可控胶凝堵漏剂的研究与应用

Study and Application of Gel-time Controllable Lost Circulation Material

针对重庆涪陵焦石坝区块页岩气开发过程中,从钻表层至完钻频繁发生溶洞、裂缝性恶性漏失,且堵漏成功率低的难题。中原固井公司通过对堵漏胶凝材料、触变剂、纤维增韧剂、膨胀剂、微胶囊及表面调节剂等材料的研究,研制出一种可控胶凝堵漏剂,并在室内对其堵漏性能、机理进行了评价、分析。可控胶凝剂对渗透性、大孔道、裂缝性和溶洞性漏失地层具有很好的堵漏效果。该堵剂适应温度为30～80℃,凝结时间可调,固化体强度常压4 h可达到5.0 MPa,8 h强度达到10 MPa以上,承压强度大于14 MPa,并具有抗水侵能力和强触留能力。现场应用的45口井,堵漏成功率达到了80%以上。可控胶凝堵漏剂为溶洞、裂缝性漏失堵漏的探索作出了积极的贡献。

In the development of theshale gas in Jiaoshiba, Fuling, Chongqing, mud losses into solution cavities or fractures have occurred frequently during the whole drilling process, and the mud losses were very difficult to be stopped. A gel-time controllable lost circulation material （LCM） has been developed for use in this area to try to control the severe mud losses. This LCM is formulated with gel materials, thixotropic agents, fibers, swelling agents, microcapsules and surfactants. The performance and mechanism of this LCM in mud loss control have been evaluated and analyzed. This gel-time controllable LCM is suitable for controlling mud losses into formations with high permeability, large-sized pores, fractures, or solution cavities. This LCM works in a temperature range of 30-80℃, and has adjustable gel time. When solidified, the LCM has compressive strength of 5.0 MPa （4 h） and 10 MPa （8 h）. Pressure bearing capacity of the set LCM is 14 MPa. The set LCM is striongly resistant to water corrosion and has strong thixotropy. 80% of mud losses in 45 wells have been successfully brought under control. This gel-time controllable LCM has played a great role in controlling mud losses into solution cavity and fracture.