(EBS)consists of the waste canister,backfill,and concrete liner.The objective of this study is to evaluate the long-term performance of the repository in the presence of continued hydrogen(H_(2))and heat release around the canister.The simulation results show that thermal pressurization and gas accumulation significantly raise the pore pressure within the EBS and surrounding host rock,while the peak pore pressure is not likely to exceed the lithostatic stress so that there is no risk of widespread hydro-fracturing in the host rock.However,tension failure and fracturing can occur at the tunnel scale because of internal gas buildup.Meanwhile,the generated H_(2) continuously migrates outward and tends to accumulate in the concrete liner and excavation disturbed zone surrounding the tunnel because of lower capillary pressure.Nevertheless,the fluids that may contain radionuclides will not leach into the confining units over a 100,000-year time frame.Our analysis indicates that for the assumed disposal system in Opalinus Clay,the generated heat and gas can gradually be transported through the host rock without significantly disturbing the isolation characteristics of the repository.展开更多
By analyzing core data from an offshore Gulf of Mexico reservoir and developing analytical solutions,it can be demonstrated that laboratory measurements on pore-volume compressibility include artifacts,leading to a mi...By analyzing core data from an offshore Gulf of Mexico reservoir and developing analytical solutions,it can be demonstrated that laboratory measurements on pore-volume compressibility include artifacts,leading to a misinterpretation of porosity and permeability trends.A systematic evaluation of poro-elastic changes in pore volumes(and quantifying any consequent fluid expulsion during reservoir compaction)suggests that poro-elastic relaxation may enhance fluid production rates from deep reservoirs by up to 25%.This value may be inadvertently inflated if the core samples used for pore-volume compressibility measurements suffered from handling damage.Nonetheless,poro-elastic fluid expulsion from the pores in producing reservoirs can provide additional lift and thus may enhance the recovery factor.Therefore,the possible contribution to well performance from poro-elastic production drive mechanisms ought to be carefully evaluated in reserves estimation.Reversely,injection wells may encounter poro-elastic suppression of injectivity due to elastic resistance,which would adversely affect the storage coefficient.By integrating geomechanical reservoir response with traditional fluid production models,reservoir model predictions of production under pressure depletion and injection conditions will be more accurate.The new insights reported here are essential for optimizing well performance,improving reservoir management,and extending the economic life of geological reservoirs.However,caution is warranted regarding pore-volume compressibility measurements.To what degree laboratory measurements of pore-volume compressibility measure true values or mainly record handling damage could not be conclusively settled in the present study.展开更多
This article aims tomodel and analyze the heat and fluid flow characteristics of a carboxymethyl cellulose(CMC)nanofluid within a convergent-divergent shaped microchannel(Two-dimensional).The base fluid,water+CMC(0.5%...This article aims tomodel and analyze the heat and fluid flow characteristics of a carboxymethyl cellulose(CMC)nanofluid within a convergent-divergent shaped microchannel(Two-dimensional).The base fluid,water+CMC(0.5%),is mixed with CuO and Al2O3 nanoparticles at volume fractions of 0.5%and 1.5%,respectively.The research is conducted through the conjugate usage of experimental and theoretical models to represent more realistic properties of the non-Newtonian nanofluid.Three types of microchannels including straight,divergent,and convergent are considered,all having the same length and identical inlet cross-sectional area.Using ANSYS FLUENT software,Navier-Stokes equations are solved for the laminar flow of the non-Newtonian nanofluid.The study examines the effects of Reynolds number,nanoparticle concentration and type,and microchannel geometry on flow and heat transfer.The results prove that the alumina nanoparticles outperform copper oxide in increasing the Nusselt number at a 0.5% volume fraction,while copper oxide nanoparticles excel at a 1.5%volume fraction.Moreover,in the selected case study,as the Reynolds number increases from 100 to 500,the Nusselt number rises by 56.26% in straight geometry,52.93% in divergent geometry,and 59.10%in convergent geometry.Besides,the Nusselt number enhances by 18.75% when transitioning from straight to convergent geometry at a Reynolds number of 500,and by 19.81%at a Reynolds number of 1000.Finally,the results of the research depict that the use of thermophysical properties derived from the experimental achievements,despite creating complexity in the modeling and the solution method,leads to more accurate and realistic outputs.展开更多
