Based on development practices of Gulong shale oil and a series of experiments on interactions between CO_(2) and the rocks and fluids of shale oil reservoirs, the application and adaptability of CO_(2) pre-fracturing...Based on development practices of Gulong shale oil and a series of experiments on interactions between CO_(2) and the rocks and fluids of shale oil reservoirs, the application and adaptability of CO_(2) pre-fracturing to the Gulong shale oil reservoirs are systematically evaluated. The pilot tests indicate that compared to wells with conventional fracturing, the wells with CO_(2) pre-fracturing demonstrate four significant characteristics: high but rapidly declined initial production, low cumulative production, high and unstable gas-oil ratio, and non-competitive liquid production. These characteristics are attributed to two facts. First, pre-fracturing with CO_(2) inhibits the cross-layer extension of the main fractures in the Gulong shale oil reservoirs, reduces the stimulated reservoir volume, weakens the fracture conductivity, and decreases the matrix permeability and porosity, ultimately impeding the engineering performance. Second, due to the confinement effect, pre-fracturing with CO_(2) increases the saturation pressure difference between the fracture-macropore system and the matrix micropore system, leading to continuous gas production and light hydrocarbon evaporation in the fracture-macropore system, and difficult extraction of crude oil in the matrix-micropore system, which affects the stable production. Under the superposition of various characteristics of Gulong shale oil reservoirs, pre-fracturing with CO_(2) has some negative impacts on reservoir stimulation (fracture extension and fracture conductivity), matrix seepage, and fluid phase and production, which restrict the application performance of CO_(2) pre-fracturing in the Gulong shale oil reservoirs.展开更多
Based on the analysis of the hydrocarbon geochemical characteristics in the Kuqa petroleum system of the Tarim Basin, this study discusses the causes and controlling factors of the phase diversities and their differen...Based on the analysis of the hydrocarbon geochemical characteristics in the Kuqa petroleum system of the Tarim Basin, this study discusses the causes and controlling factors of the phase diversities and their differences in geochemical features. According to the characteristics and differences in oil and gas phase, the petroleum system can be divided into five categories： oil reservoir, wet gas reservoir, condensate gas-rich reservoir, condensate gas-poor reservoir and dry gas reservoir. The causes for the diversities in oil and gas phases include diversities of the sources of parent material, maturity of natural gas and the process of hydrocarbon accumulation of different hydrocarbon phases. On the whole, the Jurassic and Triassic terrestrial source rocks are the main sources for the hydrocarbon in the Kuqa Depression. The small differences in parent material may cause diversities in oil and gas amount, but the impact is small. The differences in oil and gas phase are mainly affected by maturity and the accumulation process, which closely relates with each other. Oil and gas at different thermal evolution stage can be captured in different accumulation process.展开更多
Oil spills result in tremendous damage to the environment and ecosystem.In this study,several p-alkoxybenzoyl-based gelators(1,2a,2b,2c,3)synthesized from commercially available materials were designed for recovering ...Oil spills result in tremendous damage to the environment and ecosystem.In this study,several p-alkoxybenzoyl-based gelators(1,2a,2b,2c,3)synthesized from commercially available materials were designed for recovering oil from an oil–water mixture.Gels with remarkable gelation ability in various oils were characterized by nuclear magnetic resonance,Fourier transform infrared spectroscopy and X-ray diffraction to study the driving forces of self-assembly.Notably,these gelators could achieve the goal of recycling oil from the oil–water mixture at room temperature.In addition,gelator 2b could be used to remove toxic dyes from aqueous solutions with high efficiency.Therefore,these compounds were considered promising materials for oil spill recovery and dye removal due to their practicality and high efficiency.展开更多
