丛式井定向钻井造斜工具面的优化控制分析

Analysis of Optimized Control of Whipstocking Tool Face in Cluster Well Directional Drilling

丛式井钻进时直井段不能完全打直,造成造斜点处井斜方位角偏离较远。如果在造斜点处直接朝着目标方位定向造斜,受井眼惯性的影响,井底不能及时靠近设计线,从而使丛式井防碰问题更加严重。为此,从整个平台的安全角度出发,结合"三维绕障"方向计算模型,确定了初始定向工具面的安全范围,同时结合BZ34-4WP平台讨论了定向工具面不在确定的范围内时对井眼轨迹控制的影响。分析结果表明,考虑平台槽口整体安全情况和直井段轨迹数据以及目标井斜方位后,确定出初始定向工具面角的安全范围更为科学。

The straight section of cluster well cannot be straightened in drilling, resulting in the remarkable de- viation of drift azimuth at the deflection point. If directional whipstocking is conducted directly toward the target po- sition at the point, the hole bottom cannot approach the design line on time due to the hole inertia. As a result, the anti-collision problem in cluster wells will be more serious. Therefore, starting from the safety of the entire platform, the safety scope of initial directional tool face was determined referring to the calculation model of the ＂three-dimen- sional detouring barrier＂ direction. Meanwhile, the effect of directional tool face on hole trajectory beyond the deter- mined scope was discussed referring to the BZ34 -4WP platform. The analysis shows that it is more scientific to de- termine the safety scope of initial directional tool face angle after considering the overall safety condition of platform notch, straight section trajectory data and target well deviation direction.