Oil-water separation for produced water (PW) originating from an oil extraction site in South Kuwait was carried out using bleached, esterified cellulosic material from used coffee grounds. Thereafter, earth-alkaline ...Oil-water separation for produced water (PW) originating from an oil extraction site in South Kuwait was carried out using bleached, esterified cellulosic material from used coffee grounds. Thereafter, earth-alkaline metal ions, specifically calcium ions, of the de-oiled PW were removed by precipitation with sodium carbonate to give access to pure sodium chloride as industrial salt from the remaining PW. While the purity of the precipitated calcium carbonate (CaCO3) depends on the precipitation conditions, CaCO3 of up to 95.48% purity can be obtained, which makes it a salable product. The precipitation of CaCO3 decreases the amount of calcium ions in PW from 11,300 ppm to 84 ppm.展开更多
Produced water from an oil extraction site in South Kuwait was sampled after primary oil – water separation had been carried out. The produced water was filtered through a mixture of activated charcoal and esterified...Produced water from an oil extraction site in South Kuwait was sampled after primary oil – water separation had been carried out. The produced water was filtered through a mixture of activated charcoal and esterified cellulosic material gained from spent coffee grounds as a tertiary adsorption treatment. The earth-alkaline metal ions and heavy metals were separated from the de-oiled produced water by addition of either sodium or potassium hydroxide in the presence of carbon dioxide or by direct addition of solid sodium carbonate. The resulting filtrate gave salt of industrial purity upon selective crystallization on evaporation.展开更多
Most oil and gas wells worldwide are completed with low alloy carbon steel due to cost-effectiveness, despite its high susceptibility to corrosion. Corrosion in alloy steels occurs through galvanic or electrolytic rea...Most oil and gas wells worldwide are completed with low alloy carbon steel due to cost-effectiveness, despite its high susceptibility to corrosion. Corrosion in alloy steels occurs through galvanic or electrolytic reactions, resulting in the release of metallic ions. This release adversely affects the strength and integrity of production tubing. The current study focused on quantifying the amount of alloying constituents present in the produced waters of oil and gas wells using inductively coupled plasma-optical emission spectroscopy (ICP-OES) to calculate the corrosion rate on the production tubing. Two types of alloy steel tubing, API 5CT T-95 and API 5CT J55, were selected. The wells were chosen based on sweet and sour production. The levels of ions present in the produced water—Nickel, Chromium, Manganese, Molybdenum, and Iron—were measured. Ion dissolution was converted to corrosion rate using the exposed area of the tubing and the water flow rate. The study concluded that a very high corrosion rate occurs in sweet wells completed with T-95 metallurgy, whereas the corrosion rate in sour gas producers is significantly less compared to sweet producers. For the oil wells, although they are sour producers, a very low corrosion rate was observed with API 5CT J55 metallurgy. Furthermore, the study revealed that quantifying the alloying constituents in produced water is key to developing suitable corrosion projection approaches, predicting the service life of production tubing in gas and oil wells and metallic structures, and guiding production engineers to make informed decisions and timely responses to corrosion threats before failure.展开更多
Produced water(PW)from oil and gas exploration adversely affects aquatic life and living organisms,necessitating treatment before discharge to meet effluent permissible limits.This study first used activated sludge to...Produced water(PW)from oil and gas exploration adversely affects aquatic life and living organisms,necessitating treatment before discharge to meet effluent permissible limits.This study first used activated sludge to pretreat PW in a sequential batch reactor(SBR).The pretreated PW then entered a 13 L photobioreactor(PBR)containing Scenedesmus obliquus microalgae culture.Initially,10%of the PW mixed with 90%microalgae culture in the PBR.After the exponential growth of the microalgae,an additional 25%of PW was added to the PBR without extra nutrients.This study reported the growth performance of microalgae in the PBR as well as the reduction in effluent’s total organic carbon(TOC),total dissolved solids(TDS),electrical conductivity(EC),and heavy metals content.The results demonstrated removal efficiencies of 64%for TOC,49.8%for TDS,and 49.1%for EC.The results also showed reductions in barium,iron,and manganese in the effluent by 95,76,and 52%,respectively.展开更多
Produced water (PW) is the largest waste stream in the oil and gas industry. Water remains trapped for millions of years in the reservoir with oil and gas. When a hydrocarbon reservoir is infiltrated by a production w...Produced water (PW) is the largest waste stream in the oil and gas industry. Water remains trapped for millions of years in the reservoir with oil and gas. When a hydrocarbon reservoir is infiltrated by a production well, the produced fluids commonly contain water. The understanding of this water’s constituents and volumes is vital for the sustainable continuity of production operations, as PW has a number of negative impacts on the infrastructure integrity of the operation. On the other hand, PW can be an alternative source of irrigation water as well as of industrial salt. Interestingly, both the quantity as well as the quality of PW do not remain constant but can vary, both progressively and erratically, even over short periods of time. This paper discusses such a situation of variable PW in an oil and gas operation in the State of Kuwait.展开更多
Treatment of oilfield produced water was investigated using an anaerobic process coupled with micro-electrolysis （ME）, focusing on changes in chemical oxygen demand （COD） and biodegradability. Results showed that ...Treatment of oilfield produced water was investigated using an anaerobic process coupled with micro-electrolysis （ME）, focusing on changes in chemical oxygen demand （COD） and biodegradability. Results showed that COD exhibited an abnormal change in the single anaerobic system in which it increased within the first 168 hr, but then decreased to 222 mg/L after 360 hr. The biological oxygen demand （five-day） （BOD5）/COD ratio of the water increased from 0.05 to 0.15. Hydrocarbons in the wastewater, such as pectin, degraded to small molecules during the hydrolytic acidification process. Comparatively, the effect of ME was also investigated. The COD underwent a slight decrease and the BOD5/COD ratio of the water improved from 0,05 to 0.17 after ME. Removal of COD was 38.3% under the idealized ME conditions （pH 6.0）, using iron and active carbon （80 and 40 g/L, respectively）. Coupling the anaerobic process with ME accelerated the COD removal ratio （average removal was 53.3%）. Gas chromatography/mass spectrometry was used to analyze organic species conversion. This integrated system appeared to be a useful option for the treatment of water produced in oilfields.展开更多
