延长油田致密油藏水平井强封堵钻井液优选 与现场应用 与现场应用 与现场应用

Optimization and Application of Strong Plugging Drilling Fluid for Horizontal Well in Tight Oil of Yanchang Oilfield

张文哲 李 伟 王 波 刘 云

ZHANG Wenzhe LI Wei WANG Bo LIU Yun

为了加快致密油开发进程和提高延长油田致密油藏水平井钻井技术，针对现阶段延长油田致密油藏钻井所用的聚丙烯酰胺钾盐（K-PAM）聚合物钻井液体系存在流变性不佳、封堵和抑制性不足等缺点，室内对现场常用降滤失剂、抑制剂、润滑剂、封堵剂等处理剂进行优选，获得适合致密油藏使用的强封堵型纳米聚合醇水基钻井液配方，并在现场进行了应用。结果表明，聚合物降滤失剂COP-FL可显著提高体系失水造壁性，无荧光防塌润滑剂FT342抑制性较强，液体极压润滑剂JM-1整体润滑效果好，复配封堵剂无水聚合醇WJH-1和纳米乳液RL-2 可使钻井液封堵率提高 51.7%，增强井壁稳定性；将配方为 4%钠膨润土+0.2%纯碱+0.4% K-PAM+2%COP-FL+1.5% FT342+1.0% JM-1+5% WJH-1+3% RL-2的水平段强封堵型钻井液体系用于延长致密油藏两口水平井现场试验，施工过程中体系防漏失、封堵效果较好，机械钻速相比邻井提高30%，施工周期缩短35%，井下事故率降低85.7%，钻井成本减少34.7%，为延长油田致密油藏水平井的优快钻井提供了有效的技术支持。图1表4参19

In order to speed up the development of tight oil and improve the horizontal well drilling technology of tight reservoir in Yanchang oilfield，meanwhile，aiming at the polyacrylamide potassium salt（K-PAM）polymer drilling fluid system used in the current stage of Yanchang oilfield had shortcomings such as poor rheology，insufficient plugging and inhibition，the indoor optimization of the commonly used fluid loss reducer，inhibitor，lubricant，plugging agent and other treatment agent was preferred to obtain a formula of strong plugging type nano-polymeric alcohol water-based drilling fluid suitable for tight reservoir. Finally，the drilling fluid was applied in the field. The results showed that the polymer fluid loss additive COP-FL could significantly improve the water loss and wall-forming property of the system. The non-fluorescent anti-collapse lubricant FT342 had strong inhibition. The liquid extreme pressure lubricant JM-1 had good overall lubrication effect. And blocking agent anhydrous polymeric alcohol WJH-1 and nano-emulsion RL-2 could increase the drilling fluid blocking rate by 51.7%，which could enhance the wellbore stability. The horizontal section strong plugging type drilling fluid system，whose formula was 4% sodium bentonite，0.2% soda ash，0.4% K-PAM，2% COP-FL，1.5% FT342，1.0% JM-1，5% WJH-1 and 3% RL-2，was applied to two horizontal wells in tight reservoir of Yanchang oilfield. During the construction process，the system had good leakage prevention and sealing effect. The mechanical drilling speed increased by 30% compared with the adjacent one，the construction period shortened by 35% ，the downhole accident rate reduced by 85.7%，and the drilling cost reduced by 34.7%，which provided effective technical support for the excellent drilling of horizontal wells in tight reservoir of Yanchang oilfield.

10.19346/j.cnki.1000-4092.2019.02.001