Advanced analytical methodology based on comprehensive two-dimensional gas chromatography-time of flight mass spectrometry(GC×GC-TOFMS) is proposed for investigation of organic chlorides in different oilfield che...Advanced analytical methodology based on comprehensive two-dimensional gas chromatography-time of flight mass spectrometry(GC×GC-TOFMS) is proposed for investigation of organic chlorides in different oilfield chemicals.The target screening was initially carried out on 8 suspected organic chlorides by evaluating the capability of the enhanced separation and reliable identification at a trace concentration. GC×GC-TOFMS allowed for the fast and automated analysis of organic chlorides at a level of 200 μg/L. This method was subsequently applied for non-target screening of organic chlorides in different oilfield chemicals at various locations across China. 22 organic chlorides were identified and verified by comparison with pure standards in the mixed sample. Finally, this method was used to determine the content of the organic chlorides in individual samples. The result showed that the organic chloride levels in 19 of the 39 tested oilfield chemicals were above the threshold limit of 1.0 mg/L.展开更多
China Petrochemical Corporation,or Sinopec,has issued a report on its efforts at environmental protection a first for a Chinese company.The report cites strategies of China’s biggest oil refiner by capacity to reduce...China Petrochemical Corporation,or Sinopec,has issued a report on its efforts at environmental protection a first for a Chinese company.The report cites strategies of China’s biggest oil refiner by capacity to reduce environmental impact,as well as implementation of lower-carbon fuels and less-polluting production methods."The18th CPC National Congress created a blueprint for a better tomorrow of promoting ecological progress and building a beautiful China,"said Li Ganjie,vice minister of environmental protection."Chinese industrial companies should play a leading role in展开更多
The ternary-element storage and flow concept for shale oil reservoirs in Jiyang Depression of Bohai Bay Basin,East China,was proposed based on the data of more than 10000 m cores and the production of more than 60 hor...The ternary-element storage and flow concept for shale oil reservoirs in Jiyang Depression of Bohai Bay Basin,East China,was proposed based on the data of more than 10000 m cores and the production of more than 60 horizontal wells.The synergy of three elements(storage,fracture and pressure)contributes to the enrichment and high production of shale oil in Jiyang Depression.The storage element controls the enrichment of shale oil;specifically,the presence of inorganic pores and fractures,as well as laminae of lime-mud rocks,in the saline lake basin,is conducive to the storage of shale oil,and the high hydrocarbon generating capacity and free hydrocarbon content are the material basis for high production.The fracture element controls the shale oil flow;specifically,natural fractures act as flow channels for shale oil to migrate and accumulate,and induced fractures communicate natural fractures to form complex fracture network,which is fundamental to high production.The pressure element controls the high and stable production of shale oil;specifically,the high formation pressure provides the drive force for the migration and accumulation of hydrocarbons,and fracturing stimulation significantly increases the elastic energy of rock and fluid,improves the imbibition replacement of oil in the pores/fractures,and reduces the stress sensitivity,guaranteeing the stable production of shale oil for a long time.Based on the ternary-element storage and flow concept,a 3D development technology was formed,with the core techniques of 3D well pattern optimization,3D balanced fracturing,and full-cycle optimization of adjustment and control.This technology effectively guides the production and provides a support to the large-scale beneficial development of shale oil in Jiyang Depression.展开更多
Laboratory experiments,numerical simulations and fracturing technology were combined to address the problems in shale oil recovery by CO_(2)injection.The laboratory experiments were conducted to investigate the displa...Laboratory experiments,numerical simulations and fracturing technology were combined to address the problems in shale oil recovery by CO_(2)injection.The laboratory experiments were conducted to investigate the displacement mechanisms of shale oil extraction by CO_(2)injection,and the influences of CO_(2)pre-pad on shale mechanical properties.Numerical simulations were performed about influences of CO_(2)pre-pad fracturing and puff-n-huff for energy replenishment on the recovery efficiency.The findings obtained were applied to the field tests of CO_(2)pre-pad fracturing and single well puff-n-huff.The results show that the efficiency of CO_(2)puff-n-huff is affected by micro-and nano-scale effect,kerogen,adsorbed oil and so on,and a longer soaking time in a reasonable range leads to a higher exploitation degree of shale oil.In the"injection+soaking"stage,the exploitation degree of heavy hydrocarbons is enhanced by CO_(2)through its effects of solubility-diffusion and mass-transfer.In the"huff"stage,crude oil in large pores is displaced by CO_(2)to surrounding larger pores or bedding fractures and finally flows to the production well.The injection of CO_(2)pre-pad is conducive to keeping the rock brittle and reducing the fracture breakdown pressure,and the CO_(2)is liable to filter along the bedding surface,thereby creating a more complex fracture.Increasing the volume of CO_(2)pre-pad can improve the energizing effect,and enhance the replenishment of formation energy.Moreover,the oil recovery is more enhanced by CO_(2)huff-n-puff with the lower shale matrix permeability,the lower formation pressure,and the larger heavy hydrocarbon content.The field tests demonstrate a good performance with the pressure maintained well after CO_(2)pre-pad fracturing,the formation energy replenished effectively after CO_(2)huff-n-puff in a single well,and the well productivity improved.展开更多
By benchmarking with the iteration of drilling technology,fracturing technology and well placement mode for shale oil and gas development in the United States and considering the geological characteristics and develop...By benchmarking with the iteration of drilling technology,fracturing technology and well placement mode for shale oil and gas development in the United States and considering the geological characteristics and development difficulties of shale oil in the Jiyang continental rift lake basin,East China,the development technology system suitable for the geological characteristics of shale oil in continental rift lake basins has been primarily formed through innovation and iteration of the development,drilling and fracturing technologies.The technology system supports the rapid growth of shale oil production and reduces the development investment cost.By comparing it with the shale oil development technology in the United States,the prospect of the shale oil development technology iteration in continental rift lake basins is proposed.It is suggested to continuously strengthen the overall three-dimensional development,improve the precision level of engineering technology,upgrade the engineering technical indicator system,accelerate the intelligent optimization of engineering equipment,explore the application of complex structure wells,form a whole-process integrated quality management system from design to implementation,and constantly innovate the concept and technology of shale oil development,so as to promote the realization of extensive,beneficial and high-quality development of shale oil in continental rift lake basins.展开更多
