The carbonate lithofacies of the Nganzi Exploratory Block located in the Lukula Territory in the Central Kongo Province were described in the field, sampled and subjected to microscopic, mineralogical, physico-chemica...The carbonate lithofacies of the Nganzi Exploratory Block located in the Lukula Territory in the Central Kongo Province were described in the field, sampled and subjected to microscopic, mineralogical, physico-chemical and petrophysical analyses. The aim is to increase the probability of discovery of deposits following the drilling of exploration wells in the most appropriate structures. These carbonates, limestones (white, greyish and greenish) and dolomites (massive and platelets) are presented in packstone, grainstone and wackestone textures. In addition to the essential minerals of these rocks, calcite and dolomite, we find quartz, plagioclase and kaolinite. With a porosity between 11% and 19% and a permeability of 138 to 155 mD, the Nganzi carbonates, which contain up to 23% oil, constitute good oil reservoirs. The characterization of the detrital facies and the acquisition of a seismic survey of the wells is essential to have a more detailed knowledge of the oil resources of the Nganzi Block.展开更多
The Boya-02 kimberlite was identified at depth by geophysical survey work (a single-probe AM survey in 1997 and a gravity survey in 2006) that De Beers DRC Exploration carried out around anomaly 193/172/0019. This ano...The Boya-02 kimberlite was identified at depth by geophysical survey work (a single-probe AM survey in 1997 and a gravity survey in 2006) that De Beers DRC Exploration carried out around anomaly 193/172/0019. This anomaly located approximately 50 km southwest of the town of Mbuji-Mayi in the Kasaï-Oriental Province in the DRC should therefore be the subject of detailed exploration with the aim of better identifying and describing this kimberlite. Thus, through exploratory work and cross-checking of geophysical and geological data, the discovery of this Massif was made by drilling on the aeromagnetic anomaly 193/172/X298. Based on drilling, sampling and laboratory petrographic analysis reports, the Boya-02 kimberlite was classified among highly diluted re-sedimented volcaniclastic kimberlites (KVR), rich in olivine and incidentally in quartz and poor in juvenile substances. This kimberlite represents a deposit of very low economic interest following extremely high dilution. The Boya-02 kimberlite was modeled using ground magnetism data. It is a complex anomaly comprising 2 components with variable amplitude appearing on a subtly magnetized linear detail. The modeled dimensions of two components of this anomaly are 0.32 Ha and 0.2 Ha at depths of 32 m & 14 m for the deposits to the West and the East respectively. Garnet data for the Boya-02 occurrence reports a maximum Pmin value of 49.7 kbar (207 garnets). These data demonstrate the high diamond potential which assumes a conductive cratonic geotherm of 40 mWm<sup>2</sup>.展开更多
Surface hydrogen storage facilities are limited and costly,making subsurface hydrogen storage in geological formations a more viable alternative due to its substantial capacity,safety,and economic feasibility.This met...Surface hydrogen storage facilities are limited and costly,making subsurface hydrogen storage in geological formations a more viable alternative due to its substantial capacity,safety,and economic feasibility.This method is essential for large-scale hydrogen storage to support renewable energy integration,fuel cell technologies,and other applications aimed at mitigating global climate change.This review examines underground hydrogen storage(UHS)in geological formations,focusing on recent experiments,modeling and simulations,and field applications.Geological formations such as depleted oil reservoirs,salt caverns,and depleted natural gas reservoirs are identified as favorable candidates due to minimal interactions with hydrogen,leading to low hydrogen loss.Globally,80%of UHS projects utilize depleted natural gas and oil reservoirs,with over 50%focused on depleted natural gas and oil condensate reservoirs due to cost-effective existing infrastructure.Among storage options,salt caverns are the most advantageous,offering self-healing properties,low caprock permeability,large storage capacity,rapid injection and withdrawal rates,and low contamination risk.Additionally,hydrogen produced from coal is the cheapest option,costing 1.2e2 USD/kg,whereas hydrogen from renewable sources,such as water,is the most expensive at 3e13 USD/kg.Despite its higher cost,green hydrogen from water,characterized by low carbon emissions,requires further research to reduce production costs.This review highlights critical research gaps,challenges,and policy recommendations to advance UHS technologies,ensuring their role in combating climate change.展开更多
Triple mass-transport deposits （MTDs） with areas of 625, 494 and 902 km^2, respectively, have been identified on the north slope of the Xisha Trough, northern South China Sea margin. Based on high-resolution seismic...Triple mass-transport deposits （MTDs） with areas of 625, 494 and 902 km^2, respectively, have been identified on the north slope of the Xisha Trough, northern South China Sea margin. Based on high-resolution seismic reflection data and multi-beam bathymetric data, the Quaternary MTDs are characterized by typical geometric shapes and internal structures. Results of slope analysis showed that they are developed in a steep slope ranging from 5° to 35°. The head wall scarps of the MTDs arrived to 50 km in length （from headwall to termination）. Their inner structures include well developed basal shear surface, growth faults, stepping lateral scarps, erosion grooves, and frontal thrust deformation. From seismic images, the central deepwater channel system of the Xisha Trough has been filled by interbedded channel-levee deposits and thick MTDs. Therefore, we inferred that the MTDs in the deepwater channel system could be dominated by far-travelled slope failure deposits even though there are local collapses of the trough walls. And then, we drew the two-dimensional process model and three- dimensional structure model diagram af the MTDs. Combined with the regional geological setting and previous studies, we discussed the trigger mechanisms of the triple MTDs.展开更多
Neotectonic movement refers to the tectonic movement that has happened since the Cenozoic, which is the latest movement. It has the most important influence on the basins in west China, especially on the hydrocarbon a...Neotectonic movement refers to the tectonic movement that has happened since the Cenozoic, which is the latest movement. It has the most important influence on the basins in west China, especially on the hydrocarbon accumulation in the western foreland basins. We determined the time of neotectonic movement in the Kuqa Foreland Basin, which began from the Neogene, and analyzed the patterns of movement, which were continuous and fast subsidence in the vertical direction and intense lateral compression. The structure styles are that the faulting is weakened and the folding is strengthened gradually from north to south. We studied the control of neotectonic movement on the hydrocarbon accumulation process and model in the Kuqa Foreland Basin with basin simulation technique. The largest subsidence rate of the Kuqa Foreland Basin reached 1,200 m/Ma during the neotectonic movement, leading to rapid maturing of source rock within 5 Ma and a large quantity of hydrocarbon being generated and expelled. The thick neotectonic strata can form high quality reservoirs with the proved gas and oil reserves accounting for 5% and 27% of the total reserves, respectively. 86% of the structural traps were formed in the neotectonic movement period. The faults formed during the neotectonic movement serve as important migration pathways and they exist in the region where the hydrocarbon reservoirs are distributed. Abnormally high pressure caused by the intense lateral compression, thick neotectonic strata deposition and rapid hydrocarbon generation provide driving force for hydrocarbon migration. The accumulation elements match each other well over a short period, leading to many large gas fields formed later in the Kuqa Foreland Basin.展开更多
