For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmissi...For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmission power loss and the hydraulic system leakage. Based on this model, a flow-based control strategy is developed for EOP to satisfy the system flow requirement. This control strategy is verified through the forward driving simulation. The results indicate that there is a best combination for the size of mechanical oil pump(MOP) and EOP in terms of minimum energy consumption. In order to get a quick and smooth starting process, control strategies of the EOP and the on-coming clutch are proposed. The test environment on a prototype vehicle is built to verify the feasibility of the integrated EOP and its control strategies. The results show that the selected EOP can satisfy the flow requirement and a quick and smooth starting performance is achieved in the start–stop function. This research has a high value for the forward design of EOP in automatic transmissions with respect to efficiency improvement and start–stop function.展开更多
This article outlines the development of separated zone oil production in foreign countries,and details its development in China.According to the development process,production needs,technical characteristics and adap...This article outlines the development of separated zone oil production in foreign countries,and details its development in China.According to the development process,production needs,technical characteristics and adaptability of oilfields in China,the development of separate zone oil production technology is divided into four stages:flowing well zonal oil production,mechanical recovery and water blocking,hydraulically adjustable zonal oil production,and intelligent zonal production.The principles,construction processes,adaptability,advantages and disadvantages of the technology are introduced in detail.Based on the actual production situation of the oilfields in China at present,three development directions of the technology are proposed.First,the real-time monitoring and adjustment level of separated zone oil production needs to be improved by developing downhole sensor technology and two-way communication technology between ground and downhole and enhancing full life cycle service capability and adaptability to horizontal wells.Second,an integrated platform of zonal oil production and management should be built using a digital artificial lifting system.Third,integration of injection and production should be implemented through large-scale application of zonal oil production and zonal water injection to improve matching and adjustment level between the injection and production parameters,thus making the development adjustment from"lag control"to"real-time optimization"and improving the development effect.展开更多
ASP-foam (ASPF) is a system prepared by injecting natural gas into the conventional alkali- surfactant-polymer (ASP) system. Foam can be formed in the porous media by the interaction of gas and surfactant in the A...ASP-foam (ASPF) is a system prepared by injecting natural gas into the conventional alkali- surfactant-polymer (ASP) system. Foam can be formed in the porous media by the interaction of gas and surfactant in the ASP system. With the ASPF system, oil recovery is improved as the interfacial tension (IFT) is reduced to a relatively low level, and the swept volume is enlarged. In this paper, four surfactants were evaluated and characterized by IFT between ASP system and oil and the foaming performance. AI- kyl benzene sulfonate (ORS-41) was chosen as the surfactant to best reduce IFT between displacement fluids and oil and improve the foaming performance. The mechanisms of ASPF flooding were studied in this paper, the results show that the ASPF flooding not only enlarges the swept volume but also enhances the displacement efficiency. The effects of reservoir heterogeneity, the gas-liquid ratio of ASPF system, and the concentrations of polymer and surfactant on the displacement efficiency were studied. A field trial of ASPF flooding has also been conducted. Both the laboratory results and the field trial results show that the ASPF flooding can significantly increase the oil recovery, with a 30% increase in the proportion of the original oil in place recovered compared with water flooding.展开更多
Aiming at the four issues of underground storage state,exploitation mechanism,crude oil flow and efficient recovery,the key theoretical and technical issues and countermeasures for effective development of Gulong shal...Aiming at the four issues of underground storage state,exploitation mechanism,crude oil flow and efficient recovery,the key theoretical and technical issues and countermeasures for effective development of Gulong shale oil are put forward.Through key exploration and research on fluid occurrence,fluid phase change,exploitation mechanism,oil start-up mechanism,flow regime/pattern,exploitation mode and enhanced oil recovery(EOR)of shale reservoirs with different storage spaces,multi-scale occurrence states of shale oil and phase behavior of fluid in nano confined space were provided,the multi-phase,multi-scale flow mode and production mechanism with hydraulic fracture-shale bedding fracture-matrix infiltration as the core was clarified,and a multi-scale flow mathematical model and recoverable reserves evaluation method were preliminarily established.The