基于微电阻率成像测井的深煤层顶板封盖性评价方法及应用  

Detailed classification of coal structure based on micro resistivity imaging logging

作　　者：吴鹏[1] 周国晓 刘世伟[3] 姜非 梁天琦 李勇[4] WU Peng;ZHOU Guoxiao;LIU Shiwei;JIANG Fei;LIANG Tianqi;LI Yong(China United Coalbed Methane Company Limited,Beijing 100011,China;Research Institute of Petroleum Exploration and Development,PetroChinaChangqing Oilfield Company,Xi’an 710018,China;Well Tech-China Oilfield Services Limited,Beijing 101149,China;College of Geoscience andSurveying Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China)

机构地区：[1]中联煤层气有限责任公司,北京100016 [2]中国石油长庆油田公司勘探开发研究院,陕西西安710018 [3]中海油田服务股份有限公司,北京101149 [4]中国矿业大学(北京)地球科学与测绘工程学院,北京100083

出　　处：《煤炭科学技术》2024年第S01期137-144,共8页Coal Science and Technology

基　　金：国家自然科学基金资助项目(42072194)。

摘　　要：深煤层游离气含量高,资源量丰富,是天然气增储上产的重要潜力资源。顶板封盖条件是影响深煤层含气性,特别是游离气含量的重要因素。基于微电阻率成像测井技术,系统开展鄂尔多斯盆地东缘某煤层气开发区顶板岩性识别,建立了煤层顶板岩性和裂缝识别图版,分析了地应力方向,提出了有利的顶板组合类型。研究结果表明:①综合常规测井资料和电成像测井特征,可以基于静态电成像图有效区分砾岩、砂岩和泥岩等10类岩性,对应不同的伽马和声波时差测井结果,研究区煤层顶板以泥岩为主,砂岩次之;②煤层顶板裂缝主要发育有高导缝与诱导缝,高导缝显示为正弦曲线,包括张开缝和泥质充填缝,诱导缝呈现为羽状或雁行状排列,可以用于判断应力方向;③结合顶板岩性厚度、裂缝发育情况等,可划分出封盖性不同的3类煤层顶板组合,其中I类顶板电成像图像一般呈亮色且裂缝发育少,II类顶板发育较多裂隙,III类顶板图像显示裂隙切割且图像不清晰;④基于此划分了3类顶板组合条件的分布,研究区以I和II类为主,具备良好封盖性。研究明确了不同岩性在电成像测井上的显示特征,提出了基于微电阻率成像测井的深煤层顶板封盖性评价方法,可有效支撑深部煤层气甜点区带优选和井位部署。The deep coal seam has high free gas content and abundant resources,which is an important potential resource for natural gas storage and production.The gas content of deep coal seams,particularly the free gas content,is significantly influenced by the sealing con-dition of roof.Based on the micro-resistivity imaging logging technology,the roof lithology identification of certain coalbed methane pro-duction area in the eastern margin of Ordos Basin is carried out,the identification chart of coal seam roof lithology and fracture is estab-lished,the direction of ground stress is analyzed,and the favorable roof combination type is put forward.The result show that combining conventional logging data and electrical imaging characteristics,10 types of lithology such as conglomerate,sandstone and mudstone are effectively distinguished based on static electrical image,corresponding to different Gamma and acoustic time logging results.The coal seam roof in the study area is dominated by mudstone,followed by sandstone.The cracks in the roof of the coal seam mainly develop high-conductivity joints and induced joints.The high-conductivity joints are shown as sine curves,including open joints and muddy filling joints.The induced joints are arranged in feathers or geese,which can be used to determine the direction of stress.Combined with the thickness of roof lithology and the development of cracks,three types of coal seam roof combinations with different sealing properties can be divided.Among them,the electrical imaging image of type I roof is generally bright and the cracks are less developed.Type II roof de-velops more cracks.Type III roof image shows that the cracks are cut and the image is not clear.Based on the above work,the distribution of three types of roof combination conditions in the study area is divided.In the deep area,it is mainly I and II,which has good sealing per-formance.The above work clarifies the display characteristics of different lithologies in electrical imaging logging,and proposes a deep coal seam

关 键 词：微电阻率成像测井 顶板岩性 裂缝 地应力 封盖性 

分 类 号：TD712[矿业工程—矿井通风与安全] P618.11[天文地球—矿床学]