Tofigure out the process and controlling factors of gas reservoir formation in deep-waters,based on an analysis of geological features,source of natural gas and process of reservoir formation in the Liwan 3-1 gasfield...Tofigure out the process and controlling factors of gas reservoir formation in deep-waters,based on an analysis of geological features,source of natural gas and process of reservoir formation in the Liwan 3-1 gasfield,physical simulation experiment of the gas reservoir formation process has been performed,consequently,pattern and features of gas reservoir formation in the Baiyun sag has been found out.The results of the experiment show that:①the formation of the Liwan 3-1 faulted anticline gasfield is closely related to the longstanding active large faults,where natural gas is composed of a high proportion of hydrocarbons,a small amount of non-hydrocarbons,and the wet gas generated during highly mature stage shows obvious vertical migration signs;②liquid hydrocarbons associated with natural gas there are derived from source rock of the Enping&Zhuhai Formation,whereas natural gas comes mainly from source rock of the Enping Formation,and source rock of the Wenchang Formation made a little contribution during the early Eocene period as well;③although there was gas migration and accumulation,yet most of the natural gas mainly scattered and dispersed due to the stronger activity of faults in the early period;later as fault activity gradually weakened,gas started to accumulate into reservoirs in the Baiyun sag;④there is stronger vertical migration of oil and gas than lateral migration,and the places where fault links effective source rocks with reservoirs are most likely for gas accumulation;⑤effective temporal-spatial coupling of source-fault-reservoir in late stage is the key to gas reservoir formation in the Baiyun sag;⑥the nearer the distance from a trap to a large-scale fault and hydrocarbon source kitchen,the more likely gas may accumulate in the trap in late stage,therefore gas accumulation efficiency is much lower for the traps which are far away from large-scale faults and hydrocarbon source kitchens.展开更多
基金National High Technology Research and Development Program of China“Fundamental Study on Formation and Distribution of Hydrocarbon Resources in Deep-water Basins,South China Sea”(No.2009CB219400).
文摘Tofigure out the process and controlling factors of gas reservoir formation in deep-waters,based on an analysis of geological features,source of natural gas and process of reservoir formation in the Liwan 3-1 gasfield,physical simulation experiment of the gas reservoir formation process has been performed,consequently,pattern and features of gas reservoir formation in the Baiyun sag has been found out.The results of the experiment show that:①the formation of the Liwan 3-1 faulted anticline gasfield is closely related to the longstanding active large faults,where natural gas is composed of a high proportion of hydrocarbons,a small amount of non-hydrocarbons,and the wet gas generated during highly mature stage shows obvious vertical migration signs;②liquid hydrocarbons associated with natural gas there are derived from source rock of the Enping&Zhuhai Formation,whereas natural gas comes mainly from source rock of the Enping Formation,and source rock of the Wenchang Formation made a little contribution during the early Eocene period as well;③although there was gas migration and accumulation,yet most of the natural gas mainly scattered and dispersed due to the stronger activity of faults in the early period;later as fault activity gradually weakened,gas started to accumulate into reservoirs in the Baiyun sag;④there is stronger vertical migration of oil and gas than lateral migration,and the places where fault links effective source rocks with reservoirs are most likely for gas accumulation;⑤effective temporal-spatial coupling of source-fault-reservoir in late stage is the key to gas reservoir formation in the Baiyun sag;⑥the nearer the distance from a trap to a large-scale fault and hydrocarbon source kitchen,the more likely gas may accumulate in the trap in late stage,therefore gas accumulation efficiency is much lower for the traps which are far away from large-scale faults and hydrocarbon source kitchens.