Stable HCl-crude oil emulsion and its subsequent sludge formation,with detrimental impacts on oil production,may stem from acid stimulation.One major ambiguity in this process is to discern the most influential compon...Stable HCl-crude oil emulsion and its subsequent sludge formation,with detrimental impacts on oil production,may stem from acid stimulation.One major ambiguity in this process is to discern the most influential component of crude oil on the stability of formed emulsions.This fundamental question has not adequately been addressed in previous studies.In this work,the impact of de-asphalted part of crude oil(maltene)has been investigated on the acid-induced emulsion and sludge separately.Accordingly,the emulsion phase separation and the amount of formed sludge have been compared for four crude oils and their maltene samples for different concentrations of ferric ion and acidic pH values.The results of phase separation,as a criterion for emulsion stability,showed that crude oil samples formed 6 to 25 percent more stable emulsions than maltene samples,when using blank HCl.The emulsions of maltene and spent acid(pH=2)broke completely during the first 15 min after emulsification.In addition,the maltene components usually had less contribution to sludge formation in the presence of blank HCl.It was concluded that asphaltene is the key component during interaction with HCl.However,the maltene of one crude sample formed higher acid sludge in comparison to its crude oil.For acid solutions containing 3000 ppm of ferric ion,the emulsion stability increased for all crude oil and maltene samples.Moreover,the stability of some maltene emulsions increased to 48%and 100%in the presence of 3000 ppm of ferric ions.The presence of ferric ions caused forming very stable emulsions,while most of the sludge formation took place at higher pH values.Finally,it was also attained that emulsion and sludge formations could happen simultaneously.展开更多
This study analyzes total electron content(TEC)variations during two solar eclipse events that occurred on October 25,2022,and October 14,2023.The solar eclipse of October 25,2022,was a partial solar eclipse,while the...This study analyzes total electron content(TEC)variations during two solar eclipse events that occurred on October 25,2022,and October 14,2023.The solar eclipse of October 25,2022,was a partial solar eclipse,while the eclipse of October 14,2023,was an annular solar eclipse.For this study,the data of eight International GNSS Service(IGS)stations from different eclipse coverage zones are used to analyze TEC variations.It is found that the stations located in the maximum eclipse cover zone exhibited notable decreases in TEC values.The minimum variation of about 11.76%in TEC values is observed at the station situating in about 20 percent eclipse cover zone,while it varies from 22%to 38%at the stations falling in about 60 percent eclipse cover zone.The highest variation in TEC values of about 44%is found at the stations in about 80 percent eclipse cover zone.The time of occurrence of maximum depletion in TEC values at each station is in line with their longitudinal sequence.Atmospheric gravity waves(AGWs)are also observed by performing wavelet analysis on TEC data.The global TEC maps visualize and confirm observed TEC variations,providing spatial and temporal insights into the ionospheric response.This analysis highlights the influence of station location and eclipse coverage on the magnitude and spatial distribution of TEC variations.展开更多
Surfactants play a critical role in enhanced oil recovery(EOR) applications;however,their performance is often compromised in harsh reservoir conditions,such as high temperature and high salinity,due to precipitation ...Surfactants play a critical role in enhanced oil recovery(EOR) applications;however,their performance is often compromised in harsh reservoir conditions,such as high temperature and high salinity,due to precipitation caused by interactions with multivalent metal ions.Chelating agents were introduced into oilfields for various purposes due to their ability to sequester metal ions.In this work,we conducted a comprehensive investigation about chelating agent-surfactant(CS) flooding for carbonate reservoirs,as an alternative to the well-established alkaline surfactant(AS) flooding used in sandstone.The tested surfactants include sodium dodecyl sulfate(anionic)(SDS),dodecyltrimethylammonium bromide(cationic)(DTAB),Triton X100(nonionic),and a locally synthesized zwitterionic surfactant.The tested chelating agents include diethylenetriaminepentaacetic acid(DTPA),ethylenediaminetetraacetic acid,and glutamic acid N,N-diacetic acid.pH and temperature,as dominant factors in chelating agent solubility and brine stability,were modified to test chelating agent solutions of different concentrations and their mixtures with surfactants.Interfacial tension reduction by chelating agents alone,surfactants alone,and their mixtures were measured.Wettability alteration brought by chelating agents and surfactants on carbonate rock surfaces was evaluated using the static contact angle method.Based on the obtained results,chelating agents can be applied as low-cost additives for surfactant stabilization in high salinity conditions.The addition of chelating agents significantly improved the stability of SDS and DTAB in salt solutions and seawater.At a relatively low concentration(0.25 wt%),DTPA was able to stabilize DTAB of 1.00 wt% in seawater at high temperature(90℃).DTPA,among the tested three chelating agents,exhibited a