The Mn-Ce-Fe mixed oxide(MCFe)was prepared by co-precipitation and the catalytic performance was tested by using 1,2-dichlorobenzene(1,2-DCB)and furan as model molecules of PCDD/F.The effect of O_(2)concentration,SO_(...The Mn-Ce-Fe mixed oxide(MCFe)was prepared by co-precipitation and the catalytic performance was tested by using 1,2-dichlorobenzene(1,2-DCB)and furan as model molecules of PCDD/F.The effect of O_(2)concentration,SO_(2) and NO on the catalytic activity was studied.At 270℃,the MCFe oxide catalyst presents significant simultaneous removal efficiency of 75.25%and 100%for 1,2-DCB and furan,respectively.Brunauer-Emmett-Teller(BET)method(BET),X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FTIR),H_2-temperature programmed reduction(H_(2)-TPR),NH_(3)-temperature programmed desorption(NH_3-TPD)and O_(2)-TPD were used to characterize the catalysts before and after the reaction.Competition tests suggest that the oxidation behavior of furan occurred prior to that of 1,2-DCB.According to the intermediate products detected by gas chromatography-mass spectrometry(GC-MS),the by-products include chlorinated hydrocarbons,long-chain hydrocarbons,ketone,etc.Possible catalytic oxidation reaction paths are proposed.展开更多
Horizontal wells in the anisotropic reservoirs can be stimulated by hydraulic fracturing in order to create multiple finite-conductivity vertical fractures. Several methods for evaluating the productivity of the horiz...Horizontal wells in the anisotropic reservoirs can be stimulated by hydraulic fracturing in order to create multiple finite-conductivity vertical fractures. Several methods for evaluating the productivity of the horizontal wells have been presented in the literature. With such methods, however, it is still difficult to obtain an accurate result. This paper firstly presents the dimensionless conductivity theory of vertical fractures. Then models for calculating the equivalent wellbore radius and the skin factor due to flow convergence to the well bore are proposed after analyzing the steady-state flow in porous reservoirs. By applying the superposition principle to the pressure drop, a new method for evaluating the productivity of horizontal wells intercepted by multiple finite-conductivity fractures is developed. The influence of fracture conductivity and fracture half length on the horizontal well productivity is quantitatively analyzed with a synthetic case. Optimum fracture number and fracture space are further discussed in this study. The results prove that the method outlined here should be useful to design optimum fracturing of horizontal wells.展开更多
This paper presents the development and application of a production data analysis software that can analyze and forecast the production performance and reservoir properties of shale gas wells.The theories used in the ...This paper presents the development and application of a production data analysis software that can analyze and forecast the production performance and reservoir properties of shale gas wells.The theories used in the study were based on the analytical and empirical approaches.Its reliability has been confirmed through comparisons with a commercial software.Using transient data relating to multi-stage hydraulic fractured horizontal wells,it was confirmed that the accuracy of the modified hyperbolic method showed an error of approximately 4%compared to the actual estimated ultimate recovery(EUR).On the basis of the developed model,reliable productivity forecasts have been obtained by analyzing field production data relating to wells in Canada.The EUR was computed as 9.6 Bcf using the modified hyperbolic method.Employing the Pow Law Exponential method,the EUR would be 9.4 Bcf.The models developed in this study will allow in the future integration of new analytical and empirical theories in a relatively readily than commercial models.展开更多
GB/T 13245-91 1 Theme and Scope This standard specifies the method abstract, reagents, apparatus, specimen, analyzing procedure, result calculation and permissible tolerance used for determination of the total carbon ...GB/T 13245-91 1 Theme and Scope This standard specifies the method abstract, reagents, apparatus, specimen, analyzing procedure, result calculation and permissible tolerance used for determination of the total carbon with combustion gravimetric method.展开更多
Cupressus gigantca is naturally distrib-uted in the lower-middle reaches of theYaluzangbu River.It’s maximum age canreach up to 1,000 years,diameter at breastheigh (DBH) 400cm and height 45m.The
Interpretative structural model(ISM) can transform a multivariate problem into several sub-variable problems to analyze a complex industrial structure in a more efficient way by building a multi-level hierarchical str...Interpretative structural model(ISM) can transform a multivariate problem into several sub-variable problems to analyze a complex industrial structure in a more efficient way by building a multi-level hierarchical structure model. To build an ISM of a production system, the partial correlation coefficient method is proposed to obtain the adjacency matrix, which can be transformed to ISM. According to estimation of correlation coefficient, the result can give actual variable correlations and eliminate effects of intermediate variables. Furthermore, this paper proposes an effective approach using ISM to analyze the main factors and basic mechanisms that affect the energy consumption in an ethylene production system. The case study shows that the proposed energy consumption analysis method is valid and efficient in improvement of energy efficiency in ethylene production.展开更多
An approach for the economic analysis of chemical product design is proposed. It takes into account of customers' preference on product quality and economic considerations such as pricing, profit, market share, ca...An approach for the economic analysis of chemical product design is proposed. It takes into account of customers' preference on product quality and economic considerations such as pricing, profit, market share, capital investment, and operating cost. The activities needed to support business decision making – identifying product quality, estimating product cost, calculating financial metrics, and performing make–buy analysis – are discussed.The design of a Ganoderma lucidum dietary supplement, a traditional Chinese medicinal(TCM) product, is used to illustrate all the activities in this approach.展开更多
This standard specifies the method summary, reagents, apparatus, sampling, procedure, test results calculation and permissible tolerance of the determination of magnesium oxide by CyDTA volumetric method.