The reaction order plays a crucial role in evaluating the response rate of acid-rock.However,the conventional two-scale model typically assumes that the reaction order is constant as one,which can lead to significant ...The reaction order plays a crucial role in evaluating the response rate of acid-rock.However,the conventional two-scale model typically assumes that the reaction order is constant as one,which can lead to significant deviations from reality.To address this issue,this study proposes a novel multi-order dynamic model for acid-rock reaction by combining rotating disk experimental data with theoretical derivation.Through numerical simulations,this model allows for the investigation of the impact of acidification conditions on different orders of reaction,thereby providing valuable insights for on-site construction.The analysis reveals that higher response orders require higher optimal acid liquid flow rates,and lower optimal H+diffusion coefficients,and demonstrate no significant correlation with acid concentration.Consequently,it is recommended to increase the displacement and use high-viscosity acid for reservoirs with high calcite content,while reducing the displacement and using low-viscosity acid for reservoirs with high dolomite content.展开更多
To solve the problems of shear degradation and injection difficulties in conventional polymer flooding,the capsule polymer flooding for enhanced oil recovery(EOR)was proposed.The flow and oil displacement mechanisms o...To solve the problems of shear degradation and injection difficulties in conventional polymer flooding,the capsule polymer flooding for enhanced oil recovery(EOR)was proposed.The flow and oil displacement mechanisms of this technique were analyzed using multi-scale flow experiments and simulation technology.It is found that the capsule polymer flooding has the advantages of easy injection,shear resistance,controllable release in reservoir,and low adsorption retention,and it is highly capable of long-distance migration to enable viscosity increase in deep reservoirs.The higher degree of viscosity increase by capsule polymer,the stronger the ability to suppress viscous fingering,resulting in a more uniform polymer front and a larger swept range.The release performance of capsule polymer is mainly sensitive to temperature.Higher temperatures result in faster viscosity increase by capsule polymer solution.The salinity has little impact on the rate of viscosity increase.The capsule polymer flooding is suitable for high-water-cut reservoirs for which conventional polymer flooding techniques are less effective,offshore reservoirs by polymer flooding in largely spaced wells,and medium to low permeability reservoirs where conventional polymers cannot be injected efficiently.Capsule polymer flooding should be customized specifically,with the capsule particle size and release time to be determined depending on target reservoir conditions to achieve the best displacement effect.展开更多
Novel wet-phase modified expandable graphite(WMEG)particles were developed for in-depth profile control in carbonate reservoirs.The harsh environment of carbonate reservoirs(≥130℃,≥22×10^(4)mg/L)brings signifi...Novel wet-phase modified expandable graphite(WMEG)particles were developed for in-depth profile control in carbonate reservoirs.The harsh environment of carbonate reservoirs(≥130℃,≥22×10^(4)mg/L)brings significant challenges for existing profile control agents.WMEG particles were developed to address this problem.WMEG particles were synthesized via intercalation with ultrasound irradiation and chemical oxidation.The critical expansion temperature of WMEG particles is 130℃,and these particles can effectively expand 3-8 times under high temperature and high salinity water.The core flow experiments show that WMEG particles exhibit a good plugging capacity,profile control capacity,and a better-enhanced oil recovery(EOR)capacity in deep carbonate reservoirs.WMEG particles can be expanded in the formation and form larger particles that bridge the upper and lower end faces of the fracture.Then the high-permeability zones are effectively plugged,and the heterogeneity is improved,resulting in an obvious increase in oil recovery.This research provides a novel insight into future applications of profile control agents for in-depth profile control treatment in carbonate reservoirs.展开更多
Reservoir wettability plays an important role in various oil recovery processes.The origin and evolution of reservoir wettability were critically reviewed to better understand the complexity of wettability due to inte...Reservoir wettability plays an important role in various oil recovery processes.The origin and evolution of reservoir wettability were critically reviewed to better understand the complexity of wettability due to interactions in crude oil-brine-rock system,with introduction of different wetting states and their influence on fluid distribution in pore spaces.The effect of wettability on oil recovery of waterflooding was then summarized from past and recent research to emphasize the importance of wettability in oil displacement by brine.The mechanism of wettability alteration by different surfactants in both carbonate and sandstone reservoirs was analyzed,concerning their distinct surface chemistry,and different interaction patterns of surfactants with components on rock surface.Other concerns such as the combined effect of wettability alteration and interfacial tension （IFT） reduction on the imbibition process was also taken into account.Generally,surfactant induced wettability alteration for enhanced oil recovery is still in the stage of laboratory investigation.The successful application of this technique relies on a comprehensive survey of target reservoir conditions,and could be expected especially in low permeability fractured reservoirs and forced imbibition process.展开更多
