钻孔走向偏斜的初步探讨

AN APPROACH ON THE BORBHOLE TREND DEVIATON

在急倾斜构造部位大力使用硬合金回转钻进时,常常会产生弯曲度很大的走向偏斜情况。这是因为不同岩层的阻力差异使钻头受到一种平行于岩层走向的偏斜力,迫使钻头向侧方研磨井壁;在不同井径变换部位所产生的偏斜效果是不同的。这样造成钻孔沿地层走向发生有规律的定向偏斜。

Trend deviation with greater flexibl(?)ity often occurs when rotary drilling with hard alloy is employed at the position of high-dipping structure. Because of the diffe- rence in the resistance of rock stratum, a deviation force paralleling to the rock stratum acts on the drill, Consequently, the drill is forced to abrade the lateral side of the well wall. At different positions, changes in well dimension cause different deviation affects. Hence, the borehole would go along the stratum with regular, driectional de- viation.