正电胶阳离子聚合物低界面张力钻井液技术研究

根据大情字井地区的地层特点和潜在损害问题，开展了防塌和保护储层的钻井液试验研究，通过单剂流动试验。确定了MMH阳离子聚合物钻井液体系的基本配方，通过钻井液界面及表面张力的测试，探讨了减少水锁的方法及水锁机理，确定了适合大情字井地区低渗、特低渗储层的正电胶阳离子聚合物低界面张力钻井液的配方，并对其加重前后的抗温性能、抗污染性能及储层保护性能进行了室内试验评价。在黑108井的现场试验表明，该钻井液能有效防止井壁坍塌，保证井下安全，而且储层保护效果很好。

Study and Application of MMH Cation Polymer Drilling Fluid with Low Interfacial Tension

According to formation features of Daqingzijing Oilfield and its potential damage problems, experimental study on anti-caving-in and reservoir protection for drilling fluid have been carried out. A basic formula for MMH cation polymer drilling fluid is established by single-agent flow tests. By measuring interfacial and surface tension of the drilling fluid, methods of reducing water lock and mechanisms of water lock are dis cussed, a formula for MMH cation polymer drilling fluids with low interracial tension, suitable for low and ultra-low permeable reservoirs in the Daqingzijing block, is developed. Temperature, anti pollution, and payzone protection performances before and after weighting are all evaluated in lab. Its field tests in Hei 108 Well show that it can effectively prevent well wall from caving in, ensure downhole safety, and protect reservoirs.