This study focused on the quantitative analysis of the petrophysical parameters in characterizing the reservoir properties of the Srikail gas field using multi-scale wireline logs.Petrophysical parameters(shale volume...This study focused on the quantitative analysis of the petrophysical parameters in characterizing the reservoir properties of the Srikail gas field using multi-scale wireline logs.Petrophysical parameters(shale volume,porosity,water saturation and hydrocarbon saturation)were estimated from the combination of gamma ray log,resistivity log,density log and neutron log for three hydrocarbon(gas)-bearing zones at well#3.At the first time,log records at 0.1 m and 0.2 m intervals were read for this study.Result showed the average shale volume is 21.07%,53.67%and 51.71%for zone-1,zone-2 and zone-3,respectively.For these zones,the estimated average porosity was 35.89%,29.83%and 28.76%,respectively.The average water saturation of 31.54%,16.83%and 23.39%and average hydrocarbon saturation of 68.46%,83.17%and 76.61%were calculated for zone-1,zone-2 and zone-3,respectively.Thus zone-2 is regarded the most productive zone of well#3.It was found that the values of some parameters(porosity,hydrocarbon saturation and permeability)are higher than the existing results.Therefore,this study confirmed that the log reading at minute/close interval provides better quantitive values of the reservoir’s petrophysical properties.It is expected that this result will contribute to the national gas field development program in future.展开更多
Threshold pressure gradient has great importance in efficient tight gas field development as well as for research and laboratory experiments.This experimental study is carried out to investigate the threshold pressure...Threshold pressure gradient has great importance in efficient tight gas field development as well as for research and laboratory experiments.This experimental study is carried out to investigate the threshold pressure gradient in detail.Experiments are carried out with and without back pressure so that the effect of pore pressure on threshold pressure gradient may be observed.The trend of increasing or decreasing the threshold pressure gradient is totally opposite in the cases of considering and not considering the pore pressure.The results demonstrate that the pore pressure of tight gas reservoirs has great influence on threshold pressure gradient.The effects of other parameters like permeability and water saturation,in the presence of pore pressure,on threshold pressure gradient are also examined which show that the threshold pressure gradient increases with either a decrease in permeability or an increase in water saturation.Two new correlations of threshold pressure gradient on the basis of pore pressure and permeability,and pore pressure and water saturation,are also introduced.Based on these equations,new models for tight gas production are proposed.The gas slip correction factor is also considered during derivation of this proposed tight gas production models.Inflow performance relationship curves based on these proposed models show that production rates and absolute open flow potential are always be overestimated while ignoring the threshold pressure gradients.展开更多
Offshore oil and gas production has become an important growth pole to ensure national energy security.However,China's offshore oil and gas production is lack of key core technologies and weak in tool and equipmen...Offshore oil and gas production has become an important growth pole to ensure national energy security.However,China's offshore oil and gas production is lack of key core technologies and weak in tool and equipment foundation and can hardly support the optimized fast development of important fields.To solve these technological difficulties,China National Offshore Oil Corporation(CNOOC)insisted on independent technological innovation and overcame a series of key core technologies through theoretical research and key technology research and test during the 13th Five-Year Plan.And the following research results are obtained.First,several key technologies are broken through,including efficient drilling and completion in the middle and deep layers of the Bohai Sea,offshore large-scale heavy oil thermal recovery,deep-water oil and gas field development,and high temperature and high pressure well drilling and completion in the South China Sea,unconventional oil and gas stimulation,and offshore emergency rescue.Domestic first independently operated ultra deep water giant gas field,namely“Deepsea 1”is successfully put into production,so that the leap from 300 m to 1500 m of water depth and from exploration to development is realized.Second,key tools and equipment are developed,such as logging while drilling and rotary steering drilling system,deep-water drilling surface conductor,underwater emergency killing device,and underwater wellhead Christmas tree,which promote the high-quality development of China's offshore oil industry.Finally,some suggestions are proposed as follows.In the future,CNOOC shall strengthen independent technological innovation,quicken the pace to deepsea oil and gas,and continue to research key core technologies for oil and gas reserves and production increase(e.g.continuous localization of drilling and completion technologies,equipment and materials in complex fields),commingled gas production and test and green energy transformation(e.g.geothermal energy),so as to make greater contributions to ensure national energy security and build a maritime power.展开更多
基金the K.C. Wong Education Foundation (GJTD-2019-04)the Chinese Academy of Sciences as President ’s International Fellowship Initiative (PIFI) for a Postdoctoral fellow to M. Moklesur Rahman (2019PE0025).