The maximum palaeotemperature of oil-bearing sandstones in the UpperTriassic in the eastern Ordos basin has been determined by using many methods including thevitrinite reflectance, fluid inclusion, apatite fission tr...The maximum palaeotemperature of oil-bearing sandstones in the UpperTriassic in the eastern Ordos basin has been determined by using many methods including thevitrinite reflectance, fluid inclusion, apatite fission track, illite crystallinity, chlorite polytypeand diagenetic change of authigenic minerals. The thermal gradient in the Late Mesozoic wasabout 2.9-3.0℃/100m. The Upper Triassic was in a mature stage of organic matter andhydrocarbon began to be generated and migrated during this period. The palaeotemperatures ofoil-bearing sandstones were in the range of 88-110℃; those for the generation and migrationof oil ranged from 112 to 122℃. The thickness of the denuded strata overlying the UpperTriassic was 2465-2750m. The present burial depth of oil-bearing sandstones is generally from400 to 1200m. At a depth of ca. 1900m, the temperature may reach 140℃. Below this depth,organic matter was supermature and mainly generated gas.展开更多
We investigate the dynamic characteristics of oil-gas-water three-phase flow in terms of chaotic attractor comparison. In particular, we extract a statistic to characterize the dynamical difference in attractor probab...We investigate the dynamic characteristics of oil-gas-water three-phase flow in terms of chaotic attractor comparison. In particular, we extract a statistic to characterize the dynamical difference in attractor probability distribution. We first take time series from Logistic chaotic system with different parameters as examples to demonstrate the effectiveness of the method. Then we use this method to investigate the experimental signals from oil-gas-water three-phase flow. The results indicate that the extracted statistic is very sensitive to the change of flow parameters and can gain a quantitatively insight into the dynamic characteristics of different flow patterns.展开更多
The oxidation stability of lubricating oil has a critical influence on the oil performance during service. In this paper, dibenzyl-S-phenyl thioglyconitrile and other derivatives were prepared by phase transfer cataly...The oxidation stability of lubricating oil has a critical influence on the oil performance during service. In this paper, dibenzyl-S-phenyl thioglyconitrile and other derivatives were prepared by phase transfer catalysts and investigated as antioxidants. These compounds were added to oil in different concentrations. The antioxidants activities of different dosages were evaluated and the mechanism was suggested according to micelle and its thermodynamics. The oxidation of the oil has been carried out at different time intervals. The degradation of the oil has been monitored by total acid formation. Oxidation stability of lube oil was largely affected by sulphur and concentration of aromatic hydrocarbons in oil, with the increased sulphur content increasing oxidation stability. The prepared compounds gave higher oxidation stability than imported compound (IRCANOX L 135-CIBA).展开更多
Stable and transparent aminosilicone oil microemulsion of the average particle size below 0.05 micron was prepared. The interaction of the aminosilicone oil, water, complex surfactants and cosurfactant was studied by...Stable and transparent aminosilicone oil microemulsion of the average particle size below 0.05 micron was prepared. The interaction of the aminosilicone oil, water, complex surfactants and cosurfactant was studied by part pseudoternary phase diagram. The effect of cosurfactants (such as alcohol) and the mechanism of its effect on the phase behaviour of the pseudoternary system were investigated.展开更多
BZ26-6 Oilfield is a kind of deep metamorphic rock buried-hill volatile oilfield in Bohai Sea, China. Its early development plan is restricted due to the simultaneous production of oil and gas in large sections of res...BZ26-6 Oilfield is a kind of deep metamorphic rock buried-hill volatile oilfield in Bohai Sea, China. Its early development plan is restricted due to the simultaneous production of oil and gas in large sections of reservoirs, unclear understanding of formation fluid properties and uncertainty of gas-oil interface. Through theoretical research on phase recovery and experimental analysis of crude oil phase characteristics in the original formation, characteristic parameters of the equilibrium condensate gas fluid are restored and calculated. Through the superimposed phase diagram of volatile oil and condensate gas, BZ26-6 Oilfield is determined to be a volatile oil reservoir with a condensate gas cap, with formation pressure and saturation pressure of 36.1 MPa, respectively. Based on the research results of oil-gas phase behavior characteristics, the thermodynamic equations and equation