Concentration polarization and membrane fouling remain one of the major hurdles for the implementation of ultrafiltration of produced water. Although many applications for ultrafiltration were already suggested, only ...Concentration polarization and membrane fouling remain one of the major hurdles for the implementation of ultrafiltration of produced water. Although many applications for ultrafiltration were already suggested, only few were implemented on an industrial scale. Among those techniques, turbulence promoter can be more simple and effective in overcoming membrane fouling and enhancing membrane flux. As for the result that turbulence promoter increase fluid velocity, wall shear rates and produce secondary flows or instabilities, the influence of turbulence promoter was investigated on permeate flux during produced water ultrafiltration and the potential application of this arrangement for an industrial development. Experimental investigations were performed on 100 KDa molecular weight cut-off PVDF single-channel tubular membrane module using four kinds of turbulence promoters. It is observed that the significant flux enhancement in the range of 83%--164% was achieved while the hydraulic dissipated power per unit volume of permeate decreased from 31%--42%, which indicated that the using of turbulence promoter is more efficient than operation without the turbulence promoter. The effects of transmembrane pressure and cross-flow velocity with and without turbulence promoter were studied as well. Among the four kinds of turbulence promoters, winding inserts with 20.0 mm pitch and 1.0 mm wire diameter showed better performances than the others did.展开更多
The emulsion stability of oilfield produced water is related to the oil-water interfacial film strength and the zeta potential of the oil droplets. We investigated the effects of water treatment agents （corrosion inh...The emulsion stability of oilfield produced water is related to the oil-water interfacial film strength and the zeta potential of the oil droplets. We investigated the effects of water treatment agents （corrosion inhibitor SL-2, scale inhibitor HEDP, germicide 1227, and flocculant polyaluminium chloride PAC） on the stability of oilfield produced water. The influence of these treatment agents on oil-water interfacial properties and the mechanism of these agents acting on the oilfield produced water were studied by measuring the interfacial shear viscosity, interfacial tension and zeta electric potential. The results indicated that the scale inhibitor HEDP could increase the oil-water interfacial film strength, and it could also increase the absolute value of the zeta potential of oil droplets. HEDP played an important role in the stability of the emulsion. Polyaluminum chloride （PAC） reduced the stability of the emulsion by considerably decreasing the absolute value of the zeta potential of oil droplets. Corrosion inhibitor SL-2 and germicide 1227 could decrease the oil-water interfacial tension, whereas they had little influence on oil-water interfacial shear viscosity and oil-water interfacial electricity properties.展开更多
Seventy-nine strains of bioflocculant-producing bacteria were isolated from 3 activated sludge samples. Among them, strain MYC was found to have the highest and stable flocculating rate for both kaolin clay suspension...Seventy-nine strains of bioflocculant-producing bacteria were isolated from 3 activated sludge samples. Among them, strain MYC was found to have the highest and stable flocculating rate for both kaolin clay suspension and oil-field produced water. The bacterial strain was identified as Klebsiella sp. MYC according to its morphological and biochemical characteristics and 16SrDNA sequence. The optimal medium for bioflocculant production by this bacterial strain was composed of cane sugar 20 g L^-1, KH2PO4 2 g L^-1, K2HPO4 5 g L^- 1, （ NH4）2SO4 0.2 g L^-1, urea 0.5 g L^- 1 and yeast extract 0.5 g L^- 1, the initial pH being 5.5. When the suspension of kaolin clay was treated with0.5% of Klebsiella sp. MYC culture broth, the flocculating rate reached more than 90.0% in the presence of 500mg L^-1 CaCI2, while the flocculating rate for oil-field produced water was near 80.0% in a pH range of 7.0 - 9.0 with the separation of oil and suspended particles from the oil-field produced water under similar conditions. The environment-friendly nature of the bioflocculant and high flocculating rate of the strain make the bioflocculant produced by Klebsiella sp. MYC an attractive bioflocculant in oil-field produced water treatment.展开更多
Oilfield produced water is large quantities of salty water trapped in underground formations and subsisted under high temperatures and pressures that are brought to the surface along with oil during production. Produc...Oilfield produced water is large quantities of salty water trapped in underground formations and subsisted under high temperatures and pressures that are brought to the surface along with oil during production. Produced water(PW) contains a lot of pollutants such as hydrocarbons and metals, this water must be treated before disposal. Therefore, different techniques are being used to treat produced water. Electrocoagulation is an efficient treatment technique involving the dissolution of anodes and formation of electro-coagulants, while the simultaneous generation of H_2 bubbles at the cathode leads to the pollutant removal by flotation. Electrocoagulation(EC)method is one of the most promising and widely used processes to treat oilfield produced water. In the present work, a conventional internal-loop(draught tube) airlift reactor was utilized as electrocoagulation/flotation cell for PW treatment by inserting two aluminum electrodes in the riser section of the airlift reactor. The EC airlift reactor was operated in a batch mode for the liquid phase. Different experimental parameters were studied on the oil and turbidity removal efficiencies such as current density, initial pH, electrocoagulation time, and air injection.The experimental results showed that mixing of the oil droplets in the PW was accomplished using only the liquid recirculation resulted by H_2 microbubbles generated by EC process which enhanced the oil removal. The experimental results further showed that the EC time required achieving ≥ 90% oil removal efficiency decreases from 46 to 15 min when operating current density increases from 6.8 to 45.5 mA·cm^(-2). This reactor type was found to be highly efficient and less energy consuming compared to conventional existing electrochemical cells which used mechanical agitation.展开更多