The formation and distribution of hydrocarbon accumulations are jointly controlled by ＂stratigraphic facies＂ and ＂fluid potential＂, which can be abbreviated in ＂control of facies/potential on hydrocarbon accumula...The formation and distribution of hydrocarbon accumulations are jointly controlled by ＂stratigraphic facies＂ and ＂fluid potential＂, which can be abbreviated in ＂control of facies/potential on hydrocarbon accumulation＂. Facies and potential control the time-space distribution of hydrocarbon accumulation macroscopically and the petroliferous characteristics of hydrocarbon accumulation microscopically. Tectonic facies and sedimentary facies control the time-space distribution. Lithofacies and petrophysical facies control the petroliferous characteristics. Favorable facies and high porosity and permeability control hydrocarbon accumulation in the lacustrine rift basins in China. Fluid potential is represented by the work required, which comprises the work against gravity, pressure, interfacial energy and kinetic energy. Hydrocarbon migration and accumulation are controlled by the joint action of multiple driving forces, and are characterized by accumulation in the area of low potential. At the structural high, low geopotential energy caused by buoyancy control anticlinal reservoir. The formation oflithological oil pool is controlled by low interfacial energy caused by capillary force. Low compressive energy caused by overpressure and faulting activity control the formation of the faulted- block reservoir. Low geopotential energy of the basin margin caused by buoyancy control stratigraphic reservoir. The statistics of a large number of oil reservoirs show that favorable facies and low potential control hydrocarbon accumulation in the rift basin, where over 85% of the discovered hydrocarbon accumulations are distributed in the trap with favorable facies and low potentials. The case study showed that the prediction of favorable areas by application of the near source-favorable facies-low potential accumulation model correlated well with over 90% of the discovered oil pools＇ distribution of the middle section of the third member of the Shahejie Formation in the Dongying Depression, Bohai Bay Basin.展开更多
Heat production from geothermal reservoirs is a typical heat transfer process involving a cold working fluid contacting a hot rock formation.Compared to the thermal-physical characteristics of water,supercritical CO_(...Heat production from geothermal reservoirs is a typical heat transfer process involving a cold working fluid contacting a hot rock formation.Compared to the thermal-physical characteristics of water,supercritical CO_(2)(scCO_(2))has a higher heat storage capacity over a wide temperature-pressure range and may be favored as a heat transfer fluid.Singularly characteristic of scCO_(2)-based heat extraction is that the hydraulic-thermal properties of the scCO_(2) vary dramatically and dynamically with the spatial pressure gradient during unsteady-state flow along fracture.This highly nonlinear behavior presents a challenge in the accurate estimation of heat extraction efficiency in scCO_(2)-based EGS.In this paper,a thermal-h ydraulic-mechanical(THM)coupled model is developed by considering deformation of the fractured reservoir,non-Darcy flow and the varying thermal-physical properties of scCO_(2).The proposed model is validated by matching the modeling temperature distribution with published data.The results show that during continuous injection of scCO_(2),the fracture first widens and then narrows,ultimately reopening over the long term.The sequential fracture deformation behaviors are in response to the combined impacts of mechanical compression and thermally-induced deformation.By controlling the injection parameters of the scCO_(2),it is found that the heat extraction rate is positively correlated to its pore pressure or mass flow rate.The heat extraction rate can be significantly enhanced,when the inlet temperature of scCO_(2) is below its critical temperature.As a result,the heat increment recovered per unit mass of scCO_(2) decreases as the hot rock is gradually cooled.Meanwhile,the heat increment recovered per unit mass of scCO_(2) decreases by increasing the inlet temperature of scCO_(2) or its mass flow rate,but increases as the outlet pressure rises.Furthermore,multi-linear regression indicates that controlling the inlet temperature of the scCO_(2) can significantly improve the thermodynamic efficiency of heat extraction.展开更多
Microscopic seepage characteristics are critical for the evaluation of tight sandstone reservoirs.In this study,a digital core approach integrating microscopic seepage simulation and CT scanning was developed to chara...Microscopic seepage characteristics are critical for the evaluation of tight sandstone reservoirs.In this study,a digital core approach integrating microscopic seepage simulation and CT scanning was developed to characterize microscopic seepage and fracture effectiveness(the ratio of micro-fractures that contributes to fluid flow)of tight sandstones.Numerical simulations were carried out for characterizations of tight sandstones.The results show that the axial permeability of the investigated cylindrical tight sandstone from Junggar Basin in China is 0.460μm~2,while the radial permeability is 0.3723μm~2,and the axial and radial effective fracture ratios are 0.4387 and 0.4806,respectively,indicating that cracks are not fully developed and the connectivity between micro-cracks is poor.Directional permeability that is difficult to measure by laboratory experiments can be obtained readily using the proposed method in this paper.The results provide important information for improving the exploration and development of tight sandstone reservoirs.展开更多
The concept of the three-layer structure of continental basins is presented based on the characteristics of layered structure of basins. The reservoir could be classified into accumulation system assemblage, accumulat...The concept of the three-layer structure of continental basins is presented based on the characteristics of layered structure of basins. The reservoir could be classified into accumulation system assemblage, accumulation system, accumulation assemblage and reservoir. This paper discusses the characteristics of hydrocarbon accumulation system assemblages of the Zhanhua Depression, which include four kinds of genetic patterns： （1） buried-hill hydrocarbon accumulation system assemblage; （2） self-sourced accumulation system assemblage from the upper interval of member 4 to member 1 of Shahejie formation; （3） transition accumulation system assemblage from member 1 of the Shahejie formation to Dongying formation and （4） externally sourccd accumulation system assemblage in the late Tertiary. The hydrocarbon-source transport network layer consisted of faults and unconformities, which connected with the reservoir layer.展开更多
To formulate fluids with flowback water,produced water directly to improve the utilization rate of recycling and reduce the adsorption damage of slick water to reservoirs,a high salt tolerance and low adsorption drag ...To formulate fluids with flowback water,produced water directly to improve the utilization rate of recycling and reduce the adsorption damage of slick water to reservoirs,a high salt tolerance and low adsorption drag reducer was designed and prepared by introducing polar cation fragments to enhance the non-covalent interactions between the chains.The drag reducer was characterized by IR and NMR.Friction resistance and viscosity tests were conducted to evaluate its salt resistance property.Static adsorption and dynamic adsorption retention tests were carried out to evaluate the damage of this reducer to shale reservoirs.The introduction of cation units into the molecular structure can weak the shielding effect of metal cations to some extent,so the drag reducer can keep a stable molecular structure and good resistant reducing performance under high salinity.The enhancement of non-covalent interaction between chains decreased the free polarity sites,further reduced the possibility of hydrogen bonding between drag reducer molecules and shale.In high salinity condition,both the adsorption capacity of the drag reducer on the shale surface and the average damage rate to the core permeability are low.Compared with the conventional salt-tolerant system,the overall liquid cost was reduced by 17%and the production per well increased by 44%.The application of this slick water system has achieved remarkable results.展开更多
