川中地区营山构造须家河组第二段致密砂岩气藏成藏主控因素  

Main controlling factors of tight sand gas accumulation of Member 2 of Xujiahe Formation in Yingshan structure,Central Sichuan,China

作　　者：王霄[1] 徐昉昊[1] 车国琼[2] 王家树[2] 李正勇[2] 

机构地区：[1]油气藏地质及开发工程国家重点实验室(成都理工大学),成都610059 [2]中国石油西南油气田分公司川中油气矿,四川遂宁629000

出　　处：《成都理工大学学报（自然科学版）》2014年第1期18-26,共9页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国家自然科学基金资助项目(40930424);国家科技重大专项(2008ZX05001-05-01)

摘　　要：川中地区营山构造上三叠统须家河组第二段气藏的前期研究与勘探实际有一定出入,勘探成功率仅为32%,需要解决地质认识上的关键科学问题,以提高天然气勘探成效。作者分析了须二段气藏的生储、保存及圈闭条件,认为其成藏条件优越;利用Easy Ro化学动力学模型重建了烃源岩热演化史,结合包裹体均一温度以及ESR测龄再现其成藏过程,认为营山构造须二段天然气经历了3个成藏期:晚侏罗世烃类流体初次向储层充注,中-晚白垩世大规模向储层充注,晚白垩世以来构造隆升对气藏的调整和改造。须二气藏成藏的主控因素是:优质储层的发育控制天然气的富集,构造起伏控制气水分异,裂缝的发育控制储层的渗流机理和产能的高低,断层的封闭性控制南北天然气差异聚集。The previous researches on Member 2 of Upper Triassic Xujiahe Formation （T3x2） in the Yingshan structure of Sichuan Basin differ in some extent from the practical exploration results,because the exploration success rate is only 32％.This study tries to solve the key scientific issues on the geological understanding in order to improve the effectiveness of natural gas exploration.The paper analyzes the source rocks,reservoir rocks,preservation and trap conditions of the gas pool of Member 2 of Xujiahe Formation,and concludes that the accumulation condition is superior.The apatite fission track and the Easy Ro chemical kinetics simulation are used to reconstruct the thermalevolved history of hydrocarbon source rocks.Combined with the homogenization temperatures of the fluid inclusions and ESR dating,the hydrocarbon-accumulation process is reconstructed.This indicates that the natural gas of Member 2 of Xujiahe Formation has experienced 3 stages of accumulation,that is,the early injection of hydrocarbon fluid in Late Jurassic,the dominant injection period of hydrocarbon period in Middle-Late Cretaceous,and the adjustment and transformation of gas pools brought about by the tectonic uplift since Late Cretaceous.The main controlling factors of hydrocarbon-accumulation of the gas pools in Member 2 of Xujiahe Formation of the Yingshan structure pointed out in this paper are as follows.The enrichment of natural gas is controlled by the physical properties of the reservoir,the gas and water distribution in the gas reservoir is controlled by the structure amplitude,the seepage mechanism and the productivity of the reservoir are controlled by the development of the fractures,and the difference in natural gas accumulation from south to north is controlled by fault sealing.

关 键 词：川中地区 营山构造 须二段 成藏期次 成藏主控因素 

分 类 号：TE122.31[石油与天然气工程—油气勘探]