浅层煤层气大平台井眼轨迹整体优化设计技术的应用--以保德区块保8井区为例  

Application of overall optimized design technology for shallow coalbed methane large platform wellbore trajectory:A case study of Bao 8 wellblock in Baode block

作　　者：曹振义 李世超 苗强 马科迪 衣丽伟 樊洪波 CAO Zhenyi;LI Shichao;MIAO Qiang;MA Kedi;YI Liwei;FAN Hongbo(China United Coalbed Methane National Engineering Research Center Co.,Ltd.,Beijing 100028,China;Xinzhou Gas Production Management Area,PetroChina Coalbed Methane Co.,Ltd.,Xinzhou,Shanxi 036699,China;Peripheral Exploration and Development Branch,PetroChina Coalbed Methane Co.,Ltd.,Yinchuan,Ningxia 750004,China)

机构地区：[1]中联煤层气国家工程研究中心有限责任公司 [2]中石油煤层气有限责任公司忻州采气管理区 [3]中石油煤层气有限责任公司外围勘探开发分公司

出　　处：《录井工程》2025年第1期56-62,共7页Mud Logging Engineering

摘　　要：保8井区位于鄂尔多斯盆地东缘晋西挠褶带北段的保德区块,为浅层煤层气勘探开发区域。因目的层埋深浅、地层倾角大、构造变化复杂,加之井场空间有限、井位密集,导致井区钻井施工面临钻井防碰、高位垂比、大摩阻扭矩和井眼清洁困难等难题。为此,采用Landmark钻井工程设计系统进行深入分析,通过计算特定入靶井斜角、靶点埋深及靶前距条件下的造斜率与稳斜段井斜角之间的关系,基于“提前造斜、稳斜探层、井间防碰”理念,进行井眼轨迹优化设计。即采用六段制三维井眼轨迹设计提升轨迹稳定性,通过调整造斜点位置来降低摩阻和狗腿度;采用漂浮下套管工艺来解决下套管难题,避免套管螺旋屈曲;通过“ϕ80.9 mm加重钻杆+ϕ73 mm油管+ϕ60.33 mm油管”的管串组合设计,确保压裂管柱顺利下入,减少抽油杆磨损,延长其使用寿命,提高排水降压效率。该方法成功应用于保8井区,完成了35口定向井和20口水平井的钻探,水平井平均位垂比3.15,最大位垂比5.32,无轨迹碰撞事故,储层钻遇率98.2%,井身和固井质量均达到100%优良标准。优化后的井眼轨迹在钻完井、压裂管柱下入和排采抽油杆偏磨等方面表现出良好的适应性,为构建国内首个亿方级煤层气大平台提供了坚实的技术支撑,该成功经验对于国内其他浅层煤层气勘探开发具有显著的示范效应和借鉴价值。Bao 8 wellblock is located in Baode block of the northern segment of the Jinxi flexure fold belt on the eastern margin of Ordos Basin,which is a shallow coalbed methane exploration and development area.Due to the shallow burial depth,large stratigraphic dip,and complex structural changes of the target beds,as well as limited well site space and dense well locations,the drilling construction in the wellblock faces the difficulties such as drilling anticollision,high horizontal displacement to vertical depth ratio,large drag and torque and wellbore cleaning.Therefore,the Landmark drilling engineering design system is used for indepth analysis.By calculating the relationship between the buildup rate under the conditions of specific targetentering well inclination angle,burial depth of target point and pretarget displacement and deviation angle of angle holding section,the optimized design of wellbore trajectory is carried out based on the concept of"advance deflecting,stable inclination angle finding layer and interwell anticollision".The sixstage 3D wellbore trajectory design is used to improve the trajectory stability,and the friction drag and dogleg severity are reduced by adjusting the position of deflecting point.Adopt the floating casing running technology to solve the problem of casing running and avoid the casing helical buckling.The pipe string assembly of"ϕ80.9 mm heavy weight drill pipe+ϕ73 mm tubing+ϕ60.33 mm tubing"is designed to ensure the smoothly running in fracturing pipe string,reduce sucker rod wear,prolong its service life and improve drainage depression efficiency.The method was successfully applied to Bao 8 wellblock,and the drilling of 35 directional wells and 20 horizontal wells was completed.For the horizontal wells,the average horizontal displacement to vertical depth ratio is 3.15,the maximum horizontal displacement to vertical depth ratio is 5.32,there are no trajectory collision accidents,the drilling rate of the reservoirs is 98.2%,and the quality of the wellbore and cementing is up

关 键 词：浅层煤层气 大平台 水平井 定向井 钻井防碰 井眼轨迹优化 保8井区 

分 类 号：TE132.1[石油与天然气工程—油气勘探]