天然气勘探与开发2026，Vol.49Issue(3)：24-40,17.DOI:10.12055/gaskk.issn.1673-3177.2026.03.003
川中地区震旦系灯影组微生物岩优质储层成因机制
Genetic mechanisms of high-quality microbialite reservoirs in Sinian Dengying Formation of central Sichuan Basin:Constraints from numerical simulation of diagenetic evolution
摘要
Abstract
The Upper Sinian Dengying Formation in the central Sichuan Basin serves as a strategic core for deep to ultra-deep carbonate gas reservoir exploration in China,where the Anyue super-giant gasfield and the Penglai gas area have been discovered successively.However,influenced by ancient age of strata and complex tectono-diagenetic evolution process,the genetic mechanisms and distribution patterns of high-quality reservoir spaces in deep ancient carbonates are poorly understood,hindering gas exploration breakthroughs in this area.To address the issue,with the Dengying Formation microbialite reservoirs as the research object,the sedimentary characteristics of different sedimentary subfacies were systematically analyzed,and the diagenetic evolution sequences were reconstructed.Moreover,the coupled multiphase reaction-migration numerical simulation was performed by using the TOUGHREACT software.The following results are obtained.(i)The initial porosities of four subfacies,namely microbial mound,grain shoal,platform flat,and intermound/intershoal depression,are 40%,50%,15%,and 30%,respectively,showing significant difference in diagenetic evolution pathway.(ii)Supergene meteoric freshwater dissolution is crucial to the development of high-quality pores.The microbial mound subfacies achieves a peak dissolution intensity of 36.0%,far exceeding those of grain shoal(17.2%),platform flat(18.8%),and depression(11.0%).(iii)Moderate dolomitization(final dolomite content of about 79.6%in microbial mounds)reduces the compaction coefficient by 20%-30%,significantly enhancing the resistance to compaction;whereas excessive dolomitization(dolomite content＞94%in grain shoal,platform flat,and depression subfacies)may make the rock tight due to cemented fillings.(iv)The microbial mound subfacies preserves a final porosity of approximately 6.5%,while grain shoal,platform flat,and intermound/intershoal depression subfacies only have 4.2%,2.0%,and 0.7%,respectively.It is concluded that,the high-energy microbial mound subfacies represents the most favorable reservoir development zone because of its optimal diagenetic evolution pathway of"high initial porosity → intense supergene dissolution→ moderate dolomitization for compaction resistance → limited burial dissolution compensation".Priority exploration deployment is recommended for microbial mound-shoal complexes along the northern slope and platform margin of the Central Sichuan Paleo-uplift.关键词
震旦系上统灯影组/深层古老碳酸盐岩气藏/微生物岩/成岩演化/数值模拟/优质储层/白云石化/表生岩溶Key words
Upper Sinian Dengying Formation/Deep ancient carbonate gas reservoir/Microbialite/Diagenetic evolution/Numerical simulation/High-quality reservoir/Dolomitization/Supergene karst分类
能源科技引用本文复制引用
刘可禹,王梓名,卢震,谢忱,周刚,李昌伟,武鲁亚,杨鹏,严威,莫雅蔚,王晶..川中地区震旦系灯影组微生物岩优质储层成因机制[J].天然气勘探与开发,2026,49(3):24-40,17.基金项目
新型油气勘探开发国家科技重大专项项目"四川盆地全油气系统与新领域勘探技术"(编号:2025ZD1400400). （编号:2025ZD1400400）
