The Sebei gas field,located in the northern slope of the Sanhu depression in the eastern Qaidam Basin,is the largest inland biogas producing area in China.It is a typical Quaternary biogenetic gas reservoir composed o...The Sebei gas field,located in the northern slope of the Sanhu depression in the eastern Qaidam Basin,is the largest inland biogas producing area in China.It is a typical Quaternary biogenetic gas reservoir composed of multiple layers of unconsolidated sandstone.Through systematic study of gas generating mechanism of source rock,reservoir-caprock combination and trap evolution,the unique biogas accumulation model characterized by“continuous hydrocarbon generation and dynamic accumulation”is established.Its uniqueness is reflected in the biogas generation mechanism under dual effect of lowtemperature thermodynamics and microbial degradation,source-reservoir one body,self generation and self storage,dynamic source-reservoir-caprock assemblages and anticline trap formation mechanism of multi-factor mutual promotion.This understanding reveals the intrinsic factors for formation of largescale biogas field under frigid climate,high salinity and low organic matter abundance.A number of exploration and development technologies have been worked out during the exploration and development of the Sebei gas field.Among them,the low-amplitude structure identification technique,multiparameter gas-bearing detection technique,sand control and comprehensive water control technique for unconsolidated sandstone are well applied in discovering the gas field,increasing reserve,and increasing and maintaining gas production.The above understandings and key technologies have great reference significance and demonstration effect for biogas exploration and development in China and the world.展开更多
基金supported by the National Science and Technology Major Project of China(No.2016ZX05003-006).
文摘The Sebei gas field,located in the northern slope of the Sanhu depression in the eastern Qaidam Basin,is the largest inland biogas producing area in China.It is a typical Quaternary biogenetic gas reservoir composed of multiple layers of unconsolidated sandstone.Through systematic study of gas generating mechanism of source rock,reservoir-caprock combination and trap evolution,the unique biogas accumulation model characterized by“continuous hydrocarbon generation and dynamic accumulation”is established.Its uniqueness is reflected in the biogas generation mechanism under dual effect of lowtemperature thermodynamics and microbial degradation,source-reservoir one body,self generation and self storage,dynamic source-reservoir-caprock assemblages and anticline trap formation mechanism of multi-factor mutual promotion.This understanding reveals the intrinsic factors for formation of largescale biogas field under frigid climate,high salinity and low organic matter abundance.A number of exploration and development technologies have been worked out during the exploration and development of the Sebei gas field.Among them,the low-amplitude structure identification technique,multiparameter gas-bearing detection technique,sand control and comprehensive water control technique for unconsolidated sandstone are well applied in discovering the gas field,increasing reserve,and increasing and maintaining gas production.The above understandings and key technologies have great reference significance and demonstration effect for biogas exploration and development in China and the world.