Title

Relationship analysis between brittle index and electrical properties of marine shale in South China

单位

(1.油气资源与勘探技术教育部重点实验室(长江大学),湖北武汉430100;2.非常规油气湖北省协同创新中心(长江大学),湖北武汉430100;3.长江大学地球科学学院,湖北武汉430100;4.中国石油天然气集团公司东方地球物理勘探有限责任公司,河北涿州072751)

Organization

(1.Key Laboratory of Oil and Gas Resources and Exploration Technology,Ministry of Education,Wuhan 430100,China;2.Hubei Collaborative Innovation Center for Unconventional Oil and Gas,Wuhan 430100,China;3.College of Geosciences,Yangtze University,Wuhan 430100,China;4.Bureau of Geophysical Prospecting Incorporation,CNPC,Zhuozhou 072751,China)

摘要

页岩脆性是评价页岩气储层的重要参素,因此,研究页岩矿物成分及其脆性评价方法意义重大。基于南方海相筇竹寺组和龙马溪组页岩露头标本,通过矿物成分鉴定和复电阻率测试分析,发现脆性矿物和黄铁矿(FeS2)含量高的页岩具有低阻高极化率的电性响应特征,表明利用激发极化参数(IP)进行储层脆性评价具有良好的物性基础。基于矿物成分定义了脆性指数(BI),分析研究了页岩的激电参数与黄铁矿和脆性指数的相关性,初步建立了电阻率以及极化率与脆性指数和黄铁矿含量的关系模型,提出了利用电性异常特征识别和评价页岩气储层的新思路。

Abstract

The brittleness of shale is an important parameter in the evaluation of shale gas reservoir.Therefore,studying shale mineral composition and evaluation method of brittleness are significant.Through the mineral composition analysis and complex resistivity measurement based on the outcrop samples from the Qiongzhusi formation and Longmaxi formation of marine shale in South China,the characteristics of low resistivity and high polarization were revealed in the shale with high brittleness minerals and high pyrite content.These characteristics provide a geophysical prerequisite for evaluating the brittleness of shale reservoir by induced polarization (IP) parameters.The brittleness index (BI) is defined based on mineral composition.The correlation between the IP parameters of shale,pyrite content and the brittleness index are analyzed.These research preliminary established the relation models between the resistivity,the brittleness index and the pyrite content,as well as the relation models between the polarization,the brittleness index and the pyrite content.The new idea of using electrical anomaly characteristics to predict the shale gas reservoir is proposed.

关键词：

海相页岩; 矿物成分; 电阻率; 极化率; 脆性指数;

Keywords:

marine shale,; mineral composition,; resistivity,polarization,; brittleness index;

基金项目

国家重点基础研究发展计划(973计划)项目(2013CB228605)和国家自然科学基金项目(41404087,41574064,U1562109)联合资助。

DOI

10.3969/j.issn.1000-1441.2016.06.015

南方海相页岩脆性指数与电性关系分析