影响煤层气单支压裂水平井产量关键要素及提产对策——以郑庄区块开发实践为例  

Analysis of key elements affecting production and technical countermeasures to increase production of CBM fractured single horizontal wells:A case study of Zhengzhuang Block

作　　者：张晨 何萌 肖宇航 刘忠 韩晟 鲁秀芹 王子涵 吴浩宇 张倩倩 ZHANG Chen;HE Meng;XIAO Yuhang;LIU Zhong;HAN Sheng;LU Xiuqin;WANG Zihan;WU Haoyu;ZHANG Qianqian(CBM Exploration and Development Pilot Test Base,China National Petroleum Corporation,Renqiu 062552,China;Exploration and Development Research Institute,PetroChina Huabei Oilfield Company,Renqiu 062552,China)

机构地区：[1]中国石油天然气集团有限公司煤层气开采先导试验基地,河北任丘062552 [2]中国石油华北油田公司勘探开发研究院,河北任丘062552

出　　处：《煤炭科学技术》2024年第10期158-168,共11页Coal Science and Technology

基　　金：中石油前瞻性、基础性技术攻关资助项目(2021DJ2301)。

摘　　要：单支压裂水平井作为沁水煤层气田煤层气开发主体技术,支撑了气田20亿m~3/a产气量的突破。但在其规模推广应用过程中,出现井间产量差异大,局部区域适应性欠佳等系列问题,严重制约了气田煤层气产量进一步提升。一方面,众多影响单支压裂水平井产气量的关键要素已被确认,但核心关键要素却不明确;另一方面,关键要素的平面变化规律认识,普遍为简单数学外推或纯粹数学反演,缺少地质约束和修正,可靠性和分辨率低。故亟需落实影响产量核心关键要素,以此为基础建立针对性提产技术对策。首先,基于郑庄区块客观地质条件和开发生产实践认识,提出影响单支压裂水平井产量的核心关键要素初步筛选原则,并评选出纯煤层进尺、水平段倾斜幅度、全烃、GR(自然伽马)、压裂段数、平均砂量梯度、平均排量梯度、平均液量梯度、解吸压力梯度9项要素。用灰色关联分析和单因素分析方法,明确初筛9项要素与单支压裂水平井产气量间的关联程度,落实要素对产量影响的内在机制。其次,从资源基础、储量控制和改造动用3个角度,结合单支压裂水平井部署和改造设计和施工具体流程分类9项要素,并依此建立针对性的提产技术对策。在井位部署阶段,利用评价井外推资料,初步明确相对富集区域,用构造导向滤波+高频相干技术处理地震资料,圈定无隐蔽性破坏构造发育区,再钻直/斜井以获取煤层段GR和全烃,落实井位部署区资源基础;在井轨迹设计和钻井阶段,利用波形聚类技术预测井位部署区内构造煤分布规律,对地震资料叠前深度偏移处理预测井位部署区内煤层厚度和起伏变化规律,用井组模式,分批次钻井,结合近钻头地质导向技术,实钻数据实时修正局部煤层认识,增加纯煤层进尺,优化井轨迹,确保更多优质压裂段,提高储层控制;在储层改造阶段,通过GR、全烃�As the main technology of CBM development in the Qinshui CBM field,single-branch fractured horizontal wells have supported the breakthrough of 2 billion m3/year production of gas field.However,in the process of its large-scale application,there have been a series of problems,such as large difference in production among wells and poor adaptability in local areas,which seriously restrict the further improvement of CBM production in gas fields.On the one hand,although many key elements affecting the production of singlebranch fractured horizontal wells have been identified,the core key elements are not clear.On the other hand,the understanding of the change rule of key elements on the plane is generally simple mathematical extrapolation or pure mathematical inversion,which lacks geological constraints and corrections,and has low reliability and resolution.Therefore,it is urgent to clear the core key elements that affect the production,and then establish targeted technical countermeasures on this basis.First of all,based on the objective geological conditions and the understanding of development and production practice in the Zhengzhuang block,the preliminary screening principle of the core key elements affecting the production of single−branch fractured horizontal wells was proposed,and nine elements were selected,including drilling length in pure coal seam,horizontal section inclination,total hydrocarbon,GR,number of fracturing stages,average sand gradient,average displacement gradient,average fluid volume gradient and desorption pressure gradient.Then,grey correlation analysis and single element analysis were used to determine the correlation degree between the nine elements of the preliminary screening and the production of single−branch fractured horizontal wells,and determine the internal mechanism of the elements'influence on the production.Secondly,from the three perspectives of resource base,reserve control and reconstruction,combined with the specific process of a singlebranch fractured horizontal well

关 键 词：单支压裂水平井 煤层气产量 灰色关联分析 单因素分析 提产技术对策 现场先导试验 

分 类 号：TD713[矿业工程—矿井通风与安全]