stronger stabilization effect on surfactants of different ion types.When chelating agents are to be applied in brine,an optimal applicable pH range of 5-9 is recommended so not to induce solubility issue of chelating agents or stability issues of metal ions.In this range,IFT reduction is more significant at high pH,while wettability alteration is more significant at low pH.The combination of a cationic surfactant with a chelating agent forms a low adsorption wettability modifier which can change strongly oil-wet rock to water-wet conditions,thus significantly increasing the residual oil recovery from oil-wet carbonate formations.Zwitterionic and nonionic surfactants are also applicable to combine with a chelating agent for EOR purposes.Anionic surfactant SDS,however,showed a growing inhibition on the wettability alteration effect induced by EDTA as the concentration of SDS increased.展开更多
基金the financial support from the Ministry of Higher Education and Scientific Research-Iraq
文摘An electrocoagulation treatment process was developed for treatment and upgrade of petroleum refinery effluent （wastewater）, instead of the conventional methods, which can consume higher amounts of chemicals and produce larger amounts of sludge. The effect of the operation parameters, such as current density, initial pH, anode material, anode dissolution, energy consumption and electrolysis time, on treatment efficiency was investigated. The experimental results showed that the effluent can be effectively treated under optimal conditions. Fourier transform infrared （FTIR） analysis of the effluent, and scanning electron microscopy （SEM） coupled with energy dispersive analysis of X-rays （EDAX） of the sludge produced, revealed that the unwanted pollutants can be eliminated. The electrocoagulation treatment process was assessed by using the removal efficiency of chemical oxygen demand （COD）, total suspended solids （TSS）, and the general physicochemical characteristics of wastewater, and the results showed that the electrocoagulation is an efficient process for recycling of petroleum wastewater; it is faster and provides better quality of treated water than the conventional methods.
文摘Petroleum and Natural Gas still represent a considerable share in terms of energy consumption in the current global matrix, so that its exploration/exploitation is present in the market and driving activities in locations of specific complexities, as the ones along unconventional hydrocarbon resources from the Brazilian pre-salt. The daily cost of well drilling under harsh conditions can exceed US $1 million a day, turning any type of downtime or necessary maintenance during the activities to be very costly, moment in which processes optimization starts to be a key factor in costs reduction. Thus, new technologies and methods in terms of automating and optimizing the processes may be of great advantages, having its impact in total related project costs. In this context, the goal of this research is to allow a computation tool supporting achieving a more efficient drilling process, by means of drilling mechanics parameters choosiness aiming rate of penetration (ROP) maximization and mechanic specific energy (MSE) minimization. Conceptually, driven by the pre-operational drilling test curve trends, the proposed system allows it to be performed with less human influences and being updateable automatically, allowing more precision and time reduction by selecting optimum parameters. A Web Operating System (Web OS) was designed and implemented, running in online servers, granting accessibility to it with any device that has a browser and internet connection. It allows processing the drilling parameters supplied and feed into it, issuing outcomes with optimum values in a faster and precise way, allowing reducing operating time.
基金supported by the National Key Research and Development Program of China(2022YFE0206700)。
文摘1.Introduction Climate change mitigation pathways aimed at limiting global anthropogenic carbon dioxide(CO_(2))emissions while striving to constrain the global temperature increase to below 2℃—as outlined by the Intergovernmental Panel on Climate Change(IPCC)—consistently predict the widespread implementation of CO_(2)geological storage on a global scale.
基金supported by the Russian Science Foundation(23-29-00830).
文摘Morphology and growth rate of carbon dioxide hydrate on the interface between liquid carbon dioxide and humic acid solutions were studied in this work.It was found that after the growth of the hydrate film at the interface,further growth of hydrate due to the suction of water in the capillary system formed between the wall of the cuvette and the end boundary of the hydrate layer occurs.Most probably,substantial effects on the formation of this capillary system may be caused by variations in reactor wall properties,for example,hydrophobic-hydrophilic balance,roughness,etc.We found,that the rate of CO_(2) hydrate film growth on the surface of the humic acid aqueous solution is 4-fold to lower in comparison with the growth rate on the surface of pure water.We suppose that this is caused by the adsorption of humic acid associates on the surface of hydrate particles and,as a consequence,by the deceleration of the diffusion of dissolved carbon dioxide to the growing hydrate particle.