Based on long-term dynamic tracing of dissolved inorganic carbon(DIC)and stable carbon isotope(δ13CDIC)in produced water from 20 coalbed methane(CBM)wells in western Guizhou,the spatial-temporal dynamic variations of...Based on long-term dynamic tracing of dissolved inorganic carbon(DIC)and stable carbon isotope(δ13CDIC)in produced water from 20 coalbed methane(CBM)wells in western Guizhou,the spatial-temporal dynamic variations ofδ13CDIC of the GP well group produced in multi-layer commingled manner were analyzed,and the relationship between the value ofδ13CDIC and CBM productivity was examined.The produced water samples of typical wells in the GP well group were amplified and sequenced using 16S rDNA,and a geological response model ofδ13CDIC in produced water from CBM wells with multi-coal seams was put forward.The research shows that:δ13CDIC in produced water from medium-rank coal seams commonly show positive anomalies,the produced water contains more than 15 species of methanogens,and Methanobacterium is the dominant genus.The dominant methanogens sequence numbers in the produced water are positively correlated withδ13CDIC,and the positive anomaly of v is caused by reduction of methanogens,and especially hydrogenotrophic methanogens.Vertical segmentation of sedimentary facies and lithology in stratum with multi-coal seams will result in permeability and water cut segmentation,which will lead to the segmentation ofδ13CDIC and archaea community in produced water,so in the strata with better permeability and high water cut,theδ13CDIC of the produced water is abnormally enriched,and the dominant archaea is mainly Methanobacterium.In the strata with weak permeability and low water cut,theδ13CDIC of the produced water is small,and the microbial action is weak.The shallow layer close to the coal seam outcrop is likely to be affected by meteoric precipitation,so theδ13CDIC of the produced water is smaller.The geological response model ofδ13CDIC in produced water from multi-coal seams CBM wells in the medium-rank coal reveals the geological mechanism and microbial action mechanism of theδ13CDIC difference in the produced water from the multi-coal seams CBM wells.It also provides effective geochemical evidence for the superimposed fluid system controlled by sedimentary facies,and can also be used for the contribution analysis of the produced gas and water by the multi-layer CBM wells.展开更多
In order to predict the corrosion trendency of X100 pipeline steel in flowing oilfield produced water,the effect of flow rate on the corrosion behavior of X100 pipeline steel was studied under general dynamic conditio...In order to predict the corrosion trendency of X100 pipeline steel in flowing oilfield produced water,the effect of flow rate on the corrosion behavior of X100 pipeline steel was studied under general dynamic condition and simulated real working condition at the flow rate of 0.2,0.4,and 0.6 m·s^(-1).Potentiodynamic polarization curves and electrochemical impedance spectroscopy were used to study the corrosion behavior of X100 steel.Energy dispersive spectroscopy,X-ray diffraction and scanning electron microscopy were used to analyze corrosion product composition and micromorphology.The experimental results show that the corrosion is more serious under simulated real working conditions than that under the general dynamic conditions.In any case the corrosion current density increases with the increase of the flow rate,and the total impedance value decreases.The corrosion products include Fe_(3)O_(4),Fe_(2)O_(3),and FeOOH.The mass transfer and electrochemistry were simulated by flow coupled in COMSOL software.The multiphysical field coupling simulation results are closer to the engineering practice than the single flow field simulation,and similar results from the experiments were obtained.Both experimental and simulation results reveal that the higher flow rate is,the more serious corrosion appear and the more corrosion products accumulate.By combining experimental and COMSOL simulation data,the corrosion process model of X100 steel was proposed.展开更多
Large volumes of water are generated in gas- and oil-production. This includes the water that is present originally in the reservoirs, but also water that is injected into the wells. While currently much of the produc...Large volumes of water are generated in gas- and oil-production. This includes the water that is present originally in the reservoirs, but also water that is injected into the wells. While currently much of the produced water is either reinjected or disposed of after treatment, treated produced water is increasingly seen as an interesting resource, especially in water-scarce regions. This review looks at different PW treatment methods available, with an emphasis on the management of PW in oil- and gas production on the Arabian Peninsula.展开更多
In this study, Mucuna flagellipes seed extract was applied in the coagulation-flocculation of produced water （PW）. Process parameters such as pH, dosage, and settling time were investigated. Process kinetics was als...In this study, Mucuna flagellipes seed extract was applied in the coagulation-flocculation of produced water （PW）. Process parameters such as pH, dosage, and settling time were investigated. Process kinetics was also studied. Instrumental characterization of mucuna seed （MS）, mucuna seed coagulant （MSC）, and post effluent treatment settled sludge （PTSS） were carried out. The optimum decontamination efficiency of 95 % was obtained at 1 g/L MSC dosage, PW pH of 2, and rate constant of 0.0001 （L/g/s）. Characterization results indicated that MS, MSC, and PTSS were of network structure, primitive lat- tice, and thermally stable. It could be concluded that MSC would be potential biomass for the treatment of produced water under the experimental conditions.展开更多
