高性能水基钻井液在大庆油田致密油藏水平井中的应用

Application of High-Performance Water-Based Drilling Fluid for Horizontal Wells in Tight Reservoirs of Daqing Oilfield

侯杰 刘永贵 李海

Hou Jie Liu Yonggui Li Hai

中国石油大庆钻探工程公司钻井工程技术研究院, 黑龙江大庆 163413

Research Institute of Drilling Engineering & Technology, CNPC Daqing Drilling and Exploration Engineering Company, Daqing, Heilongjiang, 163413, China

针对大庆油田中浅层致密油藏水平井钻井过程中常发生造浆、缩径和剥落掉块等问题,在对致密油储层岩心进行电镜扫描、铸体薄片分析等的基础上,利用聚胺、聚合醇的"两元协同"作用提高钻井液的抑制性,利用常规物理封堵与聚合醇化学封堵相结合的"双效"封堵作用提高钻井液对微裂缝的封堵能力。采用宏观与微观相结合的抑制性评价方法优选了聚胺抑制剂,并选用与其具有良好配伍性的聚合醇等处理剂,形成了抑制性突出、封堵能力强和润滑性良好的高性能水基钻井液。室内试验结果表明,高性能水基钻井液泥页岩滚动回收率大于95%,缝宽10~50 μm的微裂缝累计出液量小于2 mL,极压润滑系数仅为0.10。该钻井液在大庆油田致密油藏的9口水平井进行了应用,均效果显著,其中龙26-平9井的井径扩大率仅为9.31%,最高机械钻速达10.58 m/h。研究表明,高性能水基钻井液能够满足大庆油田致密油藏的钻井需求。

During the drilling of middle-shallow tight oil reservoirs in the Daqing Oilfield, mud making, hole shrinkage, caving and other downhole complications are frequently observed. To evaluate the problem, SEM and cast slice analyses were performed on core samples taken from tight reservoirs, and synergistic effects of polyamine and polyalcohol were used to enhance the inhibition performances of drilling fluids. By jointly using conventional physical plugging techniques and chemical plugging using polyalcohol, the plugging performances of drilling fluids in micro-fractures were enhanced significantly. By using assessment techniques with a combination of macrofacies and microfacies, polyamine inhibition additives with optimal performances were identified. In addition, with deployment of polyalcohol and other additives with satisfactory compatibility, a high-performance water-based drilling fluid with outstanding inhibition and plugging performance was generated. Lab test results showed that the high-performance water-based drilling fluid had rolling recovery rates above 95% for shale, with total fluid production from micro-fractures with sizes of 10-50 μm less than 2 mL, and with lubrication coefficients under extreme pressures at merely 0.10. The new drilling fluid was then deployed in 9 wells drilled in tight oil reservoirs in the Daqing Oilfield where it achieved outstanding performance.In Well Long26-Ping9, an expansion of the borehole diameter was no more than 9.31%, whereas the highest ROP was 10.58 m/h. Research results showed that the high-performance water-based drilling fluid could meet demands for development of tight oil reservoirs in the Daqing Oilfield.

https://doi.org/10.11911/syztjs.201504011