川东高陡复杂构造带上二叠统油气保存条件评价  

Evaluating preservation conditions of the Upper Permian oil and gas in the highly steep and complex structural belt,eastern Sichuan Basin

作　　者：范洪缘 连承波[1] 袁倩 徐姁 范存辉[1] 庹聪 刘竞 FAN Hongyuan;LIAN Chengbo;YUAN Qian;XU Xu;FAN Cunhui;TUO Cong;LIU Jing(School of Geoscience and Technology,Southwest Petroleum University,Chengdu,Sichuan 610500,China;Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China;Chongqing Gas District,PetroChina Southwest Oil&Gasfield Company,Chongqing 400021,China)

机构地区：[1]西南石油大学地球科学与技术学院,四川成都610500 [2]中国石油西南油气田公司勘探开发研究院,四川成都610041 [3]中国石油西南油气田公司重庆气矿,重庆400021

出　　处：《天然气勘探与开发》2024年第6期53-61,共9页Natural Gas Exploration and Development

基　　金：中国石油西南油气田公司重大科技专项(编号:20230301-04)。

摘　　要：川东地区构造高陡,形成机制复杂,油气勘探难度大,为了揭示复杂构造背景下上二叠统长兴组油气保存条件的主要影响因素,在川东高陡区构造演化分析的基础上,通过平面、剖面构造解释、相关井地层水矿化度分析、地层剥蚀程度分析、区域盖层发育分析,并结合相带展布特征及相关井油气测试情况,建立川东高陡复杂构造带油气保存条件评判体系,在此体系下对该区油气保存条件进行综合分析和等级划分。研究结果表明:(1)川东高陡构造区油气保存主要受构造制约,断裂及由断裂引起的流体响应特征是影响保存条件的主要因素;(2)川东高陡区虽遭受多期构造作用,但盖层大部分仍保存较完整,礁滩体储层大面积展布,区域内构造圈闭发育,具有极大勘探潜力;(3)部分高陡背斜核部因剥蚀较严重、断裂发育密集而成为油气保存条件一般区,而各构造带之间的宽缓向斜区保存条件良好,在其他成藏要素匹配的情况下具有较大勘探潜力。There exist highly steep structures with complex forming mechanisms in eastern Sichuan Basin,making the exploration challenging.Thus,the evolution was discussed for the highly steep structural belt in an effort to unlock main controls on hydrocarbon preservation conditions in the Upper Permian Changxing Formation under the complexity.Then,the planar and sectional structural interpretation was performed,and the formation-water salinity in specific wells,formation denudation,and regional caprock extension were analyzed in combination with facies distribution and oil/gas testing of relevant wells.A system was established to evaluate the preservation conditions in such complex belt.At last,the conditions were comprehensively analyzed and classified by means of this system.Results show that(i)the preservation in the study area is principally constrained by structure,and its conditions mainly by faults and fault-induced fluid response characteristics;(ii)despite in this belt where experienced multiple-episode tectonism,the bulk of caprock is still conserved,bioreef-shoal reservoirs are massively extended,and structural traps are also developed,indicating great exploration potential;and(iii)some cores in the highly steep anticline possess very ordinary preservation conditions due to serious denudation and plentiful faults,while good conditions in the wide and gentle synclinal area among various structural belts,standing for a significant exploration prospect when the other favorable reservoir-forming assembly is available.

关 键 词：川东地区 高陡构造 早二叠世 保存条件 构造作用 

分 类 号：P618.13[天文地球—矿床学]