The conventional treatment process cannot meet the need for treatment of produced water from alka- line/surfactant/polymer flooding（ ASP produced water） in Daqing oilfield. In this study, a new type of hydro- philic...The conventional treatment process cannot meet the need for treatment of produced water from alka- line/surfactant/polymer flooding（ ASP produced water） in Daqing oilfield. In this study, a new type of hydro- philic fibre ball medium was developed through surface modification method. The hydrophilic property of the surface modified fibre ball was tested with ASP produced liquid at laboratory. The results showed that this fibre hall had higher oll degreasing efficiency, The surface components were also observed by Scanning Electron Microscope and X-ray Photoelectron Spectroscopy, the result showed that the hydrophilic fibre＇ s surface was covered by sulfonic group. Using hydrophilic fibre ball as filter medium, a new type of filter was designed to treat ASP produced water in pilot-scale experiments. The obtained results indicated that this type of filter had high capability and efficiency for the treatment of ASP produced water. This filter should have a better application prospect in oilfield produced water treatment.展开更多
Kuwaiti oil production faces a growing challenge in the increasing quantities of produced water generated in the production of oil. The high water cut of the produced fluid from the wells and the high salinity of the ...Kuwaiti oil production faces a growing challenge in the increasing quantities of produced water generated in the production of oil. The high water cut of the produced fluid from the wells and the high salinity of the produced water lead to significant degradation of subsurface equipment, specifically the production tubing. Debris generated through the degradation of the inner part of the tubing becomes a constituent of the scaling that deposits in the tubing and blocks the flow of the production fluid, inducing higher maintenance costs. This paper looks at the characteristics of the scaling in regard to the produced water and outlines the economic impact of the produced water induced degradation of the tubing structure.展开更多
Water manufactured is the primary waste source in the oil and gas industry. Because of the rising amount of waste worldwide, the environmental effect of wastewater has become a primary environmental concern in recent ...Water manufactured is the primary waste source in the oil and gas industry. Because of the rising amount of waste worldwide, the environmental effect of wastewater has become a primary environmental concern in recent years. The vast amounts involved have resulted in considerable costs to the industry for handling produced water. This research explains the wide variety of choices for water management. This research’s first phase was water minimization techniques, consisting of three different applications made in three different wells (Well 1, Well 2 and Well 3) and water recycling and reuse by two techniques. In Well 1, Mechanical shut-off technique was applied using through tubing bridge plug and 5 m cement dumped above it to isolate the watered out zone;as per water oil ration plot the water cut is decreased from 100% to 4% and the production is increased from 0 to 400 bcpd. In Well 2, Chemical shut-off technique using a polymer called Brightwater has been used to block channeling through high permeability intervals after PLT log detected it, and the result was brilliant, the water cut decreased from 60% to 25%, also the oil production increase from 500 to 3000 bopd. In Well 3, downhole separator installed in it using workover (unfortunately, this technique is not applied in middle east till the moment so this application is taken from an oil field in Canada)and the result was perfect, the water cut decreased from 70% to 28%, also the oil production increase from 44 to 100 bopd. This study tried to clarify and compare the most widely used water management techniques using one of the Western Desert (W.D.) (enhanced for oil recovery, constructed wetland).展开更多
The oil field belongs to a conventional heavy oil reservoir. Since the late development, with the application and scale expansion of chemical flooding, the treatment of produced water is more difficult, the effect of ...The oil field belongs to a conventional heavy oil reservoir. Since the late development, with the application and scale expansion of chemical flooding, the treatment of produced water is more difficult, the effect of conventional corrosion inhibitors and bactericides is poor, the water quality after treatment is poor in stability, and the water injection system pipe network is seriously corroded and blocked, which affects production. Through the research and development of a water quality stabilizer agent, the corrosion rate of polymer-containing produced water is significantly reduced after application, the corrosion rate of on-site hanging pieces is reduced to about 0.01mm/a, the reduction rate reaches 90%, the along-path bacterial content is reduced, the stability of the along-path water quality is improved, the generation of sediment in the water injection network is reduced, the water injection and polymer injection effects are effectively improved, and a positive contribution is made to further improving the oil recovery rate.展开更多
Reutilizing flowback fluid and produced water to prepare fracturing fluid is still an urgent problem that needs to be solved and is not well solved.In this work,an anti-salt associative thickener(AAT)was synthesized b...Reutilizing flowback fluid and produced water to prepare fracturing fluid is still an urgent problem that needs to be solved and is not well solved.In this work,an anti-salt associative thickener(AAT)was synthesized by free radical copolymerization,and the molecular structure of AAT was demonstrated by FTIR and 1H-NMR.Furthermore,compared with a common anti-salt thickener(HAT),the comprehensive performances of AAT were systematically investigated under the conditions of fresh water,flowback fluid and produced water in Sulige Gasfield.The results show that under the conditions of an average salinity of 34,428 mg/L and an average high-valent ion content of 4967 mg/L,AAT can present good thickening capacity,temperature and shear resistance,drag reduction efficiency,sand-carrying ability,gel-breaking property and high-effective crosslinking capacity with organic zirconium crosslinker at high salinity,which implicates the great potential and feasibility to prepare fracturing fluid by reutilizing high-salinity f lowbackfluid and produced water without further treatment.Moreover,the possible mechanisms of the associative thickener to achieve high-effective drag reduction and sand-carrying might be the existence of reversible supramolecular structures and the significant increase of viscoelasticity by shear stretching in turbulent state.At the same time,both physical and chemical interaction can make a significant contribution to high-effective crosslinking capacity of associative thickener.All results and findings can provide an important reference for the design of novel fracturing fluid and the reutilization of high salinity water in stimulation applications.展开更多
