元坝101-1H 酸性气藏超深水平井优快钻井技术

摘要

In line with the problems of low drilling rate in continental high pressure formations, severe fluid loss in marine pay zone and difficulty in geosteering in ultra-deep HTHP wells during drilling of ultra-deep horizontal wells into Yuanba sulfur-containing gas pools, the Yuanba 101-1H Well realized effective increase in drilling rate in hard land formation of tight sandstone, through extending the depth of gas drilling, using torque impactor and composite drilling technology of straight screw combined with PDC drilling bit;the use of equal-wall thickness straight screw together with EM1316 PDC drilling bit effectively increased the drilling rate in straight hole section in marine homogeneous formation of high strength and low abrasiveness. The use of adjustable high temperature screw in horizontal section, in conjunction with under-gauge double-stabilizer angle holding assembly, not only improved composite drilling rate, but aslo ensured the overall dogleg severity of the wellbore, equal to the rotary steering drilling tool in effectiveness. The double-effect wear-proof technique reduced the wear on casing and ensured the sealing performance of the string. The result of field application shows that the total depth of Yuanba 101-1H Well is 7 971 m and its vertical depth is 6 946.44 m, which is a new record in drilling and completion depth in ultra-deep horizontal wells with high sulfur content in Yuanba work area; the drilling cycle was 380 d, 54 d shorter than the designed cycle and 149.92 d shorter than the average drilling period of the previous development and appraisal horizontal wells;the increase in drilling rate was remarkable, providing favorable experiences for drilling of similar wells.%针对元坝高含硫气藏超深水平井钻井过程中存在的陆相高压层钻速慢、海相产层漏失严重、超深高温高压定向困难等问题，元坝101-1H 井通过延伸气体钻井深度、应用扭力冲击器和直螺杆配合 PDC 钻头复合钻井技术，实现了陆相致密砂岩硬地层的有效提速；采用等壁厚直螺杆配合 EM1316 PDC 钻头，实现了海相高强度低研磨均质地层直井段有效提速；在水平段采用可调式抗高温螺杆，配合欠尺寸双稳定器稳斜钻具组合，既提高了复合钻进比例又保证了井眼全角变化率，效果相当于旋转导向钻井工具；采用双效防磨技术，减少了套管磨损，保证了管柱密封性能。现场应用结果表明，元坝101-1H 井完钻井深7971 m、垂深6946.44 m，创元坝工区高含硫超深水平井完钻井深最深记录；钻井周期380 d，较设计周期缩短54 d、较前期开发评价水平井平均周期缩短149.92 d，提速效果显著，为同类井的施工提供了较好的经验。