SARP Workshop on risk analysis of agroecological zonation and optimization of crop rotation was held at CNRRI’s research center on 24—27 Oct, 1995. Experts from Philippines, India, China, and IRRI were present in th...SARP Workshop on risk analysis of agroecological zonation and optimization of crop rotation was held at CNRRI’s research center on 24—27 Oct, 1995. Experts from Philippines, India, China, and IRRI were present in the workshop. Participants exchanged the research results on the field of land use, soil erosion. optimization of rice—wheat, rice—peanut, rice—corn cropping system in the different environments, risk analysis of rice based cropping system, nitrogen balance in rice based cropping system with system approach, demonstrated models used in their studies, and discussed the ongoing cooperative research.展开更多
Deep coalbed methane(DCBM),an unconventional gas reservoir,has undergone significant advancements in recent years,sparking a growing interest in assessing pore pressure dynamics within these reservoirs.While some prod...Deep coalbed methane(DCBM),an unconventional gas reservoir,has undergone significant advancements in recent years,sparking a growing interest in assessing pore pressure dynamics within these reservoirs.While some production data analysis techniques have been adapted from conventional oil and gas wells,there remains a gap in the understanding of pore pressure generation and evolution,particularly in wells subjected to large-scale hydraulic fracturing.To address this gap,a novel technique called excess pore pressure analysis(EPPA)has been introduced to the coal seam gas industry for the first time to our knowledge,which employs dual-phase flow principles based on consolidation theory.This technique focuses on the generation and dissipation for excess pore-water pressure(EPWP)and excess pore-gas pressure(EPGP)in stimulated deep coal reservoirs.Equations have been developed respectively and numerical solutions have been provided using the finite element method(FEM).Application of this model to a representative field example reveals that excess pore pressure arises from rapid loading,with overburden weight transferred under undrained condition due to intense hydraulic fracturing,which significantly redistributes the weight-bearing role from the solid coal structure to the injected fluid and liberated gas within artificial pores over a brief timespan.Furthermore,field application indicates that the dissipation of EPWP and EPGP can be actually considered as the process of well production,where methane and water are extracted from deep coalbed methane wells,leading to consolidation for the artificial reservoirs.Moreover,history matching results demonstrate that the excess-pressure model established in this study provides a better explanation for the declining trends observed in both gas and water production curves,compared to conventional practices in coalbed methane reservoir engineering and petroleum engineering.This research not only enhances the understanding of DCBM reservoir behavior but also offers insights applicable to production analysis in other unconventional resources reliant on hydraulic fracturing.展开更多
Deep condensate gas reservoirs exhibit highly complex and variable phase behaviors,making it crucial to understand the relationship between fluid phase states and flow patterns.This study conducts a comprehensive anal...Deep condensate gas reservoirs exhibit highly complex and variable phase behaviors,making it crucial to understand the relationship between fluid phase states and flow patterns.This study conducts a comprehensive analysis of the actual production process of the deep condensate gas well A1 in a certain oilfield in China.Combining phase behavior analysis and CMG software simulations,the study systematically investigates phase transitions,viscosity,and density changes in the gas and liquid phases under different pressure conditions,with a reservoir temperature of 165°C.The research covers three crucial depletion stages of the reservoir:single-phase flow,two-phase transition,and two-phase flow.The findings indicate that retrograde condensation occurs when the pressure falls below the dew point pressure,reachingmaximum condensate liquid production at around 25MPa.As pressure decreases,gas phase density and viscosity gradually decrease,while liquid phase density and viscosity show an increasing trend.In the initial single-phase flow stage,maintaining a consistent gas-oil ratio is observed when both bottom-hole and reservoir pressures are higher than the dew point pressure.However,a sudden drop in bottom-hole pressure below the dew point triggers the production of condensate oil,significantly reducing subsequent gas and oil production.In the transitional two-phase flow stage,as the bottom-hole pressure further decreases,the reservoir exhibits a complex flow regime with coexisting areas of gas and liquid.In the subsequent two-phase flow stage,when both bottom-hole and reservoir pressures are below the dew point pressure,a significant increase in the gas-oil ratio is observed.The reservoir manifests a two-phase flow regime,devoid of single-phase gas flow areas.For lowpressure conditions in deep condensate gas reservoirs,considerations include gas injection,gas lift,and cyclic gas injection and production in surrounding wells.Additionally,techniques such as hot nitrogen or CO_(2) injection can be employed to mitigate retrograde condensation damage.The implications of this study are crucial for developing targeted development strategies and enhancing the overall development of deep condensate gas reservoirs.展开更多