feasibility of development mode with early energy replenishment and recovery factor of 3o%was discussed.Based on these,the researches of key theories and technologies for effective development of Gulong shale oil are proposed to focus on:(1)in-situ sampling and non-destructive testing of core and fluid;(2)high-temperature,high-pressure,nano-scale laboratory simulation experiment;(3)fusion of multi-scale multi-flow regime numerical simulation technology and large-scale application software;(4)waterless(CO_(2))fracturing technique and the fracturing technique for increasing the vertical fracture height;(5)early energy replenishment to enhance oil recovery;(6)lifecycle technical and economic evaluation.Moreover,a series of exploitation tests should be performed on site as soon as possible to verify the theoretical understanding,optimize the exploitation mode,form supporting technologies,and provide a generalizable development model,thereby supporting and guiding the effective development and production of Gulong shale oil.展开更多
Cold production is a challenge in the case of heavy oil because of its high viscosity and poor fluidity in reservoir conditions.Alkali-cosolvent-polymer flooding is a type of microemulsion flooding with low costs and ...Cold production is a challenge in the case of heavy oil because of its high viscosity and poor fluidity in reservoir conditions.Alkali-cosolvent-polymer flooding is a type of microemulsion flooding with low costs and possible potential for heavy oil reservoirs.However,the addition of polymer may cause problems with injection in the case of highly viscous oil.Hence,in this study the feasibility of alkali-cosolvent(AC)flooding in heavy oil reservoirs was investigated via several groups of experiments.The interfacial tension between various AC formulations and heavy crude oil was measured to select appropriate formulations.Phase behavior tests were performed to determine the most appropriate formulation and conditions for the generation of a microemulsion.Sandpack flooding experiments were carried out to investigate the displacement efficiency of the selected Ac formulation.The results showed that the interfacial tension between an AC formulation and heavy oil could be reduced to below 1o-3 mN/m but differed greatly between different types of cosolvent.A butanol random polyether series displayed good performance in reducing the water-oil interfacial tension,which made it possible to form a Type Il microemulsion in reservoir conditions.According to the results of the phase behavior tests,the optimal salinity for different formulations with four cosolvent concentrations(0.5 wt%,1 wt%,2 wt%,and 3 wt%)was 4000,8000,14000,and 20000 ppm,respectively.The results of rheological measurements showed that Type Ill microemulsion had a viscosity that was ten times that of water.The results of sandpack flooding experiments showed that,in comparison with waterflooding,the injection of a certain Ac formulation slug could reduce the injection pressure.The pressure gradient during waterflooding and AC flooding was around 870 and 30-57 kPa/m,respectively.With the addition of an AC slug,the displacement efficiency was 30%-50%higher than in the case of waterflooding.展开更多
Based on the results of drilling,tests and simulation experiments,the shales of the Cretaceous Qingshankou Formation in the Gulong Sag of the Songliao Basin are discussed with respect to hydrocarbon generation evoluti...Based on the results of drilling,tests and simulation experiments,the shales of the Cretaceous Qingshankou Formation in the Gulong Sag of the Songliao Basin are discussed with respect to hydrocarbon generation evolution,shale oil occurrence,and pore/fracture evolution mechanism.In conjunction with a substantial amount of oil testing and production data,the Gulong shale oil enrichment layers are evaluated and the production behaviors and decline law are analyzed.The results are drawn in four aspects.First,the Gulong shales are in the stage of extensive hydrocarbon expulsion when R_(0) is 1.0%-1.2%,with the peak hydrocarbon expulsion efficiency of 49.5%approximately.In the low-medium maturity stage,shale oil migrates from kerogen to rocks and organic pores/fractures.In the medium-high maturity stage,shale oil transforms from adsorbed state to free state.Second,the clay mineral intergranular pores/fractures,dissolution pores,and organic pores make up the majority of the pore structure.During the transformation,clay minerals undergo significant intergranular pore/fracture development between the minerals such as illite and illite/smectite mixed layer.A network of pores/fractures is formed by organic matter cracking.Third,free hydrocarbon content,effective porosity,total porosity,and brittle mineral content are the core indicators for the evaluation of shale oil enrichment layers.Class-I layers are defined as free hydrocarbon content equal or greater than 6.0 mg/g,effective porosity equal or greater than 3.5%,total porosity equal or greater than 8.0%,and brittle mineral content equal or greater than 50%.It is believed that the favourable oil layers are Q2-Q3 and Q8-Q9.Fourth,the horizontal wells in the core area of the light oil zone exhibit a high cumulative production in the first year,and present a hyperbolic production decline pattern,with the decline index of 0.85-0.95,the first-year decline rate of 14.5%-26.5%,and the single-well estimated ultimate recovery(EUR)greater than 2.0×10^(4)t.In practical exploration and production,more efforts will be devoted to the clarification of hydrocarbon generation and expulsion mechanisms,accurate testing of porosity and hydrocarbon content/phase of shale under formation conditions,precise delineation of the boundary of enrichment area,relationship between mechanical properties and stimulated reservoir volume,and enhanced oil recovery,in order to improve the EUR and achieve a large-scale,efficient development of shale oil.展开更多
