抗高温无固相储层保护钻井液体系

针对渤中19-6油田深层裂缝性储层环境温度高、漏失风险大等难题，利用抗高温流型调节剂、抗高温护胶剂、聚胺抑制剂及甲酸钾加重剂等材料，构建了一套抗高温无固相储层保护钻井液体系。室内评价结果表明，自制的关键处理剂抗高温护胶剂、抗高温流型调节剂的抗温能力均达到200 ℃，且具有自动破胶性能；老化后的滤液与煤油的界面张力为2.61 mN/m，表现出良好的抑制性，油藏条件下渗透率恢复值达90%以上，储层保护效果良好。该体系在渤中19-6油田成功应用8口预探井，其中渤中19-6-7井钻进垂深5 508 m，井底温度达190 ℃。该体系可用于太古界高温深井的勘探开发。

A high-temperature & solid-free drilling fluid system with the property of reservoir protection

The deep-seated fractured reservoirs in Bozhong 19-6 Oilfield are faced with high temperature, high risk of lost circulation, and other difficulties. To solve these problems, a high-temperature clay free drilling fluid system with the property of reservoir protection was developed by using high-temperature pattern adjusting agent, high-temperature colloid protecting additive, polyamine inhibitor and potassium formate weighting agent. Laboratory evaluation results show that the self-made key treating chemicals (i.e., high-temperature colloid protecting additive and high-temperature pattern adjusting agent) can be resistant to the temperature of 200 ℃, and they have the property of automatic gel breaking. The interfacial tension between the aged filtrate and the kerosene is 2.61 mN/m, indicating good inhibition. The permeability recovery under the condition of oil reservoir is over 90%, which indicates that the reservoir protection effect is good. This drilling fluid system has been successfully applied in 8 wildcat wells of Bozhong 19-6 Oilfield, among which Well Bozhong 19-6-7 has vertical depth of 5 508 m and bottom hole temperature of 190 ℃. In conclusion, this drilling system is applicable to the exploration and development of Archean high-temperature deep wells.