渤海湾盆地济阳坳陷中生界复杂岩性风化壳储层特征、质量控因与甜点模型

Characteristics， quality-controlling factors and sweet spot model of the Mesozoic weathering crust reservoirs with complex lithologies in the Jiyang Depression， Bohai Bay Basin

朱世发 贾业 马立驰 崔殿 景安语 佟欢

Shifa Zhu Ye Jia Lichi Ma Dian Cui Anyu Jing Huan Tong

以渤海湾盆地济阳坳陷中生界为研究对象，利用岩心、薄片和分析化验等资料，研究风化壳储层的复杂岩性特征、成岩作用类型和储集空间特征，分析风化壳储层质量控制因素，建立多元控储模型，为济阳坳陷乃至中国陆相含油气盆地风化壳储层勘探与开发提供地质依据。研究表明：济阳坳陷中生界风化壳储集层发育陆源碎屑岩、火山碎屑岩、火山熔岩、次火山岩和深成侵入岩等5大类12小类岩石类型。初始孔隙度较高的碎屑岩储层质量最佳。大气淡水和有机酸的溶蚀作用明显改善碎屑岩储层；气体逸散、冷凝收缩、高温熔蚀以及酸性水溶蚀对火成岩储层有建设性意义。碎屑岩储层受岩石成熟度、压实强度、早期方解石胶结和二次埋藏有机酸改造的影响显著。次生溶蚀孔是主要的储集空间类型。济阳坳陷中生界风化壳储层质量受到岩性岩相、成岩流体、构造演化及现今埋深等多个因素的综合影响，提出了五元控储模型；建立了中生界储层甜点发育模型，将有利储层分为5类：断层和不整合面窗口溶蚀带、胶结残留淋滤带、剥蚀残留淋滤带、混合溶蚀带和有利岩相对接带。

The Mesozoic reservoir in the Jiyang Depression， Bohai Bay Basin， is taken to solve the following problems faced by petroleum exploration， including lithology， diagenetic types， reservoir space， quality-controlling factors of weathering crust reservoirs， through core and thin section observation， as well as other means of lab analysis. Eventually， a multivariate reserve-controlling model is established to provide geological evidence for weathering crust reservoir exploration and development in the Jiyang Depression together with other continental basins in China. The results show that there are 12 types of rock in 5 categories in the Mesozoic weathering crust reservoir in the Jiyang Depression， including terrigenous clastic rock， pyroclastic rock， volcanic lava， subvolcanic rock and plutonic intrusive rock， among which the clastic rock reservoir is of the best with higher initial porosity. The dissolution of meteoric fresh water and organic acids serves to significantly improve the clastic reservoir quality. Gas spillage， condensation shrinkage， high-temperature and acid water dissolution are of constructive value to igneous reservoir quality. Clastic reservoirs are largely affected by compositional maturity， compaction strength， early calcite cementation and organic acid reformation during secondary burial. Secondary dissolution pores serve as the main reservoir space. The quality of weathering crust reservoir in the study area is comprehensively affected by many factors， such as lithology and lithofacies， diagenetic fluid， tectonic evolution， and present burial depth， etc.； therefore a five-element reservoir-controlling model is proposed. The development model of the Mesozoic reservoir sweet spots is established， by which the favorable reservoirs can be grouped into five types， that is， fault and unconformity window dissolution zone， residual leaching zone after cementation， residual leaching zone following denudation， mixed dissolution zone and favorable lithofacies juxtaposition zone.

10.11743/ogg20220303