The current palm oil harvesting process removes the whole fruit bunch from the palm with most of the fruit unripe, and takes the whole fruit bunch from the plantation to a processing mill. There are two consequences. ...The current palm oil harvesting process removes the whole fruit bunch from the palm with most of the fruit unripe, and takes the whole fruit bunch from the plantation to a processing mill. There are two consequences. This robs the symbiotic palm/soil eco-system of important nutrients and steadily reduces soil fertility. Poor soil fertility is now the limit to palm oil production in peninsular Malaysia despite much use of expensive fertiliser, and weak palms in unhealthy soil are prone to the fungus Ganoderma. Secondly, it takes much energy to remove the fruit from the bunch and the quantity and quality of the oil is less than that of ripe fruit. All this is because ripe fruit—which naturally becomes loose—has been defined as “a problem” in harvesting. This paper proposes covering the fruit bunch in a mesh sack whilst ripening, which prevents ripe fruit naturally from becoming loose being a problem and transforms the whole harvesting process. This allows efficient fruit separation and fruit pressing to be done at the foot of the palm tree with only the oil being removed from the plantation, both simplifying and improving the harvesting process and maintaining the organic fertility cycle, adding value in every respect.展开更多
Lower-phase microemulsions with core-shell structure were prepared by microemulsion dilution method.The high temperature resistant systems were screened and the performance evaluation experiments were conducted to cla...Lower-phase microemulsions with core-shell structure were prepared by microemulsion dilution method.The high temperature resistant systems were screened and the performance evaluation experiments were conducted to clarify the spontaneous imbibition mechanisms in ultra-low permeability and tight oil reservoirs,and to direct the field microfracture huff and puff test of oil well.The microemulsion system(O-ME)with cationic-nonionic surfactant as hydrophilic shell,No.3 white oil as oil phase core has the highest imbibition recovery;its spontaneous imbibition mechanisms include:the ultra-low interfacial tension and wettability reversal significantly reduce oil adhesion work to improve oil displacement efficiency,the nanoscale“core-shell structure”formed can easily enter micro-nano pores and throats to expand the swept volume,in addition,the remarkable effect of dispersing and solubilizing crude oil can improve the mobility of crude oil.Based on the experimental results,a microfracture huff and puff test of O-ME was carried out in Well YBD43-X506 of Shengli Oilfield.After being treated,the well had a significant increase of daily fluid production to 5 tons from 1.4 tons,and an increase of daily oil production to 2.7 tons from 1.0 ton before treatment.展开更多
Based on the analysis of the production composition of reservoirs developed by the second&tertiary recovery combination(STRC),the relationship between the overall output of the STRC project and the production leve...Based on the analysis of the production composition of reservoirs developed by the second&tertiary recovery combination(STRC),the relationship between the overall output of the STRC project and the production level during the blank water flooding stage is proposed.According to the basic principle of reservoir engineering that the“recovery factor is equal to sweeping coefficient multiplied by oil displacement efficiency”,the formula for calculating the ultimate oil recovery factor of chemical combination flooding reservoir was established.By dividing the reservoir into a series of grids according to differen-tial calculus thinking,the relationship between the ultimate recovery factor of a certain number of grids and the recovery de-gree of the reservoir was established,and then the variation law of oil production rate of the STRC reservoir was obtained.The concept of“oil rate enlargement factor of chemical combination flooding”was defined,and a production calculation method of reservoir developed by STRC was put forward based on practical oilfield development experience.The study shows that the oil production enhancing effect of STRC increases evenly with the in crease of the ratio of STRC displacement efficiency to water displacement efficiency,and increases rapidly with the increase of the ratio of recovery degree at flooding mode conversion to the water displacement efficiency.STRC is more effective in increasing oil production of reservoir with high recovery degree.Through practical tests of the alkali free binary flooding(polymer/surfactant)projects,the relative error of the oil production calculation method of STRC reservoir is about±10%,which meets the requirements of reservoir engineering.展开更多