of state are jointly used to solve the problem, and the content change curves of each component at different depths are drawn. Combined with the sensitivity analysis of numerical simulation, the gas-oil interface is determined to be -3726 m above sea level. The fluid phase analysis software, Fluidmodeler, is used to simulate volatile oil degassing and condensate gas separation experiments. In combination with oil and gas production data obtained through the production test, the specific oil recovery index and the specific gas recovery index are determined to be 0.408 m<sup>3</sup>/(MPa·d·m) and 1195 m<sup>3</sup>/(MPa·d·m), respectively. And the reasonable production capacity prediction is conducted on the early development of BZ26-6 Oilfield. The research results can provide a theoretical basis for the efficient development of similar complex oil and gas reservoirs.展开更多
We have investigated the use of flash evaporation, headspace solid-phase microextraction (HS-SPME) and steam distillation (SD) as sample concentration and preparation techniques for the analysis of volatile constituen...We have investigated the use of flash evaporation, headspace solid-phase microextraction (HS-SPME) and steam distillation (SD) as sample concentration and preparation techniques for the analysis of volatile constituents present in Houttuynia cordata Thunb. The samples were analyzed by gas chromatography (GC) and identified by mass spectrometry (MS). Comparison studies were performed. It was found that the results obtained between Headspace solid-phase microextraction HS-SPME and SD techniques were in good agreement. Seventy-nine compounds in Houttuynia cordata Thunb were identified by MS. In flash evaporation, thirty-nine compounds were identified. Discrimination in the response for many constituents studied was not observed, which can be clearly observed in SD and HS-SPME techniques. As a conclusion, HS-SPME is a powerful tool for determining the volatile constitutes present in the Houttuynia cordata.展开更多
Fast phase-transferring was adopted in ethanol solution at the condition of n (oil-soluble tea pol-yphenol): N (As3﹢) = 2:1, 4:1, 6:1, pH = 4.0, temperature 40°C - 45°C, action period of 15 h to compo...Fast phase-transferring was adopted in ethanol solution at the condition of n (oil-soluble tea pol-yphenol): N (As3﹢) = 2:1, 4:1, 6:1, pH = 4.0, temperature 40°C - 45°C, action period of 15 h to compose the target, of which the productivity was 59%, UV was 267.50, 218.00, 220.50 nm, FTIR was 6291, 34158.6, 2850.2, 1708.2;1457.3;1370.4, 1224.2, 1144.0, 760.5 cm﹣1, fluorescence value λmax = 257, 591.1, 593.7, 590.3, 591.0, 591.5, XRD λ/nm is 3.6974, 4.186, 12.0762, 15.4747, 1H-NMRδ = 0.782, 1.193, 1.483 - 1.586, 1.959 - 2.184, 2.479, 3.116, 3.970 - 3.981, 5.231 - 5.753, 6.537 - 7.300. Finally it was ascertained through XRD as double-coordinated polycrystal compound.展开更多
To compare the oil displacement mechanisms and performances of continuous phase flooding agent(traditional polymer solution) and dispersed phase flooding agent(particle-type polymer SMG dispersion), the particle phase...To compare the oil displacement mechanisms and performances of continuous phase flooding agent(traditional polymer solution) and dispersed phase flooding agent(particle-type polymer SMG dispersion), the particle phase separation of SMG dispersion migrating in pores was simulated by using the microfluidic technology. Theoretically guided by the tree fork concentration distribution of red cells in biological fluid mechanics, the concentration distribution mathematical model of SMG in different pores is established. Furthermore, the micro and macro physical simulation experiments of continuous and dispersed phase flooding agents were carried out. The results show that the continuous flooding agent enters all the swept zones and increases the flow resistance in both larger and small pores. On the contrary, the particle phase separation phenomenon occurs during the injection process of dispersed flooding agent. The SMG particles gather in the larger pore to form bridge blinding, and the carrier fluid displace oil in the small pore. Working in cooperation, the SMG particle and carrier fluid drive the residual oil in the low permeability layers step by step and achieve the goal of enhanced oil recovery. The laboratory experimental results indicate that, the oil increment and water reduction effect of dispersed flooding agent is much better than that of continuous flooding agent, which is consistent with the field test results.展开更多
