库车坳陷大北气田砂岩气层裂缝分布规律及其对产能的影响  

Distribution rule of fractures and their effect on deliverability in sandstone reservoirs,Dabei gas field,Kuqa foreland basin

作　　者：王振宇[1] 陶夏妍[1] 范鹏[1] 张福祥[2] 牛新年[2] 

机构地区：[1]西南石油大学资源与环境学院,四川成都610500 [2]中国石油塔里木油田分公司,新疆库尔勒841000

出　　处：《油气地质与采收率》2014年第2期51-56,114-115,共6页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项"塔里木盆地台盆区海相碳酸盐岩油气成藏条件有利区带评价及勘探目标优选研究"(2008ZX05004-004);四川省重点学科建设项目(SZD0414)

摘　　要：在库车坳陷山前多期推覆叠瓦构造背景下,大北气田普遍发育裂缝.利用野外露头、岩心、成像测井和试井等资料,对大北气田巴什基奇克组砂岩气层裂缝特征、分布规律及其对产能的影响进行研究.研究区裂缝类型包括构造裂缝和非构造裂缝,其中构造裂缝占95％,以高角度单一裂缝和网状裂缝为主,低角度构造裂缝较少;近南北向裂缝最为发育,其次为近东西向,裂缝主体走向与现今主应力方向基本一致,总体具有密度大、张开度小、充填程度高等特征.垂向上,巴二段比巴三段裂缝更发育,储层渗透性能更好;平面上,裂缝主要分布于背斜翼部及断层附近等应力集中区,核部相对不发育.裂缝对单井产能的影响主要表现为对渗透率的改善,裂缝对渗透率的提升可达2～4个数量级,其中裂缝面缝率和裂缝密度与产能的相关性较好,裂缝张开度为产能的必要非充分条件.The fractures of Dabei gas field are widely distributed in the multi-phase thrust-imbricate structure setting of Kuqa fore-land.According to outcrop,drilling core,imaging well logging and experiment data,fracture characteristics,the distribution rule andtheir contribution to deliverability are analyzed herein.The fractures in study area are divided into two types,structural fractures andnon-structural fractures,among which,the structural fractures account for 95%.The structural fractures are mainly composed of highdip-angle simple fractures and netted fractures,low dip-angle structural fractures are relatively rare.The predominant fracture orienta-tion is near N-S which is in accordance with the current maximum principal stress axis,followed by near E-W trending fractures.Ingeneral,the fractures are characterized by high fracture density,minor fracture opening and high filling degree.With high porosity andpermeability,the fractures of the second member of Cretaceous Bashijiqike formation are developed better than that in the third mem-ber in the vertical direction.Laterally,these fractures generally occurred in stress concentration area,such as outskirt of the anticlineand near fault,while fractures in the core of anticline are relatively rare.The impact of fracture on single well productivity is mainly fea-tured by its improvement on permeability which can access to 2 to 4 order of magnitude,among which,the fracture surface porosity andfracture density have the best correlation with productivity,fracture opening is a condition which is necessary but not sufficient to pro-ductivity.Thestudy on fracture can provide reference foracid fracturing stimulation technology.

关 键 词：裂缝特征 裂缝分布规律 构造裂缝 主应力方向 产能 大北气田 库车坳陷 

分 类 号：TE112.2[石油与天然气工程—油气勘探]