摘要
基于鄂东、沁南、黔西-滇东及准南地区232层次煤层气井原位地应力实测数据,参照Hoek-Brown分析方法,系统分析了煤层气储层宏观地应力分布规律,回归建立了不同应力参数随深度的变化曲线,研究结果表明:我国煤储层表现为中-高应力区,应力场类型呈非均匀分布,σ_H>σ_v>σ_h型和σ_v>σ_H>σ_h型为主(94%),σ_H>σ_h>σ_v型较少见且集中在浅部;煤储层侧压系数k均小于Hoek-Brown平均值,且88%实测数据较国内平均线偏低;σ_H/σ_v和k值随埋深变化均可用双曲线形态表征,整体表现为"浅部离散,深部收敛";水平主应力差与埋深具有一定的线性正相关性,而σ_H/σ_h变化不大,主要集中在1.015~1.915,平均为1.47。研究结果可为深部煤储层应力状态的判断、岩体参数的选取提供参考。
Based on the site measured data of the in-situ geostress from 232 hierarchy coalbed methane wells in East Hubei,Qinnan,Western Guizhou-Eastern Yunnan and Huainan Regions,in references to the Hoek-Brown analysis method,the macro geostress distribution law of the coalbed methane reservoir was systematically analyzed and the different stress parameters with the depth varied curve were regressively established in order to provide the references to the judgment of the stress status in the deep coal reservoir and the selection of the rock parameters. The results showed that the coal reservoir in China was in a medium-high stress area,the type of the stress field was in an inhomogeneous distribution,σH〉σv〉σh type and σv〉σH〉σh type would be 94% mainly and the σH〉σh〉σv type would be less concentrated in the shallow depth.The lateral pressure coefficients k of the coal reservoir was less than the average value of Hoek-Brown and 88% of the site measured data would be lower than the domestic average line.The σH/σvand k value varied with the depth both could be explained with the hyperbola shape and the integration would be＂dispersion in shallow and convergence in deep depth＂.The horizontal principal stress difference would have a certain linear positive correlation with the depth. While the variation of the σH/σh was not high,would be between 1.015 - 1.915 mainly and the average would be 1.47.The research results can provide reference for the judgment of the stress state of deep coal reservoirs and the selection of rock parameters.
作者
陈世达
汤达祯
陶树
许浩
李松
赵俊龙
CHEN Shida;TANG Dazhen;TAO Shu;XU Hao;LI Song;ZHAO Junlong(School of Energy,China University of Geosciences（Beijing）,Beijing 100083,China;School of Resources and Earth Sciences,China University of Mining and Technology,Xuzhou 221116,China)
出处
《煤炭科学技术》
CAS
北大核心
2018年第6期57-63,共7页
Coal Science and Technology
基金
国家科技重大专项资助项目(2016ZX05044001-003)
中国地质调查局公益性基础地质调查资助项目(DD20179362)
关键词
煤储层
煤层气
地应力
埋深
coal reservoir
coalbed methane
geostress
depth