[Objective] This study aimed to isolate an acidophilic fungus and analyze the acidophilic enzymes secreted by this fungus. [Method] A heterotrophic fungus was isolated from the leaching solution of a uranium ore in Ji...[Objective] This study aimed to isolate an acidophilic fungus and analyze the acidophilic enzymes secreted by this fungus. [Method] A heterotrophic fungus was isolated from the leaching solution of a uranium ore in Jiangxi Province using oligotrophic acid selective medium (pH 2.5), and was named RBS-6. This strain was then identified according to its colony morphology and molecular indicator rDNA-ITS. Finally, the glycoside hydrolases secreted by RBS-6 were analyzed. [Result] This fungus RBS-6 was acidophilic, and grew best at pH4.0. Its rDNA-ITS sequence shared the highest homology (98%) with that of Phialophora sp. CGMCC 3329 (GU 082377). So it was identified as a fungus of Phialophora sp., and was temporarily named as Phialophora sp. RBS-6. It can produce six glycoside hydrolases, in cluding α-galactosidase glucosidase, β-glucosidase, β-mannanase and β-glucanase. All the enzymes were acidophilic, for which the optimum reaction pH was 3.0-4.0. Among them, β-glucanase exhibited the highest activity at pH 3.5 and 50 ℃; in addition, it was heat-stable as 58% of the enzyme activity was remained after incubation at 50 ℃ for 60 min. [Conclusion] The isolated fungus which was identified as an acidophilic member of Phialophora sp., was a new strain producing acidophilic enzymes. This study supplied new data for the research on Phialophora fungi.展开更多
Carbonate reservoir patterns play an important role in the production performance of oil and gas wells,and it is usually classified through static data analysis which cannot reflect the actual well performance.This pa...Carbonate reservoir patterns play an important role in the production performance of oil and gas wells,and it is usually classified through static data analysis which cannot reflect the actual well performance.This paper takes the Tazhong No.1 gas field in the Tarim Basin,China as an example to investigate the classification of carbonate reservoirs.The classification method mainly combines well test analysis with production analysis—especially the Blasingame type curve method.Based on the characteristics of type curves for well test analysis and the Blasingame method,the relationship between the type curves and reservoir pattern was established.More than 20 wells were analyzed and the reservoirs were classified into 3 major patterns with 7 sub-classes.Furthermore,the classification results were validated by dynamic performance analysis of wells in the Tazhong No.1 gas field.On the basis of the classification results,well stimulation(i.e.water flooding in a single well) was carried out in three volatile-oil wells,and the oil recovery increased by up to 20%.展开更多
One of the important indicators of shale gas reservoir excavation is capacity evaluation,which directly affects whether large-scale shale gas reservoirs can be excavated.Capacity evaluation is the basis of system anal...One of the important indicators of shale gas reservoir excavation is capacity evaluation,which directly affects whether large-scale shale gas reservoirs can be excavated.Capacity evaluation is the basis of system analysis and dynamic prediction.Therefore,it is particularly important to conduct capacity evaluation studies on shale gas horizontal wells.In order to accurately evaluate the horizontal well productivity of shale gas staged fracturing,this paper uses a new method to evaluate the productivity of Fuling shale gas.The new method is aimed at the dynamic difference of horizontal wells and effectively analyzes the massive data,which are factors affecting the productivity of shale gas horizontal wells.According to the pressure system,production dynamic characteristics,well trajectory position,fracturing transformation mode and penetration depth,32 wells were divided into four types.Then,based on the classification,the principal component analysis methods can be used to evaluate the horizontal well productivity of shale gas.The new method of capacity evaluation has improved the accuracy by 10.25%compared with the traditional method,which provides a theoretical basis for guiding the efficient development of the horizontal wells of Fuling shale gas.展开更多
