As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crud...As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.展开更多
An interfacially active cobalt complex,cobalt dodecylbenzenesulfonate,was synthesized.Elemental analysis,atomic absorption spectroscopy,Fourier transform infrared spectroscopy（FT-IR）,thermogravimetric analysis,and s...An interfacially active cobalt complex,cobalt dodecylbenzenesulfonate,was synthesized.Elemental analysis,atomic absorption spectroscopy,Fourier transform infrared spectroscopy（FT-IR）,thermogravimetric analysis,and surface/interfacial tension determination were performed to investigate the properties of the catalyst.Results showed that the synthesized catalyst showed active interfacial behavior,decreasing the surface tension and interfacial tension between heavy oil and liquid phase to below 30 and 1.5 mN/m,respectively.The catalyst was not thermally degraded at a temperature of 400 ℃,indicating its high thermal stability.Catalytic performance of the catalyst was evaluated by carrying out aquathermolysis.The viscosity determination showed that the viscosity of the heavy oil decreased by 38%.The average molecular weight,group compositions,and average molecular structure of various samples were analyzed using elemental analysis,FT-IR,electrospray ionization Fourier transform ion cyclotron resonance（ESI FT-ICR MS）,and ～1H nuclear magnetic resonance.Results indicated that the catalyst could attack the sulfur- and O_2-type heteroatomic compounds in asphaltene and resin,especially the compounds with aromatic structure,leading to a decrease in the molecular weight and then the reduction in the viscosity of heavy oil.Therefore,the synthesized catalyst might find an application in catalytic aquathermolysis of heavy oil,especially for the high-aromaticity heavy oil with high oxygen content.展开更多
Microbial enhanced oil recovery (MEOR) is the research focus in the field of energy development as an environmentally friendly and low cost technology. MEOR can bes divided into indigenous microbial oil recovery and e...Microbial enhanced oil recovery (MEOR) is the research focus in the field of energy development as an environmentally friendly and low cost technology. MEOR can bes divided into indigenous microbial oil recovery and exogenous microbial oil recovery. The ultimate goal of indigenous microbial flooding is to enhance oil recovery via stimulation of specific indigenous microorganisms by injecting optimal nutrients. For studying the specific rule to activate the indigenous community during the long-term injection period, a series of indigenous displacement flooding experiments were carried out by using the long-core physical simulation test. The experimental results have shown that the movement of nutrients components (i.e., carbon/nitrogen/phosphorus) differed from the consumption of them. Moreover, there was a positive relationship between the nutrients concentration and bacteria concentration once observed in the produced fluid. And the trend of concentration of acetic acid was consistent with that of methanogens. When adding same activators, the impacts of selective activators to stimulate the indigenous microorganisms became worse along with the injection period, which led to less oil recovery efficiency.展开更多
An innovative perforation method of interlaced fixed perforation was put forward based on the analysis of the characteristics of fractures in various periods of perforation and conventional perforation modes.By conduc...An innovative perforation method of interlaced fixed perforation was put forward based on the analysis of the characteristics of fractures in various periods of perforation and conventional perforation modes.By conducting a large-scale perforation shooting experiments,we investigated the morphology,propagation mechanism and propagation law of the near-wellbore fractures generated during perforating processes under different fixed angle and interlaced angle combinations,and discussed the control method of near-wellbore fractures in different types of unconventional oil and gas reservoirs.The experimental results show that:(1)The interlaced fixed perforation strengthens the connectivity between the perforation tunnels not only in the same fixed plane but also in adjacent fixed planes,making it likely to form near-wellbore connected fractures which propagate in order.(2)Three kinds of micro-fractures will come up around the perforation tunnel during perforation,namely typeⅠradial micro-fracture,typeⅡoblique micro-fracture and typeⅢdivergent micro-fracture at the perforation tip,which are interconnected into complex near-wellbore fracture system.(3)Different types of perforation bullets under different combinations of fixed angles and interlaced angles result in different shapes of near-wellbore fractures propagating in different patterns.(4)By using the interlaced perforation on fixed planes,arranging fixed planes according to the spiral mode or the continuous"zigzag"shape,the desired near-wellbore fractures can be obtained,which is conducive to the manual control of main fractures in the fracturing of unconventional or complex conventional reservoirs.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(52074089 and 52104064)Natural Science Foundation of Heilongjiang Province of China(LH2019E019).
