Objective Large numbers of archeological relics from the Neolithic period are widely distributed in all tributaries of the Yellow River. The early humans tended to reside along the river valleys, and developed small b...Objective Large numbers of archeological relics from the Neolithic period are widely distributed in all tributaries of the Yellow River. The early humans tended to reside along the river valleys, and developed small but characteristically decentralized ancient valley culture. It is universally acknowledged that the agriculture exchange between China and western countries and the moderate展开更多
From observing cores of 18 wells,identifying 175 ordinary thin sections and 61 thin casting sections,energy spectrum analyses of 37 samples,homogenization temperature measurement of fluid inclusions of 11 samples,we d...From observing cores of 18 wells,identifying 175 ordinary thin sections and 61 thin casting sections,energy spectrum analyses of 37 samples,homogenization temperature measurement of fluid inclusions of 11 samples,we determine the types of diagenesis and pores of the Fuyu oil reservoir in the north Qijia region.We classified the pores and measured their plane porosity using CIA 2000,the software of rock image analysis,calculated the effect of different kinds of diagenesis on porosity,studied the controlling actions of diagenesis to pore evolution quantitatively,combined with burial history,thermal history and their diagenetic environments.Our results show that mechanical compaction and carbonate cementation are the major destructive diagenesed,developed during early diagenesis stages.The reduction in porosity by mechanical compaction and carbonate cementation are about 25% and 8%,while the destructive intensity of siliceous cementation and clay mineral cementation is relatively much smaller,i.e.,the reduction of porosity is about 2% and 0.2% Dissolution is constructive diagenesis,the increment of porosity is about 6%.There are four diagenesis evolution stages,during which the porosity reduced from 30%～38% to 2%～20%.Mechanical compaction and early cementation are the main diageneses in the early diagenesis stages,when porosity was reduced to 2%～10%.Dissolution is the main diagenesis of an A I substage of the middle diagenesis stage,when porosity increased 1%～8%.The dissolution of the A Ⅱ substage of the middle diagenesis stage affected by late cementation,raised porosity 1%～5%.The porosity varied slightly during the middle stage B.展开更多
The Daqing exploration area in the northern Songliao Basin has great potential for unconventional oil and gas resources,among which the total resources of tight oil alone exceed 109 t and is regarded as an important r...The Daqing exploration area in the northern Songliao Basin has great potential for unconventional oil and gas resources,among which the total resources of tight oil alone exceed 109 t and is regarded as an important resource base of Daqing oilfield.After years of exploration in the Qijia area,Songliao Basin,NE China,tight oil has been found in the Upper Cretaceous Qingshankou Formation.To work out tight oil’s geological characteristics,taking tight oil in Gaotaizi oil layers of the Upper Cretaceous Qingshankou Formation in northern Songliao Basin as an example,this paper systematically analyzed the geological characteristics of unconventional tight oil in Gao3 and Gao4 layers of the Qijia area,based on the data of the geological survey,well drilling journey,well logging,and test.It is that three sets of hydrocarbon source rocks(K2qn1,K2qn2+3,and K2n1)develop in the examined area,and exhibit excellent type I and II kerogens,high organic matter abundance,and moderate maturity.The reservoir is generally composed of thin-bedded mudstone,siltstone,and sandstone,and presents poor porosity(average 8.5 vol.%)and air permeability(average 4 mD).The main reservoir space primarily includes intergranular pores,secondary soluble pores,and intergranular soluble pores.Three types of orifice throats were identified,namely fine throat,extra-fine throat,and micro-fine throat.The siltstone is generally oil-bearing,the reservoirs with slime and calcium become worse oil-bearing,and the mudstone has no obvious oil-bearing characteristics.The brittleness indices of the sandstone in the tight oil reservoir range from 40%to 60%,and those of the mudstone range from 40%to 45%,indicating a better brittleness of the tight oil reservoir.Based on the study of typical core hole data,this paper gives a comprehensive evaluation of the properties of the tight oil and establishes a tight oil single well composite bar chart as well as the initial evaluation system with the core of properties in the tight oil reservoir.This study has theoretical guiding significance and practical application value for tight oil exploration and evaluation in the Qijia area.展开更多
