超低侵害油气层保护剂NPL-2的研制及应用

The Development and Application of Ultra-low Permeability Reservoir Protection Agent NPL-2

室内通过对骨架材料和聚合物成膜材料的优选,研制出了超低侵害油气层保护剂NPL-2,并评价了超低侵害钻井液对砂床及微裂缝的封堵效果。结果表明,NPL-2具有广谱的封堵承压能力,加入3%NPL-2的钻井液在粒径为0.45-0.90 mm的模拟砂床中的侵入深度小于5 cm,可以封堵0.4 mm的人造裂缝,2-4 min内形成的超低侵害泥饼承压能力大于10 MPa;用西部地区岩心进行渗透率恢复实验,渗透率恢复值达90%以上,具有良好的油气层保护能力;在高温高压条件下依然具有好的封堵承压能力,可用于深井复杂地层中。NPL-2在大古1井、AD7井、元坝5井等进行了现场应用,成功解决了长裸眼井段的承压问题,提高了钻井液的油气层保护效果。

NPL-2,a permeability protection agent for ultra-low permeability reservoirs was developed through laboratory study.Evaluation of NPL-2 using sand pack and micro-fracture showed that NPL-2 has a wide application in sealing/plugging and pressure containment.A drilling fluid treated with 3% NPL-2 had an invasion depth of less than 5cm in a sand pack of 0.45～0.90 mm particle sizes.NPL-2 can seal an artificial fracture of 0.4 mm width,and the pressure containment of the internal mud cake formed with the drilling fluid in 2～4 min was as high as 10 MPa.Permeability recovery on a core was about 90%.NPL-2 functions well at high temperatures and thus can be used in deep wells.The application of NPL-2 in Well Dagu-1,Well AD7,and Well Yuanba5 was very successful.