Although mining production depends on various equipments, significant amount of production loss can be attributed a specific equipment or fleet. Bottleneck is defined not only by production loss but also by our satisf...Although mining production depends on various equipments, significant amount of production loss can be attributed a specific equipment or fleet. Bottleneck is defined not only by production loss but also by our satisfaction from the equipment. The user satisfaction could be measured as machine effectiveness.Mining literatures on performance improvement and optimization of equipment operations assert importance of availability, utilization and production performance as key parameters. These three parameters are useful for evaluating effectiveness of equipment. Mine production index(MPI), which can represent the effect of these factors, has been applied for continuous operation in mining. MPI uses Fuzzy Delphi Analytical Hierarchy Process to determine importance of each three parameter for individual equipment. A case study in a Swedish open pit mine was done to evaluate the field application of MPI.The results reveal that crusher is the bottleneck equipment in studied mine. As a methodical approach,an algorithm which uses MPI and detects bottleneck in continuous mining operation has been proposed.展开更多
In order to overcome the defects that the analysis of multi-well typical curves of shale gas reservoirs is rarely applied to engineering,this study proposes a robust production data analysis method based on deconvolut...In order to overcome the defects that the analysis of multi-well typical curves of shale gas reservoirs is rarely applied to engineering,this study proposes a robust production data analysis method based on deconvolution,which is used for multi-well inter-well interference research.In this study,a multi-well conceptual trilinear seepage model for multi-stage fractured horizontal wells was established,and its Laplace solutions under two different outer boundary conditions were obtained.Then,an improved pressure deconvolution algorithm was used to normalize the scattered production data.Furthermore,the typical curve fitting was carried out using the production data and the seepage model solution.Finally,some reservoir parameters and fracturing parameters were interpreted,and the intensity of inter-well interference was compared.The effectiveness of the method was verified by analyzing the production dynamic data of six shale gas wells in Duvernay area.The results showed that the fitting effect of typical curves was greatly improved due to the mutual restriction between deconvolution calculation parameter debugging and seepage model parameter debugging.Besides,by using the morphological characteristics of the log-log typical curves and the time corresponding to the intersection point of the log-log typical curves of two models under different outer boundary conditions,the strength of the interference between wells on the same well platform was well judged.This work can provide a reference for the optimization of well spacing and hydraulic fracturing measures for shale gas wells.展开更多
From a time value of revenue point of view,it is preferred that the time between reservoir stimulation and oil production response is small.Heavy oil combustion processes have a lag time between air injection and liqu...From a time value of revenue point of view,it is preferred that the time between reservoir stimulation and oil production response is small.Heavy oil combustion processes have a lag time between air injection and liquid production,but the common practice in production data analysis uses simultaneous injection and production data when seeking a relationship between them.In this research,the time scales of production for the Kerrobert toe-to-heel air injection(THAI)heavy oil project in Saskatchewan,Canada,is analyzed by using cross correlation analysis,i.e.time delay analysis between air injection and oil production.The results reveal two time scales with respect to production response with two distinctive recovery mechanisms:(1)a short time scale response(nearly instantaneous)where oil production peaks right after air injection(directly after opening production well)reflecting cold heavy oil production mechanisms,and(2)a longer time scale(of order of 100-300 days)response where peak production occurs associated with the collective phenomena of air injection,heat generating reactions,heat transfer,and finally,heated mobilized heavy oil drainage to the production well.This understanding of the two time scales and associated production mechanisms provides a basis for improving the performance of THAI.展开更多
