Based on first-hand material from the geological exploration of petroleum,we made a detailed study of the tectonic development in the Early Cretaceous and the distribution of basement rifts in the Songliao Basin.The s...Based on first-hand material from the geological exploration of petroleum,we made a detailed study of the tectonic development in the Early Cretaceous and the distribution of basement rifts in the Songliao Basin.The sedimentary characteristics of this epoch and the tectono-paleogeography of the basin were expounded.The results show that in its early stages,the Songliao Basin was characterized by a detached faulted basin in which mainly lake facies developed among mountains.It became gradually one lake during the late stages of the Early Cretaceous.During this period,the fault activity in the Songliao Basin changed from a turbulent to a quiet development,the water area from small separated lakes to one large lake,in which the sedimentary facies were divided into asymmetric eastern and western parts.In the basin a volcanic clastic rock-alluvial fan system developed and a fan delta-lake-small delta-river system was mainly deposired.Our research also shows that the basement rifts not only controlled the distribution of fault depressions and the tectonic development in the Early Cretaceous,but had also an effect on the orientation of sedimentation,source area and river system,which determine the tectonopaleogeography of the Early Cretaceous.展开更多
We investigated the geological factors associated with unsuccessful exploration wells in the northern margin of the Qaidam basin to better understand their cause.The structural situation,the hydrocarbon accumulation m...We investigated the geological factors associated with unsuccessful exploration wells in the northern margin of the Qaidam basin to better understand their cause.The structural situation,the hydrocarbon accumulation mechanism and unsuccessful well data collected from 1996 to 2005 were studied.The results show that the main geological factors associated with unsuccessful exploration wells are a lack of effective source rocks and a lack of effective traps,as well as the migration-accumulation conditions that exist in this area.The basin was reformed by Meso-Cenozoic tectonic evolution.Multi-stage tectonic activities have both positive and negative effects on hydrocarbon accumulation.Source rocks distribution,effective migration channels,effective traps and the tectonic evolution effects on hydrocarbons should be the key objects for further studies.展开更多
文摘Based on first-hand material from the geological exploration of petroleum,we made a detailed study of the tectonic development in the Early Cretaceous and the distribution of basement rifts in the Songliao Basin.The sedimentary characteristics of this epoch and the tectono-paleogeography of the basin were expounded.The results show that in its early stages,the Songliao Basin was characterized by a detached faulted basin in which mainly lake facies developed among mountains.It became gradually one lake during the late stages of the Early Cretaceous.During this period,the fault activity in the Songliao Basin changed from a turbulent to a quiet development,the water area from small separated lakes to one large lake,in which the sedimentary facies were divided into asymmetric eastern and western parts.In the basin a volcanic clastic rock-alluvial fan system developed and a fan delta-lake-small delta-river system was mainly deposired.Our research also shows that the basement rifts not only controlled the distribution of fault depressions and the tectonic development in the Early Cretaceous,but had also an effect on the orientation of sedimentation,source area and river system,which determine the tectonopaleogeography of the Early Cretaceous.
基金Project XQ-2004-01 supported by the National Oil Project of China
文摘We investigated the geological factors associated with unsuccessful exploration wells in the northern margin of the Qaidam basin to better understand their cause.The structural situation,the hydrocarbon accumulation mechanism and unsuccessful well data collected from 1996 to 2005 were studied.The results show that the main geological factors associated with unsuccessful exploration wells are a lack of effective source rocks and a lack of effective traps,as well as the migration-accumulation conditions that exist in this area.The basin was reformed by Meso-Cenozoic tectonic evolution.Multi-stage tectonic activities have both positive and negative effects on hydrocarbon accumulation.Source rocks distribution,effective migration channels,effective traps and the tectonic evolution effects on hydrocarbons should be the key objects for further studies.
