【摘要】 针对常规深水钻井液体系无法适应南海西部深水高温高压的地层环境等问题,室内研制及优选了抗高温增黏提切剂HTV-8、抗高温降滤失剂4%SMP-2+4%SPNH+3%DYFT-2以及水合物抑制剂5%NaCl+10%KCOOH,以此为基础构建了一套抗220℃深水高密度钻井液体系,并对其性能进行系统评价。结果表明,该钻井液体系在深水"低温-高温-低温"的温度变化条件下仍能保持稳定的流变性能,具有良好的抗低温和抗高温性能;钻井液体系对储层钻屑的滚动回收率达90%以上,而泥饼黏滞系数低至0.136 3,沉降因子为0.5左右,说明钻井液体系具有良好的抑制性、润滑性和沉降稳定性;钻井液体系中分别加入1.2%CaCl₂、1.2%MgCl₂、15%钻屑后,黏度、动切力和滤失量的变化幅度均不大,说明钻井液体系具有良好的抗污染能力;钻井液体系在4℃、20 MPa条件下无水合物生成,具有良好的水合物抑制能力;经过钻井液体系污染后的天然岩心渗透率恢复值在85%以上,说明钻井液体系具有良好的储层保护效果。更多还原

【Abstract】 In terms of the problem that deepwater drilling fluid system can not adapt to the the deepwater high temperature and high pressure formation environment in the western South China Sea,we developed and optimized anti-high temperature tackifying and shear strength-improving agent HTV-8,anti-high temperature filtrate reducer 4%SMP-2+4%SPNH+3%DYFT-2,and hydrate inhibitor 5%NaCl+10%KCOOH in the laboratory,thereby,we constructed a set of deepwater high density drilling fluid system resistant to 220 ℃,and evaluated its performance systematically.The results show that the drilling fluid system can maintain stable rheological property under the temperature change of "low temperature-high temperature-low temperature" in deepwater,and has good resistance to low temperature and high temperature.The rolling recovery of the drilling fluid system to the drilling cuttings is over 90%,while the viscosity coefficient of the mud cake is as low as 0.136 3 and the settlement factor is about 0.5,indicating that the drilling fluid system has good inhibition,lubrication,and sedimentation stability.When 1.2%CaCl₂,1.2%MgCl₂,or 15% cuttings,respectively,is added into the drilling fluid system,the variations of the viscosity,shear force,and filtrate rate loss are negligible,indicating that the drilling fluid system has a good anti-pollution capacity.Under the conditions of 4 ℃ and 20 MPa,the drilling fluid system has no hydrate formation,indicating that the drilling fluid system has a good hydrate inhibition ability.The permeability recovery value of natural core after drilling fluid system pollution is more than 85%,indicating that the drilling fluid system has a good reservoir protection effect.更多还原