长岭断陷龙凤山地区下白垩统地层压力特征及其对油气成藏的影响  

Pressure Characteristics and Its Influence on Hydrocarbon Accumulation of Lower Cretaceous Formation in Longfengshan Area,Changling Faulted Depression

作　　者：宋昊[1] 蒋有录[1] 侯帅 陈杏霞[2] Song Hao;Jiang Youlu;Hou Shuai;Chen Xingxia(China University of Petroleum(East China),Qingdao,Shandong 266580,China;Northeast Oil&Gas Branch of SINOPEC,Changchun,Jilin 130062,China)

机构地区：[1]中国石油大学(华东),山东青岛266580 [2]中国石化东北油气分公司,吉林长春130062

出　　处：《特种油气藏》2022年第2期42-50,共9页Special Oil & Gas Reservoirs

基　　金：中国石化东北油气分公司油气勘探项目“龙凤山火石岭组火山岩成藏机理及主控因素研究”(DBKJ20190005)。

摘　　要：长岭断陷龙凤山地区下白垩统油气资源丰富,油气分布受异常压力控制明显,研究地层压力特征及其对油气成藏的影响具有重要意义。利用实测地层压力和测井资料,对龙凤山地区下白垩统地层压力特征进行分析,探讨沙河子组超压成因;利用包裹体均一温度-盐度法并结合盆地模拟技术,恢复地层古压力演化过程,以明确地层压力演化对油气成藏的影响。结果表明:研究区下白垩统自下而上地层压力结构为常压-超压-常压,沙河子组为生烃增压成因的超压;北部洼陷带为研究区超压中心,地层压力向四周过渡为常压;地层压力演化经历了早期生烃增压、压力初次释放、晚期生烃增压、压力再次释放、压力缓慢累积等演化阶段;沙河子组烃源岩生烃过程中产生的超压为油气运移的主要动力,油气沿着剩余地层压力下降的方向运移,主要富集于东南缓坡带中。研究结果对长岭断陷龙凤山地区勘探开发的深入具有一定的指导意义。Longfengshan Area in Changling Faulted Depression is abundant in Lower Cretaceous hydrocarbon resources,and the hydrocarbon distribution is obviously controlled by abnormal pressure,so it is important to study the characteristics of formation pressure and its influence on hydrocarbon.The measured formation pressure and logging data were used to analyze the pressure characteristics of Lower Cretaceous Formation in Longfengshan Area and explore the causes of the overpressure in Shahezi Formation.The evolution of formation paleopressure was restored by the inclusion homogenization temperature-salinity method in combination with the basin modeling technology to determine the influence of formation pressure evolution on hydrocarbon accumulation.The results showed that the bottom-up pressure of Lower Cretaceous Formation in the study area was normal pressure,overpressure and normal pressure,and Shahezi Formation was under overpressure due to pressurization during hydrocarbon generation;the northern subsag belt was at the center of overpressure in the study area,and the formation pressure transited to normal pressure in all directions;the evolution of formation pressure experienced five stages:pressurization during early hydrocarbon generation,initial pressure release,pressurization during late hydrocarbon generation,secondary pressure release,and slow pressure accumulation;the overpressure generated in hydrocarbon generation of source rocks of Shahezi Formation was the main driving force of hydrocarbon migration,and the hydrocarbon migrated along the direction of the remaining formation pressure drop and mainly accumulated in the southeast gentle slope belt.The study results have a certain guiding significance for the in-depth exploration and development of Longfengshan area,Changling Faulted Depression.

关 键 词：异常高压 生烃增压 古压力演化 油气成藏 包裹体 长岭断陷 

分 类 号：TE122[石油与天然气工程—油气勘探]