高滤失承压堵漏技术

高滤失承压堵漏技术是以高滤失堵漏剂进行封堵漏层提高地层承压能力的堵漏技术，该技术在压差作用下堵漏浆迅速滤失，形成填塞层封堵漏失通道，钻井液在填塞层表面发生滤失形成致密的泥饼，达到提高地层承压能力的目的。研制了一种高滤失堵漏剂，对钻井液流变性没有影响，堵漏浆30 s内API滤失量达180 mL以上，用重晶石粉可加重堵漏浆密度至2.3 g/cm3。室内模拟封堵不同尺寸的缝隙性漏失，承压能力达到7 MPa。高滤失承压堵漏技术进行了7井次现场试验，结果表明:该技术堵漏一次成功率达71%，堵漏时间短3～4 h，为优质高效地钻井施工提供了技术保障。 

Lost Circulation Control with High Filtration Lost Circulation Materials

Lost circulation materials with high filtration rate can be used in plugging mud loss zones and enhancing the pressure bearing capacity of the formation. The lost circulation material (LCM) losses its liquids swiftly when spotted at the loss zones and the solids of the LCM formed solid plugs inside the channels through which the mud losses. Drilling fluid flowing passing the surfaces of the solid plugs losses its liquids and forms dense mud cakes on the surfaces of the solid plugs, thereby increasing the pressure bearing capacity of the formation. A high filtration rate LCM has been developed for use in lost circulation control. It has almost no effect on mud rheology, and the volume of the filtrate in 30 s was 180 mL. It can be weighted to 2.3 g/cm3 with barite. In laboratory experiments, the high filtration rate LCM was tried on simulated fractures of different widths, and the pressure bearing capacity was 7 MPa. The high filtration rate LCM has been tried in field operations 7 times in different wells. It has been shown that the success rate using the high filtration rate LCM was 71%, and the time spent in controlling mud loss was only 3-4 h. The successful application of the high filtration rate LCM has provided technical support to high quality high efficiency drilling operations.