天然气工业2018，Vol.38Issue(2)：16-24,9.DOI:10.3787/j.issn.1000-0976.2018.02.003
四川盆地中部中二叠统热液白云岩储渗空间类型及成因
Space types and origins of hydrothermal dolomite reservoirs in the Middle Permian strata, Central Sichuan Basin
摘要
Abstract
Recently commercial gas flows have been obtained in several wells in the Middle Permian Qixia and Maokou strata in NW Sichuan Basin,where a great potential of natural gas exploration has been proven.However,opinions vary on the origins of the Permian dolomite reservoirs in this study area,no unanimous conclusion has ever been drawn.In view of this,based on core observation,microscopic thin section analysis,and the corresponding geochemical indexes in carbon,oxygen,strontium isotopes,and reservoirs inclusions homogenization temperature,an analysis was made on the hydrothermal dolomite reservoir types and facies characteristics,as well as such reservoir origins and their main controlling factors.The following findings were obtained.(1) The Middle Permian limestone strata such as Maokou,Qixia,etc.have undergone structurally controlled hydrothermal activities and eventually hydrothermal dolomite reservoir facies were developed including typical hydrothermal mineral assemblages like saddle dolomites,fluorite and celestites,and hydrothermal breccia structures.(2) Compared to host limestones like micritic limestones,etc.,medium-fine crystalline dolomites and saddle dolomites were displayed as δ18O negative migration and 87Sr/86Sr positive migration.(3) The hydrothermal dolomite reservoir space is mainly composed of hydrothermal dissolved pores,hydrothermal intercrystalline pores,hydrothermal dissolved vugs,and hydrothermal enlarged fractures.In conclusion,it is demonstrated that the development and distribution of hydrothermal dolomite reservoir facies,controlled by large basement-rooted faults,are mainly distributed,from the seismic data,in a "lenticular form" in the area which is featured by "concave" seismic reflection;and that the organic combination of the Middle Permian hydrothermal dolomite reservoirs,underlying hydrocarbon source rocks and the overlying seal strata will be possibly a favorable exploration target in this study area.关键词
四川盆地中部/中二叠世/栖霞组/茅口组/白云岩储集层/热液白云岩/储渗空间/储集相/锶同位素Key words
Sichuan Basin/Central/Middle Permian/Qixia Fm/Maokou Fm/Dolomite reservoir/Hydrothermal dolomite/Reserve-permeate space/Reservoir facies/Strontium isotope引用本文复制引用
蒋裕强,谷一凡,李开鸿,李顺,罗明生,何冰..四川盆地中部中二叠统热液白云岩储渗空间类型及成因[J].天然气工业,2018,38(2):16-24,9.基金项目
国家科技重大专项“四川盆地大型碳酸盐岩气田开发示范工程”(编号:2016ZX05052). （编号:2016ZX05052）
