准噶尔盆地玛湖地区防斜钻具组合优化设计

Optimal Design of Anti-Inclination Bottom Hole Assembly in Mahu Area,Junggar Basin

针对准噶尔盆地玛湖地区地层情况复杂、油层位置深,钻直井过程中易出现井斜的问题,基于二维纵横弯曲梁模型和平衡趋势法原理建立了防斜钻具组合防斜纠斜能力评价方法。分析了底部钻具组合结构参数、钻进参数以及地层参数和钻头各向异性对BHA(底部钻具组合)防斜纠斜能力的影响。结果表明,钟摆钻具组合和塔式钻具组合易受钻压影响;单弯螺杆导向钻具组合对钻压的适应性比较强;地层倾角是制约被动式防斜钻具组合“防斜打直”能力的主控因素。基于分析结果,以玛52井为例,进行了钻具组合优化设计,达到了降斜的目的,对玛湖地区提高钻井速度,节约成本具有实际指导意义。

Aiming at the complex formation conditions and deep oil layers in the Mahu area,the well deviation is prone to occur in the process of drilling vertical wells.Based on the two-dimensional vertical and horizontal bending beam method model and the principle of the equilibrium trend method,the author established an evaluation method for the anti-inclination and deviation-correcting ability of the anti-deviation BHA.The influences of BHA structural parameters,drilling parameters,formation parameters and bit anisotropy on the deviation correction capability of BHA are analyzed.The results show that the pendulum BHA and the tapered BHA are easily affected by the weight-on-bit;the single-bend PDM guided BHA has a relatively strong adaptability to the weight-on-bit;and the formation dip angle is the main controlling factor restricting the ability of passive anti-deflection BHA to"anti-deflect and hole straightening".Based on the analysis results,taking Well Ma52 as an example,the optimal design of the BHA was carried out to achieve the purpose of reducing the deviation,which has practical guiding significance for improving the drilling speed and saving costs in the Mahu area.