A series of marine natural gas fields were recently discovered in oolitic dolomites of the Lower Triassic Feixianguan formation, northeastern Sichuan Basin, southwest China. The mechanism forming these reservoir dolom...A series of marine natural gas fields were recently discovered in oolitic dolomites of the Lower Triassic Feixianguan formation, northeastern Sichuan Basin, southwest China. The mechanism forming these reservoir dolomites is debatable, limiting the ability to characterize these reservoir successfully. Based on the investigation of the representative Dukouhe, Luojiazhai, and Puguang areas, this issue was addressed by examining the distribution, petrology, and geochemistry of the dolomites, the most comprehensive study to date was provided. Dolomitization occurred at a very early stage of diagenesis, as shown by the petrological features of the rock fabric. Vadose silt, which is composed primarily of dolomitic clasts, is found in the primary and secondary pores of the oolitic dolomite. This indicates that the overlying strata were subjected to dolomitization when the Feixianguan formation was located in the vadose zone. Therefore, it may be inferred that the dolomitization which occurred before the formation was exposed to meteoric conditions. The spatial distribution and geochemical characteristics of the dolomite indicate that dolomitization occurred as a result of seepage reflux. The degree of dolomitization decreases with increasing distance from the evaporative lagoon. Furthermore, the type and porosity of the dolomite vary in different zones of the upward-shoaling sequence, with the porosity gradually decreasing from the highest layer to the lowest layer. This reflects a close relationship between dolomitization and seawater evaporation during the formation of the dolomite. Geochemical analysis provided further evidence for the relationship between the dolomitization fluid and the coeval seawater. The 87Sr/86Sr and 813C isotopes, as well as the abundances of trace elements, Fe and Mn, indicate that seawater concentrated by evaporation acted as the dolomitization fluid. These results also show that dolomitization most likely occurred in a semi-closed diagenetic environment. Therefore, the main mechanism of oolitic dolomite formation is seepage reflux, which occurred at an early stage of diagenesis.展开更多
A fault is not simply a plane, but a zone consisting of a series of broken planes or lower faults. The greater the scale of faults, the wider and more complex the fault zone is. Fault-sealing properties are influenced...A fault is not simply a plane, but a zone consisting of a series of broken planes or lower faults. The greater the scale of faults, the wider and more complex the fault zone is. Fault-sealing properties are influenced by the fault zone itself, whose fault displacement, depth, net-to-gross-ratio of mudstone, fault plane angle, and fault mechanical properties play important controlling roles. The sealing of hydrocarbon by the fault zone depends on whether the fault zone can form a continuous sealing zone and if the pore throats connecting those fault zones are small enough. The concept of fault zone-sealing potential is proposed here, and a quantitative formula is established by using a great amount of practical statistical data as well as the fuzzy comprehensive evaluation method, which is a comprehensive characterization parameter to judge whether or not fault zones could seal oil hydrocarbon. The greater the value of the fault zone-sealing potential, the better sealed the fault is. For example, with increasing depth, the sealing degree of the Xin 68 Fault in the Dongxin 1 oilfield changes greatly, reflecting the complexity of fault-sealing properties.展开更多
Based on analysis of newly collected 3D seismic and drilled well data,the geological structure and fault system of Baodao sag have been systematically examined to figure out characteristics of the transition fault ter...Based on analysis of newly collected 3D seismic and drilled well data,the geological structure and fault system of Baodao sag have been systematically examined to figure out characteristics of the transition fault terrace belt and its control on the formation of natural gas reservoirs.The research results show that the Baodao sag has the northern fault terrace belt,central depression belt and southern slope belt developed,among them,the northern fault terrace belt consists of multiple transition fault terrace belts such as Baodao B,A and C from west to east which control the source rocks,traps,reservoirs,oil and gas migration and hydrocarbon enrichment in the Baodao sag.The activity of the main fault of the transition belt in the sedimentary period of Yacheng Formation in the Early Oligocene controlled the hydrocarbon generation kitchen and hydrocarbon generation potential.From west to east,getting closer to the provenance,the transition belt increased in activity strength,thickness of source rock and scale of delta,and had multiple hydrocarbon generation depressions developed.The main fault had local compression under the background of tension and torsion,giving rise to composite traps under the background of large nose structure,and the Baodao A and Baodao C traps to the east are larger than Baodao B trap.Multiple fault terraces controlled the material source input from the uplift area to form large delta sand bodies,and the synthetic transition belt of the west and middle sections and the gentle slope of the east section of the F12 fault in the Baodao A transition belt controlled the input of two major material sources,giving rise to a number of delta lobes in the west and east branches.The large structural ridge formed under the control of the main fault close to the hydrocarbon generation center allows efficient migration and accumulation of oil and gas.The combination mode and active time of the main faults matched well with the natural gas charging period,resulting in the hydrocarbon gas enrichment.Baodao A transition belt is adjacent to Baodao 27,25 and 21 lows,where large braided river delta deposits supplied by Shenhu uplift provenance develop,and it is characterized by large structural ridges allowing high efficient hydrocarbon accumulation,parallel combination of main faults and early cessation of faulting activity,so it is a favorable area for hydrocarbon gas accumulation.Thick high-quality gas reservoirs have been revealed through drilling,leading to the discovery of the first large-scale gas field in Baodo 21-1 of Baodao sag.This discovery also confirms that the north transition zone of Songnan-Baodao sag has good reservoir forming conditions,and the transition fault terrace belt has great exploration potential eastward.展开更多
