In order to accurately evaluate the fracturing stimulation effect of horizontal wells in shale gas reservoirs,it is suggested to establish a model to predict the temperature distribution in the wellbore of horizontal ...In order to accurately evaluate the fracturing stimulation effect of horizontal wells in shale gas reservoirs,it is suggested to establish a model to predict the temperature distribution in the wellbore of horizontal well and an inversion model of DTS data by using MCMC algorithm,and optimize the production profile interpretation process.In this paper,the characteristics of temperature profile of fractured horizontal wells in shale gas reservoirs were analyzed and the main factors affecting the temperature profile were figured out.Finally,the newly established inversion model was applied to the production profile interpretation of one case well in a certain shale gas reservoir.And the following research results were obtained.First,the temperature profile of fractured horizontal wells is in the shape of irregular“saw tooth”,and each“saw tooth”corresponds to an effective hydraulic fracture with fluid inflow.Second,the longer the fracture is,the greater the wellbore temperature drop at the corresponding fracture location is,and the gas flow rate in the fracture is positively correlated with the temperature drop.Third,from the perspective of influence degree,the factors influencing the temperature profile of fractured horizontal wells in shale gas reservoirs are ranked from the strong to the weak as follows:fracture half-length,gas flow rate,permeability of stimulated area,wellbore diameter,fracture conductivity,horizontal inclination angle,and comprehensive thermal conductivity,among which,the first three are main controlling factors.Fourth,the MCMC inversion method is applied to invert the DST temperature data of the case well.The temperature profile predicted in the model is better accordant with the measured DTS profile,and the absolute error of the predicted temperature at different levels of effective hydraulic fractures is less than 0.02°C.The interpreted gas flow rate of each fracturing stage is closer to the field measurement,and the deviation of the maximum gas flow rate of a single fracturing stage is only 180.35 m^(3)/d.The absolute error between single-well gas production rate and gas production rate measured at the wellhead is less than 3 m^(3)/d,which proves the reliability of this newly developed inversion model.展开更多
With the continuous development of China's social economy, the demand for natural resources is also increasing day by day. As an important guarantee energy for China’s economic development, China’s petrochemical...With the continuous development of China's social economy, the demand for natural resources is also increasing day by day. As an important guarantee energy for China’s economic development, China’s petrochemical industry is also developing with the progress of society. Today, China’s petrochemical industry has gradually stepped into the forefront of the world. As a non renewable resource, oil is an important resource formed by the geological process of the earth for thousands of years. Nowadays, the increasing demand for oil resources in the international community has led to the depletion of oil resources, and the oil exploitation project has gradually become difficult and complex. Therefore, under the social environment of shortage of oil resources, effective measures must be taken to comprehensively improve the oilfield production through the annulus liquid production profile logging technology, so as to ensure the oilfield production efficiency. This paper will comb and analyze the application of annulus liquid production profile logging in the oilfield.展开更多
Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the ti...Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the tight matrix,complex fracture system,low production level of producers,and low recovery factor ofMblock in Xinjiang oilfield,it is selected for on-site pilot test of nitrogen foam flooding.Detailed flooding scheme is made and the test results are evaluated respectively both for producers and injectors.The pressure index,filling degree,and fluid injection profile are found to be all improved in injectors after injection of nitrogen foam.The oil production,water cut and liquid production file are also improved in most of the producers,with the natural decline rate in the test area become slow.Results show that nitrogen foam flooding technology can be good technical storage for enhanced oil recovery in low permeability reservoir.展开更多
There is lack of performance monitoring technologies and related standards and specifications in the Puguang gas field,which is ultra-deep with high sulfur content.In this paper,five key technologies of dynamic monito...There is lack of performance monitoring technologies and related standards and specifications in the Puguang gas field,which is ultra-deep with high sulfur content.In this paper,five key technologies of dynamic monitoring were developed and the related standards and specifications were formulated by investigating high-sulfur gas fields at home and abroad,combined with equipment development,laboratory experiments,theoretical research and field tests.The five key technologies include gas production profile logging,downhole sampling and fluid phase analysis,dynamic water invasion prediction and water producing horizon identification,gas well productivity testing and evaluation,and development monitoring and safety control of high-sulfur ultra-deep wells.Then,these key technologies were applied for verification in the Puguang gas field.And the following research results were obtained.First,the sulfur-resistant gas production profile logging tool has a tem-perature resistance of 175℃and pressure resistance of 105 MPa.Forty-three well times gas production profile logging is carried out with a success ratio of 