In today’s rapidly developing modern society,automobiles,as an important part of transportation and industrial fields,play a pivotal role.With the improvement of people’s living standards and the increase in traffic...In today’s rapidly developing modern society,automobiles,as an important part of transportation and industrial fields,play a pivotal role.With the improvement of people’s living standards and the increase in traffic demand,the automobile manufacturing industry has been continuously developing and growing globally.However,to cope with increasingly fierce market competition and ever-changing consumer demands,the automobile manufacturing industry is also facing the challenges of improving production efficiency,reducing costs,and improving product quality.In this context,automation technology has gradually become a major trend in the automobile manufacturing industry.As an important support of modern industry,automation technology has shown great application potential in many fields.From industrial production to daily life,automation technology can be seen everywhere.In the field of manufacturing,especially in automobile manufacturing,the application of automation technology is getting more and more attention.Automated production lines,intelligent robots,and automated warehousing systems have all changed the face of automobile manufacturing to varying degrees,bringing companies higher efficiency,more stable quality,and greater competitive advantages.The application trend of this automation technology in various fields not only meets the needs of modern industry for efficient,precise,and sustainable development but also provides new ideas and paths for the future development of the automobile manufacturing industry.展开更多
This study attempts to reconcile data envelopment analysis (DEA) with the production function approach in economics. We examine not only the inputs of capital and labor, but also the ranges of these inputs in producti...This study attempts to reconcile data envelopment analysis (DEA) with the production function approach in economics. We examine not only the inputs of capital and labor, but also the ranges of these inputs in production process steps, and endogenously derive a Leontief production function. The Leontief production functions shift northeasterly owing to mechanization, which is the replacement of labor inputs by capital inputs in some steps. Consequently, we describe the efficient frontier as the convex hull of the Leontief production functions. Furthermore, we consider the possibility of efficient production below the efficient frontier.展开更多
Background:Oil palm is a tropical crop with worldwide plantings approaching 20 million ha and large areas in Indonesia,Malaysia and Thailand.The plantations are readily managed as silvopastoral systems incorporating c...Background:Oil palm is a tropical crop with worldwide plantings approaching 20 million ha and large areas in Indonesia,Malaysia and Thailand.The plantations are readily managed as silvopastoral systems incorporating cattle grazing(Oil Palm Silvopastoral System for Cattle,OPSC)but there is a need for analytical tools and data to understand system herbage supply and feed conversion efficiency(FCE).Methods:Metabolic energy budgeting was used to estimate herbage harvested by cattle in three OPSC subsystems,9 and 12 years after oil palm establishment,and FCE of the subsystems was determined.Understorey herbage was also analysed for nutritive value,botanical composition and herbage accumulation within one grazing‐regrowth cycle.Results:The herbage‐harvested estimate was 2.0−2.4 t dry matter(DM)ha^(-1) year^(-1) for 9 year old subsystems and 1.4-1.7 tDMha^(-1) year^(-1) for a 12 year old subsystem.Herbage metabolisable energy(ME)was 8.3−8.5 MJ kg^(-1) DM and crude protein(CP)was 15%-16%DM.FCE values for subsystems ranged from 32 to 94 kg DM kg^(-1) liveweight‐gain.Conclusions:Herbage DM yield is declining,while herbage ME is marginal but CP is adequate.FCE is suboptimal but can be optimised by defining the trajectory of declining herbage production with canopy closure as plantations age and matching stocking rate to herbage supply using a comparativestocking‐rate‐type statistic.展开更多
基金Project(51405010)supported by the National Natural Science Foundation of ChinaProject(2011BAG09B00)supported by the National Science and Technology Support Program of China
文摘For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmission power loss and the hydraulic system leakage. Based on this model, a flow-based control strategy is developed for EOP to satisfy the system flow requirement. This control strategy is verified through the forward driving simulation. The results indicate that there is a best combination for the size of mechanical oil pump(MOP) and EOP in terms of minimum energy consumption. In order to get a quick and smooth starting process, control strategies of the EOP and the on-coming clutch are proposed. The test environment on a prototype vehicle is built to verify the feasibility of the integrated EOP and its control strategies. The results show that the selected EOP can satisfy the flow requirement and a quick and smooth starting performance is achieved in the start–stop function. This research has a high value for the forward design of EOP in automatic transmissions with respect to efficiency improvement and start–stop function.
