川中古隆起北斜坡灯四段天然气成藏特征
Characteristics of natural gas accumulation in the northern slope of the middle Sichuan paleo-uplift
马奎 1张本健 1徐少立 1严威 1周刚 1张新 1武鲁亚 1蒋航 1王文之 1许翔1
作者信息
- 1. 中国石油西南油气田分公司勘探开发研究院,四川 成都 610041
- 折叠
摘要
继四川盆地川中古隆起安岳万亿方大气田发现之后,在古隆起斜坡区海相多层系又获得了勘探发现.其中古隆起斜坡蓬莱气区灯影组四段(灯四段)成藏条件优越,可能是盆地下一个深层油气富集的重要领域.结合地震和测井资料分析,对蓬莱气区灯四段成藏条件进行评价,指出勘探有利区,并展望其勘探潜力.研究表明:①灯四段大型台缘带发育厚层块状丘滩相孔隙性储层,储集岩性主要为藻凝块白云岩、藻砂屑白云岩,储层厚169 m,平均孔隙度为3.1%.②沉积微地貌和同沉积断裂共同控制了蓬莱气区灯四段台缘相带分异,灯四段上倾方向发育台内洼地相带,具备岩性封堵条件.且台缘带发育丘滩体和丘滩间洼地2种亚相,具备多个大型岩性圈闭发育地质条件,岩性圈闭总面积达2 650 km2.③蓬莱气区灯四段油气原位聚集,经历了古油藏形成、原油裂解成气和气藏调整定型3个阶段,形成了现今多个大型构造—岩性油气藏群.
Abstract
After the discovery of the Anyue trillion gas field in the Central Sichuan Basin paleo-uplift,marine multilayer systems in the slope area of the paleo-uplift were discovered.The fourth member of Dengying Forma-tion(Deng 4 Member)in the Penglai gas area of the ancient uplift slope has superior reservoir formation condi-tions,which may be an important area for deep oil and gas accumulation in the basin.Based on the analysis of seismic and logging data,the reservoir formation conditions of the Deng 4 Member in the Penglai gas area are evaluated,the favorable exploration areas are pointed out,and the exploration potential is prospected.Research has shown that:(1)Thick block shaped mound beach facies porous reservoirs are developed in the large plat-form margin zone of the Deng 4 Member,with reservoir lithology mainly consisting of algal tuff dolomite,algal sand debris dolomite,mud powder crystal dolomite,and siliceous dolomite.The reservoir is 169 m thick and has an average porosity of 3.1%.(2)The sedimentary micro geomorphology and synsedimentary faults jointly control the differentiation of the platform margin facies belt in the Penglai gas area,and the platform depression facies belt is developed in the upward dipping direction of the Deng 4 Member,which has the conditions for lith-ological sealing.And there are two subfacies developed in the platform margin zone,namely the mound beach body and the depression between the mound beach,which have multiple geological conditions for the develop-ment of large-scale lithologic traps.The total area of lithologic traps is 2 650 km2.(3)The in-situ accumulation of oil and gas in the Deng 4 Member in Penglai gas bearing area has gone through three stages:the formation of ancient oil reservoirs,the cracking of crude oil into gas,and the adjustment and finalization of gas reservoirs,forming multiple large-scale structural lithologic oil and gas reservoir groups today.
关键词
蓬莱气区/灯四段/岩性圈闭/构造—岩性气藏/原位聚集Key words
Penglai gas bearing area/The fourth member of Sinian Dengying Formation/Lithological traps/Structural lithologic gas reservoirs/In-situ aggregation引用本文复制引用
基金项目
中国石油西南油气田分公司科技项目(20230301-25)
出版年
2024
NETL
NSTL
万方数据