哈萨克斯坦滨里海盆地F区块盐下油气成藏模式及勘探潜力

Exploration Potential and Hydrocarbon Accumulation Pattern of F Block in Pre-Caspian Basin,Kazakhstan

滨里海盆地盐下层系油气成藏地质条件复杂,发育不同类型圈闭和油气藏。为指明有利勘探目标,本文充分利用、钻井、岩心、测井、三维地震及区域地质资料,对滨里海盆地北部F区块盐下油气藏基本地质特征和成藏模式进行了剖析,认为区块内盐下层系主要发育2套优质烃源岩,5套储集性能良好的碳酸盐岩储集层及4种圈闭类型。在此基础上,结合周边已发现油田的地质背景,探讨了盐下层系油气成藏模式,指出了重点勘探区域及勘探层系。研究表明,F区块盐下油气藏主要分布在发育碳酸盐岩储层的有利相带,位于主要油气运移通道,其上覆盖层为区域分布的盐层,具备形成大型盐下油气藏的石油地质条件,勘探潜力大。

The hydrocarbon accumulation condition of pre- salt strata in Pre-caspian basin is very complex with multiple types of traps and oil- gas reservoirs developed. In order to point out favorable exploration target,this paper focuses on the study of basic geological characteristics and hydrocarbon accumulation pattern for pre- salt reservoir in F block,northern part of Pre-caspian basin,by making full use of drilling data,core samples,logging data,3D seismic data,and regional geological knowledge. It is suggested that there are two sets of high- quality source rocks,five sets of carbonate reservoirs with good reservoir properties and four types of traps. Based on the study above,hydrocarbon accumulation pattern for pre- salt reservoir is discussed and formed,and target areas and formations for exploration are proposed,considering geological background of neighboring oilfields. It is indicated that pre-salt reservoir of F block is distributed in the favorable area where carbonate reservoir developed,and meanwhile on the main hydrocarbon migration pathway,sealed by overlying salt cap rock regional developed. The strata are of advantageous geological conditions for large- scale pre- salt reservoir,and great exploration potential.