This paper presents the properties of fluid inclusions found in sphalerite from Latala epithermal base and precious metal deposit(Central Iran),which is hosted in Cenozoic volcanicsedimentary host-rocks.The Latala Dep...This paper presents the properties of fluid inclusions found in sphalerite from Latala epithermal base and precious metal deposit(Central Iran),which is hosted in Cenozoic volcanicsedimentary host-rocks.The Latala Deposit represents an example of vein type,base metal deposits in the Miduk porphyry copper deposits(PCDs)in southern Urumieh-Dokhtar magmatic belt(UDMB).Mineralization in Latala epithermal base and precious metal vein type formed in 3 stages and sphalerite-quartz veins occur in stages 2 and 3.Stage 2 quartz-sphalerite veins are associated with chalcopyrite and zoned sphalerite,along with quartz+hematite,and Stage 3 quartz-sphalerite veins contain galena+sphalerite+chalcopyrite and quartz with overgrowth of calcite.Mineralization in Stage 3 occurs as replacement bodies and contains Fe-poor sphalerite without zoning in the outer parts of the deposit.This paper focuses on fluid inclusions in veins bearing sphalerite and quartz.The fluid inclusion homogenization temperatures and salinity in sphalerite(some with typical zoning)range from 144 to 285℃and from 0.2 wt.%to 7.6 wt.%NaCl eq.Sphalerite and fluid inclusions of the Latala base and precious metal deposit formed from relatively low-T and low-salinity solutions.Raman spectroscopy analyses indicate a high percentage of CO2 in the gas phase of fluid inclusions in Fe-poor sphalerites,as expected with melting temperature for CO2 of-56.6℃,and significant amounts of H2.Lack of reduced carbon species(methane and lighter hydrocarbons)was confirmed in the petrographic study using UV light and Raman spectroscopy.High amounts of H2 in fluid inclusions of Fe-poor sphalerite can be the result of different intensities of alteration and diffusion processes.The common occurrences of CO2 in fluid inclusions have originated from magma degassing and dissolution of carbonates.Theδ^34S values for sulfide minerals in galena of sphalerite bearing veins vary between-9.8‰and-1.0‰,and theδ^34S values calculated for H2 S are between-7.1‰and+0.6‰.These values correspond to magmatic sulfur whit possible interaction with wall rocks.Magmatic fluids were successively diluted during cooling and continuous ascent.Secondary boiling would lead to variable amounts of potassic or prophylactic alteration and the hydrogen diffusion into the inclusions hosted in sphalerite of Latala.展开更多
Mineralogical, geochemical, and textural analyses of the white sandstones （Abu Thora Fm.） of Carboniferous in the Abu Rodeiyim region show that they are fluviomarine, well-sorted, highpurity, and high-grade silica S...Mineralogical, geochemical, and textural analyses of the white sandstones （Abu Thora Fm.） of Carboniferous in the Abu Rodeiyim region show that they are fluviomarine, well-sorted, highpurity, and high-grade silica SiO2 （average 99.56%）. The results indicate that by simple treatment, the white sandstones can reach a high degree of purity, suitable for different industrial purposes （e.g. manufacture of silicon photovoltaic, crystal, and TV screens, art, and domestic and optical glass）.展开更多
The distribution and marketing of petroleum products are the sources of energy for the various activities of human society and household supply. We spent our time researching the competitive factors to reduce the time...The distribution and marketing of petroleum products are the sources of energy for the various activities of human society and household supply. We spent our time researching the competitive factors to reduce the time of distribution of petroleum products, by setting up a computer system based on Dijkstra’s algorithm our contribution will solve a real problem of delivery with direct targeting of gas stations. We set up a tool to help to map based on the method of operational research starting with the identification of delivery point, mapping and then applying the algorithm. Mainly the graph theory and the optimal path in a network by a short path using the method of Dijkstra for the design we used the UML language, the programming we used the JAVA language with very appreciable results to finish with a conclusion.展开更多
Rare Earth Elements(REE)are a group of chemicallycoherent elements that are critical to a wide range of modern high technology applications and the critical strategic role of REE to the economic development of the U.S...Rare Earth Elements(REE)are a group of chemicallycoherent elements that are critical to a wide range of modern high technology applications and the critical strategic role of REE to the economic development of the U.S.A.,European Union and Japan has been recognised.China holds a near monopoly over the supply of REE and REE products-accounting for around 95%of the global supply in 2010.These factors triggered a rush to discover REE deposits and develop REE production outside of China.展开更多
The Pressure-Volume-Temperature(PVT)properties of crude oil are typically determined through laboratory analysis during the early phases of exploration and fielddevelopment.However,due to extensive data required,time-...The Pressure-Volume-Temperature(PVT)properties of crude oil are typically determined through laboratory analysis during the early phases of exploration and fielddevelopment.However,due to extensive data required,time-consuming nature,and high costs,laboratory methods are often not preferred.Machine learning,with its efficiencyand rapid convergence,has emerged as a promising alternative for PVT properties estimation.This study employs the modified particle swarm optimization-based group method of data handling(PSO-GMDH)to develop predictive models for estimating both the oil formation volume factor(OFVF)and bubble point pressure(P_(b)).Data from the Mpyo oil fieldin Uganda were used to create the models.The input parameters included solution gas-oil ratio(R_(s)),oil American Petroleum Institute gravity(API),specificgravity(SG),and reservoir temperature(T).The results demonstrated that PSO-GMDH outperformed backpropagation neural networks(BPNN)and radial basis function neural networks(RBFNN),achieving higher correlation coefficientsand lower prediction errors during training and testing.For OFVF prediction,PSO-GMDH yielded a correlation coefficient(R)of 0.9979(training)and 0.9876(testing),with corresponding root mean square error(RMSE)values of 0.0021 and 0.0099,and mean absolute error(MAE)values of 0.00055 and 0.00256,respectively.For P_(b)prediction,R was 0.9994(training)and 0.9876(testing),with RMSE values of 6.08 and 8.26,and MAE values of 1.35 and 2.63.The study also revealed that R_(s)significantlyimpacts OFVF and P_(b)predictions compared to other input parameters.The models followed physical laws and remained stable,demonstrating that PSO-GMDH is a robust and efficientmethod for predicting OFVF and P_(b),offering a time and cost-effective alternative.展开更多
The porosity of a rock is one of the most important reservoir properties. It controls the reservoir storage capacity. In other words, porosity quantifies the amount of fluids that the rock can store. Most of the world...The porosity of a rock is one of the most important reservoir properties. It controls the reservoir storage capacity. In other words, porosity quantifies the amount of fluids that the rock can store. Most of the world＇s giant fields produce hydrocarbons from carbonate reservoirs. Carbonate rocks contain more than 50% of the world＇s hydrocarbon reserves. Porosity and compressional wave velocity of 41 carbonate samples were determined under ambient conditions in laboratory. The samples were collected from seven shallow wells in west Tushka area, south Western Desert, Egypt. This paper evaluates the well known Wyllie and Raymer equations, an empirical linear equation, and a generalized model for porosity estimation from compressional wave velocity of saturated carbonate samples. Based on the comparison of the predicting identified to provide the most reliable porosity estimation. qualities, the Raymer equation and the empirical linear equation were展开更多
