基于机械比能聚类分析的深层煤岩水平段岩性判识方法  

Lithology identification of deep coal horizontal section based on mechanical specific energy cluster analysis

作　　者：熊冬 王翔[2] 马新仿[1] 张士诚[1] 王雷 张遂安[1] 郭天魁[4] 刘美娟 贺甲元 XIONG Dong;WANG Xiang;MA Xinfang;ZHANG Shicheng;WANG Lei;ZHANG Suian;GUO Tiankui;LIU Meijuan;HE Jiayuan(College of Petroleum Engineering,China University of Petroleum-Beijing,Beijing 102249,China;Sinopec North China petroleum Company,Zhengzhou,Henan 450006,China;College of Petroleum Engineering,Yangtze University,Wuhan,Hubei 430100,China;School of Petroleum Engineering,China University of Petroleum-East China,Qingdao,Shandong 266580,China;School of Electrical Engineering,Xi'an Jiaotong University,Xi'an,Shaanxi 710065,China;Sinopec Petroleum Exploration&Production Research Institute,Beijing 100083,China)

机构地区：[1]中国石油大学(北京)石油工程学院,北京市102249 [2]中国石化华北分公司 [3]长江大学石油工程学院 [4]中国石油大学(华东)石油工程学院 [5]西安交通大学电气工程学院 [6]中国石化石油勘探开发研究院,北京市100083

出　　处：《天然气工业》2025年第2期114-124,共11页Natural Gas Industry

基　　金：中国石化科技部攻关课题项目“深部煤层气钻井与增产技术研究”(编号:P23207);国家自然科学基金基础科学中心项目“超深特深层油气钻采流动调控”(编号:52288101)。

摘　　要：中国2000 m以深的深层煤岩气地质条件复杂,钻井易垮塌,导致水平井随钻地质导向工具难以使用,而基于岩屑分析钻遇岩性基本依赖经验且存在滞后性,水平井钻探过程中钻头易偏离优质煤岩储层。为此,考虑摩阻与水力能量影响对井口钻井参数进行了修正,得到井底钻头破岩参数与机械比能,然后结合导眼井测井岩性解释成果确定不同岩性地层中井底钻头破岩参数与机械比能范围,最后基于灰色聚类分析理论,形成了基于机械比能聚类分析的深层煤岩水平段岩性判识方法。研究结果表明:①不同岩性的钻井参数与机械比能具有明显的区分度,煤岩中钻进时具有高钻速、低钻时、低转速、低机械比能的特征;②选取扭矩、钻时与机械比能作为钻头在顶板石灰岩、煤岩与底板泥岩中钻进的岩性判识聚类指标,采用熵权法确定聚类指标权重,误判的深度位置数量仅占整个导眼井数据的5.63%;③X井钻遇石灰岩段总长度约125 m,判识结果与实际结果相差5 m,误差为4%,Y井水平段全部钻遇煤岩,2口井的判识结果与实际岩屑分析结果相符合。结论认为,基于机械比能聚类分析的深层煤岩水平段岩性判识方法具有需求数据量小、计算过程简单、速度快的特点,可以满足深层煤岩钻井实时、快速钻遇地层岩性判识的需求,有助于煤岩气水平井段钻遇率的提高,对煤岩气规模效益开发具有重要现实意义。The deep coal-rock gas reservoirs below 2000 m in China have complicated geological conditions,and the coal seam is prone to collapse during the drilling process,making it difficult to apply geosteering tool for horizontal well while drilling.The analysis of drilled lithologies based on cuttings basically depend on experience and is lagged,so the drill bit easily deviates from the high-quality coal rock reservoirs in the process of horizontal well drilling.To solve these problems,this paper modifies the wellhead drilling parameters,with consideration of the effect of friction and hydraulic energy,and obtains drill bit's rock breaking parameters and mechanical specific energy at the bottom hole.Then,the rock breaking parameters and mechanical specific energy range of drill bit at the bottom hole in different lithologies are determined based on the results of logging lithology interpretation in the pilot borehole.Finally,a method for lithology identification of deep coal horizontal section based on mechanical specific energy cluster analysis is developed according to the theory of gray cluster analysis.The following results are obtained.First,different lithologies have apparent differentiation in drilling parameters and mechanical specific energy.The drilling in coal rocks is characterized by high ROP,short drill time,low rotation speed and low mechanical specific energy.Second,torque,drill time and mechanical specific energy are selected as the lithology identification cluster indexes for the drilling of drill bit in roof limestone,coal and floor mudstone,and the entropy weight method is used to determine the weights of cluster indexes,with the misjudged depth positions only accounting for 5.63%of the whole pilot borehole.Third,the limestone sections drilled in Well X is totally 125 m long,which is 5 m different from the identification result,i.e.,an error of 4%.The horizontal section of Well Y completely runs through coal rocks.The identification results of these two wells are accordant with the actual cuttings a

关 键 词：深部煤层(岩)气 机械比能 钻井工程 水平井 灰色理论 聚类分析 岩性判识 

分 类 号：TE242[石油与天然气工程—油气井工程]