Produced water,a byproduct of oil and gas extraction,presents significant environmental challenges if not properly treated.This review focuses on advancements in two primary offshore deoiling technologies,namely:induc...Produced water,a byproduct of oil and gas extraction,presents significant environmental challenges if not properly treated.This review focuses on advancements in two primary offshore deoiling technologies,namely:induced gas flotation and hydrocyclones,tracing their evolution from the 1940s to the present.The study provides a detailed comparison of these technologies in terms of efficiency,energy consumption,and waste generation,offering both qualitative and quantitative assessments.Particular attention is given to the integration of hydrocyclone-induced gas flotation(HIGF)systems,which enhance oil removal efficiency while reducing energy consumption,making them an important solution in offshore produced water management.Additionally,the review identifies specific design improvements in flotation units,such as multistage configurations,and explores the role of operational control in optimizing hydrocyclone performance.Global variations in produced water discharge standards are examined,emphasising the need for stricter environmental regulations.In addition,this study highlights the combined use of hydrocyclone and flotation technologies as a comprehensive approach for addressing both environmental and operational challenges in offshore produced water treatment.展开更多
文摘Oil-water separation for produced water (PW) originating from an oil extraction site in South Kuwait was carried out using bleached, esterified cellulosic material from used coffee grounds. Thereafter, earth-alkaline metal ions, specifically calcium ions, of the de-oiled PW were removed by precipitation with sodium carbonate to give access to pure sodium chloride as industrial salt from the remaining PW. While the purity of the precipitated calcium carbonate (CaCO3) depends on the precipitation conditions, CaCO3 of up to 95.48% purity can be obtained, which makes it a salable product. The precipitation of CaCO3 decreases the amount of calcium ions in PW from 11,300 ppm to 84 ppm.
文摘Produced water from an oil extraction site in South Kuwait was sampled after primary oil – water separation had been carried out. The produced water was filtered through a mixture of activated charcoal and esterified cellulosic material gained from spent coffee grounds as a tertiary adsorption treatment. The earth-alkaline metal ions and heavy metals were separated from the de-oiled produced water by addition of either sodium or potassium hydroxide in the presence of carbon dioxide or by direct addition of solid sodium carbonate. The resulting filtrate gave salt of industrial purity upon selective crystallization on evaporation.
文摘Most oil and gas wells worldwide are completed with low alloy carbon steel due to cost-effectiveness, despite its high susceptibility to corrosion. Corrosion in alloy steels occurs through galvanic or electrolytic reactions, resulting in the release of metallic ions. This release adversely affects the strength and integrity of production tubing. The current study focused on quantifying the amount of alloying constituents present in the produced waters of oil and gas wells using inductively coupled plasma-optical emission spectroscopy (ICP-OES) to calculate the corrosion rate on the production tubing. Two types of alloy steel tubing, API 5CT T-95 and API 5CT J55, were selected. The wells were chosen based on sweet and sour production. The levels of ions present in the produced water—Nickel, Chromium, Manganese, Molybdenum, and Iron—were measured. Ion dissolution was converted to corrosion rate using the exposed area of the tubing and the water flow rate. The study concluded that a very high corrosion rate occurs in sweet wells completed with T-95 metallurgy, whereas the corrosion rate in sour gas producers is significantly less compared to sweet producers. For the oil wells, although they are sour producers, a very low corrosion rate was observed with API 5CT J55 metallurgy. Furthermore, the study revealed that quantifying the alloying constituents in produced water is key to developing suitable corrosion projection approaches, predicting the service life of production tubing in gas and oil wells and metallic structures, and guiding production engineers to make informed decisions and timely responses to corrosion threats before failure.
基金Membranes and Water Security IRC,KFUPM.Funding no.INMW2304。
文摘Produced water(PW)from oil and gas exploration adversely affects aquatic life and living organisms,necessitating treatment before discharge to meet effluent permissible limits.This study first used activated sludge to pretreat PW in a sequential batch reactor(SBR).The pretreated PW then entered a 13 L photobioreactor(PBR)containing Scenedesmus obliquus microalgae culture.Initially,10%of the PW mixed with 90%microalgae culture in the PBR.After the exponential growth of the microalgae,an additional 25%of PW was added to the PBR without extra nutrients.This study reported the growth performance of microalgae in the PBR as well as the reduction in effluent’s total organic carbon(TOC),total dissolved solids(TDS),electrical conductivity(EC),and heavy metals content.The results demonstrated removal efficiencies of 64%for TOC,49.8%for TDS,and 49.1%for EC.The results also showed reductions in barium,iron,and manganese in the effluent by 95,76,and 52%,respectively.
文摘Produced water (PW) is the largest waste stream in the oil and gas industry. Water remains trapped for millions of years in the reservoir with oil and gas. When a hydrocarbon reservoir is infiltrated by a production well, the produced fluids commonly contain water. The understanding of this water’s constituents and volumes is vital for the sustainable continuity of production operations, as PW has a number of negative impacts on the infrastructure integrity of the operation. On the other hand, PW can be an alternative source of irrigation water as well as of industrial salt. Interestingly, both the quantity as well as the quality of PW do not remain constant but can vary, both progressively and erratically, even over short periods of time. This paper discusses such a situation of variable PW in an oil and gas operation in the State of Kuwait.