文摘This study focused on the quantitative analysis of the petrophysical parameters in characterizing the reservoir properties of the Srikail gas field using multi-scale wireline logs.Petrophysical parameters(shale volume,porosity,water saturation and hydrocarbon saturation)were estimated from the combination of gamma ray log,resistivity log,density log and neutron log for three hydrocarbon(gas)-bearing zones at well#3.At the first time,log records at 0.1 m and 0.2 m intervals were read for this study.Result showed the average shale volume is 21.07%,53.67%and 51.71%for zone-1,zone-2 and zone-3,respectively.For these zones,the estimated average porosity was 35.89%,29.83%and 28.76%,respectively.The average water saturation of 31.54%,16.83%and 23.39%and average hydrocarbon saturation of 68.46%,83.17%and 76.61%were calculated for zone-1,zone-2 and zone-3,respectively.Thus zone-2 is regarded the most productive zone of well#3.It was found that the values of some parameters(porosity,hydrocarbon saturation and permeability)are higher than the existing results.Therefore,this study confirmed that the log reading at minute/close interval provides better quantitive values of the reservoir’s petrophysical properties.It is expected that this result will contribute to the national gas field development program in future.
基金supported by the National Science Foundation(51674279,51804328)Major National Science and Technology Project(2017ZX05009-001,2017ZX05069,2017ZX05072)+4 种基金Shandong Province Key Research and Development Program(2018GSF116004)Shandong Province Natural Science Foundation(ZR2018BEE008,ZR2018BEE018)Fundamental Research Funds for the Central Universities(18CX02168A)China Postdoctoral Science Foundation(2018M630813)Postdoctoral Applied Research Project Foundation of Qingdao city(BY201802003)。
文摘Threshold pressure gradient has great importance in efficient tight gas field development as well as for research and laboratory experiments.This experimental study is carried out to investigate the threshold pressure gradient in detail.Experiments are carried out with and without back pressure so that the effect of pore pressure on threshold pressure gradient may be observed.The trend of increasing or decreasing the threshold pressure gradient is totally opposite in the cases of considering and not considering the pore pressure.The results demonstrate that the pore pressure of tight gas reservoirs has great influence on threshold pressure gradient.The effects of other parameters like permeability and water saturation,in the presence of pore pressure,on threshold pressure gradient are also examined which show that the threshold pressure gradient increases with either a decrease in permeability or an increase in water saturation.Two new correlations of threshold pressure gradient on the basis of pore pressure and permeability,and pore pressure and water saturation,are also introduced.Based on these equations,new models for tight gas production are proposed.The gas slip correction factor is also considered during derivation of this proposed tight gas production models.Inflow performance relationship curves based on these proposed models show that production rates and absolute open flow potential are always be overestimated while ignoring the threshold pressure gradients.
基金Project supported by the Science and Technology Project of CNOOC China Limited "Drilling and Completion Risk Evaluation and Countermeasure Study of Ultra High Temperature and High Pressure Development Wel1"(No.YXKY-ZX 09 2021).
文摘Offshore oil and gas production has become an important growth pole to ensure national energy security.However,China's offshore oil and gas production is lack of key core technologies and weak in tool and equipment foundation and can hardly support the optimized fast development of important fields.To solve these technological difficulties,China National Offshore Oil Corporation(CNOOC)insisted on independent technological innovation and overcame a series of key core technologies through theoretical research and key technology research and test during the 13th Five-Year Plan.And the following research results are obtained.First,several key technologies are broken through,including efficient drilling and completion in the middle and deep layers of the Bohai Sea,offshore large-scale heavy oil thermal recovery,deep-water oil and gas field development,and high temperature and high pressure well drilling and completion in the South China Sea,unconventional oil and gas stimulation,and offshore emergency rescue.Domestic first independently operated ultra deep water giant gas field,namely“Deepsea 1”is successfully put into production,so that the leap from 300 m to 1500 m of water depth and from exploration to development is realized.Second,key tools and equipment are developed,such as logging while drilling and rotary steering drilling system,deep-water drilling surface conductor,underwater emergency killing device,and underwater wellhead Christmas tree,which promote the high-quality development of China's offshore oil industry.Finally,some suggestions are proposed as follows.In the future,CNOOC shall strengthen independent technological innovation,quicken the pace to deepsea oil and gas,and continue to research key core technologies for oil and gas reserves and production increase(e.g.continuous localization of drilling and completion technologies,equipment and materials in complex fields),commingled gas production and test and green energy transformation(e.g.geothermal energy),so as to make greater contributions to ensure national energy security and build a maritime power.