Experimental and theoretical studies of the mechanisms of vibration stimulation of oil recovery in watered fields lead to the conclusion that resonance oscillations develop in fractured-block formations. These oscilla...Experimental and theoretical studies of the mechanisms of vibration stimulation of oil recovery in watered fields lead to the conclusion that resonance oscillations develop in fractured-block formations. These oscillations, caused by weak but long-lasting and frequency-stable influences, create the conditions for ultrasonic wave’s generation in the layers, which are capable of destroying thickened oil membranes in reservoir cracks. For fractured-porous reservoirs in the process of exploitation by the method of water high-pressure oil displacement, the possibility of intensifying ultrasonic vibrations can have an important technological significance. Even a very weak ultrasound can destroy, over a long period of time, the viscous oil membranes formed in the cracks between the blocks, which can be the reason for lowering the permeability of the layers and increasing the oil recovery. To describe these effects, it is necessary to consider the wave process in a hierarchically blocky environment and theoretically simulate the mechanism of the appearance of self-oscillations under the action of relaxation shear stresses. For the analysis of seism acoustic response in time on fixed intervals along the borehole an algorithm of phase diagrams of the state of many-phase medium is suggested.展开更多
The pore structure and oil content of shales have an important influence on the oil mobility and enrichment.In this study,the lacustrine shale samples from the Qingshankou Formation(Q1)of Songliao Basin were selected....The pore structure and oil content of shales have an important influence on the oil mobility and enrichment.In this study,the lacustrine shale samples from the Qingshankou Formation(Q1)of Songliao Basin were selected.TOC,pyrolysis,XRD and nitrogen adsorption were performed on the original and extracted shale samples.Then the influence of mineral composition and organic matter(OM)on the development of nano-scale pore,the oil phase states and mobility were analyzed.The Q1 shale samples can be sub-divided into three types according to the isotherm characteristics.Type A samples are characterized by high kerogen content,with oil mainly existing in the free phase state.Type B samples are characterized by medium kerogen content,oil mainly exists in the absorbed phase state.Type C samples are characterized by low kerogen content,with trace oil found in the absorbed phase state.Nano-scale organic pores are well developed in the Q1 Formation.Oil is primarily found in the pore spaces with diameters less than 10 nm,this being the pore size threshold for mobile shale oil.When TOC>2.0 wt%and EOM>1.0 wt%,Q1 Formation shale oil mobility is high,resulting in prospective drilling targets.展开更多
基金Supported by the National Natural Science Foundation of China(U22B2075)。
文摘Based on development practices of Gulong shale oil and a series of experiments on interactions between CO_(2) and the rocks and fluids of shale oil reservoirs, the application and adaptability of CO_(2) pre-fracturing to the Gulong shale oil reservoirs are systematically evaluated. The pilot tests indicate that compared to wells with conventional fracturing, the wells with CO_(2) pre-fracturing demonstrate four significant characteristics: high but rapidly declined initial production, low cumulative production, high and unstable gas-oil ratio, and non-competitive liquid production. These characteristics are attributed to two facts. First, pre-fracturing with CO_(2) inhibits the cross-layer extension of the main fractures in the Gulong shale oil reservoirs, reduces the stimulated reservoir volume, weakens the fracture conductivity, and decreases the matrix permeability and porosity, ultimately impeding the engineering performance. Second, due to the confinement effect, pre-fracturing with CO_(2) increases the saturation pressure difference between the fracture-macropore system and the matrix micropore system, leading to continuous gas production and light hydrocarbon evaporation in the fracture-macropore system, and difficult extraction of crude oil in the matrix-micropore system, which affects the stable production. Under the superposition of various characteristics of Gulong shale oil reservoirs, pre-fracturing with CO_(2) has some negative impacts on reservoir stimulation (fracture extension and fracture conductivity), matrix seepage, and fluid phase and production, which restrict the application performance of CO_(2) pre-fracturing in the Gulong shale oil reservoirs.