文摘This study investigates the mineralogy and mineral-chemistry of a newly discovered Au-Ag-Bi-Te mineralization at the Aydindere Fe-Cu skarn deposit,within the Pontides Tectonic Unit,northeastern Turkey.The mineralization is developed in the skarn zone at the contact between Upper Cretaceous andesite-pyroclastic rocks and a Paleocene–Eocene I-type granitoid.The principal ore minerals of the Aydindere Fe-Cu deposit are oxides(magnetite),sulfides(pyrite-chalcopyritegalena-sphalerite),tellurides/sulfotellurides(tetradymite,hessite),sulfosalts(wittichenite,emplectite,aikinite) and native gold-electrum.Skarn minerals include anhydrous phases(garnet) formed in a prograde stage and hydrous phases(amphibole,epidote,chlorite),which were formed in a retrograde stage in association with quartz,adularia,apatite and late calcite.Sulfides,tellurides and sulfosalts are introduced during the retrograde stage.The Au-Ag-Bi-Te mineralization was detected for the first time within the western ore body of the Aydindere deposit,and occurs in calcite-bearing sulfide bodies that cut magnetite-garnet-amphibole-epidote skarns with magnetite ores of different grade,including massive magnetite.Chlorite geothermometry indicates formation of the Au-Ag-BiTe mineralization at temperatures between 300 and 250 ℃,during the retrograde skarn evolution.Assuming the temperature is ~275 ℃,logfS_(2) =-10.5 to-13,logfO_(2) =-37 to-33,and logf Te2 values range from approximately-12 to-8.5 were estimated.The available mineralogical and geological data(presences of magnetite,oxidized-type tellurides/sulfotellurides,and andraditic garnets,and absence of pyrrhotite and arsenopyrite) suggest that Aydindere is an oxidized Au-bearing skarn deposit.The discovery of Au-Ag-Bi-Te mineralization at Aydindere increases its productivity and requires more detailed exploration in the deposit for precious(Au,Ag) and critical(Bi,Te) metals.
文摘The utilization of liquefied petroleum gas (LPG) as an alternative automobile fuel in Nigeria was studied, focusing on varying different blend ratios of propane and butane as an alternative fuel in a single-cylinder, four-stroke, and spark ignition (SI) engine. Ricardo WAVE, 1-Dimensional engine simulator was used to model the internal combustion engine where the different blend ratios of propane and butane (P100, P90B10, P80B20, P70B30, P60B40 and P50B50) were tested and compared with a gasoline engine operating under same conditions. From the simulation results for the different LPG blends, there was no significant difference in the engine performance and emissions, but when compared with pure gasoline, it was observed that the LPG showed improved engine performance and lower emissions. The engine power output in using the blends was 25% higher compared to using gasoline;CO emission was 50% less, UHC was 20% less while NO<sub>x</sub> at low speed was significantly lower.
文摘In the design of building structures,joint efforts must be decided to resolve the depth of competent layers across the intended site to safeguard the durability of civil engineering structures and to avert the disastrous consequences of structural failure and collapse.In this study,an integrated methodology that employed DC resistivity tomography involving 2-D and 3-D techniques and geotechnical-soil analysis was used to evaluate subsoil conditions for engineering site investigation at Okerenkoko primary school,in the Warri-southwest area of Delta State,to adduce the phenomena responsible for the visible cracks/structural failure observed in the buildings.The results obtained brought to light the geological structure beneath the subsurface,which consists of four geoelectric layers identified as topsoil,dry/lithified upper sandy layer,wet sand(water-saturated)and peat/clay/sandy clayey soil(highly water-saturated).The deeply-seated peat/clay materials(ρ≤20Ωm)were delineated in the study area to the depths of 17.1 m and 19.8 m from 2-D and 3-D tomography respectively.3-D images presented as horizontal depth slices revealed the dominance of very low resistivity materials i.e.peat/clay/sandy clay within the fourth,fifth and sixth layers at depths ranging from 8.68-12.5 m,12.5-16.9 m and 16.9-21.9 m respectively.The dominance of mechanically unstable peat/clay/sandy clay layers beneath the subsurface,which are highly mobile in response to volumetric changes,is responsible for the noticeable cracks/failure detected on structures within the study site.These observations were validated by a geotechnical test of soil samples in the study area.Atterberg’s limits of the samples revealed plasticity indices of zero.Thus,the soil samples within the depth analyzed were representatives of sandy soil that does not possess any plasticity.The methods justifiably provided relevant information on the subsurface geology beneath the study site and should be appropriated as major tools for engineering site assessment/geotechnical projects.
文摘Fluid imbibition from hydraulic fractures into shale formations is mainly affected by a combination of capillary forces and viscous resistance,both of which are closely related to the pore geometry.This study established five self-imbibition models with idealized pore structures and conducted a comparative analysis of these models.These models include circular,square,and equilateral triangular capillaries;a triangular star-shaped cross-section formed by three tangent spherical particles;and a traditional porous medium representation method.All these models are derived based on Newton’s second law,where capillary pressure is described by the Young-Laplace equation and viscous resistance is characterized by the Hagen-Poiret equation and Darcy’s law.All derived models predict that the fluid imbibition distance is proportional to the square root of time,in accordance with the classical Lucas-Washburn law.However,different pore structures exhibit significantly different characteristic imbibition rates.Compared to the single pore model,the conventional Darcy’s law-based model for porous media predicts significantly lower imbibition rates,which is consistent with the relatively slower uptake rates in actual shale nanoscale pore networks.These findings emphasize the important role played by pore geometry in fluid imbibition dynamics and further point to the need for optimizing pore structure to extend fluid imbibition duration in shale reservoirs in practical operations.