Based on rock mineral and geochemical analysis, microscopic observation, physical property measurement, and thin laminae separation test, etc., the characteristics of typical laminae of the Paleogene Shahejie Formatio...Based on rock mineral and geochemical analysis, microscopic observation, physical property measurement, and thin laminae separation test, etc., the characteristics of typical laminae of the Paleogene Shahejie Formation carbonate-rich shale in the Jiyang Depression were analyzed, and the organic matter abundance, reservoir properties, and oil-bearing properties of different laminae were compared. Typical shale storage-seepage structures were classified, and the mobility of oil in different types of shale storage-seepage structure was compared. The results show that the repeated superposition of mud laminae and calcite laminae are the main layer structure of carbonate-rich shales. The calcite laminae are divided into micritic calcite laminae, sparry calcite laminae and fibrous calcite vein. The mud-rich laminae are the main contributor to the organic matter abundance and porosity of shale, with the best hydrocarbon generation potential, reservoir capacity, and oil-bearing property. The micritic calcite laminae also have relatively good hydrocarbon generation potential, reservoir capacity and oil-bearing property. The sparry calcite laminae and fibrous calcite vein have good permeability and conductivity. Four types of shale storage-seepage structure are developed in the carbonate-rich shale, and the mobility of oil in each type of storage-seepage structure is in descending order: sparry calcite laminae enriched shale storage-seepage structure, mixed calcite laminae enriched shale storage-seepage structure, fibrous calcite vein enriched shale storage-seepage structure, and micritic calcite laminae enriched shale storage-seepage structure. The exploration targets of carbonate-rich shale in the Jiyang Depression Shahejie Formation are different in terms of storage-seepage structure at different thermal evolution stages.展开更多
The control of micro-wettability of pore-throat on shale oil occurrence in different types of reservoir spaces remains unclear.Take the shale oil reservoir of the Permian Lucaogou Formation in the Jimusar Sag,Junggar ...The control of micro-wettability of pore-throat on shale oil occurrence in different types of reservoir spaces remains unclear.Take the shale oil reservoir of the Permian Lucaogou Formation in the Jimusar Sag,Junggar Basin as an example,the reservoir space in laminated shale and the control of micro-wettability of pore-throat on shale oil occurrence were studied by using scanning electron microscope(SEM),multi-stage pyrolysis,quantitative fluorescence,nuclear magnetic resonance(NMR)and other techniques.The results show that there are mainly two types of laminated shale in the Lucaogou Formation,namely laminated shale rich in volcanic materials+terrigenous felsic,and laminated shale rich in volcanic materials+carbonate.The former type contains feldspar dissolution pores and intergranular pores,mainly with felsic mineral components around the pore-throats,which are water-wet and control the free shale oil.The latter type contains carbonate intercrystalline pores and organic pores,mainly with oil-wet mineral components around the pore-throats,which control the adsorbed shale oil.The oil-wet mineral components around the pore-throats are conducive to oil accumulation,but reduce the proportion of free oil.In the Lucaogou Formation,free oil,with high maturity and light quality,mainly occurs in the laminated shale rich in volcanic materials+terrigenous felsic.展开更多
Composite sucker rods are widely used in oil fields because of light weight,high strength,and corrosion resistance.Bonded technology becomes the primary connection method of composites.However,the joints with composit...Composite sucker rods are widely used in oil fields because of light weight,high strength,and corrosion resistance.Bonded technology becomes the primary connection method of composites.However,the joints with composite sucker rods are prone to debone and fracture.The connected characteristics are less considered,so the failure mechanism of the joint is still unclear.Based on the cohesive zone model(CZM)and the Johnson-Cook constitutive model,a novel full-scale numerical model of the joint with composite sucker rod was established,and verified by pull-out experiments.The mechanical properties and slip characteristics of the joint were studied,and the damaged procession of the joint was explored.The results showed that:a)the numerical model was in good agreement with the experimental results,and the error is within 5%;b)the von Mises stress,shear stress,and interface stress distributed symmetrically along the circumferential path increased gradually from the fixed end to the loading end;c)the first-bonded interface near the loading end was damaged at first,followed by debonding of the second-bonded interface,leading to the complete shear fracture of the epoxy,and resulted in the debonding of the joint with composite sucker rod,which can provide a theoretical basis for the structural design and optimization of the joint.展开更多
Sinopec Corp., China’s largest oil refiner, saw its oil and gas output rise 4.83 percent year-on-year in 2012 to 427.62 million barrels of oil equivalent, according to preliminary data released recently by the oil gi...Sinopec Corp., China’s largest oil refiner, saw its oil and gas output rise 4.83 percent year-on-year in 2012 to 427.62 million barrels of oil equivalent, according to preliminary data released recently by the oil giant. The company’s crude oil production grew 2.04 percent to 328.28 million barrels in 2012. About 93.4 percent展开更多
基金supported by grants from the contract of China Petrochemical Corporation (3020001914-ZC0607-0013)the National Natural Science Foundation of China (20107073)+1 种基金the Guangdong Science and Technology Project (2014B030301030)the Innovative Research Team in University (No.IRT13078)
文摘Advanced analytical methodology based on comprehensive two-dimensional gas chromatography-time of flight mass spectrometry(GC×GC-TOFMS) is proposed for investigation of organic chlorides in different oilfield chemicals.The target screening was initially carried out on 8 suspected organic chlorides by evaluating the capability of the enhanced separation and reliable identification at a trace concentration. GC×GC-TOFMS allowed for the fast and automated analysis of organic chlorides at a level of 200 μg/L. This method was subsequently applied for non-target screening of organic chlorides in different oilfield chemicals at various locations across China. 22 organic chlorides were identified and verified by comparison with pure standards in the mixed sample. Finally, this method was used to determine the content of the organic chlorides in individual samples. The result showed that the organic chloride levels in 19 of the 39 tested oilfield chemicals were above the threshold limit of 1.0 mg/L.
