王府断陷火石岭组火山岩储层裂缝特征与分布规律

Fracture characteristics and distribution of volcanic reservoir of Huoshiling Formation in Wangfu fault depression

以岩芯裂缝和薄片资料为基础,结合成像测井技术和地震资料研究王府断陷火石岭组火山岩储层裂缝特征及分布规律。该区火山岩储层发育原生裂缝和构造-后生裂缝,原生裂缝张开度小,对改善储层意义不大;而构造-后生裂缝张开度大,延伸较远,能提高储层的储渗能力。通过FMI成像测井可识别出高导缝、高阻缝、微裂缝和钻井诱导缝,其中高导缝和微裂缝一般为有效裂缝。根据高导缝走向和构造特征,将研究区火山岩储层裂缝分为3个区:北部区、中部区和南部区,其中北部区和南部区受顺直断裂控制,高导缝具有两个优势走向;中部区受交叉断裂控制,高导缝为一个优势走向。中部区裂缝平均密度最高,倾角属性也显示为有利裂缝区,可以作为勘探和井位部署的重点区域。

The fracture characteristics and distribution of volcanic reservoir of Huoshiling Formation in Wangfu fault depression were studied based on fractures in rock cores and thin sections,combined with imaging logging and seismic data. The fractures of volcanic reservoir are classified into the primary and the structural-secondary fracture. The primary fracture has less contribution to improve the property of volcanic reservoir,while the structuralsecondary fracture makes sence for the reservoir due to its wide openness and long extension. High-conductive fracture,high-resistant fracture,microfracture and drilling induced fracture can be identified with Formation Micro Scanner Image（ FMI）. Typically,high-conductive fracture and microfracture are efficient. The fracture of fracture of volcanic reservoir can be divided into the northern,the middle and the southern zones,with different features of high-conductive fracture strike and structure. In the northern and southern zones,the structure is controlled by straight faults,and the high-conductive fractures are in two dominant strike directions. While the structure in the middle zone is principally controlled by cross-faults,and the high-conductive fractures are only in one prevalent strike. The mean density of fracture in the middle zone is the highest among the three,and the diagram of dip attitude also shows that the middle zone is the favorable area. Thus,the middle zone is a key area for exploration and well deployment.