100%.Second,the high-sulfur downhole pressure sampler has a temperature resistance of 150℃and pressure resistance of 70 MPa.Seven well times downhole pressure sampling is carried out with a success ratio of 100%.Third,elemental sulfur is precipitated in the formation when the formation pressure drops to 29.5 MPa.And no sulfur is deposited in the wellbore when the production rate of gas well is higher than 20×10^(4)m^(3)/d.Fourth,water producing horizons can be identified accurately and water breakthrough time of gas wells can be predicted by using water producing horizon identification technology and dynamic water invasion prediction model.Water influx rates can be controlled and water-free gas production period of gas wells can be extended by optimizing and adjusting the working systems of gas wells.And fifth,full coverage of gas well productivity testing is realized by using the testing technology of"downhole implanted gauge&cable delivery&wellhead flow-variable rate",pressure calculation model and well testing interpretation model,and the productivity evaluation results of gas wells are accurate.Sixth,the dynamic gas tight pressure of the cable multi-stage leakage control system of super-high pressure and gas tightness is 50 MPa,and the processing technology for waste gas of blowout hookup is applied to 143 well times testing operation with zero leakage and zero pollution.In conclusion,these performance monitoring technologies have been playing an important role in scientifically formulating the production and reserves increase measures and ensuring long-term stable production of the Puguang gas field.展开更多
Despite increased international efforts to control schistosomiasis using preventive chemotherapy,several challenges still exist in reaching the target populations.Until recently,preschool-aged children had been exclud...Despite increased international efforts to control schistosomiasis using preventive chemotherapy,several challenges still exist in reaching the target populations.Until recently,preschool-aged children had been excluded from the recommended target population for mass drug administration,i.e.primary school children aged 6-15 years.Our studies and those of others provided the evidence base for the need to treat preschool-aged children that led to recommendations by the World Health Organization to include preschool-aged children in treatment programmes in 2010.The major challenge now lies in the unavailability of a child-size formulation of the appropriate anthelmintic drug,praziquantel.The currently available formulation of praziquantel presents several problems.First,it is a large tablet,making it difficult for young children and infants to swallow it and thus requires its breaking/crushing to allow for safe uptake.Second,it is bitter so it is often mixed with a sweetener to make it palatable for young children.Third,the current formulation of 600 mg does not allow for flexible dose adjustments for this age group.Thus,there is a need to formulate a child-appropriate praziquantel tablet.This paper discusses the target product profile for paediatric praziquantel,as well as knowledge gaps pertinent to the successful control of schistosome infection and disease in preschool-aged children.展开更多
Background Detection of infection with Mycobacterium leprae allows timely prophylactic treatment,thereby reducing transmission as well as the risk of permanent,leprosy-associated nerve damage.However,since there is no...Background Detection of infection with Mycobacterium leprae allows timely prophylactic treatment,thereby reducing transmission as well as the risk of permanent,leprosy-associated nerve damage.However,since there is no worldwide-implemented standard test for M.leprae infection,detection of infection in asymptomatic individuals remains a major challenge for control programs in endemic areas.In previous studies,we developed and fiield-tested a lateral flow assay(LFA)quantitatively detecting human IgM against M./eprae-specific phenolic glycolipid I(anti-PGL-I),a marker for both active and past infection.This rapid test utilizes luminescent,background-free,up-converting reporter particles(UCP)and immunochromatography(i.e.the UCP-LF test platform)for accurate quantitation of anti-PGL-I IgM without operator bias.The aim of this study was to evaluate the final version of this quantitative UCP-based rapid test(i.e.PGL-I QURapid),using serum and fingerstick blood(FSB).Methods The test comprises a lateral flow strip,in a standard plastic or biodegradable cassette.It can be provided with a humanized,recombinant control to monitor test performance and calculate accurate anti-PGL-I IgM levels.The performance of this QUR-test was assessed using serum and FSB from patients with leprosy(n=214),tubercu-losis(n=20),buruli ulcer(n=19),leishmaniasis(n=14),non-tuberculous mycobacterial(n=35)infections,as well as healthy Dutch individuals(n=710)and humanized,recombinant anti-PGL-I IgM antibodies.Plot receiver operating characteristic curves were created and sensitivity(Sn),specificity(Sp)and the area under the curve were calculated to evaluate test performance.Results Test results classified multibacillary leprosy patients with 95.0%Sn and 100%Sp using serum and 91.5%Sn and 99.8%Sp using FSB.Qualitative test results could be read after 2 min flow time,with accurate quantitation from 10 min onwards.The new anti-PGL-I IgM control supports production of batches with predetermined seroposi-tivity thresholds and monitoring of the PGL-I QUR-test in various settings.Conclusion The operational version of the PGL-I QURapid with point-of-care applicability,meets the WHO target product profile criteria.Thus,this QUR-test is ready for public health implementations.展开更多
基金supported by the National Major Science and Technology Project“Comprehensive evaluation of horizontal well completion and key technique with high-temperature-resistant and anti-migration slurry”(No.:2016ZX 05021-005-009HZ).
