中文摘要：

针对丛式井侧钻水平井设计过程中需要避开已钻障碍井的问题,分别根据障碍井段为直井段和定向井段,将障碍物抽象为圆柱和圆环模型,运用矢量代数给出了障碍物轴线方程,并根据侧钻点方向线、靶点方向线与障碍物是否相交,确定绕障井的剖面类型。以绕障轨道总长度最短为优化目标,以绕障轨道距障碍物的最近距离、最大井斜变化率、最大方位变化率以及最大井眼曲率为约束条件,建立了丛式井侧钻绕障水平井轨道最优化设计模型。根据不同的绕障类型进行了实例计算,结果表明所提出的最优化模型能够得到井眼轨道总长度最短的轨道,并满足安全绕障距离及井斜变化率、方位变化率、井眼曲率的要求。该方法避免了复杂的试算和校核,并且适用于其他类型绕障井的轨道设计。

英文摘要：

There is the problem to bypass obstacle in the sidetracking horizontal well trajectory design of cluster well, which makes the trajectory design process become complicated. The obstacles are assumed to be drilled vertical well section and directional well section, and they are described as a part of cylinder and annulus separately. The axis equations of the obstacles are obtained using vector alge- bra. The trajectory types of the bypassing obstacle horizontal well are determined according to the geometrical relationships between the directional line of sidetracking point, the directional line of target point and the axis of obstacle. Taking the shortest bypassing obstacle trajectory length of the horizontal well as objective function, taking the nearest distance between the bypassing obstacle trajectory and the obstacle well section, the maximum deviation rate, the maximum azimuth change rate and the maximum borehole curvature as con- straints, the optimum design model for sidetracking horizontal well bypassing obstacle in cluster well was established. The case calcula- tion results of different trajectory types of bypassing obstacle horizontal wells show that the shortest borehole trajectory which meets the requirements to safe bypassing distance, deviation rate, azimuth change rate and borehole curvature can be obtained using the estab- lished optimum model. The optimum design method avoids complex trial calculation and check, and it is also applicable to the trajectory design of other types of bypassing obstacle wells.