双保型油田水无固相钻井液体系

Research and Application of Dual-protective Oilfield Water Drilling Fluids System Without Solid

针对塔河油田奥陶系碳酸盐岩储层开发过程中,常规聚磺钻井液体系含不酸溶固相漏失后污染储层,磺化类处理剂不符合绿色开发理念等技术难题,因地制宜地引入油田水配制无固相钻井液,避免了固相对储层的损害,并优选出了抗高温抗钙增黏剂、流型调节剂、抗高温抗钙聚合物降滤失剂等关键处理剂,开发出了双保型油田水无固相钻井液体系。室内评价数据显示,该钻井液抗温可达150℃,动塑比高达0.68~0.76 Pa/mPa·s,生物毒性指标EC50高达28600 mg/L,生物降解指标BOD5/CODCr高达21.35%,为无毒易降解钻井液体系,动态渗透率恢复值高达91.8%,具有良好的储层保护性能。研发的双保型油田水无固相钻井液体系成功在10多口深侧钻井应用,应用效果显著。

During the development of the carbonate reservoir of the Tahe oilfield,the conventional polysulfonate drilling fluid damages reservoir duo to non-acid-soluble solid phase after loss,and sulfonalized agent does not conform to the concept of green development.The oilfield water is introduced to formulate a solid free drilling fluid to avoid damage reservoir from solid,and the key treatment agents such as anti-high temperature anti-calcium viscosifier,flow pattern modifiers,high-temperature anti-calcium polymer filtrate reducer.The dual-protective oilfield water drilling fluids system without solid was developed.Indoor evaluation datas show that the drilling fluid was heat resistant to 150℃,the ratio between yield point and plastic viscosity is as high as 0.68~0.76 Pa/mPa·s,the EC50 value of biological toxicity indicators is as high as 28,600 mg/L,and the bio-degradation index BOD5/CODCr is as high as 21.35%.The dynamic permeability recovery value is as high as 91.8%,which has good formation damage control performance.The developed dual-protective oilfield water drilling fluids without solid were successfully used in more than ten sidetrack wells,and the application effect was significant.