文摘In order to accurately evaluate the fracturing stimulation effect of horizontal wells in shale gas reservoirs,it is suggested to establish a model to predict the temperature distribution in the wellbore of horizontal well and an inversion model of DTS data by using MCMC algorithm,and optimize the production profile interpretation process.In this paper,the characteristics of temperature profile of fractured horizontal wells in shale gas reservoirs were analyzed and the main factors affecting the temperature profile were figured out.Finally,the newly established inversion model was applied to the production profile interpretation of one case well in a certain shale gas reservoir.And the following research results were obtained.First,the temperature profile of fractured horizontal wells is in the shape of irregular“saw tooth”,and each“saw tooth”corresponds to an effective hydraulic fracture with fluid inflow.Second,the longer the fracture is,the greater the wellbore temperature drop at the corresponding fracture location is,and the gas flow rate in the fracture is positively correlated with the temperature drop.Third,from the perspective of influence degree,the factors influencing the temperature profile of fractured horizontal wells in shale gas reservoirs are ranked from the strong to the weak as follows:fracture half-length,gas flow rate,permeability of stimulated area,wellbore diameter,fracture conductivity,horizontal inclination angle,and comprehensive thermal conductivity,among which,the first three are main controlling factors.Fourth,the MCMC inversion method is applied to invert the DST temperature data of the case well.The temperature profile predicted in the model is better accordant with the measured DTS profile,and the absolute error of the predicted temperature at different levels of effective hydraulic fractures is less than 0.02°C.The interpreted gas flow rate of each fracturing stage is closer to the field measurement,and the deviation of the maximum gas flow rate of a single fracturing stage is only 180.35 m^(3)/d.The absolute error between single-well gas production rate and gas production rate measured at the wellhead is less than 3 m^(3)/d,which proves the reliability of this newly developed inversion model.
文摘With the continuous development of China's social economy, the demand for natural resources is also increasing day by day. As an important guarantee energy for China’s economic development, China’s petrochemical industry is also developing with the progress of society. Today, China’s petrochemical industry has gradually stepped into the forefront of the world. As a non renewable resource, oil is an important resource formed by the geological process of the earth for thousands of years. Nowadays, the increasing demand for oil resources in the international community has led to the depletion of oil resources, and the oil exploitation project has gradually become difficult and complex. Therefore, under the social environment of shortage of oil resources, effective measures must be taken to comprehensively improve the oilfield production through the annulus liquid production profile logging technology, so as to ensure the oilfield production efficiency. This paper will comb and analyze the application of annulus liquid production profile logging in the oilfield.
基金supported by the Prospective and Fundamental Project of CNPC“Study on the EOR Technology by Foam Flooding(2021DJ1603)”by Open Fund of State Key Laboratory of Enhanced Oil Recovery,CNPC(2022-KFKT-29).
文摘Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the tight matrix,complex fracture system,low production level of producers,and low recovery factor ofMblock in Xinjiang oilfield,it is selected for on-site pilot test of nitrogen foam flooding.Detailed flooding scheme is made and the test results are evaluated respectively both for producers and injectors.The pressure index,filling degree,and fluid injection profile are found to be all improved in injectors after injection of nitrogen foam.The oil production,water cut and liquid production file are also improved in most of the producers,with the natural decline rate in the test area become slow.Results show that nitrogen foam flooding technology can be good technical storage for enhanced oil recovery in low permeability reservoir.
基金Project supported by the National Major Science and Technology Project“Safe&Effective Development of High-Sulfur Gas Reservoir(PhaseⅢ)”(No.:2016ZX05017)the Sinopec’s“Ten-Project”Scientific Research Project“Enhanced Gas Recovery Technology for Ultra-Deep&High-Sulfur Gas Field”(No.:P18062).
