摘要
塔里木盆地克深气田白垩系巴什基奇克组砂岩储层是库车山前的主力产气层,具有埋藏深度大、基质物性差的特征,构造裂缝普遍发育,特征及分布复杂,且对单井产量影响较大。目前针对该地区裂缝的研究已投入大量的工作,研究内容主要包括基于钻井岩心、成像测井等资料的裂缝精细描述;多方法多轮次裂缝分布规律预测等,但是受到取心程度、地震资料品质、常规测井资料等限制,裂缝预测的效果不佳。考虑到克深气田超深层致密砂岩储层裂缝具有多尺度特征,且不同尺度裂缝的发育特征、成因及分布规律有所不同,研究将裂缝进行分级,系统地梳理了各级裂缝及其组合的发育特征和规律,并探索了裂缝与产量的关系。研究认为:(1)综合考虑裂缝的长度、开度、发育特征等因素,将克深气田储层裂缝划分为"Ⅰ级裂缝—米级裂缝"、"Ⅱ级裂缝—颗粒贯穿缝"、"Ⅲ级裂缝—粒缘缝"三级裂缝;(2)根据各级裂缝的尺度、成因及组合特征,建立了克深气田储层三级裂缝组合,即"Ⅰ级裂缝组合—优势裂缝带"、"Ⅱ级裂缝组合—优势裂缝及伴生缝"、"Ⅲ级裂缝组合—粒缘缝网";(3)克深气田储层多尺度缝网有效沟通砂体和砂层组,连通粒间溶蚀扩大孔,产生粒内溶孔及微孔隙,提高储层的渗流能力,对单井产量影响较大,是超深层致密砂岩储层天然气高产、稳产的关键。
As the main gas production layer,the sandstone reservoir of Cretaceous Bashijiqike Formation of Keshen Gasfield in Tarim Basin is characterized by large depth,poor matrix properties,widespread structural fractures and complicated characteristics and distribution,which have large influence on gas production.A lot of efforts have been put into the research on the fracture in this area,the research includes refined fracture description on the basis of core and imaging logging data;multi-methods and multi-times fracture distribution pattern prediction.However,the above studies are limited by core availability,seismic data quality,well logging data,etc.,so the results of fracture prediction were not good.Considering the fractures of super-deep tight sandstone reservoir of Keshen Gasfield having the characteristic of multiscale,and the development characteristics,origin and distribution pattern of fractures with different sizes being different,this study defined fracture classes,systematically summarized the development characteristics and distribution patterns of fractures at different scales and their groups,and explored the relationship between fractures and producing capacity.The following understandings are obtained：（1）Based on fracture length,aperture,development characteristics,etc.,fractures of reservoir in Keshen Gasfield are divided into three classes,namely the first order fracture-meter-scale fractures,the second order fracture-grain penetrating fractures,the third order fracture-grain margin fractures;（2）Based on fracture sizes,origin,and combination characteristics,three classes of fracture combinations of reservoir in Keshen Gasfield are recognized,namely the first order fracture combination-dominant fracture belt;the second order fracture combinationdominant fractures and associated fractures;the third order fracture combination-grain margin fracture network;（3）The multi-scale fracture networks of reservoir in Keshen Gasfield effectively made the sand bodies and sand groups communicated,connected the intergranular dissolution pores and produced intragranular dissolved pores,which enhanced filtration capacity of the reservoir and was the key factor of high and stable yields of the gas in super-deep tight sandstone reservoir.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2017年第11期1668-1677,共10页
Natural Gas Geoscience
基金
中国石油天然气股份公司重大专项"库车前陆深层油气地质理论与勘探目标评价"(编号:2014E-2101)
国家科技重大专项课题"塔里木前陆盆地油气成藏
关键勘探技术与新领域目标优选"(编号:2016ZX05003-004)联合资助
关键词
塔里木盆地
克深气田
超深层致密砂岩储层
三级裂缝
三级裂缝组合
裂缝与产量的关系
Tarim Basin
Keshen Gasfield
Super-deep tight sandstone reservoir
Three level fractures
Three level fracture combinations
Fracture-production relationship