文摘As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.
基金the financial support from the Key Programs of Science and Technology of SINPOEC (Grant No. P11093)
文摘An interfacially active cobalt complex,cobalt dodecylbenzenesulfonate,was synthesized.Elemental analysis,atomic absorption spectroscopy,Fourier transform infrared spectroscopy（FT-IR）,thermogravimetric analysis,and surface/interfacial tension determination were performed to investigate the properties of the catalyst.Results showed that the synthesized catalyst showed active interfacial behavior,decreasing the surface tension and interfacial tension between heavy oil and liquid phase to below 30 and 1.5 mN/m,respectively.The catalyst was not thermally degraded at a temperature of 400 ℃,indicating its high thermal stability.Catalytic performance of the catalyst was evaluated by carrying out aquathermolysis.The viscosity determination showed that the viscosity of the heavy oil decreased by 38%.The average molecular weight,group compositions,and average molecular structure of various samples were analyzed using elemental analysis,FT-IR,electrospray ionization Fourier transform ion cyclotron resonance（ESI FT-ICR MS）,and ～1H nuclear magnetic resonance.Results indicated that the catalyst could attack the sulfur- and O_2-type heteroatomic compounds in asphaltene and resin,especially the compounds with aromatic structure,leading to a decrease in the molecular weight and then the reduction in the viscosity of heavy oil.Therefore,the synthesized catalyst might find an application in catalytic aquathermolysis of heavy oil,especially for the high-aromaticity heavy oil with high oxygen content.
文摘Microbial enhanced oil recovery (MEOR) is the research focus in the field of energy development as an environmentally friendly and low cost technology. MEOR can bes divided into indigenous microbial oil recovery and exogenous microbial oil recovery. The ultimate goal of indigenous microbial flooding is to enhance oil recovery via stimulation of specific indigenous microorganisms by injecting optimal nutrients. For studying the specific rule to activate the indigenous community during the long-term injection period, a series of indigenous displacement flooding experiments were carried out by using the long-core physical simulation test. The experimental results have shown that the movement of nutrients components (i.e., carbon/nitrogen/phosphorus) differed from the consumption of them. Moreover, there was a positive relationship between the nutrients concentration and bacteria concentration once observed in the produced fluid. And the trend of concentration of acetic acid was consistent with that of methanogens. When adding same activators, the impacts of selective activators to stimulate the indigenous microorganisms became worse along with the injection period, which led to less oil recovery efficiency.
基金Supported by the China National Science and Technology Major Project(2017ZX05009-003).
文摘An innovative perforation method of interlaced fixed perforation was put forward based on the analysis of the characteristics of fractures in various periods of perforation and conventional perforation modes.By conducting a large-scale perforation shooting experiments,we investigated the morphology,propagation mechanism and propagation law of the near-wellbore fractures generated during perforating processes under different fixed angle and interlaced angle combinations,and discussed the control method of near-wellbore fractures in different types of unconventional oil and gas reservoirs.The experimental results show that:(1)The interlaced fixed perforation strengthens the connectivity between the perforation tunnels not only in the same fixed plane but also in adjacent fixed planes,making it likely to form near-wellbore connected fractures which propagate in order.(2)Three kinds of micro-fractures will come up around the perforation tunnel during perforation,namely typeⅠradial micro-fracture,typeⅡoblique micro-fracture and typeⅢdivergent micro-fracture at the perforation tip,which are interconnected into complex near-wellbore fracture system.(3)Different types of perforation bullets under different combinations of fixed angles and interlaced angles result in different shapes of near-wellbore fractures propagating in different patterns.(4)By using the interlaced perforation on fixed planes,arranging fixed planes according to the spiral mode or the continuous"zigzag"shape,the desired near-wellbore fractures can be obtained,which is conducive to the manual control of main fractures in the fracturing of unconventional or complex conventional reservoirs.