基金Supported by the National Key Research and Development Program of China(2018YFE0196000)National Science and Technology Major Project of China(2016ZX05010-006)CNPC Scientific Research and Technical Development Project(2019B-4113)
文摘This article outlines the development of separated zone oil production in foreign countries,and details its development in China.According to the development process,production needs,technical characteristics and adaptability of oilfields in China,the development of separate zone oil production technology is divided into four stages:flowing well zonal oil production,mechanical recovery and water blocking,hydraulically adjustable zonal oil production,and intelligent zonal production.The principles,construction processes,adaptability,advantages and disadvantages of the technology are introduced in detail.Based on the actual production situation of the oilfields in China at present,three development directions of the technology are proposed.First,the real-time monitoring and adjustment level of separated zone oil production needs to be improved by developing downhole sensor technology and two-way communication technology between ground and downhole and enhancing full life cycle service capability and adaptability to horizontal wells.Second,an integrated platform of zonal oil production and management should be built using a digital artificial lifting system.Third,integration of injection and production should be implemented through large-scale application of zonal oil production and zonal water injection to improve matching and adjustment level between the injection and production parameters,thus making the development adjustment from"lag control"to"real-time optimization"and improving the development effect.
基金supported by the Daqing Oilfield Limited Company
文摘ASP-foam (ASPF) is a system prepared by injecting natural gas into the conventional alkali- surfactant-polymer (ASP) system. Foam can be formed in the porous media by the interaction of gas and surfactant in the ASP system. With the ASPF system, oil recovery is improved as the interfacial tension (IFT) is reduced to a relatively low level, and the swept volume is enlarged. In this paper, four surfactants were evaluated and characterized by IFT between ASP system and oil and the foaming performance. AI- kyl benzene sulfonate (ORS-41) was chosen as the surfactant to best reduce IFT between displacement fluids and oil and improve the foaming performance. The mechanisms of ASPF flooding were studied in this paper, the results show that the ASPF flooding not only enlarges the swept volume but also enhances the displacement efficiency. The effects of reservoir heterogeneity, the gas-liquid ratio of ASPF system, and the concentrations of polymer and surfactant on the displacement efficiency were studied. A field trial of ASPF flooding has also been conducted. Both the laboratory results and the field trial results show that the ASPF flooding can significantly increase the oil recovery, with a 30% increase in the proportion of the original oil in place recovered compared with water flooding.
基金Supported by the National Natural Science Foundation of China(U22B2075).