文摘China Petrochemical Corporation,or Sinopec,has issued a report on its efforts at environmental protection a first for a Chinese company.The report cites strategies of China’s biggest oil refiner by capacity to reduce environmental impact,as well as implementation of lower-carbon fuels and less-polluting production methods."The18th CPC National Congress created a blueprint for a better tomorrow of promoting ecological progress and building a beautiful China,"said Li Ganjie,vice minister of environmental protection."Chinese industrial companies should play a leading role in
基金Supported by Sinopec Key Science and Technology Research Project(P21060)。
文摘The ternary-element storage and flow concept for shale oil reservoirs in Jiyang Depression of Bohai Bay Basin,East China,was proposed based on the data of more than 10000 m cores and the production of more than 60 horizontal wells.The synergy of three elements(storage,fracture and pressure)contributes to the enrichment and high production of shale oil in Jiyang Depression.The storage element controls the enrichment of shale oil;specifically,the presence of inorganic pores and fractures,as well as laminae of lime-mud rocks,in the saline lake basin,is conducive to the storage of shale oil,and the high hydrocarbon generating capacity and free hydrocarbon content are the material basis for high production.The fracture element controls the shale oil flow;specifically,natural fractures act as flow channels for shale oil to migrate and accumulate,and induced fractures communicate natural fractures to form complex fracture network,which is fundamental to high production.The pressure element controls the high and stable production of shale oil;specifically,the high formation pressure provides the drive force for the migration and accumulation of hydrocarbons,and fracturing stimulation significantly increases the elastic energy of rock and fluid,improves the imbibition replacement of oil in the pores/fractures,and reduces the stress sensitivity,guaranteeing the stable production of shale oil for a long time.Based on the ternary-element storage and flow concept,a 3D development technology was formed,with the core techniques of 3D well pattern optimization,3D balanced fracturing,and full-cycle optimization of adjustment and control.This technology effectively guides the production and provides a support to the large-scale beneficial development of shale oil in Jiyang Depression.
基金Supported by Basic and Forward-Looking Project of the Science and Technology Department of SINOPEC(P22213-4)。
文摘Laboratory experiments,numerical simulations and fracturing technology were combined to address the problems in shale oil recovery by CO_(2)injection.The laboratory experiments were conducted to investigate the displacement mechanisms of shale oil extraction by CO_(2)injection,and the influences of CO_(2)pre-pad on shale mechanical properties.Numerical simulations were performed about influences of CO_(2)pre-pad fracturing and puff-n-huff for energy replenishment on the recovery efficiency.The findings obtained were applied to the field tests of CO_(2)pre-pad fracturing and single well puff-n-huff.The results show that the efficiency of CO_(2)puff-n-huff is affected by micro-and nano-scale effect,kerogen,adsorbed oil and so on,and a longer soaking time in a reasonable range leads to a higher exploitation degree of shale oil.In the"injection+soaking"stage,the exploitation degree of heavy hydrocarbons is enhanced by CO_(2)through its effects of solubility-diffusion and mass-transfer.In the"huff"stage,crude oil in large pores is displaced by CO_(2)to surrounding larger pores or bedding fractures and finally flows to the production well.The injection of CO_(2)pre-pad is conducive to keeping the rock brittle and reducing the fracture breakdown pressure,and the CO_(2)is liable to filter along the bedding surface,thereby creating a more complex fracture.Increasing the volume of CO_(2)pre-pad can improve the energizing effect,and enhance the replenishment of formation energy.Moreover,the oil recovery is more enhanced by CO_(2)huff-n-puff with the lower shale matrix permeability,the lower formation pressure,and the larger heavy hydrocarbon content.The field tests demonstrate a good performance with the pressure maintained well after CO_(2)pre-pad fracturing,the formation energy replenished effectively after CO_(2)huff-n-puff in a single well,and the well productivity improved.