基金supported by the Water Pollution Control and Management Project,China(No. 2009ZX07208)the Ministry of Science and Technology,China,for partially funding this study
文摘Treatment of oilfield produced water was investigated using an anaerobic process coupled with micro-electrolysis （ME）, focusing on changes in chemical oxygen demand （COD） and biodegradability. Results showed that COD exhibited an abnormal change in the single anaerobic system in which it increased within the first 168 hr, but then decreased to 222 mg/L after 360 hr. The biological oxygen demand （five-day） （BOD5）/COD ratio of the water increased from 0.05 to 0.15. Hydrocarbons in the wastewater, such as pectin, degraded to small molecules during the hydrolytic acidification process. Comparatively, the effect of ME was also investigated. The COD underwent a slight decrease and the BOD5/COD ratio of the water improved from 0,05 to 0.17 after ME. Removal of COD was 38.3% under the idealized ME conditions （pH 6.0）, using iron and active carbon （80 and 40 g/L, respectively）. Coupling the anaerobic process with ME accelerated the COD removal ratio （average removal was 53.3%）. Gas chromatography/mass spectrometry was used to analyze organic species conversion. This integrated system appeared to be a useful option for the treatment of water produced in oilfields.
基金The National Basic Research Program (973) of China (No. 2004CB418505)
文摘Concentration polarization and membrane fouling remain one of the major hurdles for the implementation of ultrafiltration of produced water. Although many applications for ultrafiltration were already suggested, only few were implemented on an industrial scale. Among those techniques, turbulence promoter can be more simple and effective in overcoming membrane fouling and enhancing membrane flux. As for the result that turbulence promoter increase fluid velocity, wall shear rates and produce secondary flows or instabilities, the influence of turbulence promoter was investigated on permeate flux during produced water ultrafiltration and the potential application of this arrangement for an industrial development. Experimental investigations were performed on 100 KDa molecular weight cut-off PVDF single-channel tubular membrane module using four kinds of turbulence promoters. It is observed that the significant flux enhancement in the range of 83%--164% was achieved while the hydraulic dissipated power per unit volume of permeate decreased from 31%--42%, which indicated that the using of turbulence promoter is more efficient than operation without the turbulence promoter. The effects of transmembrane pressure and cross-flow velocity with and without turbulence promoter were studied as well. Among the four kinds of turbulence promoters, winding inserts with 20.0 mm pitch and 1.0 mm wire diameter showed better performances than the others did.
文摘The emulsion stability of oilfield produced water is related to the oil-water interfacial film strength and the zeta potential of the oil droplets. We investigated the effects of water treatment agents （corrosion inhibitor SL-2, scale inhibitor HEDP, germicide 1227, and flocculant polyaluminium chloride PAC） on the stability of oilfield produced water. The influence of these treatment agents on oil-water interfacial properties and the mechanism of these agents acting on the oilfield produced water were studied by measuring the interfacial shear viscosity, interfacial tension and zeta electric potential. The results indicated that the scale inhibitor HEDP could increase the oil-water interfacial film strength, and it could also increase the absolute value of the zeta potential of oil droplets. HEDP played an important role in the stability of the emulsion. Polyaluminum chloride （PAC） reduced the stability of the emulsion by considerably decreasing the absolute value of the zeta potential of oil droplets. Corrosion inhibitor SL-2 and germicide 1227 could decrease the oil-water interfacial tension, whereas they had little influence on oil-water interfacial shear viscosity and oil-water interfacial electricity properties.
文摘Seventy-nine strains of bioflocculant-producing bacteria were isolated from 3 activated sludge samples. Among them, strain MYC was found to have the highest and stable flocculating rate for both kaolin clay suspension and oil-field produced water. The bacterial strain was identified as Klebsiella sp. MYC according to its morphological and biochemical characteristics and 16SrDNA sequence. The optimal medium for bioflocculant production by this bacterial strain was composed of cane sugar 20 g L^-1, KH2PO4 2 g L^-1, K2HPO4 5 g L^- 1, （ NH4）2SO4 0.2 g L^-1, urea 0.5 g L^- 1 and yeast extract 0.5 g L^- 1, the initial pH being 5.5. When the suspension of kaolin clay was treated with0.5% of Klebsiella sp. MYC culture broth, the flocculating rate reached more than 90.0% in the presence of 500mg L^-1 CaCI2, while the flocculating rate for oil-field produced water was near 80.0% in a pH range of 7.0 - 9.0 with the separation of oil and suspended particles from the oil-field produced water under similar conditions. The environment-friendly nature of the bioflocculant and high flocculating rate of the strain make the bioflocculant produced by Klebsiella sp. MYC an attractive bioflocculant in oil-field produced water treatment.
文摘Oilfield produced water is large quantities of salty water trapped in underground formations and subsisted under high temperatures and pressures that are brought to the surface along with oil during production. Produced water(PW) contains a lot of pollutants such as hydrocarbons and metals, this water must be treated before disposal. Therefore, different techniques are being used to treat produced water. Electrocoagulation is an efficient treatment technique involving the dissolution of anodes and formation of electro-coagulants, while the simultaneous generation of H_2 bubbles at the cathode leads to the pollutant removal by flotation. Electrocoagulation(EC)method is one of the most promising and widely used processes to treat oilfield produced water. In the present work, a conventional internal-loop(draught tube) airlift reactor was utilized as electrocoagulation/flotation cell for PW treatment by inserting two aluminum electrodes in the riser section of the airlift reactor. The EC airlift reactor was operated in a batch mode for the liquid phase. Different experimental parameters were studied on the oil and turbidity removal efficiencies such as current density, initial pH, electrocoagulation time, and air injection.The experimental results showed that mixing of the oil droplets in the PW was accomplished using only the liquid recirculation resulted by H_2 microbubbles generated by EC process which enhanced the oil removal. The experimental results further showed that the EC time required achieving ≥ 90% oil removal efficiency decreases from 46 to 15 min when operating current density increases from 6.8 to 45.5 mA·cm^(-2). This reactor type was found to be highly efficient and less energy consuming compared to conventional existing electrochemical cells which used mechanical agitation.