Generally the irreducible water saturation of low permeability gas reservoir is quite high which leads to the permeability stress sensibility and threshold pressure gradient. Under the assumption that permeability var...Generally the irreducible water saturation of low permeability gas reservoir is quite high which leads to the permeability stress sensibility and threshold pressure gradient. Under the assumption that permeability varies with experimental law of the pseudo pressure drop, according to concepts of perturbable ellipses and equivalent developing regulations, the calculation method of stable production of hydraulically fractured gas well in low permeability reservoirs is investigated with threshold pressure. And productivity curve is drawn and analyzed. The result shows that, permeability modulus and threshold pressure have effect on production of fractured gas well. The higher the permeability modulus and the threshold pressure, the lower the production is. Therefore, the impact of stress sensitive and threshold pressure must he considered when analyzing the productivity of vertical fracture well in low permeability gas reservoir.展开更多
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(LQ23E060002)the National Natural Science Foundation of China(51976192)。
文摘The Mn-Ce-Fe mixed oxide(MCFe)was prepared by co-precipitation and the catalytic performance was tested by using 1,2-dichlorobenzene(1,2-DCB)and furan as model molecules of PCDD/F.The effect of O_(2)concentration,SO_(2) and NO on the catalytic activity was studied.At 270℃,the MCFe oxide catalyst presents significant simultaneous removal efficiency of 75.25%and 100%for 1,2-DCB and furan,respectively.Brunauer-Emmett-Teller(BET)method(BET),X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FTIR),H_2-temperature programmed reduction(H_(2)-TPR),NH_(3)-temperature programmed desorption(NH_3-TPD)and O_(2)-TPD were used to characterize the catalysts before and after the reaction.Competition tests suggest that the oxidation behavior of furan occurred prior to that of 1,2-DCB.According to the intermediate products detected by gas chromatography-mass spectrometry(GC-MS),the by-products include chlorinated hydrocarbons,long-chain hydrocarbons,ketone,etc.Possible catalytic oxidation reaction paths are proposed.
文摘Horizontal wells in the anisotropic reservoirs can be stimulated by hydraulic fracturing in order to create multiple finite-conductivity vertical fractures. Several methods for evaluating the productivity of the horizontal wells have been presented in the literature. With such methods, however, it is still difficult to obtain an accurate result. This paper firstly presents the dimensionless conductivity theory of vertical fractures. Then models for calculating the equivalent wellbore radius and the skin factor due to flow convergence to the well bore are proposed after analyzing the steady-state flow in porous reservoirs. By applying the superposition principle to the pressure drop, a new method for evaluating the productivity of horizontal wells intercepted by multiple finite-conductivity fractures is developed. The influence of fracture conductivity and fracture half length on the horizontal well productivity is quantitatively analyzed with a synthetic case. Optimum fracture number and fracture space are further discussed in this study. The results prove that the method outlined here should be useful to design optimum fracturing of horizontal wells.
基金supported by the Energy Efficiency&Resources Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)granted financial resource from the Ministry of Trade,Industry&Energy,Republic of Korea(No.20172510102090).
文摘This paper presents the development and application of a production data analysis software that can analyze and forecast the production performance and reservoir properties of shale gas wells.The theories used in the study were based on the analytical and empirical approaches.Its reliability has been confirmed through comparisons with a commercial software.Using transient data relating to multi-stage hydraulic fractured horizontal wells,it was confirmed that the accuracy of the modified hyperbolic method showed an error of approximately 4%compared to the actual estimated ultimate recovery(EUR).On the basis of the developed model,reliable productivity forecasts have been obtained by analyzing field production data relating to wells in Canada.The EUR was computed as 9.6 Bcf using the modified hyperbolic method.Employing the Pow Law Exponential method,the EUR would be 9.4 Bcf.The models developed in this study will allow in the future integration of new analytical and empirical theories in a relatively readily than commercial models.
文摘GB/T 13245-91 1 Theme and Scope This standard specifies the method abstract, reagents, apparatus, specimen, analyzing procedure, result calculation and permissible tolerance used for determination of the total carbon with combustion gravimetric method.