Understanding the effects of mineral composition on geomechanical characteristics is critical in order to design and optimize the hydraulic fracturing necessary for shale gas reservoir production.Fundamental informati...Understanding the effects of mineral composition on geomechanical characteristics is critical in order to design and optimize the hydraulic fracturing necessary for shale gas reservoir production.Fundamental information is still missing in effects of mineral content and the experimental methodologies used.This paper provided an in-depth assessment of the various experimental methodologies and their applications in the relationship between the mineralogical and geomechanical features of the shale formation.The results revealed that more brittle minerals increase their strength,but chemical reaction that creats pores decrease their strength.High content of carbonate or quartz increases a rock's brittleness,while a high content of clay increases a rock's plasticity and decreases its brittleness.As phyllosilicate content increases,the uniaxial compressive strength decreases,and this could be because phyllosilicate minerals have a weakening effect on the mineral bond.Young's modulus often climb as clay minerals decline and as silica with carbonate concentration rises,however Poisson's ratio increases in relation to an increase in clay minerals,which also increases the ductility of the reservoir shale rock.However,compared to minerals and matrix,does not significantly impact the strength of shale rock.Besides,the benefits and drawbacks of using uniaxial and triaxial compression,ultrasonic testing,and nano-indentation techniques in unconventional reservoirs were described.The findings suggest that,because of the possibility for experimental testing repeatability for increased accuracy,ultrasonic testing is the most appropriate experimental approach in the scenes of assessing static and dynamic geomechanical properties of reservoir shale rock.We suggested that numerically-based simulation of experimental techniques used for shale geomechanical evaluations and numer-ical modeling of heterogeneous shale rock samples will be necessary in light of the limitations faced in the ap-plications of experimental techniques for shale geomechanical evaluation.展开更多
In this work we interpret the data showing unusually strong velocity dispersion of P-waves (up to 30%) and attenuation in a relatively narrow frequency range. The cross-hole and VSP data were measured in a reservoir, ...In this work we interpret the data showing unusually strong velocity dispersion of P-waves (up to 30%) and attenuation in a relatively narrow frequency range. The cross-hole and VSP data were measured in a reservoir, which is in the porous zone of the Silurian Kankakee Limestone Formation formed by vertical fractures within a porous matrix saturated by oil, and gas patches. Such a medium exhibits significant attenuation due to wave-induced fluid flow across the interfaces between different types of inclusions (fractures, fluid patches) and background. Other models of intrinsic attenuation (in particular squirt flow models) cannot explain the amount of observed dispersion when using realistic rock properties. In order to interpret data in a satisfactory way we develop a superposition model for fractured porous rocks accounting also for the patchy saturation effect.展开更多
The Pamir region, located to the northwest of the Tibetan Plateau, provides important information that can aid the understanding of the plateau＇s tectonic evolution. Here we present new findings on the deforma- tion ...The Pamir region, located to the northwest of the Tibetan Plateau, provides important information that can aid the understanding of the plateau＇s tectonic evolution. Here we present new findings on the deforma- tion geometry and timing of the Wupoer thrust belt at the northeastem margin of Pamir. Field investigations and interpretations of seismic profiles indicate that the eastern portion of the Wupoer thrust belt is dominated by an underlying foreland basin and an overlying piggy-back basin. A regional unconformity occurs between the Pliocene （N2） and the underlying Miocene （NI） or Paleogene （Pg） strata associated with two other local unconformities between Lower Pleistocene （Q1） and N2 and between Middle Pleistocene （Q2-4） and Q1 strata. Results of structural restorations suggest that compres- sional deformation was initiated during the latest Miocene to earliest Pliocene, contributing a total shortening magnitude of 48.6 km with a total shortening rate of 48.12%, most of which occurred in the period from the latest Miocene to earliest Pliocene. These results, com- bined with previous studies on the Kongur and Tarshkor- gan extensional system, suggest an interesting picture of strong piedmont compressional thrusting activity concur- rent with interorogen extensional rifting. Combining these results with previously published work on the lithospheric architecture of the Pamir, we propose that gravitational collapse drove the formation of simultaneous extensional and compressional structures with a weak, ductile middle crustal layer acting as a decollement along which both the extensional and compressional faults merged.展开更多
The two mechanisms of gas dissolving in water, interstice filling and aquation, are proposed. General equations of gas solubility have been deduced from the mechanisms and experimental observations. Dependence of Henr...The two mechanisms of gas dissolving in water, interstice filling and aquation, are proposed. General equations of gas solubility have been deduced from the mechanisms and experimental observations. Dependence of Henry’s coefficient on temperature, pressure, aquation equilibrium constant and gas molecular wlume is discussed. The theoretical equations were verified by experimental data, which shows that the theoretical results of the solubility of methane are in good agreement with the experimental data in the range of 20 -160℃ and under a pressure of less than 60 MPa.展开更多
文摘The carbonate lithofacies of the Nganzi Exploratory Block located in the Lukula Territory in the Central Kongo Province were described in the field, sampled and subjected to microscopic, mineralogical, physico-chemical and petrophysical analyses. The aim is to increase the probability of discovery of deposits following the drilling of exploration wells in the most appropriate structures. These carbonates, limestones (white, greyish and greenish) and dolomites (massive and platelets) are presented in packstone, grainstone and wackestone textures. In addition to the essential minerals of these rocks, calcite and dolomite, we find quartz, plagioclase and kaolinite. With a porosity between 11% and 19% and a permeability of 138 to 155 mD, the Nganzi carbonates, which contain up to 23% oil, constitute good oil reservoirs. The characterization of the detrital facies and the acquisition of a seismic survey of the wells is essential to have a more detailed knowledge of the oil resources of the Nganzi Block.