基金supported by the Tarim Oil Field Research InstituteNational Natural Science Foundation (sanctified number:40602016)National Key Basic Research and Development Projects (Itemnumber:113404GJ0003)
文摘Based on the analysis of the hydrocarbon geochemical characteristics in the Kuqa petroleum system of the Tarim Basin, this study discusses the causes and controlling factors of the phase diversities and their differences in geochemical features. According to the characteristics and differences in oil and gas phase, the petroleum system can be divided into five categories： oil reservoir, wet gas reservoir, condensate gas-rich reservoir, condensate gas-poor reservoir and dry gas reservoir. The causes for the diversities in oil and gas phases include diversities of the sources of parent material, maturity of natural gas and the process of hydrocarbon accumulation of different hydrocarbon phases. On the whole, the Jurassic and Triassic terrestrial source rocks are the main sources for the hydrocarbon in the Kuqa Depression. The small differences in parent material may cause diversities in oil and gas amount, but the impact is small. The differences in oil and gas phase are mainly affected by maturity and the accumulation process, which closely relates with each other. Oil and gas at different thermal evolution stage can be captured in different accumulation process.
文摘Oil spills result in tremendous damage to the environment and ecosystem.In this study,several p-alkoxybenzoyl-based gelators(1,2a,2b,2c,3)synthesized from commercially available materials were designed for recovering oil from an oil–water mixture.Gels with remarkable gelation ability in various oils were characterized by nuclear magnetic resonance,Fourier transform infrared spectroscopy and X-ray diffraction to study the driving forces of self-assembly.Notably,these gelators could achieve the goal of recycling oil from the oil–water mixture at room temperature.In addition,gelator 2b could be used to remove toxic dyes from aqueous solutions with high efficiency.Therefore,these compounds were considered promising materials for oil spill recovery and dye removal due to their practicality and high efficiency.
基金This study was supported by the cooperative research project of the Petroleum Administration of the Yanchang Oil Field,Shaanxi,and the Northwest University.
文摘The maximum palaeotemperature of oil-bearing sandstones in the UpperTriassic in the eastern Ordos basin has been determined by using many methods including thevitrinite reflectance, fluid inclusion, apatite fission track, illite crystallinity, chlorite polytypeand diagenetic change of authigenic minerals. The thermal gradient in the Late Mesozoic wasabout 2.9-3.0℃/100m. The Upper Triassic was in a mature stage of organic matter andhydrocarbon began to be generated and migrated during this period. The palaeotemperatures ofoil-bearing sandstones were in the range of 88-110℃; those for the generation and migrationof oil ranged from 112 to 122℃. The thickness of the denuded strata overlying the UpperTriassic was 2465-2750m. The present burial depth of oil-bearing sandstones is generally from400 to 1200m. At a depth of ca. 1900m, the temperature may reach 140℃. Below this depth,organic matter was supermature and mainly generated gas.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.41174109 and 61104148)the National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No.2011ZX05020-006)the Tianjin City High School Science and Technology Fund Planning Project,China(Grant No.20130718)
文摘We investigate the dynamic characteristics of oil-gas-water three-phase flow in terms of chaotic attractor comparison. In particular, we extract a statistic to characterize the dynamical difference in attractor probability distribution. We first take time series from Logistic chaotic system with different parameters as examples to demonstrate the effectiveness of the method. Then we use this method to investigate the experimental signals from oil-gas-water three-phase flow. The results indicate that the extracted statistic is very sensitive to the change of flow parameters and can gain a quantitatively insight into the dynamic characteristics of different flow patterns.