文摘Renewable energy technologies, while often labeled as clean or net-zero alternatives to fossil fuels, involve substantial use of critical minerals in products like electric vehicles, solar panels, wind turbines, and battery storage systems. This aspect is frequently underappreciated, yet studies indicate it could be a significant area of environmental impact. For instance, research has shown that a typical electric vehicle needs around six times the mineral resources of a conventional vehicle, while an onshore wind turbine requires nine times the mineral input compared to a gas power plant of similar capacity. This paper seeks to analyze the environmental effects linked to the critical minerals required by certain renewable energy technologies. The study begins with an estimation of the future megawatt capacities for each type of renewable technology. Next, it calculates the specific mineral quantities necessary for each model, followed by an assessment of the environmental repercussions tied to their extraction and processing. The results highlight the unique environmental challenges posed by the rising demand for minerals in solar and wind energy systems, taking into account various adoption scenarios.
文摘Shale gas,a type of unconventional natural gas found within shale formations,has emerged as a significant source of energy globally.The West Bokaro Basin,part of the Damodar Valley,is known for its rich coal deposits and complex geological history.The basin's stratigraphy includes significant coal-bearing formations interbedded with shales,which may be potential sources of shale gas.The key formations in the basin include the Barakar Formation,which is the primary coal-bearing unit,and the Raniganj Formation,which contains substantial shale intervals.These formations exhibit varying thicknesses,organic content,thermal maturity,and mechanical strength,all of which are critical factors influencing shale gas potential.The assessment of shale gas potential in the West Bokaro Basin involves evaluating the organic richness,thermal maturity,pore characteristics,geochemistry,and mineralogy of the shale formations.Apart from organic richness and thermal maturity,the shale formations must be friable,as they generally lack natural permeability.This study aims to present a comprehensive analysis of the prospects of shale gas in the West Bokaro Basin based on the organic petrography,geochemistry,mineralogical study,Fourier Transform Infrared Spectroscopy(FTIR)analysis,and low-pressure N_(2) adsorption analysis.The dark color,greasy touch,and high total organic carbon(TOC)content(5.88%-22.84%)provided an initial clue for the shale's potential as a source rock.Results from organic petrographic analysis suggest that these shales contain kerogen type Ⅲ,which is a known indicator of gas-prone zones.The random vitrinite reflectance(R_(o),0.80%-0.91%)and the temperature of maximum pyrolysis yield(Tmax,434-448℃)indicate that the organic matter has attained the sufficient thermal maturity required for the generation of hydrocarbons.FTIR and X-ray diffraction(XRD)analyses identified inorganic entities and high quartz content in the shale samples,confirming their friability.The brittleness index(BI)calculated using X-ray fluorescence(XRF)data showed BI values above 0.48,indicating that the shales are brittle,which is advantageous for hydraulic fracturing.The high quartz content in the shale might act as a natural proppant,enhancing gas extraction efficiency.These findings suggest that the West Bokaro shales hold promise for economically viable shale gas production.
文摘Hydraulic fracturing is a commonly used stimulation technique for production optimization in various geological formations such as tight sandstone,shale,coal bed methane,and heat extraction in geothermal reservoirs.Breakdown pressure is a vital component in hydraulic fracture job design,which is affected by various parameters including rock strength and depth.Various methods including modelling and experimental approaches exist to quantify the breakdown pressure.There have been many strategies to reduce this pressure for efficient and economical hydraulic fracture jobs,especially when this pressure exceeds pump capacity.This study provides a detailed review of breakdown pressure in terms of fundamentals,influencing factors,and estimation approaches.In addition,different strategies are also presented to reduce the breakdown pressure along with cost analysis.Lastly,research gaps pertinent to this area are highlighted for emphasis in future research.Specifically,it has been found that high breakdown pressure is associated with challenges,but there are no comprehensive techniques and strategies to lower this pressure in formations with very high in situ stress profiles or complicated tectonic settings.Developing such methods is important to minimize operational failures,lower costs and reduce the environmental risks during reservoir exploitation.This study reviews the fundamentals,influencing factors,and estimation methods of breakdown pressure and provides a deep understanding of the strategies for its reduction.The study also presents the cost analyses,and highlights research gaps for future investigation.
