An optimization method of fracturing fluid volume strength was introduced taking well X-1 in Biyang Sag of Nanxiang Basin as an example.The characteristic curves of capillary pressure and relative permeability were ob...An optimization method of fracturing fluid volume strength was introduced taking well X-1 in Biyang Sag of Nanxiang Basin as an example.The characteristic curves of capillary pressure and relative permeability were obtained from history matching between forced imbibition experimental data and core-scale reservoir simulation results and taken into a large scale reservoir model to mimic the forced imbibition behavior during the well shut-in period after fracturing.The optimization of the stimulated reservoir volume(SRV)fracturing fluid volume strength should meet the requirements of estimated ultimate recovery(EUR),increased oil recovery by forced imbibition and enhancement of formation pressure and the fluid volume strength of fracturing fluid should be controlled around a critical value to avoid either insufficiency of imbibition displacement caused by insufficient fluid amount or increase of costs and potential formation damage caused by excessive fluid amount.Reservoir simulation results showed that SRV fracturing fluid volume strength positively correlated with single-well EUR and an optimal fluid volume strength existed,above which the single-well EUR increase rate kept decreasing.An optimized increase of SRV fracturing fluid volume and shut-in time would effectively increase the formation pressure and enhance well production.Field test results of well X-1 proved the practicality of established optimization method of SRV fracturing fluid volume strength on significant enhancement of shale oil well production.展开更多
Surface roughness plays a significant role in floatability of coal.In the present paper,coking coal surface was polished by three different sandpapers and the surface properties were characterized by contact angle and...Surface roughness plays a significant role in floatability of coal.In the present paper,coking coal surface was polished by three different sandpapers and the surface properties were characterized by contact angle and roughness measurements.The effect of surface roughness on floatability was investigated by adhesion force measurement system for measuring interaction forces between droplets/bubbles and coking coal surfaces with different roughness.The results showed that the contact angle decreased with increasing roughness yet the adhesion force between the water droplet and coal surface increased owing to the increased contact line and the appearance of line pinning.Maximum adhesion forces between water and surfaces were 111.70,125.48,and 136.42μN when the roughness was 0.23,0.98,and 2.79 μm,respectively.In contrast,under a liquid environment,the adhesion forces between air bubble/oil droplet and coal surfaces were decreased with increasing roughness because of the restriction by water.Maximum adhesion forces of increasing roughness were 97.14,42.76,and 17.86 μN measured at interfaces between air bubble and coal surfaces and 169.48,145.84,and 121.02 lN between oil droplet and surfaces,respectively.Decreasing roughness could be beneficial to the spreading of oil droplets and the adhesion of bubbles which is conducive to flotation separation.展开更多
We show experimentally that when an unfocused continuous wave（CW） laser beam is obliquely incident onto the surface of a millimeter-sized mineral oil drop on sucrose solution, it will exert a pushing force on the oi...We show experimentally that when an unfocused continuous wave（CW） laser beam is obliquely incident onto the surface of a millimeter-sized mineral oil drop on sucrose solution, it will exert a pushing force on the oil drop, making it move forwards along the surface of the sucrose solution. However, after a period of time, the oil drop stops moving. This can be explained as the phenomenon caused by the change of Abraham momentum, the optical gradient force, and friction together.展开更多
Considering the demands,situations and trends in respect to global climate change,carbon neutrality and energy transition,the achievements and significance of the global green energy transition and the new energy revo...Considering the demands,situations and trends in respect to global climate change,carbon neutrality and energy transition,the achievements and significance of the global green energy transition and the new energy revolution of China are summarized,and the“Energy Triangle”theory is proposed.The research indicates that the energy technology revolution is driving a dual transformation in global energy:the black“shale oil and gas revolution”in North America and the green“new energy revolution”in China.The green energy revolution of China has achieved significant milestones in wind-solar-hydrogen-energy storage technologies,leading the world in photovoltaic and wind power.The country has developed the world's largest,most comprehensive,and competitive new energy innovation,industrial and value chains,along with the largest clean power supply system globally.New quality productive forces represent the green productive forces.The green“new energy revolution”of China has accelerated the transformation of its energy structure and the global shift towards clean energy,promoting a new win-win model for the global green and low-carbon transition.Under the backdrop of a carbon-neutral goal-driven energy transition,the“Energy Triangle”theory within the framework of new quality productive forces explains the correlation and development of energy security,economic growth,and environmental sustainability throughout the evolution from fossil fuels to new energy systems,culminating in an