基金Supported by the National Natural Science Foundation of China(41772155)the National Science and Technology Major Project of China(2016ZX05044-002)
文摘Based on long-term dynamic tracing of dissolved inorganic carbon(DIC)and stable carbon isotope(δ13CDIC)in produced water from 20 coalbed methane(CBM)wells in western Guizhou,the spatial-temporal dynamic variations ofδ13CDIC of the GP well group produced in multi-layer commingled manner were analyzed,and the relationship between the value ofδ13CDIC and CBM productivity was examined.The produced water samples of typical wells in the GP well group were amplified and sequenced using 16S rDNA,and a geological response model ofδ13CDIC in produced water from CBM wells with multi-coal seams was put forward.The research shows that:δ13CDIC in produced water from medium-rank coal seams commonly show positive anomalies,the produced water contains more than 15 species of methanogens,and Methanobacterium is the dominant genus.The dominant methanogens sequence numbers in the produced water are positively correlated withδ13CDIC,and the positive anomaly of v is caused by reduction of methanogens,and especially hydrogenotrophic methanogens.Vertical segmentation of sedimentary facies and lithology in stratum with multi-coal seams will result in permeability and water cut segmentation,which will lead to the segmentation ofδ13CDIC and archaea community in produced water,so in the strata with better permeability and high water cut,theδ13CDIC of the produced water is abnormally enriched,and the dominant archaea is mainly Methanobacterium.In the strata with weak permeability and low water cut,theδ13CDIC of the produced water is small,and the microbial action is weak.The shallow layer close to the coal seam outcrop is likely to be affected by meteoric precipitation,so theδ13CDIC of the produced water is smaller.The geological response model ofδ13CDIC in produced water from multi-coal seams CBM wells in the medium-rank coal reveals the geological mechanism and microbial action mechanism of theδ13CDIC difference in the produced water from the multi-coal seams CBM wells.It also provides effective geochemical evidence for the superimposed fluid system controlled by sedimentary facies,and can also be used for the contribution analysis of the produced gas and water by the multi-layer CBM wells.
基金Funded by the Beijing Municipal Natural Science Foundation(No.3192013)the National Natural Science Foundation of China(No.51774046)。
文摘In order to predict the corrosion trendency of X100 pipeline steel in flowing oilfield produced water,the effect of flow rate on the corrosion behavior of X100 pipeline steel was studied under general dynamic condition and simulated real working condition at the flow rate of 0.2,0.4,and 0.6 m·s^(-1).Potentiodynamic polarization curves and electrochemical impedance spectroscopy were used to study the corrosion behavior of X100 steel.Energy dispersive spectroscopy,X-ray diffraction and scanning electron microscopy were used to analyze corrosion product composition and micromorphology.The experimental results show that the corrosion is more serious under simulated real working conditions than that under the general dynamic conditions.In any case the corrosion current density increases with the increase of the flow rate,and the total impedance value decreases.The corrosion products include Fe_(3)O_(4),Fe_(2)O_(3),and FeOOH.The mass transfer and electrochemistry were simulated by flow coupled in COMSOL software.The multiphysical field coupling simulation results are closer to the engineering practice than the single flow field simulation,and similar results from the experiments were obtained.Both experimental and simulation results reveal that the higher flow rate is,the more serious corrosion appear and the more corrosion products accumulate.By combining experimental and COMSOL simulation data,the corrosion process model of X100 steel was proposed.
文摘Large volumes of water are generated in gas- and oil-production. This includes the water that is present originally in the reservoirs, but also water that is injected into the wells. While currently much of the produced water is either reinjected or disposed of after treatment, treated produced water is increasingly seen as an interesting resource, especially in water-scarce regions. This review looks at different PW treatment methods available, with an emphasis on the management of PW in oil- and gas production on the Arabian Peninsula.
文摘In this study, Mucuna flagellipes seed extract was applied in the coagulation-flocculation of produced water （PW）. Process parameters such as pH, dosage, and settling time were investigated. Process kinetics was also studied. Instrumental characterization of mucuna seed （MS）, mucuna seed coagulant （MSC）, and post effluent treatment settled sludge （PTSS） were carried out. The optimum decontamination efficiency of 95 % was obtained at 1 g/L MSC dosage, PW pH of 2, and rate constant of 0.0001 （L/g/s）. Characterization results indicated that MS, MSC, and PTSS were of network structure, primitive lat- tice, and thermally stable. It could be concluded that MSC would be potential biomass for the treatment of produced water under the experimental conditions.
文摘The conventional treatment process cannot meet the need for treatment of produced water from alka- line/surfactant/polymer flooding（ ASP produced water） in Daqing oilfield. In this study, a new type of hydro- philic fibre ball medium was developed through surface modification method. The hydrophilic property of the surface modified fibre ball was tested with ASP produced liquid at laboratory. The results showed that this fibre hall had higher oll degreasing efficiency, The surface components were also observed by Scanning Electron Microscope and X-ray Photoelectron Spectroscopy, the result showed that the hydrophilic fibre＇ s surface was covered by sulfonic group. Using hydrophilic fibre ball as filter medium, a new type of filter was designed to treat ASP produced water in pilot-scale experiments. The obtained results indicated that this type of filter had high capability and efficiency for the treatment of ASP produced water. This filter should have a better application prospect in oilfield produced water treatment.
