JY69-4HF井轨迹控制技术优化

Optimization of Well JY69-4HF Trajectory Control Technology

Y69-4HF井是位于川东高陡褶皱带构造上的一口非常规水平井,完钻井深为4 874m,水平段长为1 328m,水平段井斜在71°~82°。水平段井斜调整范围大,增加了施工过程的难度和风险。在直井段采用塔式钟摆钻具组合达到防斜打直效果,根据实钻情况调整钻进参数,加强测斜监控,将防碰风险控制在最低;在三开定向段和水平段采用水力振荡器将定向过程中的静摩擦变为动摩擦,有效减少托压现象,显著提高机械钻速;利用随钻Gamma配合钻时、全烃值的分析有效解决Gamma滞后问题,帮助判断井底地层变化,特别是涧草沟组高井下风险地层。

Well JY69--4HF is an unconventional horizontal well located in high dipping fold--belt structure of east Sichuan. Its drilled depth is 4 874 meters, its horizontal interval, 1,328 meters and its deviation is from 71~ to 82~. Large adjustment range of horizontal interval deviation makes work progress more difficult and higher risk. Tower--type pendulum drill assembly is used in vertical interval to prevent borehole devia- tion and drive vertical well. Drilling parameters are adjusted according to real drilling to strengthen borehole surveying control and anti--collision risk control. Hydroscillator is used in the third spud--in directed seg- ment and horizontal interval to transform static friction into dynamical friction in the process of orientation to reduce backing pressure and improve the penetration rate. The analysis of drilling time and total hydrocar- bon value is matched with while--drilling Gamma to effectively solve delayed Gamma and help estimate downhole formation change, especially downhole high risk formation in Jiancaogou Formation.