energy revolution.Compared to the global energy resource endowment,the energy resources of China are characterized by abundant coal,limited oil and gas,and unlimited wind and photovoltaic energy.Moving forward,the energy strategies of China will focus on the advancement of technologies to clean coal for carbon emission reduction,increase gas output while stabilizing oil production,increase green energy while enhancing new energy,and achieve intelligent integration.Vigorously developing new energy is an essential step in maintaining the energy security of China,and establishing a carbon-neutral“super energy system”is a necessary choice.It is crucial to enhance the international competitiveness of China in new energy development,promote high-quality energy productive forces,support the country's transition to an“energy power”,and strive for“energy independence”.展开更多
With the increasing oil demand, the construction of oil energy reserves in China needs to be further strengthened. However, given that there has been no research on the main influencing factors of crude oil temperatur...With the increasing oil demand, the construction of oil energy reserves in China needs to be further strengthened. However, given that there has been no research on the main influencing factors of crude oil temperature drop in storage tanks under actual dynamically changing environments, this paper considers the influence of dynamic thermal environment and internal crude oil physical properties on the fluctuating changes in crude oil temperature. A theoretical model of the unsteady-state temperature drop heat transfer process is developed from a three-dimensional perspective. According to the temperature drop variation law of crude oil storage tank under the coupling effect of various heat transfer modes such as external forced convection, thermal radiation, and internal natural convection, the external dynamic thermal environment influence zone, the internal crude oil physical property influence zone, and the intermediate transition zone of the tank are proposed. And the multiple non-linear regression method is used to quantitatively characterize the influence of external ambient temperature, solar radiation, wind speed, internal crude oil density, viscosity, and specific heat capacity on the temperature drop of crude oil in each influencing zone. The results of this paper not only quantitatively explain the main influencing factors of the oil temperature drop in the top, wall, and bottom regions of the tank, but also provide a theoretical reference for oil security reserves under a dynamic thermal environment.展开更多
The origin of overpressure and its effect on petroleum accumulation in the large Permian/Triassic conglomerate oil province in the Mahu Sag,Junggar Basin have been investigated based on comprehensive analysis of log c...The origin of overpressure and its effect on petroleum accumulation in the large Permian/Triassic conglomerate oil province in the Mahu Sag,Junggar Basin have been investigated based on comprehensive analysis of log curve combinations,loading-unloading curves,sonic velocity-density cross-plot,and porosity comparison data.The study results show that there are two kinds of normal compaction models in the study area,namely,two-stage linear model and exponent model;overpressure in the large conglomerate reservoirs including Lower Triassic Baikouquan Formation and Permian Upper and Lower Wu’erhe Formations is the result of pressure transfer,and the source of overpressure is the overpressure caused by hydrocarbon generation of Permian Fengcheng Formation major source rock.The petroleum migrated through faults under the driving of hydrocarbon generation overpressure into the reservoirs to accumulate,forming the Permian and Triassic overpressure oil and gas reservoirs.The occurrence and distribution of overpressure are controlled by the source rock maturity and strike-slip faults connecting the source rock and conglomerate reservoirs formed from Indosinian Movement to Himalayan Movement.As overpressure is the driving force for petroleum migration in the large Mahu oil province,the formation and distribution of petroleum reservoirs above the source rock in this area may have a close relationship with the occurrence of overpressure.展开更多
To thoroughly understand the dynamic mechanism of hydrocarbon expulsion from deep source rocks,in this study,five types of hydrocarbon expulsion dynamics(thermal expansion,hydrocarbon diffusion,compaction,product volu...To thoroughly understand the dynamic mechanism of hydrocarbon expulsion from deep source rocks,in this study,five types of hydrocarbon expulsion dynamics(thermal expansion,hydrocarbon diffusion,compaction,product volume expansion,and capillary pressure difference(CPD))are studied.A model is proposed herein to evaluate the relative contribution of different dynamics for hydrocarbon expulsion using the principle of mass balance,and the model has been applied to the Cambrian source rocks in the Tarim Basin.The evaluation results show that during hydrocarbon expulsion from the source rocks,the relative contribution of CPD is the largest(>50%),followed by compaction(10%-40%),product volume expansion(5%-30%),and thermal expansion(2%-20%).The relative contribution of diffusion to hydrocarbon expulsion is minimal(<10%).These results demonstrate that CPD plays an important role in the hydrocarbon expulsion process of deep source rocks.The hydrocarbon expulsion process of source rocks can be categorized into three stages based on the contribution of different dynamics to the process:the first stage is dominated by compaction and diffusion to expel hydrocarbons,the second stage is dominated by product volume expansion and CPD,and the third stage is dominated by product volume expansion and CPD.This research offers new insights into hydrocarbon exploration in tight oil and gas reservoirs.展开更多
