川东南地区寒武系洗象池群储层成因及分布规律  

Genesis and distribution laws of reservoirs of Cambrian Xixiangchi Group in southeastern Sichuan

作　　者：曹环宇 徐祖新 高俊杰 李炳弢 CAO Huanyu;XU Zuxin;GAO Junjie;LI Bingtao(Exploration Research Institute of SINOPEC Exploration Company,Chengdu 610041,China)

机构地区：[1]中国石化勘探分公司勘探研究院,四川成都610041

出　　处：《断块油气田》2024年第1期50-59,共10页Fault-Block Oil & Gas Field

基　　金：国家自然科学基金企业联合基金项目“海相深层油气富集机理与关键工程技术基础研究”(U19B6003)。

摘　　要：四川盆地寒武系洗象池群勘探历史悠久,但勘探程度相对较低。川东南地区PQ1井在洗象池群测试获得工业气流,揭示了寒武系洗象池群具有良好的勘探潜力。结合钻井与野外露头等资料,依据全球可对比的确定等时界面与岩性、电性界面,可以将洗象池群划分为4个四级层序,分别对应洗一段—洗四段。川东南地区洗一段—洗二段沉积期继承早期隆凹相间的地貌格局,以填平补齐作用为主;洗三段—洗四段沉积期沉积地貌差异小,地层厚度变化小,为相对稳定浅水沉积。川东南地区洗三段—洗四段沉积于陆表海潮坪环境,具有向上变浅的沉积旋回频繁叠置的特征,可划分为潮下带—潮间带沉积序列与潮下带—潮间带—潮上带沉积序列2种类型。川东南地区洗象池群储层单层厚度小,非均质性较强,储集空间以晶间孔、晶间溶孔和裂缝为主。储层发育受沉积作用、溶蚀作用与晚期构造作用三方面因素的控制。潮间带浅滩是川东南地区洗象池群储层发育的基础,受准同生期溶蚀与埋藏期溶蚀作用的影响形成主要储集空间,晚期构造作用改善储集性能,形成相对优质储层。The Cambrian Xixiangchi Group in Sichuan Basin has a long history of exploration,but the degree of exploration is relatively low.Industrial gas flow was detected in Xixiangchi Group from Well PQ1 in southeastern Sichuan,which indicates that the Cambrian Xixiangchi Group has good exploration potential.Combining with drilling and field outcrop data,the Xixiangchi Group can be divided into four fourth-order sequences corresponding to the Xi 1 to Xi 4 Member respectively based on the globally comparable defined isochronous interfaces and lithological,electrical interfaces.Xi 1 to Xi 2 Member in southeast Sichuan area inherits the early uplift and depression interphase geomorphology pattern and is dominated by filling and leveling.There is little difference of sedimentary geomorphology and little change of stratum thickness in Xi 3 and Xi 4 Member of Xixiangchi Group sedimentary period,which is a relatively stable shallow water sedimentation.Xi 3 and Xi 4 Member in southeastern Sichuan was sedimented in the epicontinental tidal flat environment with the characteristics of frequent superposition of upward shallower sedimentary cycles.It can be divided into two types,subtidal-intertidal sedimentary sequence and subtidal-intertidal-supratidal sedimentary sequence.The reservoir monolayer of Xixiangchi Group in southeastern Sichuan is thin and strongly heterogeneous,and the reservoir space is dominated by intercrystalline pores,intercrystalline dissolved pores and fractures.Reservoir development is controlled by three factors:sedimentation,dissolution and late tectonism.The intertidal shoals are the foundation of reservoir development of Xixiangchi Group in southeastern Sichuan Basin,and the main reservoir space is controlled by the penecontemporaneous dissolution and burial period dissolution.Late tectonism improved reservoir performance and formed relatively high quality reservoirs.

关 键 词：层序地层 沉积储层 碳氧同位素 洗象池群 寒武系 川东南地区 

分 类 号：TE122.2[石油与天然气工程—油气勘探]