文摘Kuwaiti oil production faces a growing challenge in the increasing quantities of produced water generated in the production of oil. The high water cut of the produced fluid from the wells and the high salinity of the produced water lead to significant degradation of subsurface equipment, specifically the production tubing. Debris generated through the degradation of the inner part of the tubing becomes a constituent of the scaling that deposits in the tubing and blocks the flow of the production fluid, inducing higher maintenance costs. This paper looks at the characteristics of the scaling in regard to the produced water and outlines the economic impact of the produced water induced degradation of the tubing structure.
文摘Water manufactured is the primary waste source in the oil and gas industry. Because of the rising amount of waste worldwide, the environmental effect of wastewater has become a primary environmental concern in recent years. The vast amounts involved have resulted in considerable costs to the industry for handling produced water. This research explains the wide variety of choices for water management. This research’s first phase was water minimization techniques, consisting of three different applications made in three different wells (Well 1, Well 2 and Well 3) and water recycling and reuse by two techniques. In Well 1, Mechanical shut-off technique was applied using through tubing bridge plug and 5 m cement dumped above it to isolate the watered out zone;as per water oil ration plot the water cut is decreased from 100% to 4% and the production is increased from 0 to 400 bcpd. In Well 2, Chemical shut-off technique using a polymer called Brightwater has been used to block channeling through high permeability intervals after PLT log detected it, and the result was brilliant, the water cut decreased from 60% to 25%, also the oil production increase from 500 to 3000 bopd. In Well 3, downhole separator installed in it using workover (unfortunately, this technique is not applied in middle east till the moment so this application is taken from an oil field in Canada)and the result was perfect, the water cut decreased from 70% to 28%, also the oil production increase from 44 to 100 bopd. This study tried to clarify and compare the most widely used water management techniques using one of the Western Desert (W.D.) (enhanced for oil recovery, constructed wetland).
文摘The oil field belongs to a conventional heavy oil reservoir. Since the late development, with the application and scale expansion of chemical flooding, the treatment of produced water is more difficult, the effect of conventional corrosion inhibitors and bactericides is poor, the water quality after treatment is poor in stability, and the water injection system pipe network is seriously corroded and blocked, which affects production. Through the research and development of a water quality stabilizer agent, the corrosion rate of polymer-containing produced water is significantly reduced after application, the corrosion rate of on-site hanging pieces is reduced to about 0.01mm/a, the reduction rate reaches 90%, the along-path bacterial content is reduced, the stability of the along-path water quality is improved, the generation of sediment in the water injection network is reduced, the water injection and polymer injection effects are effectively improved, and a positive contribution is made to further improving the oil recovery rate.
基金supported financially by the Introduction Pro gram of Tianchi Talent on Young Doctor in Xinjiang(grant No.2023TCXZGCY01)the Science and Technology Project of CNPC Western Drilling Engineering Co.,LTD(grant No.2023XZ201).
文摘Reutilizing flowback fluid and produced water to prepare fracturing fluid is still an urgent problem that needs to be solved and is not well solved.In this work,an anti-salt associative thickener(AAT)was synthesized by free radical copolymerization,and the molecular structure of AAT was demonstrated by FTIR and 1H-NMR.Furthermore,compared with a common anti-salt thickener(HAT),the comprehensive performances of AAT were systematically investigated under the conditions of fresh water,flowback fluid and produced water in Sulige Gasfield.The results show that under the conditions of an average salinity of 34,428 mg/L and an average high-valent ion content of 4967 mg/L,AAT can present good thickening capacity,temperature and shear resistance,drag reduction efficiency,sand-carrying ability,gel-breaking property and high-effective crosslinking capacity with organic zirconium crosslinker at high salinity,which implicates the great potential and feasibility to prepare fracturing fluid by reutilizing high-salinity f lowbackfluid and produced water without further treatment.Moreover,the possible mechanisms of the associative thickener to achieve high-effective drag reduction and sand-carrying might be the existence of reversible supramolecular structures and the significant increase of viscoelasticity by shear stretching in turbulent state.At the same time,both physical and chemical interaction can make a significant contribution to high-effective crosslinking capacity of associative thickener.All results and findings can provide an important reference for the design of novel fracturing fluid and the reutilization of high salinity water in stimulation applications.
文摘Produced water,a byproduct of oil and gas extraction,presents significant environmental challenges if not properly treated.This review focuses on advancements in two primary offshore deoiling technologies,namely:induced gas flotation and hydrocyclones,tracing their evolution from the 1940s to the present.The study provides a detailed comparison of these technologies in terms of efficiency,energy consumption,and waste generation,offering both qualitative and quantitative assessments.Particular attention is given to the integration of hydrocyclone-induced gas flotation(HIGF)systems,which enhance oil removal efficiency while reducing energy consumption,making them an important solution in offshore produced water management.Additionally,the review identifies specific design improvements in flotation units,such as multistage configurations,and explores the role of operational control in optimizing hydrocyclone performance.Global variations in produced water discharge standards are examined,emphasising the need for stricter environmental regulations.In addition,this study highlights the combined use of hydrocyclone and flotation technologies as a comprehensive approach for addressing both environmental and operational challenges in offshore produced water treatment.