文摘The preservation of the integrity of CO_(2) injection wells holds immense significance for the efficacy of Carbon Capture and Storage (CCS) projects.This is attributable to the fact that a wellbore exhibiting robust mechanical and flow integrity substantially diminishes the likelihood of CO_(2) leakage into the overlying aquifer or release to the atmosphere,thereby curtailing associated risks.Given the potential hazards and repercussions stemming from the failure of CO_(2) injection wells,encompassing environmental catastrophes,financial implications,and health risks,it is imperative to earnestly address these challenges through adept management and monitoring protocols.This study aims to advance the current understanding and enhance the management of wellbore integrity issues in CO_(2) injection wells.Accordingly,this review paper undertakes a thorough exploration of the primary factors influencing wellbore integrity in CO_(2) injection wells.Furthermore,it delineates a pressing necessity for more exhaustive investigations regarding the influence of CO_(2) injection rate,CO_(2) purity,and wellbore geometry on wellbore integrity.
基金supported by the National Natural Science Foundation of China(Grant No.U22A20574)the Hainan Province Science and Technology Special Fund(Grant No.ZDYF2023GXJS009).
文摘Shale formations have recently gained plenty of attention owing to their large amounts of reserves.Horizontal drilling and hydraulic fracturing are the proposed approaches for the development of shale formations.The extended information of the mechanical properties of shale formation is crucial for designing a successful hydraulic fracturing operation.On the other hand,the mechanical properties of such organic-rich formations are greatly affected by the mechanical characteristics of the present kerogen(organic matter),which dramatically changes during the maturation process.In this study,a Qingshankou shale sample containing kerogen type I is mechanically investigated at different maturity levels using the grid nanoindentation approach.To this end,the original immature sample is artificially matured during hydrous(HP)and anhydrous(AHP)pyrolysis.More than 930 nanoindentation tests were performed on grids of 9×8 on the surface of 13 samples with different maturities.The test results showed that the presence of water during pyrolysis can significantly affect the shale sample's mechanical characteristics.In higher temperatures and higher levels of maturity,the role of water becomes more pronounced.During hydrous pyrolysis,kerogen produces larger amounts of oil and bitumen,which become progressively porous.While the original sample showed a Young's modulus value of more than 48 GPa,and it fluctuated between approximately 19 and 32 GPa during the HP scenario and between 17 and 34 GPa during the AHP process.In terms of hardness,the original sample exhibited an initial value of about 1.1 GPa and more mature samples reflected hardness values in the range of approximately 0.3 and 0.97 GPa in both scenarios.According to the trends of mechanical properties during maturation,mechanical properties decreased at the initial stage of maturation and remained relatively constant during the oil window.Then,another decline was detected at the wet-gas window's closure.In the dry-gas window,HP and AHP scenarios exhibited different behaviors mainly due to the chemical structure of the kerogen residue.
文摘Understanding the active tectonic processes in the Nandakini Watershed is imperative for evaluating geological hazards and seismic risks,as well as for informing land-use planning and natural resource management strategies in the region.Tectonic geomorphology serves as a vital tool for characterizing recent tectonic movements.This research employs GIS techniques to elucidate tectonic activity and its influence on drainage patterns in the Nandakini Watershed,utilizing morphometric parameters derived from SRTM DEM data.Morphometric indices are employed to assess the tectonic movement within drainage basins,capturing both areal and linear factors such as drainage density,texture,circulatory and bifurcation ratios,and stream length ratios.The linear and areal morphometric indices are categorized into three classes representing varying degrees of active tectonic activity.These classifications are then utilized to compute the relative active tectonic index(IRAT).In addition,geomorphic parameters include hypsometric integral,stream length-gradient index,normalized steepness index,chi gradient index,and swath profiles.The majority of the studied region is in an extremely high to moderately active tectonic zone.Large-scale faults and thrusts within the basins are closely correlated with these zones that have been identified.The integrated methodology of GIS-based morphometric analysis and geomorphic study enables the identification of deformed landforms associated with ongoing tectonic activity.Furthermore,these results offer valuable insights for informing watershed management strategies and promoting sustainable land use planning initiatives.
基金Funding was provided by the U.S.Department of Energy,Office of Nuclear Energy,Spent Fuel and Waste Disposition,under Contract Number DE-AC02-05CH11231 with Lawrence Berkeley National Laboratory(LBNL).