文摘The Boya-02 kimberlite was identified at depth by geophysical survey work (a single-probe AM survey in 1997 and a gravity survey in 2006) that De Beers DRC Exploration carried out around anomaly 193/172/0019. This anomaly located approximately 50 km southwest of the town of Mbuji-Mayi in the Kasaï-Oriental Province in the DRC should therefore be the subject of detailed exploration with the aim of better identifying and describing this kimberlite. Thus, through exploratory work and cross-checking of geophysical and geological data, the discovery of this Massif was made by drilling on the aeromagnetic anomaly 193/172/X298. Based on drilling, sampling and laboratory petrographic analysis reports, the Boya-02 kimberlite was classified among highly diluted re-sedimented volcaniclastic kimberlites (KVR), rich in olivine and incidentally in quartz and poor in juvenile substances. This kimberlite represents a deposit of very low economic interest following extremely high dilution. The Boya-02 kimberlite was modeled using ground magnetism data. It is a complex anomaly comprising 2 components with variable amplitude appearing on a subtly magnetized linear detail. The modeled dimensions of two components of this anomaly are 0.32 Ha and 0.2 Ha at depths of 32 m & 14 m for the deposits to the West and the East respectively. Garnet data for the Boya-02 occurrence reports a maximum Pmin value of 49.7 kbar (207 garnets). These data demonstrate the high diamond potential which assumes a conductive cratonic geotherm of 40 mWm<sup>2</sup>.
基金the Chinese Scholarship Council for their support(Grant No.2022GXZ005733).
文摘Surface hydrogen storage facilities are limited and costly,making subsurface hydrogen storage in geological formations a more viable alternative due to its substantial capacity,safety,and economic feasibility.This method is essential for large-scale hydrogen storage to support renewable energy integration,fuel cell technologies,and other applications aimed at mitigating global climate change.This review examines underground hydrogen storage(UHS)in geological formations,focusing on recent experiments,modeling and simulations,and field applications.Geological formations such as depleted oil reservoirs,salt caverns,and depleted natural gas reservoirs are identified as favorable candidates due to minimal interactions with hydrogen,leading to low hydrogen loss.Globally,80%of UHS projects utilize depleted natural gas and oil reservoirs,with over 50%focused on depleted natural gas and oil condensate reservoirs due to cost-effective existing infrastructure.Among storage options,salt caverns are the most advantageous,offering self-healing properties,low caprock permeability,large storage capacity,rapid injection and withdrawal rates,and low contamination risk.Additionally,hydrogen produced from coal is the cheapest option,costing 1.2e2 USD/kg,whereas hydrogen from renewable sources,such as water,is the most expensive at 3e13 USD/kg.Despite its higher cost,green hydrogen from water,characterized by low carbon emissions,requires further research to reduce production costs.This review highlights critical research gaps,challenges,and policy recommendations to advance UHS technologies,ensuring their role in combating climate change.
基金The National Natural Science Foundation of China under contract Nos 41306057 and 40906028the Open Fund of the Key Laboratory of Submarine Geosciences,State Oceanic Administration under contract No.KLSG1406
文摘Triple mass-transport deposits （MTDs） with areas of 625, 494 and 902 km^2, respectively, have been identified on the north slope of the Xisha Trough, northern South China Sea margin. Based on high-resolution seismic reflection data and multi-beam bathymetric data, the Quaternary MTDs are characterized by typical geometric shapes and internal structures. Results of slope analysis showed that they are developed in a steep slope ranging from 5° to 35°. The head wall scarps of the MTDs arrived to 50 km in length （from headwall to termination）. Their inner structures include well developed basal shear surface, growth faults, stepping lateral scarps, erosion grooves, and frontal thrust deformation. From seismic images, the central deepwater channel system of the Xisha Trough has been filled by interbedded channel-levee deposits and thick MTDs. Therefore, we inferred that the MTDs in the deepwater channel system could be dominated by far-travelled slope failure deposits even though there are local collapses of the trough walls. And then, we drew the two-dimensional process model and three- dimensional structure model diagram af the MTDs. Combined with the regional geological setting and previous studies, we discussed the trigger mechanisms of the triple MTDs.