In this work,Saudi heavy crude oil(SHCO)was upgraded by the hydrodynamic cavitation technique.The collapse of cavitation bubbles instantly produces extreme conditions such as high temperature,pressure,and jet flow and...In this work,Saudi heavy crude oil(SHCO)was upgraded by the hydrodynamic cavitation technique.The collapse of cavitation bubbles instantly produces extreme conditions such as high temperature,pressure,and jet flow and strong shear forces,which can play a significant role in the upgradation process.The results revealed that the viscosity and Conradson carbon residue of SHCO decreased from 13.61 to 7.22 mm^(2)/s and from 7.16%to 6.48%,respectively.True boiling point distillation findings showed that the vacuum residue(VR)decreased by 1%.Atmospheric-pressure photoionization Fourier-transform ion cyclotron resonance mass spectrometry,X-ray diffraction,dynamic light scattering,Fourier-transform infrared spectroscopy,and scanning electron microscopy were employed to characterize the molecular composition,crystalline structure,asphaltene aggregate particle size distribution,functional groups,and morphology,respectively,to understand the effects of hydrodynamic cavitation on asphaltenes.The obtained results demonstrate that hydrodynamic cavitation upgradation reduced the interaction forces between the asphaltene molecules,weakening the crystalline structure of the asphaltene aggregates,reducing the degree of association of the aromatic compounds in SHCO and asphaltenes,and decreasing the average particle size.The delayed coking properties of the VR were further investigated,and the cavitation treatment was found to decrease the coke yield by 1.85%and increase the liquid and gas yields by 1.52%and 0.33%,respectively.Hence,hydrodynamic cavitation can effectively enhance the processing performance of crude oil by improving the properties and structural characteristics of asphaltenes.展开更多
文摘An optimization method of fracturing fluid volume strength was introduced taking well X-1 in Biyang Sag of Nanxiang Basin as an example.The characteristic curves of capillary pressure and relative permeability were obtained from history matching between forced imbibition experimental data and core-scale reservoir simulation results and taken into a large scale reservoir model to mimic the forced imbibition behavior during the well shut-in period after fracturing.The optimization of the stimulated reservoir volume(SRV)fracturing fluid volume strength should meet the requirements of estimated ultimate recovery(EUR),increased oil recovery by forced imbibition and enhancement of formation pressure and the fluid volume strength of fracturing fluid should be controlled around a critical value to avoid either insufficiency of imbibition displacement caused by insufficient fluid amount or increase of costs and potential formation damage caused by excessive fluid amount.Reservoir simulation results showed that SRV fracturing fluid volume strength positively correlated with single-well EUR and an optimal fluid volume strength existed,above which the single-well EUR increase rate kept decreasing.An optimized increase of SRV fracturing fluid volume and shut-in time would effectively increase the formation pressure and enhance well production.Field test results of well X-1 proved the practicality of established optimization method of SRV fracturing fluid volume strength on significant enhancement of shale oil well production.
基金This work was supported by the Jiangsu Natural Science Fund-Youth Fund(BK20190639)National Nature Science Foundation of China(Nos.21978318,51904300,and 51922106)National Key R&D Program of China(2020YFC1908803).
文摘Surface roughness plays a significant role in floatability of coal.In the present paper,coking coal surface was polished by three different sandpapers and the surface properties were characterized by contact angle and roughness measurements.The effect of surface roughness on floatability was investigated by adhesion force measurement system for measuring interaction forces between droplets/bubbles and coking coal surfaces with different roughness.The results showed that the contact angle decreased with increasing roughness yet the adhesion force between the water droplet and coal surface increased owing to the increased contact line and the appearance of line pinning.Maximum adhesion forces between water and surfaces were 111.70,125.48,and 136.42μN when the roughness was 0.23,0.98,and 2.79 μm,respectively.In contrast,under a liquid environment,the adhesion forces between air bubble/oil droplet and coal surfaces were decreased with increasing roughness because of the restriction by water.Maximum adhesion forces of increasing roughness were 97.14,42.76,and 17.86 μN measured at interfaces between air bubble and coal surfaces and 169.48,145.84,and 121.02 lN between oil droplet and surfaces,respectively.Decreasing roughness could be beneficial to the spreading of oil droplets and the adhesion of bubbles which is conducive to flotation separation.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.90921009 and 11274401)
文摘We show experimentally that when an unfocused continuous wave（CW） laser beam is obliquely incident onto the surface of a millimeter-sized mineral oil drop on sucrose solution, it will exert a pushing force on the oil drop, making it move forwards along the surface of the sucrose solution. However, after a period of time, the oil drop stops moving. This can be explained as the phenomenon caused by the change of Abraham momentum, the optical gradient force, and friction together.