文摘Aiming at the four issues of underground storage state,exploitation mechanism,crude oil flow and efficient recovery,the key theoretical and technical issues and countermeasures for effective development of Gulong shale oil are put forward.Through key exploration and research on fluid occurrence,fluid phase change,exploitation mechanism,oil start-up mechanism,flow regime/pattern,exploitation mode and enhanced oil recovery(EOR)of shale reservoirs with different storage spaces,multi-scale occurrence states of shale oil and phase behavior of fluid in nano confined space were provided,the multi-phase,multi-scale flow mode and production mechanism with hydraulic fracture-shale bedding fracture-matrix infiltration as the core was clarified,and a multi-scale flow mathematical model and recoverable reserves evaluation method were preliminarily established.The feasibility of development mode with early energy replenishment and recovery factor of 3o%was discussed.Based on these,the researches of key theories and technologies for effective development of Gulong shale oil are proposed to focus on:(1)in-situ sampling and non-destructive testing of core and fluid;(2)high-temperature,high-pressure,nano-scale laboratory simulation experiment;(3)fusion of multi-scale multi-flow regime numerical simulation technology and large-scale application software;(4)waterless(CO_(2))fracturing technique and the fracturing technique for increasing the vertical fracture height;(5)early energy replenishment to enhance oil recovery;(6)lifecycle technical and economic evaluation.Moreover,a series of exploitation tests should be performed on site as soon as possible to verify the theoretical understanding,optimize the exploitation mode,form supporting technologies,and provide a generalizable development model,thereby supporting and guiding the effective development and production of Gulong shale oil.
基金support from the National Natural Science Foundation of China(52174034)the Sichuan Science and Technology Program(2021YFH0081).
文摘Cold production is a challenge in the case of heavy oil because of its high viscosity and poor fluidity in reservoir conditions.Alkali-cosolvent-polymer flooding is a type of microemulsion flooding with low costs and possible potential for heavy oil reservoirs.However,the addition of polymer may cause problems with injection in the case of highly viscous oil.Hence,in this study the feasibility of alkali-cosolvent(AC)flooding in heavy oil reservoirs was investigated via several groups of experiments.The interfacial tension between various AC formulations and heavy crude oil was measured to select appropriate formulations.Phase behavior tests were performed to determine the most appropriate formulation and conditions for the generation of a microemulsion.Sandpack flooding experiments were carried out to investigate the displacement efficiency of the selected Ac formulation.The results showed that the interfacial tension between an AC formulation and heavy oil could be reduced to below 1o-3 mN/m but differed greatly between different types of cosolvent.A butanol random polyether series displayed good performance in reducing the water-oil interfacial tension,which made it possible to form a Type Il microemulsion in reservoir conditions.According to the results of the phase behavior tests,the optimal salinity for different formulations with four cosolvent concentrations(0.5 wt%,1 wt%,2 wt%,and 3 wt%)was 4000,8000,14000,and 20000 ppm,respectively.The results of rheological measurements showed that Type Ill microemulsion had a viscosity that was ten times that of water.The results of sandpack flooding experiments showed that,in comparison with waterflooding,the injection of a certain Ac formulation slug could reduce the injection pressure.The pressure gradient during waterflooding and AC flooding was around 870 and 30-57 kPa/m,respectively.With the addition of an AC slug,the displacement efficiency was 30%-50%higher than in the case of waterflooding.
基金Supported by the National Natural Science Foundation Project(42090020,42090025)Strategic Research of Oil and Gas Development Major Project of Ministry of Science and TechnologyPetroChina Scientific Research and Technological Development Project(2019E2601).