基金supported by the Foundation Project of State Key Laboratory of Petroleum Resources and Prospecting (PRPDX2008-05)the "973" National Key Basic Research Program (2006CB202308)
文摘Neotectonic movement refers to the tectonic movement that has happened since the Cenozoic, which is the latest movement. It has the most important influence on the basins in west China, especially on the hydrocarbon accumulation in the western foreland basins. We determined the time of neotectonic movement in the Kuqa Foreland Basin, which began from the Neogene, and analyzed the patterns of movement, which were continuous and fast subsidence in the vertical direction and intense lateral compression. The structure styles are that the faulting is weakened and the folding is strengthened gradually from north to south. We studied the control of neotectonic movement on the hydrocarbon accumulation process and model in the Kuqa Foreland Basin with basin simulation technique. The largest subsidence rate of the Kuqa Foreland Basin reached 1,200 m/Ma during the neotectonic movement, leading to rapid maturing of source rock within 5 Ma and a large quantity of hydrocarbon being generated and expelled. The thick neotectonic strata can form high quality reservoirs with the proved gas and oil reserves accounting for 5% and 27% of the total reserves, respectively. 86% of the structural traps were formed in the neotectonic movement period. The faults formed during the neotectonic movement serve as important migration pathways and they exist in the region where the hydrocarbon reservoirs are distributed. Abnormally high pressure caused by the intense lateral compression, thick neotectonic strata deposition and rapid hydrocarbon generation provide driving force for hydrocarbon migration. The accumulation elements match each other well over a short period, leading to many large gas fields formed later in the Kuqa Foreland Basin.
基金Project(2012CB214803)supported by the Major State Basic Research Development Program,ChinaProject(2011ZX5017-001-HZO2)supported by the National Science & Technology Special Project,China+1 种基金Project(2011D-5006-0105)supported by the PetroChina Research Fund,ChinaProject(SZD0414)supported by the Key Subject Construction Project of Sichuan Province,China
文摘A series of marine natural gas fields were recently discovered in oolitic dolomites of the Lower Triassic Feixianguan formation, northeastern Sichuan Basin, southwest China. The mechanism forming these reservoir dolomites is debatable, limiting the ability to characterize these reservoir successfully. Based on the investigation of the representative Dukouhe, Luojiazhai, and Puguang areas, this issue was addressed by examining the distribution, petrology, and geochemistry of the dolomites, the most comprehensive study to date was provided. Dolomitization occurred at a very early stage of diagenesis, as shown by the petrological features of the rock fabric. Vadose silt, which is composed primarily of dolomitic clasts, is found in the primary and secondary pores of the oolitic dolomite. This indicates that the overlying strata were subjected to dolomitization when the Feixianguan formation was located in the vadose zone. Therefore, it may be inferred that the dolomitization which occurred before the formation was exposed to meteoric conditions. The spatial distribution and geochemical characteristics of the dolomite indicate that dolomitization occurred as a result of seepage reflux. The degree of dolomitization decreases with increasing distance from the evaporative lagoon. Furthermore, the type and porosity of the dolomite vary in different zones of the upward-shoaling sequence, with the porosity gradually decreasing from the highest layer to the lowest layer. This reflects a close relationship between dolomitization and seawater evaporation during the formation of the dolomite. Geochemical analysis provided further evidence for the relationship between the dolomitization fluid and the coeval seawater. The 87Sr/86Sr and 813C isotopes, as well as the abundances of trace elements, Fe and Mn, indicate that seawater concentrated by evaporation acted as the dolomitization fluid. These results also show that dolomitization most likely occurred in a semi-closed diagenetic environment. Therefore, the main mechanism of oolitic dolomite formation is seepage reflux, which occurred at an early stage of diagenesis.
基金the project "Study on Technology to Increase the Recovery Ratio in Oilfields with Complex Fault Block" (P01035), a Science and Technology Promotion Project in the Tenth Five-Year Plan of SINOPECT
文摘A fault is not simply a plane, but a zone consisting of a series of broken planes or lower faults. The greater the scale of faults, the wider and more complex the fault zone is. Fault-sealing properties are influenced by the fault zone itself, whose fault displacement, depth, net-to-gross-ratio of mudstone, fault plane angle, and fault mechanical properties play important controlling roles. The sealing of hydrocarbon by the fault zone depends on whether the fault zone can form a continuous sealing zone and if the pore throats connecting those fault zones are small enough. The concept of fault zone-sealing potential is proposed here, and a quantitative formula is established by using a great amount of practical statistical data as well as the fuzzy comprehensive evaluation method, which is a comprehensive characterization parameter to judge whether or not fault zones could seal oil hydrocarbon. The greater the value of the fault zone-sealing potential, the better sealed the fault is. For example, with increasing depth, the sealing degree of the Xin 68 Fault in the Dongxin 1 oilfield changes greatly, reflecting the complexity of fault-sealing properties.
基金Supported by the CNOOC Science and Technology Project(KJZH-2021-0003-00,CNOOC-KJ 135 ZDXM 38 ZJ 03 ZJ).
