三塘湖盆地马朗凹陷芦草沟组储层特征及裂缝分布规律

Reservoir Characteristics and Fracture Distributing Laws of Lucaogou Formation in Malang Sag of Santanghu Basin

中二叠统芦草沟组(P2l)是三塘湖盆地马朗凹陷主要含油层系之一。从岩性、基质孔渗、孔隙结构等多个方面对马朗凹陷芦草沟组储层基本特征进行了描述,证明了该层系基质完全具备储集油气的基本物质条件,是油藏最主要的储集空间。同时根据岩心描述、地层倾角和成像测井等资料,对芦草沟组油藏的裂缝发育特征进行了全面细致的描述和分析,搞清了裂缝与岩性、层厚以及构造部位之间的关系,明确了裂缝在构造中分布的有利部位,提出了有效裂缝密度的大小是控制单井产量高低的主要原因,并最终指出芦草沟组油藏均为裂缝性油藏。这些结论为今后油田的勘探评价、储量升级和开发可行性论证提供了重要的依据。

Lucaogou Formation in Middle Permian is one of the main oil-bearing series in Malang Sag of Santanghu Basin.The basic characteristics of the reservoir of the Formation are represented in this paper from the aspects of lithology,pore structures and permeability of the matrix.It proves that the matrix of the Formation has significant reservoir potential and serves as the main reservoir spaces.Based on the data of core description,dip,and imaging logging,thorough description and analysis are conducted on the fracture development characteristics of reservoirs in Lucaogou Formation.The relationship between the fracture and the lithology,stratum thickness,and structural location is figured out,as well as the favorable distribution of the fractures is identified in the Formation.What's more,the author puts forward that the density of effective fractures controls the single-well output and the reservoirs of the Formation are fractured reservoirs.The conclusions achieved in this paper will provide a solid basis for the exploration evaluation,reserve upgrading and demonstration of development feasibility of oilfields in the future.