伊拉克哈法亚油田Mishrif组碳酸盐岩储层防漏堵漏技术

为了解决哈法亚油田Mishrif组碳酸盐岩裂缝溶洞型储层钻进过程中钻井液漏失严重的问题，根据该油田的地质和地层特征，分析了裂缝类型、漏失因素和漏失程度，根据目标区域漏失速率统计结果，结合现场实际，进行了漏失类型区域划分；针对不同漏失类型区域优选堵漏材料和堵漏浆配方，形成了渗漏区、部分漏失区的防漏堵漏技术，恶性漏失区、完全漏失区的综合治理技术。2019年以来，Mishrif组碳酸盐岩储层防漏堵漏技术在21口定向井进行了应用，与前3年未用该技术时的平均水平相比，每口井平均漏失量由472 m3降至29 m3，复杂时率降低12.5%，钻井周期缩短8.5%，取得了良好的现场应用效果。Mishrif组碳酸盐岩储层防漏堵漏技术为解决其他区块碳酸盐岩裂缝溶洞型储层钻井漏失难题提供了技术途径。 

Antileaking and Lost Circulation Control Technology for the Mishrif Carbonate Reservoir in the Halfaya Oilfield of Iraq

In order to solve the problem of mud loss in the drilling operations of fractured-vuggy Mishrif carbonate reservoirs in the Halfaya Oilfield, we analyzed such elements as fracture type, leakage factors, and degree of leakage according to the geological and formation conditions of the Halfaya Oilfield. The target area was classified and then zoned in terms of leakage type based on leakage rate statistics and field investigation. In addition, plugging materials and formulas were optimized for different leakage zones, forming the prevention and control technology of the leakage and partial leakage areas as well as the comprehensive treatment technology for the massive leakage area and the complete leakage area. This technology was applied in 21 directional wells in Mishrif carbonate reservoirs since 2019 and resulted in a satisfying application effect. Compared with 2016-2018, the mud loss per well has dropped from 472 m3 to 29 m3 ; complex well drilling dealing time rate has been cut by 12.5%; and drilling cycle has been reduced by 8.5%. This technology provides guidance in the form of a reference for solving the problem of mud loss in the drilling of fractured-vuggy carbonate reservoirs in other similar blocks.