文摘Based on analysis of newly collected 3D seismic and drilled well data,the geological structure and fault system of Baodao sag have been systematically examined to figure out characteristics of the transition fault terrace belt and its control on the formation of natural gas reservoirs.The research results show that the Baodao sag has the northern fault terrace belt,central depression belt and southern slope belt developed,among them,the northern fault terrace belt consists of multiple transition fault terrace belts such as Baodao B,A and C from west to east which control the source rocks,traps,reservoirs,oil and gas migration and hydrocarbon enrichment in the Baodao sag.The activity of the main fault of the transition belt in the sedimentary period of Yacheng Formation in the Early Oligocene controlled the hydrocarbon generation kitchen and hydrocarbon generation potential.From west to east,getting closer to the provenance,the transition belt increased in activity strength,thickness of source rock and scale of delta,and had multiple hydrocarbon generation depressions developed.The main fault had local compression under the background of tension and torsion,giving rise to composite traps under the background of large nose structure,and the Baodao A and Baodao C traps to the east are larger than Baodao B trap.Multiple fault terraces controlled the material source input from the uplift area to form large delta sand bodies,and the synthetic transition belt of the west and middle sections and the gentle slope of the east section of the F12 fault in the Baodao A transition belt controlled the input of two major material sources,giving rise to a number of delta lobes in the west and east branches.The large structural ridge formed under the control of the main fault close to the hydrocarbon generation center allows efficient migration and accumulation of oil and gas.The combination mode and active time of the main faults matched well with the natural gas charging period,resulting in the hydrocarbon gas enrichment.Baodao A transition belt is adjacent to Baodao 27,25 and 21 lows,where large braided river delta deposits supplied by Shenhu uplift provenance develop,and it is characterized by large structural ridges allowing high efficient hydrocarbon accumulation,parallel combination of main faults and early cessation of faulting activity,so it is a favorable area for hydrocarbon gas accumulation.Thick high-quality gas reservoirs have been revealed through drilling,leading to the discovery of the first large-scale gas field in Baodo 21-1 of Baodao sag.This discovery also confirms that the north transition zone of Songnan-Baodao sag has good reservoir forming conditions,and the transition fault terrace belt has great exploration potential eastward.
基金supported by the Ministry of Science, Research and Technology of Iran and TRIGGER Program。
文摘This paper presents the properties of fluid inclusions found in sphalerite from Latala epithermal base and precious metal deposit(Central Iran),which is hosted in Cenozoic volcanicsedimentary host-rocks.The Latala Deposit represents an example of vein type,base metal deposits in the Miduk porphyry copper deposits(PCDs)in southern Urumieh-Dokhtar magmatic belt(UDMB).Mineralization in Latala epithermal base and precious metal vein type formed in 3 stages and sphalerite-quartz veins occur in stages 2 and 3.Stage 2 quartz-sphalerite veins are associated with chalcopyrite and zoned sphalerite,along with quartz+hematite,and Stage 3 quartz-sphalerite veins contain galena+sphalerite+chalcopyrite and quartz with overgrowth of calcite.Mineralization in Stage 3 occurs as replacement bodies and contains Fe-poor sphalerite without zoning in the outer parts of the deposit.This paper focuses on fluid inclusions in veins bearing sphalerite and quartz.The fluid inclusion homogenization temperatures and salinity in sphalerite(some with typical zoning)range from 144 to 285℃and from 0.2 wt.%to 7.6 wt.%NaCl eq.Sphalerite and fluid inclusions of the Latala base and precious metal deposit formed from relatively low-T and low-salinity solutions.Raman spectroscopy analyses indicate a high percentage of CO2 in the gas phase of fluid inclusions in Fe-poor sphalerites,as expected with melting temperature for CO2 of-56.6℃,and significant amounts of H2.Lack of reduced carbon species(methane and lighter hydrocarbons)was confirmed in the petrographic study using UV light and Raman spectroscopy.High amounts of H2 in fluid inclusions of Fe-poor sphalerite can be the result of different intensities of alteration and diffusion processes.The common occurrences of CO2 in fluid inclusions have originated from magma degassing and dissolution of carbonates.Theδ^34S values for sulfide minerals in galena of sphalerite bearing veins vary between-9.8‰and-1.0‰,and theδ^34S values calculated for H2 S are between-7.1‰and+0.6‰.These values correspond to magmatic sulfur whit possible interaction with wall rocks.Magmatic fluids were successively diluted during cooling and continuous ascent.Secondary boiling would lead to variable amounts of potassic or prophylactic alteration and the hydrogen diffusion into the inclusions hosted in sphalerite of Latala.
文摘Mineralogical, geochemical, and textural analyses of the white sandstones （Abu Thora Fm.） of Carboniferous in the Abu Rodeiyim region show that they are fluviomarine, well-sorted, highpurity, and high-grade silica SiO2 （average 99.56%）. The results indicate that by simple treatment, the white sandstones can reach a high degree of purity, suitable for different industrial purposes （e.g. manufacture of silicon photovoltaic, crystal, and TV screens, art, and domestic and optical glass）.
文摘The distribution and marketing of petroleum products are the sources of energy for the various activities of human society and household supply. We spent our time researching the competitive factors to reduce the time of distribution of petroleum products, by setting up a computer system based on Dijkstra’s algorithm our contribution will solve a real problem of delivery with direct targeting of gas stations. We set up a tool to help to map based on the method of operational research starting with the identification of delivery point, mapping and then applying the algorithm. Mainly the graph theory and the optimal path in a network by a short path using the method of Dijkstra for the design we used the UML language, the programming we used the JAVA language with very appreciable results to finish with a conclusion.
文摘Rare Earth Elements(REE)are a group of chemicallycoherent elements that are critical to a wide range of modern high technology applications and the critical strategic role of REE to the economic development of the U.S.A.,European Union and Japan has been recognised.China holds a near monopoly over the supply of REE and REE products-accounting for around 95%of the global supply in 2010.These factors triggered a rush to discover REE deposits and develop REE production outside of China.
基金support from the Chinese Scholarship Council(Grant No.2022GXZ005733)。
文摘The Pressure-Volume-Temperature(PVT)properties of crude oil are typically determined through laboratory analysis during the early phases of exploration and fielddevelopment.However,due to extensive data required,time-consuming nature,and high costs,laboratory methods are often not preferred.Machine learning,with its efficiencyand rapid convergence,has emerged as a promising alternative for PVT properties estimation.This study employs the modified particle swarm optimization-based group method of data handling(PSO-GMDH)to develop predictive models for estimating both the oil formation volume factor(OFVF)and bubble point pressure(P_(b)).Data from the Mpyo oil fieldin Uganda were used to create the models.The input parameters included solution gas-oil ratio(R_(s)),oil American Petroleum Institute gravity(API),specificgravity(SG),and reservoir temperature(T).The results demonstrated that PSO-GMDH outperformed backpropagation neural networks(BPNN)and radial basis function neural networks(RBFNN),achieving higher correlation coefficientsand lower prediction errors during training and testing.For OFVF prediction,PSO-GMDH yielded a correlation coefficient(R)of 0.9979(training)and 0.9876(testing),with corresponding root mean square error(RMSE)values of 0.0021 and 0.0099,and mean absolute error(MAE)values of 0.00055 and 0.00256,respectively.For P_(b)prediction,R was 0.9994(training)and 0.9876(testing),with RMSE values of 6.08 and 8.26,and MAE values of 1.35 and 2.63.The study also revealed that R_(s)significantlyimpacts OFVF and P_(b)predictions compared to other input parameters.The models followed physical laws and remained stable,demonstrating that PSO-GMDH is a robust and efficientmethod for predicting OFVF and P_(b),offering a time and cost-effective alternative.