文摘An important challenge in ensuring the long-term effectiveness of geological nuclear waste disposal is predicting the transportation of decay heat and gases released from nuclear waste canisters.In this study,thermo-hydromechanical(THM)coupled simulations were conducted using the TOUGH + FLAC3D simulator to predict the THM behaviors of a generic nuclear waste repository over 100,000 years following closure.The designed engineered barrier system(EBS)consists of the waste canister,backfill,and concrete liner.The objective of this study is to evaluate the long-term performance of the repository in the presence of continued hydrogen(H_(2))and heat release around the canister.The simulation results show that thermal pressurization and gas accumulation significantly raise the pore pressure within the EBS and surrounding host rock,while the peak pore pressure is not likely to exceed the lithostatic stress so that there is no risk of widespread hydro-fracturing in the host rock.However,tension failure and fracturing can occur at the tunnel scale because of internal gas buildup.Meanwhile,the generated H_(2) continuously migrates outward and tends to accumulate in the concrete liner and excavation disturbed zone surrounding the tunnel because of lower capillary pressure.Nevertheless,the fluids that may contain radionuclides will not leach into the confining units over a 100,000-year time frame.Our analysis indicates that for the assumed disposal system in Opalinus Clay,the generated heat and gas can gradually be transported through the host rock without significantly disturbing the isolation characteristics of the repository.
基金support provided by the College of Petroleum Engineering&Geosciences(CPG)at King Fahd University of Petroleum&Minerals(KFUPM).
文摘By analyzing core data from an offshore Gulf of Mexico reservoir and developing analytical solutions,it can be demonstrated that laboratory measurements on pore-volume compressibility include artifacts,leading to a misinterpretation of porosity and permeability trends.A systematic evaluation of poro-elastic changes in pore volumes(and quantifying any consequent fluid expulsion during reservoir compaction)suggests that poro-elastic relaxation may enhance fluid production rates from deep reservoirs by up to 25%.This value may be inadvertently inflated if the core samples used for pore-volume compressibility measurements suffered from handling damage.Nonetheless,poro-elastic fluid expulsion from the pores in producing reservoirs can provide additional lift and thus may enhance the recovery factor.Therefore,the possible contribution to well performance from poro-elastic production drive mechanisms ought to be carefully evaluated in reserves estimation.Reversely,injection wells may encounter poro-elastic suppression of injectivity due to elastic resistance,which would adversely affect the storage coefficient.By integrating geomechanical reservoir response with traditional fluid production models,reservoir model predictions of production under pressure depletion and injection conditions will be more accurate.The new insights reported here are essential for optimizing well performance,improving reservoir management,and extending the economic life of geological reservoirs.However,caution is warranted regarding pore-volume compressibility measurements.To what degree laboratory measurements of pore-volume compressibility measure true values or mainly record handling damage could not be conclusively settled in the present study.
文摘This article aims tomodel and analyze the heat and fluid flow characteristics of a carboxymethyl cellulose(CMC)nanofluid within a convergent-divergent shaped microchannel(Two-dimensional).The base fluid,water+CMC(0.5%),is mixed with CuO and Al2O3 nanoparticles at volume fractions of 0.5%and 1.5%,respectively.The research is conducted through the conjugate usage of experimental and theoretical models to represent more realistic properties of the non-Newtonian nanofluid.Three types of microchannels including straight,divergent,and convergent are considered,all having the same length and identical inlet cross-sectional area.Using ANSYS FLUENT software,Navier-Stokes equations are solved for the laminar flow of the non-Newtonian nanofluid.The study examines the effects of Reynolds number,nanoparticle concentration and type,and microchannel geometry on flow and heat transfer.The results prove that the alumina nanoparticles outperform copper oxide in increasing the Nusselt number at a 0.5% volume fraction,while copper oxide nanoparticles excel at a 1.5%volume fraction.Moreover,in the selected case study,as the Reynolds number increases from 100 to 500,the Nusselt number rises by 56.26% in straight geometry,52.93% in divergent geometry,and 59.10%in convergent geometry.Besides,the Nusselt number enhances by 18.75% when transitioning from straight to convergent geometry at a Reynolds number of 500,and by 19.81%at a Reynolds number of 1000.Finally,the results of the research depict that the use of thermophysical properties derived from the experimental achievements,despite creating complexity in the modeling and the solution method,leads to more accurate and realistic outputs.