文摘Based on the results of drilling,tests and simulation experiments,the shales of the Cretaceous Qingshankou Formation in the Gulong Sag of the Songliao Basin are discussed with respect to hydrocarbon generation evolution,shale oil occurrence,and pore/fracture evolution mechanism.In conjunction with a substantial amount of oil testing and production data,the Gulong shale oil enrichment layers are evaluated and the production behaviors and decline law are analyzed.The results are drawn in four aspects.First,the Gulong shales are in the stage of extensive hydrocarbon expulsion when R_(0) is 1.0%-1.2%,with the peak hydrocarbon expulsion efficiency of 49.5%approximately.In the low-medium maturity stage,shale oil migrates from kerogen to rocks and organic pores/fractures.In the medium-high maturity stage,shale oil transforms from adsorbed state to free state.Second,the clay mineral intergranular pores/fractures,dissolution pores,and organic pores make up the majority of the pore structure.During the transformation,clay minerals undergo significant intergranular pore/fracture development between the minerals such as illite and illite/smectite mixed layer.A network of pores/fractures is formed by organic matter cracking.Third,free hydrocarbon content,effective porosity,total porosity,and brittle mineral content are the core indicators for the evaluation of shale oil enrichment layers.Class-I layers are defined as free hydrocarbon content equal or greater than 6.0 mg/g,effective porosity equal or greater than 3.5%,total porosity equal or greater than 8.0%,and brittle mineral content equal or greater than 50%.It is believed that the favourable oil layers are Q2-Q3 and Q8-Q9.Fourth,the horizontal wells in the core area of the light oil zone exhibit a high cumulative production in the first year,and present a hyperbolic production decline pattern,with the decline index of 0.85-0.95,the first-year decline rate of 14.5%-26.5%,and the single-well estimated ultimate recovery(EUR)greater than 2.0×10^(4)t.In practical exploration and production,more efforts will be devoted to the clarification of hydrocarbon generation and expulsion mechanisms,accurate testing of porosity and hydrocarbon content/phase of shale under formation conditions,precise delineation of the boundary of enrichment area,relationship between mechanical properties and stimulated reservoir volume,and enhanced oil recovery,in order to improve the EUR and achieve a large-scale,efficient development of shale oil.
文摘The current palm oil harvesting process removes the whole fruit bunch from the palm with most of the fruit unripe, and takes the whole fruit bunch from the plantation to a processing mill. There are two consequences. This robs the symbiotic palm/soil eco-system of important nutrients and steadily reduces soil fertility. Poor soil fertility is now the limit to palm oil production in peninsular Malaysia despite much use of expensive fertiliser, and weak palms in unhealthy soil are prone to the fungus Ganoderma. Secondly, it takes much energy to remove the fruit from the bunch and the quantity and quality of the oil is less than that of ripe fruit. All this is because ripe fruit—which naturally becomes loose—has been defined as “a problem” in harvesting. This paper proposes covering the fruit bunch in a mesh sack whilst ripening, which prevents ripe fruit naturally from becoming loose being a problem and transforms the whole harvesting process. This allows efficient fruit separation and fruit pressing to be done at the foot of the palm tree with only the oil being removed from the plantation, both simplifying and improving the harvesting process and maintaining the organic fertility cycle, adding value in every respect.
基金Supported by the National Natural Science Foundation of China(52174046)Innovation Foundation of China National Petroleum Corporation(2021DQ02-0202)Science Foundation of China University of Petroleum(Beijing)(2462020XKBH013).
文摘Lower-phase microemulsions with core-shell structure were prepared by microemulsion dilution method.The high temperature resistant systems were screened and the performance evaluation experiments were conducted to clarify the spontaneous imbibition mechanisms in ultra-low permeability and tight oil reservoirs,and to direct the field microfracture huff and puff test of oil well.The microemulsion system(O-ME)with cationic-nonionic surfactant as hydrophilic shell,No.3 white oil as oil phase core has the highest imbibition recovery;its spontaneous imbibition mechanisms include:the ultra-low interfacial tension and wettability reversal significantly reduce oil adhesion work to improve oil displacement efficiency,the nanoscale“core-shell structure”formed can easily enter micro-nano pores and throats to expand the swept volume,in addition,the remarkable effect of dispersing and solubilizing crude oil can improve the mobility of crude oil.Based on the experimental results,a microfracture huff and puff test of O-ME was carried out in Well YBD43-X506 of Shengli Oilfield.After being treated,the well had a significant increase of daily fluid production to 5 tons from 1.4 tons,and an increase of daily oil production to 2.7 tons from 1.0 ton before treatment.
基金Supported by the National Science and Technology Major Project of China (2016ZX05010).