基金Supported by the National Science and Technology Major Special Project Secretariat(2022-5596510-000064)Petro China Science and Technology Special Project(2021ZZ01-05)。
文摘Considering the demands,situations and trends in respect to global climate change,carbon neutrality and energy transition,the achievements and significance of the global green energy transition and the new energy revolution of China are summarized,and the“Energy Triangle”theory is proposed.The research indicates that the energy technology revolution is driving a dual transformation in global energy:the black“shale oil and gas revolution”in North America and the green“new energy revolution”in China.The green energy revolution of China has achieved significant milestones in wind-solar-hydrogen-energy storage technologies,leading the world in photovoltaic and wind power.The country has developed the world's largest,most comprehensive,and competitive new energy innovation,industrial and value chains,along with the largest clean power supply system globally.New quality productive forces represent the green productive forces.The green“new energy revolution”of China has accelerated the transformation of its energy structure and the global shift towards clean energy,promoting a new win-win model for the global green and low-carbon transition.Under the backdrop of a carbon-neutral goal-driven energy transition,the“Energy Triangle”theory within the framework of new quality productive forces explains the correlation and development of energy security,economic growth,and environmental sustainability throughout the evolution from fossil fuels to new energy systems,culminating in an energy revolution.Compared to the global energy resource endowment,the energy resources of China are characterized by abundant coal,limited oil and gas,and unlimited wind and photovoltaic energy.Moving forward,the energy strategies of China will focus on the advancement of technologies to clean coal for carbon emission reduction,increase gas output while stabilizing oil production,increase green energy while enhancing new energy,and achieve intelligent integration.Vigorously developing new energy is an essential step in maintaining the energy security of China,and establishing a carbon-neutral“super energy system”is a necessary choice.It is crucial to enhance the international competitiveness of China in new energy development,promote high-quality energy productive forces,support the country's transition to an“energy power”,and strive for“energy independence”.
基金supported by the National Natural Science Foundation of China(52104064)(52074089)the China Postdoctoral Science Foundation(2020M681074)+3 种基金Heilongjiang Provincial Natural Science Foundation of China(YQ2023E006)University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(UNPYSCT-2020152)Postdoctoral Science Foundation of Heilongjiang Province in China(LBH-TZ2106)(LBH-Z20122)Northeast Petroleum University Talents Introduction Fund(2019KQ18).
文摘With the increasing oil demand, the construction of oil energy reserves in China needs to be further strengthened. However, given that there has been no research on the main influencing factors of crude oil temperature drop in storage tanks under actual dynamically changing environments, this paper considers the influence of dynamic thermal environment and internal crude oil physical properties on the fluctuating changes in crude oil temperature. A theoretical model of the unsteady-state temperature drop heat transfer process is developed from a three-dimensional perspective. According to the temperature drop variation law of crude oil storage tank under the coupling effect of various heat transfer modes such as external forced convection, thermal radiation, and internal natural convection, the external dynamic thermal environment influence zone, the internal crude oil physical property influence zone, and the intermediate transition zone of the tank are proposed. And the multiple non-linear regression method is used to quantitatively characterize the influence of external ambient temperature, solar radiation, wind speed, internal crude oil density, viscosity, and specific heat capacity on the temperature drop of crude oil in each influencing zone. The results of this paper not only quantitatively explain the main influencing factors of the oil temperature drop in the top, wall, and bottom regions of the tank, but also provide a theoretical reference for oil security reserves under a dynamic thermal environment.