基金financially supported by the National Science Foundation of China (grant No. 41571177)
文摘Objective Large numbers of archeological relics from the Neolithic period are widely distributed in all tributaries of the Yellow River. The early humans tended to reside along the river valleys, and developed small but characteristically decentralized ancient valley culture. It is universally acknowledged that the agriculture exchange between China and western countries and the moderate
基金the National Basic Research Program of China (No.2009 CB219306)the Important National Science & Technology Specific Projects (No.2009GYXQ14)
文摘From observing cores of 18 wells,identifying 175 ordinary thin sections and 61 thin casting sections,energy spectrum analyses of 37 samples,homogenization temperature measurement of fluid inclusions of 11 samples,we determine the types of diagenesis and pores of the Fuyu oil reservoir in the north Qijia region.We classified the pores and measured their plane porosity using CIA 2000,the software of rock image analysis,calculated the effect of different kinds of diagenesis on porosity,studied the controlling actions of diagenesis to pore evolution quantitatively,combined with burial history,thermal history and their diagenetic environments.Our results show that mechanical compaction and carbonate cementation are the major destructive diagenesed,developed during early diagenesis stages.The reduction in porosity by mechanical compaction and carbonate cementation are about 25% and 8%,while the destructive intensity of siliceous cementation and clay mineral cementation is relatively much smaller,i.e.,the reduction of porosity is about 2% and 0.2% Dissolution is constructive diagenesis,the increment of porosity is about 6%.There are four diagenesis evolution stages,during which the porosity reduced from 30%～38% to 2%～20%.Mechanical compaction and early cementation are the main diageneses in the early diagenesis stages,when porosity was reduced to 2%～10%.Dissolution is the main diagenesis of an A I substage of the middle diagenesis stage,when porosity increased 1%～8%.The dissolution of the A Ⅱ substage of the middle diagenesis stage affected by late cementation,raised porosity 1%～5%.The porosity varied slightly during the middle stage B.
基金funded by the shale oil and gas geological survey project in Quemoco sag,Qiangtang Basin of China Geological Survey(DD20221855,DD20230315).
文摘The Daqing exploration area in the northern Songliao Basin has great potential for unconventional oil and gas resources,among which the total resources of tight oil alone exceed 109 t and is regarded as an important resource base of Daqing oilfield.After years of exploration in the Qijia area,Songliao Basin,NE China,tight oil has been found in the Upper Cretaceous Qingshankou Formation.To work out tight oil’s geological characteristics,taking tight oil in Gaotaizi oil layers of the Upper Cretaceous Qingshankou Formation in northern Songliao Basin as an example,this paper systematically analyzed the geological characteristics of unconventional tight oil in Gao3 and Gao4 layers of the Qijia area,based on the data of the geological survey,well drilling journey,well logging,and test.It is that three sets of hydrocarbon source rocks(K2qn1,K2qn2+3,and K2n1)develop in the examined area,and exhibit excellent type I and II kerogens,high organic matter abundance,and moderate maturity.The reservoir is generally composed of thin-bedded mudstone,siltstone,and sandstone,and presents poor porosity(average 8.5 vol.%)and air permeability(average 4 mD).The main reservoir space primarily includes intergranular pores,secondary soluble pores,and intergranular soluble pores.Three types of orifice throats were identified,namely fine throat,extra-fine throat,and micro-fine throat.The siltstone is generally oil-bearing,the reservoirs with slime and calcium become worse oil-bearing,and the mudstone has no obvious oil-bearing characteristics.The brittleness indices of the sandstone in the tight oil reservoir range from 40%to 60%,and those of the mudstone range from 40%to 45%,indicating a better brittleness of the tight oil reservoir.Based on the study of typical core hole data,this paper gives a comprehensive evaluation of the properties of the tight oil and establishes a tight oil single well composite bar chart as well as the initial evaluation system with the core of properties in the tight oil reservoir.This study has theoretical guiding significance and practical application value for tight oil exploration and evaluation in the Qijia area.