文摘Cupressus gigantca is naturally distrib-uted in the lower-middle reaches of theYaluzangbu River.It’s maximum age canreach up to 1,000 years,diameter at breastheigh (DBH) 400cm and height 45m.The
基金Supported by the National Natural Science Foundation of China(61374166,6153303)the Doctoral Fund of Ministry of Education of China(20120010110010)the Fundamental Research Funds for the Central Universities(YS1404,JD1413,ZY1502)
文摘Interpretative structural model(ISM) can transform a multivariate problem into several sub-variable problems to analyze a complex industrial structure in a more efficient way by building a multi-level hierarchical structure model. To build an ISM of a production system, the partial correlation coefficient method is proposed to obtain the adjacency matrix, which can be transformed to ISM. According to estimation of correlation coefficient, the result can give actual variable correlations and eliminate effects of intermediate variables. Furthermore, this paper proposes an effective approach using ISM to analyze the main factors and basic mechanisms that affect the energy consumption in an ethylene production system. The case study shows that the proposed energy consumption analysis method is valid and efficient in improvement of energy efficiency in ethylene production.
文摘An approach for the economic analysis of chemical product design is proposed. It takes into account of customers' preference on product quality and economic considerations such as pricing, profit, market share, capital investment, and operating cost. The activities needed to support business decision making – identifying product quality, estimating product cost, calculating financial metrics, and performing make–buy analysis – are discussed.The design of a Ganoderma lucidum dietary supplement, a traditional Chinese medicinal(TCM) product, is used to illustrate all the activities in this approach.
文摘This standard specifies the method summary, reagents, apparatus, sampling, procedure, test results calculation and permissible tolerance of the determination of magnesium oxide by CyDTA volumetric method.
文摘SARP Workshop on risk analysis of agroecological zonation and optimization of crop rotation was held at CNRRI’s research center on 24—27 Oct, 1995. Experts from Philippines, India, China, and IRRI were present in the workshop. Participants exchanged the research results on the field of land use, soil erosion. optimization of rice—wheat, rice—peanut, rice—corn cropping system in the different environments, risk analysis of rice based cropping system, nitrogen balance in rice based cropping system with system approach, demonstrated models used in their studies, and discussed the ongoing cooperative research.
基金supported by the National Natural Science Foundation of China(Nos.42272195 and 42130802)supported by the Key Applied Science and Technology Project of PetroChina(No.2023ZZ18)the Major Science and Technology Project of Changqing Oilfield(No.2023DZZ01).
文摘Deep coalbed methane(DCBM),an unconventional gas reservoir,has undergone significant advancements in recent years,sparking a growing interest in assessing pore pressure dynamics within these reservoirs.While some production data analysis techniques have been adapted from conventional oil and gas wells,there remains a gap in the understanding of pore pressure generation and evolution,particularly in wells subjected to large-scale hydraulic fracturing.To address this gap,a novel technique called excess pore pressure analysis(EPPA)has been introduced to the coal seam gas industry for the first time to our knowledge,which employs dual-phase flow principles based on consolidation theory.This technique focuses on the generation and dissipation for excess pore-water pressure(EPWP)and excess pore-gas pressure(EPGP)in stimulated deep coal reservoirs.Equations have been developed respectively and numerical solutions have been provided using the finite element method(FEM).Application of this model to a representative field example reveals that excess pore pressure arises from rapid loading,with overburden weight transferred under undrained condition due to intense hydraulic fracturing,which significantly redistributes the weight-bearing role from the solid coal structure to the injected fluid and liberated gas within artificial pores over a brief timespan.Furthermore,field application indicates that the dissipation of EPWP and EPGP can be actually considered as the process of well production,where methane and water are extracted from deep coalbed methane wells,leading to consolidation for the artificial reservoirs.Moreover,history matching results demonstrate that the excess-pressure model established in this study provides a better explanation for the declining trends observed in both gas and water production curves,compared to conventional practices in coalbed methane reservoir engineering and petroleum engineering.This research not only enhances the understanding of DCBM reservoir behavior but also offers insights applicable to production analysis in other unconventional resources reliant on hydraulic fracturing.
基金funding from the Key Research Project of Tarim Oilfield Company of Petrochina(671023060003)for this study.