文摘The oxidation stability of lubricating oil has a critical influence on the oil performance during service. In this paper, dibenzyl-S-phenyl thioglyconitrile and other derivatives were prepared by phase transfer catalysts and investigated as antioxidants. These compounds were added to oil in different concentrations. The antioxidants activities of different dosages were evaluated and the mechanism was suggested according to micelle and its thermodynamics. The oxidation of the oil has been carried out at different time intervals. The degradation of the oil has been monitored by total acid formation. Oxidation stability of lube oil was largely affected by sulphur and concentration of aromatic hydrocarbons in oil, with the increased sulphur content increasing oxidation stability. The prepared compounds gave higher oxidation stability than imported compound (IRCANOX L 135-CIBA).
文摘Stable and transparent aminosilicone oil microemulsion of the average particle size below 0.05 micron was prepared. The interaction of the aminosilicone oil, water, complex surfactants and cosurfactant was studied by part pseudoternary phase diagram. The effect of cosurfactants (such as alcohol) and the mechanism of its effect on the phase behaviour of the pseudoternary system were investigated.
文摘BZ26-6 Oilfield is a kind of deep metamorphic rock buried-hill volatile oilfield in Bohai Sea, China. Its early development plan is restricted due to the simultaneous production of oil and gas in large sections of reservoirs, unclear understanding of formation fluid properties and uncertainty of gas-oil interface. Through theoretical research on phase recovery and experimental analysis of crude oil phase characteristics in the original formation, characteristic parameters of the equilibrium condensate gas fluid are restored and calculated. Through the superimposed phase diagram of volatile oil and condensate gas, BZ26-6 Oilfield is determined to be a volatile oil reservoir with a condensate gas cap, with formation pressure and saturation pressure of 36.1 MPa, respectively. Based on the research results of oil-gas phase behavior characteristics, the thermodynamic equations and equation of state are jointly used to solve the problem, and the content change curves of each component at different depths are drawn. Combined with the sensitivity analysis of numerical simulation, the gas-oil interface is determined to be -3726 m above sea level. The fluid phase analysis software, Fluidmodeler, is used to simulate volatile oil degassing and condensate gas separation experiments. In combination with oil and gas production data obtained through the production test, the specific oil recovery index and the specific gas recovery index are determined to be 0.408 m<sup>3</sup>/(MPa·d·m) and 1195 m<sup>3</sup>/(MPa·d·m), respectively. And the reasonable production capacity prediction is conducted on the early development of BZ26-6 Oilfield. The research results can provide a theoretical basis for the efficient development of similar complex oil and gas reservoirs.
文摘We have investigated the use of flash evaporation, headspace solid-phase microextraction (HS-SPME) and steam distillation (SD) as sample concentration and preparation techniques for the analysis of volatile constituents present in Houttuynia cordata Thunb. The samples were analyzed by gas chromatography (GC) and identified by mass spectrometry (MS). Comparison studies were performed. It was found that the results obtained between Headspace solid-phase microextraction HS-SPME and SD techniques were in good agreement. Seventy-nine compounds in Houttuynia cordata Thunb were identified by MS. In flash evaporation, thirty-nine compounds were identified. Discrimination in the response for many constituents studied was not observed, which can be clearly observed in SD and HS-SPME techniques. As a conclusion, HS-SPME is a powerful tool for determining the volatile constitutes present in the Houttuynia cordata.
文摘Fast phase-transferring was adopted in ethanol solution at the condition of n (oil-soluble tea pol-yphenol): N (As3﹢) = 2:1, 4:1, 6:1, pH = 4.0, temperature 40°C - 45°C, action period of 15 h to compose the target, of which the productivity was 59%, UV was 267.50, 218.00, 220.50 nm, FTIR was 6291, 34158.6, 2850.2, 1708.2;1457.3;1370.4, 1224.2, 1144.0, 760.5 cm﹣1, fluorescence value λmax = 257, 591.1, 593.7, 590.3, 591.0, 591.5, XRD λ/nm is 3.6974, 4.186, 12.0762, 15.4747, 1H-NMRδ = 0.782, 1.193, 1.483 - 1.586, 1.959 - 2.184, 2.479, 3.116, 3.970 - 3.981, 5.231 - 5.753, 6.537 - 7.300. Finally it was ascertained through XRD as double-coordinated polycrystal compound.