基金Supported by the Strategic Research and Technical Consultation Project of Sinopec Science and Technology CommissionSinopec Major Science and Technology Project(P22037)。
文摘By benchmarking with the iteration of drilling technology,fracturing technology and well placement mode for shale oil and gas development in the United States and considering the geological characteristics and development difficulties of shale oil in the Jiyang continental rift lake basin,East China,the development technology system suitable for the geological characteristics of shale oil in continental rift lake basins has been primarily formed through innovation and iteration of the development,drilling and fracturing technologies.The technology system supports the rapid growth of shale oil production and reduces the development investment cost.By comparing it with the shale oil development technology in the United States,the prospect of the shale oil development technology iteration in continental rift lake basins is proposed.It is suggested to continuously strengthen the overall three-dimensional development,improve the precision level of engineering technology,upgrade the engineering technical indicator system,accelerate the intelligent optimization of engineering equipment,explore the application of complex structure wells,form a whole-process integrated quality management system from design to implementation,and constantly innovate the concept and technology of shale oil development,so as to promote the realization of extensive,beneficial and high-quality development of shale oil in continental rift lake basins.
基金financially supported by the National Natural Science Foundation of China(Project No.51874336)the National Key Technologies Research and Development Program of China during the 13th Five-Year Plan Period(Project No.2017ZX005030005)。
文摘The reaction order plays a crucial role in evaluating the response rate of acid-rock.However,the conventional two-scale model typically assumes that the reaction order is constant as one,which can lead to significant deviations from reality.To address this issue,this study proposes a novel multi-order dynamic model for acid-rock reaction by combining rotating disk experimental data with theoretical derivation.Through numerical simulations,this model allows for the investigation of the impact of acidification conditions on different orders of reaction,thereby providing valuable insights for on-site construction.The analysis reveals that higher response orders require higher optimal acid liquid flow rates,and lower optimal H+diffusion coefficients,and demonstrate no significant correlation with acid concentration.Consequently,it is recommended to increase the displacement and use high-viscosity acid for reservoirs with high calcite content,while reducing the displacement and using low-viscosity acid for reservoirs with high dolomite content.
基金Supported by the Joint Funds of the National Natural Science Foundation of China(U21B2070)Natural Science Foundation of China(52374061)。
文摘To solve the problems of shear degradation and injection difficulties in conventional polymer flooding,the capsule polymer flooding for enhanced oil recovery(EOR)was proposed.The flow and oil displacement mechanisms of this technique were analyzed using multi-scale flow experiments and simulation technology.It is found that the capsule polymer flooding has the advantages of easy injection,shear resistance,controllable release in reservoir,and low adsorption retention,and it is highly capable of long-distance migration to enable viscosity increase in deep reservoirs.The higher degree of viscosity increase by capsule polymer,the stronger the ability to suppress viscous fingering,resulting in a more uniform polymer front and a larger swept range.The release performance of capsule polymer is mainly sensitive to temperature.Higher temperatures result in faster viscosity increase by capsule polymer solution.The salinity has little impact on the rate of viscosity increase.The capsule polymer flooding is suitable for high-water-cut reservoirs for which conventional polymer flooding techniques are less effective,offshore reservoirs by polymer flooding in largely spaced wells,and medium to low permeability reservoirs where conventional polymers cannot be injected efficiently.Capsule polymer flooding should be customized specifically,with the capsule particle size and release time to be determined depending on target reservoir conditions to achieve the best displacement effect.
基金financially supported by the National Natural Science Foundation of China(No.52074335)China University of Petroleum(East China)Independent Innovation Research Program:Oilfield Chemistry and Enhanced Oil Recovery(27RA2302015)+1 种基金Innovation Fund Project for Graduate Student of China University of Petroleum(East China)the Fundamental Research Funds for the Central Universities(No.24CX04003A)。
文摘Novel wet-phase modified expandable graphite(WMEG)particles were developed for in-depth profile control in carbonate reservoirs.The harsh environment of carbonate reservoirs(≥130℃,≥22×10^(4)mg/L)brings significant challenges for existing profile control agents.WMEG particles were developed to address this problem.WMEG particles were synthesized via intercalation with ultrasound irradiation and chemical oxidation.The critical expansion temperature of WMEG particles is 130℃,and these particles can effectively expand 3-8 times under high temperature and high salinity water.The core flow experiments show that WMEG particles exhibit a good plugging capacity,profile control capacity,and a better-enhanced oil recovery(EOR)capacity in deep carbonate reservoirs.WMEG particles can be expanded in the formation and form larger particles that bridge the upper and lower end faces of the fracture.Then the high-permeability zones are effectively plugged,and the heterogeneity is improved,resulting in an obvious increase in oil recovery.This research provides a novel insight into future applications of profile control agents for in-depth profile control treatment in carbonate reservoirs.
文摘Reservoir wettability plays an important role in various oil recovery processes.The origin and evolution of reservoir wettability were critically reviewed to better understand the complexity of wettability due to interactions in crude oil-brine-rock system,with introduction of different wetting states and their influence on fluid distribution in pore spaces.The effect of wettability on oil recovery of waterflooding was then summarized from past and recent research to emphasize the importance of wettability in oil displacement by brine.The mechanism of wettability alteration by different surfactants in both carbonate and sandstone reservoirs was analyzed,concerning their distinct surface chemistry,and different interaction patterns of surfactants with components on rock surface.Other concerns such as the combined effect of wettability alteration and interfacial tension （IFT） reduction on the imbibition process was also taken into account.Generally,surfactant induced wettability alteration for enhanced oil recovery is still in the stage of laboratory investigation.The successful application of this technique relies on a comprehensive survey of target reservoir conditions,and could be expected especially in low permeability fractured reservoirs and forced imbibition process.
