Abstract: To exactly calculating the build rate of building motor assemblies and others is a key point of correct prediction and control for bit trajectory in horizontal drilling.Based on analysis of many prediction methods and research of distingufshing feature of horizontal drilling,a new method,named limiting curvature is presented in this paper to determine the build rate of bottom hole assemblies,including to bent housing motors and others.A discussion and comparison was made between the three point geometry and limiting curvature.This method in introduced in this paper also.Furthermore,applications of the new method are given on calculating the build rate and choosing tools,designing configuration of the bent housing motors,predicting and controlling of bit trajectory in both horizontal and directional drillings.

Key words: horizontal well, trajectory control, trajectory prediction, study

摘要： 水平井井眼轨道预测和控制问题的技术关键是准确计算各种造斜工具的造斜能力.在综合分析定向井轨道预测方法和水平井预测控制特点的基础上,提出了一种计算导向动力钻具和各种转盘钻钻具组合造斜能力的新方法——“极限曲率法”,并对国际上当前流行的“三点定圆法”及极限曲率法作了讨论和对比;给出了极限曲率法在计算工具造斜能力和工具选型、系列工具的总体设计和井眼轨道的预测控制这三方面的应用实例,表明该方法是一种与实践相符程度较高、实用性较好的新方法.

关键词: 水平井, 轨道控制, 轨道预测, 分析研究