文摘Deep condensate gas reservoirs exhibit highly complex and variable phase behaviors,making it crucial to understand the relationship between fluid phase states and flow patterns.This study conducts a comprehensive analysis of the actual production process of the deep condensate gas well A1 in a certain oilfield in China.Combining phase behavior analysis and CMG software simulations,the study systematically investigates phase transitions,viscosity,and density changes in the gas and liquid phases under different pressure conditions,with a reservoir temperature of 165°C.The research covers three crucial depletion stages of the reservoir:single-phase flow,two-phase transition,and two-phase flow.The findings indicate that retrograde condensation occurs when the pressure falls below the dew point pressure,reachingmaximum condensate liquid production at around 25MPa.As pressure decreases,gas phase density and viscosity gradually decrease,while liquid phase density and viscosity show an increasing trend.In the initial single-phase flow stage,maintaining a consistent gas-oil ratio is observed when both bottom-hole and reservoir pressures are higher than the dew point pressure.However,a sudden drop in bottom-hole pressure below the dew point triggers the production of condensate oil,significantly reducing subsequent gas and oil production.In the transitional two-phase flow stage,as the bottom-hole pressure further decreases,the reservoir exhibits a complex flow regime with coexisting areas of gas and liquid.In the subsequent two-phase flow stage,when both bottom-hole and reservoir pressures are below the dew point pressure,a significant increase in the gas-oil ratio is observed.The reservoir manifests a two-phase flow regime,devoid of single-phase gas flow areas.For lowpressure conditions in deep condensate gas reservoirs,considerations include gas injection,gas lift,and cyclic gas injection and production in surrounding wells.Additionally,techniques such as hot nitrogen or CO_(2) injection can be employed to mitigate retrograde condensation damage.The implications of this study are crucial for developing targeted development strategies and enhancing the overall development of deep condensate gas reservoirs.
基金Supported by Manufacture - Learning - Research Cooperation Project of Education Department of Jiangxi Province(GJJ09008)Nuclear Power Development Projects [COSTIND, (2009)1230]~~
文摘[Objective] This study aimed to isolate an acidophilic fungus and analyze the acidophilic enzymes secreted by this fungus. [Method] A heterotrophic fungus was isolated from the leaching solution of a uranium ore in Jiangxi Province using oligotrophic acid selective medium (pH 2.5), and was named RBS-6. This strain was then identified according to its colony morphology and molecular indicator rDNA-ITS. Finally, the glycoside hydrolases secreted by RBS-6 were analyzed. [Result] This fungus RBS-6 was acidophilic, and grew best at pH4.0. Its rDNA-ITS sequence shared the highest homology (98%) with that of Phialophora sp. CGMCC 3329 (GU 082377). So it was identified as a fungus of Phialophora sp., and was temporarily named as Phialophora sp. RBS-6. It can produce six glycoside hydrolases, in cluding α-galactosidase glucosidase, β-glucosidase, β-mannanase and β-glucanase. All the enzymes were acidophilic, for which the optimum reaction pH was 3.0-4.0. Among them, β-glucanase exhibited the highest activity at pH 3.5 and 50 ℃; in addition, it was heat-stable as 58% of the enzyme activity was remained after incubation at 50 ℃ for 60 min. [Conclusion] The isolated fungus which was identified as an acidophilic member of Phialophora sp., was a new strain producing acidophilic enzymes. This study supplied new data for the research on Phialophora fungi.
基金financial support from"Major Projects about Carbonate Reservoirs of Petrochina (2008E-0610-08)""Young Innovation Fund Project of Research Institute of Petroleum Exploration and Development (2009-A-17-13)"
文摘Carbonate reservoir patterns play an important role in the production performance of oil and gas wells,and it is usually classified through static data analysis which cannot reflect the actual well performance.This paper takes the Tazhong No.1 gas field in the Tarim Basin,China as an example to investigate the classification of carbonate reservoirs.The classification method mainly combines well test analysis with production analysis—especially the Blasingame type curve method.Based on the characteristics of type curves for well test analysis and the Blasingame method,the relationship between the type curves and reservoir pattern was established.More than 20 wells were analyzed and the reservoirs were classified into 3 major patterns with 7 sub-classes.Furthermore,the classification results were validated by dynamic performance analysis of wells in the Tazhong No.1 gas field.On the basis of the classification results,well stimulation(i.e.water flooding in a single well) was carried out in three volatile-oil wells,and the oil recovery increased by up to 20%.
文摘One of the important indicators of shale gas reservoir excavation is capacity evaluation,which directly affects whether large-scale shale gas reservoirs can be excavated.Capacity evaluation is the basis of system analysis and dynamic prediction.Therefore,it is particularly important to conduct capacity evaluation studies on shale gas horizontal wells.In order to accurately evaluate the horizontal well productivity of shale gas staged fracturing,this paper uses a new method to evaluate the productivity of Fuling shale gas.The new method is aimed at the dynamic difference of horizontal wells and effectively analyzes the massive data,which are factors affecting the productivity of shale gas horizontal wells.According to the pressure system,production dynamic characteristics,well trajectory position,fracturing transformation mode and penetration depth,32 wells were divided into four types.Then,based on the classification,the principal component analysis methods can be used to evaluate the horizontal well productivity of shale gas.The new method of capacity evaluation has improved the accuracy by 10.25%compared with the traditional method,which provides a theoretical basis for guiding the efficient development of the horizontal wells of Fuling shale gas.
