密集井网直井段井眼轨道交碰风险计算新方法  

A new method for calculating the wellbore collision risk of vertical sections of dense cluster wells

作　　者：李琪[1] 刘毅 王六鹏[1] 高云文[3] 张燕娜[3] 张明[1] LI Qi;LIU Yi;WANG Liupeng;GAO Yunwen;ZHANG Yanna;ZHANG Ming(College of Petroleum Engineering,Xi'an Shiyou University,Xi’an 710065,Shaanxi,China;No.2 Gas Production Plant,PetroChina Changqing Oilfield Company,Yulin 719000,Shaanxi,China;Oil and Gas Technology Institute,PetroChina Changqing Oilfield Company,Xi’an 710018,Shaanxi,China)

机构地区：[1]西安石油大学石油工程学院,陕西省西安市710065 [2]长庆油田分公司第二采气厂,陕西省榆林市719000 [3]长庆油田分公司油气工艺研究院

出　　处：《石油钻采工艺》2021年第1期29-33,共5页Oil Drilling & Production Technology

基　　金：国家自然科学基金“基于多源信息和智能计算的钻井异常自适应预警方法研究”(编号:51574194)。

摘　　要：井眼防碰是密集丛式井网定向井施工面临的一个主要难题,为了有效减小密集井网加密井直井段井眼交碰风险,综合考虑名义间距、基准井和比较井的井径之和以及邻井数等因素,在分析Brooks运用概率评价井眼交碰方法的基础上,提出了比较全面的密集丛式井网井眼交碰风险计算新方法。该方法以基准井井眼中心轴线为圆心、基准井与比较井间名义间距为半径作圆,通过基准井、比较井井径之和与此圆周长的比值计算偏移概率,采用井眼测点位置坐标的正态分布概率密度函数沿井深方向的定积分计算交碰概率,基准井与比较井的实际交碰概率为偏移概率与交碰概率的乘积,通过基准井与各比较井实际交碰概率求和确定综合交碰风险,并将综合交碰风险按照行业标准划分为3个风险等级,得到以综合交碰风险为评价指标的风险评价方法。该方法可定量评价一口基准井与多口比较井之间的综合交碰风险,对加密井钻井防碰理论研究及指导生产实践具有重要意义。Wellbore anti-collision is an important difficulty in the construction of directional wells of dense cluster wells.In order to effectively reduce the collision risks of the vertical sections of the infill wells of dense cluster wells,a new comprehensive method for calculating the wellbore collision risks of dense cluster wells was put forward by considering nominal spacing,diameter sum of reference well and comparison well and number of neighboring wells comprehensively after the probability based Brooks wellbore collision evaluation method was analyzed.In this new method,a circle is set by taking the central axis of the wellbore of reference well as the center and the nominal spacing between reference well and comparison well as the radius.Migration probability is calculated by using the ratio of the diameter sum of reference well and comparison well to the circumference of the circle,and the collision probability is calculated by using the definite integral of the probability density function of normal distribution at the coordinate of wellbore measurement point in the direction of well depth.The actual collision probability between reference well and comparison well is the product of the migration probability and the collision probability.The comprehensive collision probability is determined by summing the collision probability between the reference well and each comparison well,and it is classified into three risk levels according to industry standards.In this way,a collision risk evaluation method that takes the comprehensive collision risk as an evaluation index is developed.This method can quantitatively evaluate the comprehensive collision risk between a reference well and multiple comparison wells,and is of important significance to anti-collision theory research and production practice guidance of infill wells.

关 键 词：密集井网 加密井 交碰概率 计算方法 

分 类 号：TE24[石油与天然气工程—油气井工程]