文摘Stable HCl-crude oil emulsion and its subsequent sludge formation,with detrimental impacts on oil production,may stem from acid stimulation.One major ambiguity in this process is to discern the most influential component of crude oil on the stability of formed emulsions.This fundamental question has not adequately been addressed in previous studies.In this work,the impact of de-asphalted part of crude oil(maltene)has been investigated on the acid-induced emulsion and sludge separately.Accordingly,the emulsion phase separation and the amount of formed sludge have been compared for four crude oils and their maltene samples for different concentrations of ferric ion and acidic pH values.The results of phase separation,as a criterion for emulsion stability,showed that crude oil samples formed 6 to 25 percent more stable emulsions than maltene samples,when using blank HCl.The emulsions of maltene and spent acid(pH=2)broke completely during the first 15 min after emulsification.In addition,the maltene components usually had less contribution to sludge formation in the presence of blank HCl.It was concluded that asphaltene is the key component during interaction with HCl.However,the maltene of one crude sample formed higher acid sludge in comparison to its crude oil.For acid solutions containing 3000 ppm of ferric ion,the emulsion stability increased for all crude oil and maltene samples.Moreover,the stability of some maltene emulsions increased to 48%and 100%in the presence of 3000 ppm of ferric ions.The presence of ferric ions caused forming very stable emulsions,while most of the sludge formation took place at higher pH values.Finally,it was also attained that emulsion and sludge formations could happen simultaneously.
基金the Global GNSS-TEC data processing has been supported by JSPS KAKENHI Grant Number 16H06286。
文摘This study analyzes total electron content(TEC)variations during two solar eclipse events that occurred on October 25,2022,and October 14,2023.The solar eclipse of October 25,2022,was a partial solar eclipse,while the eclipse of October 14,2023,was an annular solar eclipse.For this study,the data of eight International GNSS Service(IGS)stations from different eclipse coverage zones are used to analyze TEC variations.It is found that the stations located in the maximum eclipse cover zone exhibited notable decreases in TEC values.The minimum variation of about 11.76%in TEC values is observed at the station situating in about 20 percent eclipse cover zone,while it varies from 22%to 38%at the stations falling in about 60 percent eclipse cover zone.The highest variation in TEC values of about 44%is found at the stations in about 80 percent eclipse cover zone.The time of occurrence of maximum depletion in TEC values at each station is in line with their longitudinal sequence.Atmospheric gravity waves(AGWs)are also observed by performing wavelet analysis on TEC data.The global TEC maps visualize and confirm observed TEC variations,providing spatial and temporal insights into the ionospheric response.This analysis highlights the influence of station location and eclipse coverage on the magnitude and spatial distribution of TEC variations.
基金supported by the College of Petroleum Engineering&Geoscience (CPG) at King Fahd University of Petroleum and Minerals (KFUPM)。
文摘Surfactants play a critical role in enhanced oil recovery(EOR) applications;however,their performance is often compromised in harsh reservoir conditions,such as high temperature and high salinity,due to precipitation caused by interactions with multivalent metal ions.Chelating agents were introduced into oilfields for various purposes due to their ability to sequester metal ions.In this work,we conducted a comprehensive investigation about chelating agent-surfactant(CS) flooding for carbonate reservoirs,as an alternative to the well-established alkaline surfactant(AS) flooding used in sandstone.The tested surfactants include sodium dodecyl sulfate(anionic)(SDS),dodecyltrimethylammonium bromide(cationic)(DTAB),Triton X100(nonionic),and a locally synthesized zwitterionic surfactant.The tested chelating agents include diethylenetriaminepentaacetic acid(DTPA),ethylenediaminetetraacetic acid,and glutamic acid N,N-diacetic acid.pH and temperature,as dominant factors in chelating agent solubility and brine stability,were modified to test chelating agent solutions of different concentrations and their mixtures with surfactants.Interfacial tension reduction by chelating agents alone,surfactants alone,and their mixtures were measured.Wettability alteration brought by chelating agents and surfactants on carbonate rock surfaces was evaluated using the static contact angle method.Based on the obtained results,chelating agents can be applied as low-cost additives for surfactant stabilization in high salinity conditions.The addition of chelating agents significantly improved the stability of SDS and DTAB in salt solutions and seawater.At a relatively low concentration(0.25 wt%),DTPA was able to stabilize DTAB of 1.00 wt% in seawater at high temperature(90℃).DTPA,among the tested three chelating agents,exhibited a stronger stabilization effect on surfactants of different ion types.When chelating agents are to be applied in brine,an optimal applicable pH range of 5-9 is recommended so not to induce solubility issue of chelating agents or stability issues of metal ions.In this range,IFT reduction is more significant at high pH,while wettability alteration is more significant at low pH.The combination of a cationic surfactant with a chelating agent forms a low adsorption wettability modifier which can change strongly oil-wet rock to water-wet conditions,thus significantly increasing the residual oil recovery from oil-wet carbonate formations.Zwitterionic and nonionic surfactants are also applicable to combine with a chelating agent for EOR purposes.Anionic surfactant SDS,however,showed a growing inhibition on the wettability alteration effect induced by EDTA as the concentration of SDS increased.