基金Supported by the China Postdoctoral Science Foundation(Grant No.2018M641610)China National Science and Technology Major Project(2016ZX05025-003)
文摘To compare the oil displacement mechanisms and performances of continuous phase flooding agent(traditional polymer solution) and dispersed phase flooding agent(particle-type polymer SMG dispersion), the particle phase separation of SMG dispersion migrating in pores was simulated by using the microfluidic technology. Theoretically guided by the tree fork concentration distribution of red cells in biological fluid mechanics, the concentration distribution mathematical model of SMG in different pores is established. Furthermore, the micro and macro physical simulation experiments of continuous and dispersed phase flooding agents were carried out. The results show that the continuous flooding agent enters all the swept zones and increases the flow resistance in both larger and small pores. On the contrary, the particle phase separation phenomenon occurs during the injection process of dispersed flooding agent. The SMG particles gather in the larger pore to form bridge blinding, and the carrier fluid displace oil in the small pore. Working in cooperation, the SMG particle and carrier fluid drive the residual oil in the low permeability layers step by step and achieve the goal of enhanced oil recovery. The laboratory experimental results indicate that, the oil increment and water reduction effect of dispersed flooding agent is much better than that of continuous flooding agent, which is consistent with the field test results.
文摘Experimental and theoretical studies of the mechanisms of vibration stimulation of oil recovery in watered fields lead to the conclusion that resonance oscillations develop in fractured-block formations. These oscillations, caused by weak but long-lasting and frequency-stable influences, create the conditions for ultrasonic wave’s generation in the layers, which are capable of destroying thickened oil membranes in reservoir cracks. For fractured-porous reservoirs in the process of exploitation by the method of water high-pressure oil displacement, the possibility of intensifying ultrasonic vibrations can have an important technological significance. Even a very weak ultrasound can destroy, over a long period of time, the viscous oil membranes formed in the cracks between the blocks, which can be the reason for lowering the permeability of the layers and increasing the oil recovery. To describe these effects, it is necessary to consider the wave process in a hierarchically blocky environment and theoretically simulate the mechanism of the appearance of self-oscillations under the action of relaxation shear stresses. For the analysis of seism acoustic response in time on fixed intervals along the borehole an algorithm of phase diagrams of the state of many-phase medium is suggested.
基金financially supported by the National Natural Science Foundation of China(No.41972156)the Science and Technology Project of Heilongjiang Province(No.2020ZX05A01)
文摘The pore structure and oil content of shales have an important influence on the oil mobility and enrichment.In this study,the lacustrine shale samples from the Qingshankou Formation(Q1)of Songliao Basin were selected.TOC,pyrolysis,XRD and nitrogen adsorption were performed on the original and extracted shale samples.Then the influence of mineral composition and organic matter(OM)on the development of nano-scale pore,the oil phase states and mobility were analyzed.The Q1 shale samples can be sub-divided into three types according to the isotherm characteristics.Type A samples are characterized by high kerogen content,with oil mainly existing in the free phase state.Type B samples are characterized by medium kerogen content,oil mainly exists in the absorbed phase state.Type C samples are characterized by low kerogen content,with trace oil found in the absorbed phase state.Nano-scale organic pores are well developed in the Q1 Formation.Oil is primarily found in the pore spaces with diameters less than 10 nm,this being the pore size threshold for mobile shale oil.When TOC>2.0 wt%and EOM>1.0 wt%,Q1 Formation shale oil mobility is high,resulting in prospective drilling targets.
