摘要
Polymer drilling fluid with high inhibition and high concentration of calcium ion is formed,in which the main additives are inorganic-organic monomer polymer SIOP,amphoteric sulfonic copolymer CPS-2000,anti-collapse agent polyaluminum AOP-1 and solid-phase chemical cleaner ZSC-201.The drilling fluid system has the calcium ion beyond 1.5 g/L and has a good inhibitive property,with temperature-resistance reaching 180 ℃,with salt-resistance saturated and with calcium-resistance 30 g/L.It has a good rheology behavior.It is used in nonresistant strata,such as gypsum salt bed,hard brittle bed,mud shale prone to hydration,poor-cement igneous rock and micro-fracture developed bed,in Zhongyuan,Tahe,Tazhong Oilfields and the oilfields of southwestern area.The application results show that the complex conditions(because of the problem of drilling fluid) don′t appear in the bottom hole of application well and the borehole diameter is regular.Average hole diameter enlargement rate is less than 5.17%.The success rate of running casing is 100% and the electrical logging success rate is 95.45% for one time.