Plugging and flexible cement slurry system
article source:OMAX post time:2014-09-15
Technology characteristics: By adding the specially conditioned hydrophilic fiber which can be evenly dispersed in the slurry can prevent lost circulation and increase the cement’s toughness. After plugging a2mm-wide fracture with the fiber, the formation can bear the pressure of over 7Mpa. And meanwhile it can increase the slurry’s shear stress and improve the displacement efficiency with little thickening effect.
Application situation: By December 2010, this had been used in more than 50 wells in Tarim oilfield, Tahe oilfield, northeasternSichuanarea and Sichuan-Chongqing area. The density of the slurry onsite spans from1.2 g/cm3 to2.3 g/cm3. With the mud returning to the well head before cementing operation, it can basically ensure the cementing operation of no lost circulation, or even with the mud losing the return before cementing operation, it can also greatly increase the return depth of the slurry. Being used in the cement plug, one step plugging success rate is over 80%.