基金Supported by the National Natural Science Foundation of China(41502132)the China National Science and Technology Major Project(2017ZX05001-004)
文摘The origin of overpressure and its effect on petroleum accumulation in the large Permian/Triassic conglomerate oil province in the Mahu Sag,Junggar Basin have been investigated based on comprehensive analysis of log curve combinations,loading-unloading curves,sonic velocity-density cross-plot,and porosity comparison data.The study results show that there are two kinds of normal compaction models in the study area,namely,two-stage linear model and exponent model;overpressure in the large conglomerate reservoirs including Lower Triassic Baikouquan Formation and Permian Upper and Lower Wu’erhe Formations is the result of pressure transfer,and the source of overpressure is the overpressure caused by hydrocarbon generation of Permian Fengcheng Formation major source rock.The petroleum migrated through faults under the driving of hydrocarbon generation overpressure into the reservoirs to accumulate,forming the Permian and Triassic overpressure oil and gas reservoirs.The occurrence and distribution of overpressure are controlled by the source rock maturity and strike-slip faults connecting the source rock and conglomerate reservoirs formed from Indosinian Movement to Himalayan Movement.As overpressure is the driving force for petroleum migration in the large Mahu oil province,the formation and distribution of petroleum reservoirs above the source rock in this area may have a close relationship with the occurrence of overpressure.
基金This study is financially supported by the Joint Fund of the National Natural Science Foundation of China under grant number U19B6003-02-04the Science Foundation of China University of Petroleum,Beijing,under grant number 2462020BJRC005 and 2462022YXZZ007+1 种基金the National Natural Science Foundation of China under grant number 42102145the China National Petroleum Corporation's"14th Five-Year Plan"major scientific projecs under grant number 2021DJ0101.
文摘To thoroughly understand the dynamic mechanism of hydrocarbon expulsion from deep source rocks,in this study,five types of hydrocarbon expulsion dynamics(thermal expansion,hydrocarbon diffusion,compaction,product volume expansion,and capillary pressure difference(CPD))are studied.A model is proposed herein to evaluate the relative contribution of different dynamics for hydrocarbon expulsion using the principle of mass balance,and the model has been applied to the Cambrian source rocks in the Tarim Basin.The evaluation results show that during hydrocarbon expulsion from the source rocks,the relative contribution of CPD is the largest(>50%),followed by compaction(10%-40%),product volume expansion(5%-30%),and thermal expansion(2%-20%).The relative contribution of diffusion to hydrocarbon expulsion is minimal(<10%).These results demonstrate that CPD plays an important role in the hydrocarbon expulsion process of deep source rocks.The hydrocarbon expulsion process of source rocks can be categorized into three stages based on the contribution of different dynamics to the process:the first stage is dominated by compaction and diffusion to expel hydrocarbons,the second stage is dominated by product volume expansion and CPD,and the third stage is dominated by product volume expansion and CPD.This research offers new insights into hydrocarbon exploration in tight oil and gas reservoirs.
基金This work was financially supported by the Research Program of China Petrochemical Corporation(SINOPEC 117017-8 and 119022-2).
文摘In this work,Saudi heavy crude oil(SHCO)was upgraded by the hydrodynamic cavitation technique.The collapse of cavitation bubbles instantly produces extreme conditions such as high temperature,pressure,and jet flow and strong shear forces,which can play a significant role in the upgradation process.The results revealed that the viscosity and Conradson carbon residue of SHCO decreased from 13.61 to 7.22 mm^(2)/s and from 7.16%to 6.48%,respectively.True boiling point distillation findings showed that the vacuum residue(VR)decreased by 1%.Atmospheric-pressure photoionization Fourier-transform ion cyclotron resonance mass spectrometry,X-ray diffraction,dynamic light scattering,Fourier-transform infrared spectroscopy,and scanning electron microscopy were employed to characterize the molecular composition,crystalline structure,asphaltene aggregate particle size distribution,functional groups,and morphology,respectively,to understand the effects of hydrodynamic cavitation on asphaltenes.The obtained results demonstrate that hydrodynamic cavitation upgradation reduced the interaction forces between the asphaltene molecules,weakening the crystalline structure of the asphaltene aggregates,reducing the degree of association of the aromatic compounds in SHCO and asphaltenes,and decreasing the average particle size.The delayed coking properties of the VR were further investigated,and the cavitation treatment was found to decrease the coke yield by 1.85%and increase the liquid and gas yields by 1.52%and 0.33%,respectively.Hence,hydrodynamic cavitation can effectively enhance the processing performance of crude oil by improving the properties and structural characteristics of asphaltenes.