文摘Based on the analysis of the production composition of reservoirs developed by the second&tertiary recovery combination(STRC),the relationship between the overall output of the STRC project and the production level during the blank water flooding stage is proposed.According to the basic principle of reservoir engineering that the“recovery factor is equal to sweeping coefficient multiplied by oil displacement efficiency”,the formula for calculating the ultimate oil recovery factor of chemical combination flooding reservoir was established.By dividing the reservoir into a series of grids according to differen-tial calculus thinking,the relationship between the ultimate recovery factor of a certain number of grids and the recovery de-gree of the reservoir was established,and then the variation law of oil production rate of the STRC reservoir was obtained.The concept of“oil rate enlargement factor of chemical combination flooding”was defined,and a production calculation method of reservoir developed by STRC was put forward based on practical oilfield development experience.The study shows that the oil production enhancing effect of STRC increases evenly with the in crease of the ratio of STRC displacement efficiency to water displacement efficiency,and increases rapidly with the increase of the ratio of recovery degree at flooding mode conversion to the water displacement efficiency.STRC is more effective in increasing oil production of reservoir with high recovery degree.Through practical tests of the alkali free binary flooding(polymer/surfactant)projects,the relative error of the oil production calculation method of STRC reservoir is about±10%,which meets the requirements of reservoir engineering.
文摘In today’s rapidly developing modern society,automobiles,as an important part of transportation and industrial fields,play a pivotal role.With the improvement of people’s living standards and the increase in traffic demand,the automobile manufacturing industry has been continuously developing and growing globally.However,to cope with increasingly fierce market competition and ever-changing consumer demands,the automobile manufacturing industry is also facing the challenges of improving production efficiency,reducing costs,and improving product quality.In this context,automation technology has gradually become a major trend in the automobile manufacturing industry.As an important support of modern industry,automation technology has shown great application potential in many fields.From industrial production to daily life,automation technology can be seen everywhere.In the field of manufacturing,especially in automobile manufacturing,the application of automation technology is getting more and more attention.Automated production lines,intelligent robots,and automated warehousing systems have all changed the face of automobile manufacturing to varying degrees,bringing companies higher efficiency,more stable quality,and greater competitive advantages.The application trend of this automation technology in various fields not only meets the needs of modern industry for efficient,precise,and sustainable development but also provides new ideas and paths for the future development of the automobile manufacturing industry.
文摘This study attempts to reconcile data envelopment analysis (DEA) with the production function approach in economics. We examine not only the inputs of capital and labor, but also the ranges of these inputs in production process steps, and endogenously derive a Leontief production function. The Leontief production functions shift northeasterly owing to mechanization, which is the replacement of labor inputs by capital inputs in some steps. Consequently, we describe the efficient frontier as the convex hull of the Leontief production functions. Furthermore, we consider the possibility of efficient production below the efficient frontier.
基金The Government of Malaysia through Universiti Malaysia Sabah and the Ministry of Higher Education of Malaysia,Grant/Award Numbers:GKP0019‐STWN‐2016,SDK0010‐2017。
文摘Background:Oil palm is a tropical crop with worldwide plantings approaching 20 million ha and large areas in Indonesia,Malaysia and Thailand.The plantations are readily managed as silvopastoral systems incorporating cattle grazing(Oil Palm Silvopastoral System for Cattle,OPSC)but there is a need for analytical tools and data to understand system herbage supply and feed conversion efficiency(FCE).Methods:Metabolic energy budgeting was used to estimate herbage harvested by cattle in three OPSC subsystems,9 and 12 years after oil palm establishment,and FCE of the subsystems was determined.Understorey herbage was also analysed for nutritive value,botanical composition and herbage accumulation within one grazing‐regrowth cycle.Results:The herbage‐harvested estimate was 2.0−2.4 t dry matter(DM)ha^(-1) year^(-1) for 9 year old subsystems and 1.4-1.7 tDMha^(-1) year^(-1) for a 12 year old subsystem.Herbage metabolisable energy(ME)was 8.3−8.5 MJ kg^(-1) DM and crude protein(CP)was 15%-16%DM.FCE values for subsystems ranged from 32 to 94 kg DM kg^(-1) liveweight‐gain.Conclusions:Herbage DM yield is declining,while herbage ME is marginal but CP is adequate.FCE is suboptimal but can be optimised by defining the trajectory of declining herbage production with canopy closure as plantations age and matching stocking rate to herbage supply using a comparativestocking‐rate‐type statistic.