文摘There is lack of performance monitoring technologies and related standards and specifications in the Puguang gas field,which is ultra-deep with high sulfur content.In this paper,five key technologies of dynamic monitoring were developed and the related standards and specifications were formulated by investigating high-sulfur gas fields at home and abroad,combined with equipment development,laboratory experiments,theoretical research and field tests.The five key technologies include gas production profile logging,downhole sampling and fluid phase analysis,dynamic water invasion prediction and water producing horizon identification,gas well productivity testing and evaluation,and development monitoring and safety control of high-sulfur ultra-deep wells.Then,these key technologies were applied for verification in the Puguang gas field.And the following research results were obtained.First,the sulfur-resistant gas production profile logging tool has a tem-perature resistance of 175℃and pressure resistance of 105 MPa.Forty-three well times gas production profile logging is carried out with a success ratio of 100%.Second,the high-sulfur downhole pressure sampler has a temperature resistance of 150℃and pressure resistance of 70 MPa.Seven well times downhole pressure sampling is carried out with a success ratio of 100%.Third,elemental sulfur is precipitated in the formation when the formation pressure drops to 29.5 MPa.And no sulfur is deposited in the wellbore when the production rate of gas well is higher than 20×10^(4)m^(3)/d.Fourth,water producing horizons can be identified accurately and water breakthrough time of gas wells can be predicted by using water producing horizon identification technology and dynamic water invasion prediction model.Water influx rates can be controlled and water-free gas production period of gas wells can be extended by optimizing and adjusting the working systems of gas wells.And fifth,full coverage of gas well productivity testing is realized by using the testing technology of"downhole implanted gauge&cable delivery&wellhead flow-variable rate",pressure calculation model and well testing interpretation model,and the productivity evaluation results of gas wells are accurate.Sixth,the dynamic gas tight pressure of the cable multi-stage leakage control system of super-high pressure and gas tightness is 50 MPa,and the processing technology for waste gas of blowout hookup is applied to 143 well times testing operation with zero leakage and zero pollution.In conclusion,these performance monitoring technologies have been playing an important role in scientifically formulating the production and reserves increase measures and ensuring long-term stable production of the Puguang gas field.
基金The discussion presented in this paper is based on current and previous collaborative work funded by the Thrasher Research Fund,the WHO and the Wellcome Trust。
文摘Despite increased international efforts to control schistosomiasis using preventive chemotherapy,several challenges still exist in reaching the target populations.Until recently,preschool-aged children had been excluded from the recommended target population for mass drug administration,i.e.primary school children aged 6-15 years.Our studies and those of others provided the evidence base for the need to treat preschool-aged children that led to recommendations by the World Health Organization to include preschool-aged children in treatment programmes in 2010.The major challenge now lies in the unavailability of a child-size formulation of the appropriate anthelmintic drug,praziquantel.The currently available formulation of praziquantel presents several problems.First,it is a large tablet,making it difficult for young children and infants to swallow it and thus requires its breaking/crushing to allow for safe uptake.Second,it is bitter so it is often mixed with a sweetener to make it palatable for young children.Third,the current formulation of 600 mg does not allow for flexible dose adjustments for this age group.Thus,there is a need to formulate a child-appropriate praziquantel tablet.This paper discusses the target product profile for paediatric praziquantel,as well as knowledge gaps pertinent to the successful control of schistosome infection and disease in preschool-aged children.
基金This study was made possible thanks to a grant from the Q.M.Gastmann-Wichers foundation(AG).
文摘Background Detection of infection with Mycobacterium leprae allows timely prophylactic treatment,thereby reducing transmission as well as the risk of permanent,leprosy-associated nerve damage.However,since there is no worldwide-implemented standard test for M.leprae infection,detection of infection in asymptomatic individuals remains a major challenge for control programs in endemic areas.In previous studies,we developed and fiield-tested a lateral flow assay(LFA)quantitatively detecting human IgM against M./eprae-specific phenolic glycolipid I(anti-PGL-I),a marker for both active and past infection.This rapid test utilizes luminescent,background-free,up-converting reporter particles(UCP)and immunochromatography(i.e.the UCP-LF test platform)for accurate quantitation of anti-PGL-I IgM without operator bias.The aim of this study was to evaluate the final version of this quantitative UCP-based rapid test(i.e.PGL-I QURapid),using serum and fingerstick blood(FSB).Methods The test comprises a lateral flow strip,in a standard plastic or biodegradable cassette.It can be provided with a humanized,recombinant control to monitor test performance and calculate accurate anti-PGL-I IgM levels.The performance of this QUR-test was assessed using serum and FSB from patients with leprosy(n=214),tubercu-losis(n=20),buruli ulcer(n=19),leishmaniasis(n=14),non-tuberculous mycobacterial(n=35)infections,as well as healthy Dutch individuals(n=710)and humanized,recombinant anti-PGL-I IgM antibodies.Plot receiver operating characteristic curves were created and sensitivity(Sn),specificity(Sp)and the area under the curve were calculated to evaluate test performance.Results Test results classified multibacillary leprosy patients with 95.0%Sn and 100%Sp using serum and 91.5%Sn and 99.8%Sp using FSB.Qualitative test results could be read after 2 min flow time,with accurate quantitation from 10 min onwards.The new anti-PGL-I IgM control supports production of batches with predetermined seroposi-tivity thresholds and monitoring of the PGL-I QUR-test in various settings.Conclusion The operational version of the PGL-I QURapid with point-of-care applicability,meets the WHO target product profile criteria.Thus,this QUR-test is ready for public health implementations.