文摘The porosity of a rock is one of the most important reservoir properties. It controls the reservoir storage capacity. In other words, porosity quantifies the amount of fluids that the rock can store. Most of the world＇s giant fields produce hydrocarbons from carbonate reservoirs. Carbonate rocks contain more than 50% of the world＇s hydrocarbon reserves. Porosity and compressional wave velocity of 41 carbonate samples were determined under ambient conditions in laboratory. The samples were collected from seven shallow wells in west Tushka area, south Western Desert, Egypt. This paper evaluates the well known Wyllie and Raymer equations, an empirical linear equation, and a generalized model for porosity estimation from compressional wave velocity of saturated carbonate samples. Based on the comparison of the predicting identified to provide the most reliable porosity estimation. qualities, the Raymer equation and the empirical linear equation were
文摘Understanding the effects of mineral composition on geomechanical characteristics is critical in order to design and optimize the hydraulic fracturing necessary for shale gas reservoir production.Fundamental information is still missing in effects of mineral content and the experimental methodologies used.This paper provided an in-depth assessment of the various experimental methodologies and their applications in the relationship between the mineralogical and geomechanical features of the shale formation.The results revealed that more brittle minerals increase their strength,but chemical reaction that creats pores decrease their strength.High content of carbonate or quartz increases a rock's brittleness,while a high content of clay increases a rock's plasticity and decreases its brittleness.As phyllosilicate content increases,the uniaxial compressive strength decreases,and this could be because phyllosilicate minerals have a weakening effect on the mineral bond.Young's modulus often climb as clay minerals decline and as silica with carbonate concentration rises,however Poisson's ratio increases in relation to an increase in clay minerals,which also increases the ductility of the reservoir shale rock.However,compared to minerals and matrix,does not significantly impact the strength of shale rock.Besides,the benefits and drawbacks of using uniaxial and triaxial compression,ultrasonic testing,and nano-indentation techniques in unconventional reservoirs were described.The findings suggest that,because of the possibility for experimental testing repeatability for increased accuracy,ultrasonic testing is the most appropriate experimental approach in the scenes of assessing static and dynamic geomechanical properties of reservoir shale rock.We suggested that numerically-based simulation of experimental techniques used for shale geomechanical evaluations and numer-ical modeling of heterogeneous shale rock samples will be necessary in light of the limitations faced in the ap-plications of experimental techniques for shale geomechanical evaluation.
基金supported by the Deutsche Forschungsgemeinschaft (Grant Nos. MU 1725/1-3 and MU 1725/2-1)the Consortium Project PHASE
文摘In this work we interpret the data showing unusually strong velocity dispersion of P-waves (up to 30%) and attenuation in a relatively narrow frequency range. The cross-hole and VSP data were measured in a reservoir, which is in the porous zone of the Silurian Kankakee Limestone Formation formed by vertical fractures within a porous matrix saturated by oil, and gas patches. Such a medium exhibits significant attenuation due to wave-induced fluid flow across the interfaces between different types of inclusions (fractures, fluid patches) and background. Other models of intrinsic attenuation (in particular squirt flow models) cannot explain the amount of observed dispersion when using realistic rock properties. In order to interpret data in a satisfactory way we develop a superposition model for fractured porous rocks accounting also for the patchy saturation effect.
文摘The Pamir region, located to the northwest of the Tibetan Plateau, provides important information that can aid the understanding of the plateau＇s tectonic evolution. Here we present new findings on the deforma- tion geometry and timing of the Wupoer thrust belt at the northeastem margin of Pamir. Field investigations and interpretations of seismic profiles indicate that the eastern portion of the Wupoer thrust belt is dominated by an underlying foreland basin and an overlying piggy-back basin. A regional unconformity occurs between the Pliocene （N2） and the underlying Miocene （NI） or Paleogene （Pg） strata associated with two other local unconformities between Lower Pleistocene （Q1） and N2 and between Middle Pleistocene （Q2-4） and Q1 strata. Results of structural restorations suggest that compres- sional deformation was initiated during the latest Miocene to earliest Pliocene, contributing a total shortening magnitude of 48.6 km with a total shortening rate of 48.12%, most of which occurred in the period from the latest Miocene to earliest Pliocene. These results, com- bined with previous studies on the Kongur and Tarshkor- gan extensional system, suggest an interesting picture of strong piedmont compressional thrusting activity concur- rent with interorogen extensional rifting. Combining these results with previously published work on the lithospheric architecture of the Pamir, we propose that gravitational collapse drove the formation of simultaneous extensional and compressional structures with a weak, ductile middle crustal layer acting as a decollement along which both the extensional and compressional faults merged.
基金Project supported by China National Petroleum Corporation
文摘The two mechanisms of gas dissolving in water, interstice filling and aquation, are proposed. General equations of gas solubility have been deduced from the mechanisms and experimental observations. Dependence of Henry’s coefficient on temperature, pressure, aquation equilibrium constant and gas molecular wlume is discussed. The theoretical equations were verified by experimental data, which shows that the theoretical results of the solubility of methane are in good agreement with the experimental data in the range of 20 -160℃ and under a pressure of less than 60 MPa.