文摘Although mining production depends on various equipments, significant amount of production loss can be attributed a specific equipment or fleet. Bottleneck is defined not only by production loss but also by our satisfaction from the equipment. The user satisfaction could be measured as machine effectiveness.Mining literatures on performance improvement and optimization of equipment operations assert importance of availability, utilization and production performance as key parameters. These three parameters are useful for evaluating effectiveness of equipment. Mine production index(MPI), which can represent the effect of these factors, has been applied for continuous operation in mining. MPI uses Fuzzy Delphi Analytical Hierarchy Process to determine importance of each three parameter for individual equipment. A case study in a Swedish open pit mine was done to evaluate the field application of MPI.The results reveal that crusher is the bottleneck equipment in studied mine. As a methodical approach,an algorithm which uses MPI and detects bottleneck in continuous mining operation has been proposed.
基金financial support from PetroChina Innovation Foundation。
文摘In order to overcome the defects that the analysis of multi-well typical curves of shale gas reservoirs is rarely applied to engineering,this study proposes a robust production data analysis method based on deconvolution,which is used for multi-well inter-well interference research.In this study,a multi-well conceptual trilinear seepage model for multi-stage fractured horizontal wells was established,and its Laplace solutions under two different outer boundary conditions were obtained.Then,an improved pressure deconvolution algorithm was used to normalize the scattered production data.Furthermore,the typical curve fitting was carried out using the production data and the seepage model solution.Finally,some reservoir parameters and fracturing parameters were interpreted,and the intensity of inter-well interference was compared.The effectiveness of the method was verified by analyzing the production dynamic data of six shale gas wells in Duvernay area.The results showed that the fitting effect of typical curves was greatly improved due to the mutual restriction between deconvolution calculation parameter debugging and seepage model parameter debugging.Besides,by using the morphological characteristics of the log-log typical curves and the time corresponding to the intersection point of the log-log typical curves of two models under different outer boundary conditions,the strength of the interference between wells on the same well platform was well judged.This work can provide a reference for the optimization of well spacing and hydraulic fracturing measures for shale gas wells.
基金support from the Department of Chemical and Petroleum Engineering at the University of Calgary,the University of Calgary’s Canada First Research Excellence Fund program(the Global Research Initiative for Sustainable Low-Carbon Unconventional Resources)
文摘From a time value of revenue point of view,it is preferred that the time between reservoir stimulation and oil production response is small.Heavy oil combustion processes have a lag time between air injection and liquid production,but the common practice in production data analysis uses simultaneous injection and production data when seeking a relationship between them.In this research,the time scales of production for the Kerrobert toe-to-heel air injection(THAI)heavy oil project in Saskatchewan,Canada,is analyzed by using cross correlation analysis,i.e.time delay analysis between air injection and oil production.The results reveal two time scales with respect to production response with two distinctive recovery mechanisms:(1)a short time scale response(nearly instantaneous)where oil production peaks right after air injection(directly after opening production well)reflecting cold heavy oil production mechanisms,and(2)a longer time scale(of order of 100-300 days)response where peak production occurs associated with the collective phenomena of air injection,heat generating reactions,heat transfer,and finally,heated mobilized heavy oil drainage to the production well.This understanding of the two time scales and associated production mechanisms provides a basis for improving the performance of THAI.
文摘Generally the irreducible water saturation of low permeability gas reservoir is quite high which leads to the permeability stress sensibility and threshold pressure gradient. Under the assumption that permeability varies with experimental law of the pseudo pressure drop, according to concepts of perturbable ellipses and equivalent developing regulations, the calculation method of stable production of hydraulically fractured gas well in low permeability reservoirs is investigated with threshold pressure. And productivity curve is drawn and analyzed. The result shows that, permeability modulus and threshold pressure have effect on production of fractured gas well. The higher the permeability modulus and the threshold pressure, the lower the production is. Therefore, the impact of stress sensitive and threshold pressure must he considered when analyzing the productivity of vertical fracture well in low permeability gas reservoir.