文摘The formation and distribution of hydrocarbon accumulations are jointly controlled by ＂stratigraphic facies＂ and ＂fluid potential＂, which can be abbreviated in ＂control of facies/potential on hydrocarbon accumulation＂. Facies and potential control the time-space distribution of hydrocarbon accumulation macroscopically and the petroliferous characteristics of hydrocarbon accumulation microscopically. Tectonic facies and sedimentary facies control the time-space distribution. Lithofacies and petrophysical facies control the petroliferous characteristics. Favorable facies and high porosity and permeability control hydrocarbon accumulation in the lacustrine rift basins in China. Fluid potential is represented by the work required, which comprises the work against gravity, pressure, interfacial energy and kinetic energy. Hydrocarbon migration and accumulation are controlled by the joint action of multiple driving forces, and are characterized by accumulation in the area of low potential. At the structural high, low geopotential energy caused by buoyancy control anticlinal reservoir. The formation oflithological oil pool is controlled by low interfacial energy caused by capillary force. Low compressive energy caused by overpressure and faulting activity control the formation of the faulted- block reservoir. Low geopotential energy of the basin margin caused by buoyancy control stratigraphic reservoir. The statistics of a large number of oil reservoirs show that favorable facies and low potential control hydrocarbon accumulation in the rift basin, where over 85% of the discovered hydrocarbon accumulations are distributed in the trap with favorable facies and low potentials. The case study showed that the prediction of favorable areas by application of the near source-favorable facies-low potential accumulation model correlated well with over 90% of the discovered oil pools＇ distribution of the middle section of the third member of the Shahejie Formation in the Dongying Depression, Bohai Bay Basin.
基金The financial support from the National Natural Science Foundation of China(Nos.41772154 and 42102338)Natural Science Foundation of Shandong Province(Nos.ZR2019MA009 and ZR2020QE115)SDUST Research Fund of China(No.2018TDJH102)。
文摘Heat production from geothermal reservoirs is a typical heat transfer process involving a cold working fluid contacting a hot rock formation.Compared to the thermal-physical characteristics of water,supercritical CO_(2)(scCO_(2))has a higher heat storage capacity over a wide temperature-pressure range and may be favored as a heat transfer fluid.Singularly characteristic of scCO_(2)-based heat extraction is that the hydraulic-thermal properties of the scCO_(2) vary dramatically and dynamically with the spatial pressure gradient during unsteady-state flow along fracture.This highly nonlinear behavior presents a challenge in the accurate estimation of heat extraction efficiency in scCO_(2)-based EGS.In this paper,a thermal-h ydraulic-mechanical(THM)coupled model is developed by considering deformation of the fractured reservoir,non-Darcy flow and the varying thermal-physical properties of scCO_(2).The proposed model is validated by matching the modeling temperature distribution with published data.The results show that during continuous injection of scCO_(2),the fracture first widens and then narrows,ultimately reopening over the long term.The sequential fracture deformation behaviors are in response to the combined impacts of mechanical compression and thermally-induced deformation.By controlling the injection parameters of the scCO_(2),it is found that the heat extraction rate is positively correlated to its pore pressure or mass flow rate.The heat extraction rate can be significantly enhanced,when the inlet temperature of scCO_(2) is below its critical temperature.As a result,the heat increment recovered per unit mass of scCO_(2) decreases as the hot rock is gradually cooled.Meanwhile,the heat increment recovered per unit mass of scCO_(2) decreases by increasing the inlet temperature of scCO_(2) or its mass flow rate,but increases as the outlet pressure rises.Furthermore,multi-linear regression indicates that controlling the inlet temperature of the scCO_(2) can significantly improve the thermodynamic efficiency of heat extraction.
基金financially supported by the National Natural Science Foundation of China(Grant No.41972138)the Technology Major Project of China(Grant No.ZD2019-183007,2016ZX05002-002)。
文摘Microscopic seepage characteristics are critical for the evaluation of tight sandstone reservoirs.In this study,a digital core approach integrating microscopic seepage simulation and CT scanning was developed to characterize microscopic seepage and fracture effectiveness(the ratio of micro-fractures that contributes to fluid flow)of tight sandstones.Numerical simulations were carried out for characterizations of tight sandstones.The results show that the axial permeability of the investigated cylindrical tight sandstone from Junggar Basin in China is 0.460μm~2,while the radial permeability is 0.3723μm~2,and the axial and radial effective fracture ratios are 0.4387 and 0.4806,respectively,indicating that cracks are not fully developed and the connectivity between micro-cracks is poor.Directional permeability that is difficult to measure by laboratory experiments can be obtained readily using the proposed method in this paper.The results provide important information for improving the exploration and development of tight sandstone reservoirs.
文摘The concept of the three-layer structure of continental basins is presented based on the characteristics of layered structure of basins. The reservoir could be classified into accumulation system assemblage, accumulation system, accumulation assemblage and reservoir. This paper discusses the characteristics of hydrocarbon accumulation system assemblages of the Zhanhua Depression, which include four kinds of genetic patterns： （1） buried-hill hydrocarbon accumulation system assemblage; （2） self-sourced accumulation system assemblage from the upper interval of member 4 to member 1 of Shahejie formation; （3） transition accumulation system assemblage from member 1 of the Shahejie formation to Dongying formation and （4） externally sourccd accumulation system assemblage in the late Tertiary. The hydrocarbon-source transport network layer consisted of faults and unconformities, which connected with the reservoir layer.
