定向随钻扩孔钻压分配及优化

深井大斜度井扩孔难题一直没得到较好解决,传统的方法是采用液力扩眼工具进行钻后扩孔。然而,钻后扩孔实践表明,随着井斜增加,钻后扩孔难度增大,钻后扩孔在定向井中一般在32°以内。为此,引进了53/4 in×51/2 in×43/4 in CSDR5211S-B2定向随钻扩孔钻头。扩孔钻头钻压分配关系对工具面稳定和机械钻速具有重要影响。介绍了定向随钻扩孔钻头特性,分析了钻压分配关系,并对钻压分配进行优化。优化后的钻压应用于塔河油田TH10410CH2井定向随钻扩孔试验。应用结果表明,根据扩孔钻头偏心部分所要求钻压,计算出定向随钻扩孔钻头施工最大钻压不超过40 kN;在20～40 kN钻压工况下,定向随钻扩孔钻进过程中无憋跳现象、工具面平稳、井眼轨迹平滑、机械钻速高,说明该井优化的钻压合理。

WOB Distribution and Optimization in the Directional Reaming While Drilling

The reaming difficulty in deep wells and highly deviated wells has so far not yet been solved satisfactorily.The traditional method is to use hydraulic reamer to carry out post-drilling hole enlargement.However,the post-drilling reaming practice shows that with the increase in hole inclination the difficulty increases in post-drilling reaming.Post-drilling reaming is generally conducted within 32° in directional wells.Therefore,the 5 3/4 in×5 1/2 in×4 3/4 in CSDR5211S-B2 directional reaming while drilling(DRWD) reamer bit was introduced.The reamer bit pressure distribution relation has remarkable effect on tool face stability and rate of penetration.The property of DRWD bit was introduced.The WOB distribution relation was analyzed,thereby the WOB distribution was optimized.The optimized result was applied in the DRWD test in Well TH10410CH2 in Tahe Oilfield.The application shows that the maximum DRWD WOB in operation is no more than 40 kN according to the WOB required by the eccentric part of reamer bit.Under the WOB condition of 20~40 kN there is no pressure building and boost in the process of DRWD.The tool face is stable,the hole trajectory is smooth and the rate of penetration is high.This indicates that the optimized WOB for this well is reasonable.