聚合醇封堵性能室内研究

RESEARCH ON THE SEALING PROPERTY OF POLYMERIC ALCOHOL

水化膨胀和分散作用是引起泥页岩井壁不稳定的主要原因之一。一旦有水相进入泥页岩中,其强度就会大幅度的降低,所以通过增强体系的抑制性来防水化而稳定井壁的效果往往不是很理想,传统的封堵剂颗粒太大,不能进入泥页岩的微孔隙中起到封堵作用。聚合醇可以利用其浊点特性,在低温时随溶液一起进入微孔隙中,在被地温加热过程中析出微粒,此微粒在微孔隙中堆积、填塞、最终堵死裂缝,彻底地阻断了水相进入泥页岩的通道,有效的防止井壁水化失稳。

Hydration expansion and disaggregation can cause wellface instability. The strength of shale would reduce when water entered shale micro-fracture, so the improving the inhibitive capability of mud couldn't stabilize the wellface. Traditional blocking agent couldn't enter micro-fracture to plug the thirsty formation for its granula was big. Polymeric alcohol have a cloud point temperature, that is polymeric alcohol can dissolve in water below cloud point temperature and separate out from the water when temperature is above the cloud point temperature. Polymeric alcohol entered micro-fracture at low temperature and the fine grains were separated out when it was heated by the formation temperature, the polyglycol particulate could plug the micro-fracture and prevent water entering shale, thus, the wellface instability was prevented effectively.