基金Supported by the China National Science and Technology Major Project(2017ZX05023003)National Science Fund for Distinguished Young Scholars(51525404)
文摘To formulate fluids with flowback water,produced water directly to improve the utilization rate of recycling and reduce the adsorption damage of slick water to reservoirs,a high salt tolerance and low adsorption drag reducer was designed and prepared by introducing polar cation fragments to enhance the non-covalent interactions between the chains.The drag reducer was characterized by IR and NMR.Friction resistance and viscosity tests were conducted to evaluate its salt resistance property.Static adsorption and dynamic adsorption retention tests were carried out to evaluate the damage of this reducer to shale reservoirs.The introduction of cation units into the molecular structure can weak the shielding effect of metal cations to some extent,so the drag reducer can keep a stable molecular structure and good resistant reducing performance under high salinity.The enhancement of non-covalent interaction between chains decreased the free polarity sites,further reduced the possibility of hydrogen bonding between drag reducer molecules and shale.In high salinity condition,both the adsorption capacity of the drag reducer on the shale surface and the average damage rate to the core permeability are low.Compared with the conventional salt-tolerant system,the overall liquid cost was reduced by 17%and the production per well increased by 44%.The application of this slick water system has achieved remarkable results.
基金Supported by the China National Science and Technology Major Project(2017ZX05049-004)Sinopec Project(P22083,P23084).
文摘Based on rock mineral and geochemical analysis, microscopic observation, physical property measurement, and thin laminae separation test, etc., the characteristics of typical laminae of the Paleogene Shahejie Formation carbonate-rich shale in the Jiyang Depression were analyzed, and the organic matter abundance, reservoir properties, and oil-bearing properties of different laminae were compared. Typical shale storage-seepage structures were classified, and the mobility of oil in different types of shale storage-seepage structure was compared. The results show that the repeated superposition of mud laminae and calcite laminae are the main layer structure of carbonate-rich shales. The calcite laminae are divided into micritic calcite laminae, sparry calcite laminae and fibrous calcite vein. The mud-rich laminae are the main contributor to the organic matter abundance and porosity of shale, with the best hydrocarbon generation potential, reservoir capacity, and oil-bearing property. The micritic calcite laminae also have relatively good hydrocarbon generation potential, reservoir capacity and oil-bearing property. The sparry calcite laminae and fibrous calcite vein have good permeability and conductivity. Four types of shale storage-seepage structure are developed in the carbonate-rich shale, and the mobility of oil in each type of storage-seepage structure is in descending order: sparry calcite laminae enriched shale storage-seepage structure, mixed calcite laminae enriched shale storage-seepage structure, fibrous calcite vein enriched shale storage-seepage structure, and micritic calcite laminae enriched shale storage-seepage structure. The exploration targets of carbonate-rich shale in the Jiyang Depression Shahejie Formation are different in terms of storage-seepage structure at different thermal evolution stages.
基金Supported by the National Natural Scienceof China(42072161,41821002)Central University Basic Research Project(22CX07008A)。
文摘The control of micro-wettability of pore-throat on shale oil occurrence in different types of reservoir spaces remains unclear.Take the shale oil reservoir of the Permian Lucaogou Formation in the Jimusar Sag,Junggar Basin as an example,the reservoir space in laminated shale and the control of micro-wettability of pore-throat on shale oil occurrence were studied by using scanning electron microscope(SEM),multi-stage pyrolysis,quantitative fluorescence,nuclear magnetic resonance(NMR)and other techniques.The results show that there are mainly two types of laminated shale in the Lucaogou Formation,namely laminated shale rich in volcanic materials+terrigenous felsic,and laminated shale rich in volcanic materials+carbonate.The former type contains feldspar dissolution pores and intergranular pores,mainly with felsic mineral components around the pore-throats,which are water-wet and control the free shale oil.The latter type contains carbonate intercrystalline pores and organic pores,mainly with oil-wet mineral components around the pore-throats,which control the adsorbed shale oil.The oil-wet mineral components around the pore-throats are conducive to oil accumulation,but reduce the proportion of free oil.In the Lucaogou Formation,free oil,with high maturity and light quality,mainly occurs in the laminated shale rich in volcanic materials+terrigenous felsic.
基金Innovation fund project for graduate students of ChinaUniversity of Petroleum(East China)(No.22CX04032A)the Fundamental Research Funds for the CentralUniversities on this study is gratefully acknowledged+2 种基金the support of‘National Natural Science Foundation of China’(No.52304015)‘Postdoctoral Innovation Project of Shandong Province’(No.SDCX-ZG-202203098)‘Qingdao Postdoctoral Grant Project’(No.qdyy20210083).
文摘Composite sucker rods are widely used in oil fields because of light weight,high strength,and corrosion resistance.Bonded technology becomes the primary connection method of composites.However,the joints with composite sucker rods are prone to debone and fracture.The connected characteristics are less considered,so the failure mechanism of the joint is still unclear.Based on the cohesive zone model(CZM)and the Johnson-Cook constitutive model,a novel full-scale numerical model of the joint with composite sucker rod was established,and verified by pull-out experiments.The mechanical properties and slip characteristics of the joint were studied,and the damaged procession of the joint was explored.The results showed that:a)the numerical model was in good agreement with the experimental results,and the error is within 5%;b)the von Mises stress,shear stress,and interface stress distributed symmetrically along the circumferential path increased gradually from the fixed end to the loading end;c)the first-bonded interface near the loading end was damaged at first,followed by debonding of the second-bonded interface,leading to the complete shear fracture of the epoxy,and resulted in the debonding of the joint with composite sucker rod,which can provide a theoretical basis for the structural design and optimization of the joint.
文摘Sinopec Corp., China’s largest oil refiner, saw its oil and gas output rise 4.83 percent year-on-year in 2012 to 427.62 million barrels of oil equivalent, according to preliminary data released recently by the oil giant. The company’s crude oil production grew 2.04 percent to 328.28 million barrels in 2012. About 93.4 percent
