钻井过程循环温度敏感性因素分析与应用

Analysis and application of circulating temperature sensitivity factors in drilling process

钻井过程中循环温度对井下工具的影响越来越明显,四川盆地储气库、页岩气不断向深层发展,井底导向工具受循环温度影响故障频发,严重制约了钻井进度。该研究采用Landmark软件通过不同钻井液体系、钻井液密度、井口注入温度、水平段长、施工排量等参数进行模拟,得出了影响钻井过程循环温度敏感因素。模拟结果表明:1)调整不同的钻井敏感性因素可导致钻井循环温度增大或减小,即采用地面降温方法可以降低井底循环温度2.459~7.432℃,改变排量可以降低循环温度5.866℃,水基钻井液可降低井底循环温度5.866℃,提高钻井液密度可增加井底循环温度1.944~4.154℃;2)地面降温方法可以降低钻井液入口温度,间接降低井底循环温度,降低幅度为5℃。推荐采用地面降温方法降低钻井液循环入口温度为降低井底循环温度的工程方法。

In the process of drilling, the influence of circulating temperature on downhole tools is more and more obvious. The gas storage and shale gas in Sichuan Basin continue to develop to the deep layer. The bottom hole steering tools are affected by the circulating temperature, which seriously restricts the drilling progress.In order to accurately grasp the sensitive factors affecting the circulating temperature, Landmark software is used to simulate different drilling fluid systems, drilling fluid density, wellhead injection temperature, horizontal section length, construction displacement and other parameters. The sensitive factors affecting the circulation temperature in the drilling process are obtained. The simulation results show that: 1) Adjusting different drilling sensitivity factors can lead to the increase or decrease of the drilling circulating temperature, that is, the bottom hole circulating temperature can be reduced by 2.459 ~ 7.432 ℃ by using surface cooling method, and 5.866 ℃ can be reduced by changing the displacement, and the bottom hole circulating temperature can be reduced by 5.866 ℃ by water-based drilling fluid, and the bottom hole circulating temperature can be increased by 1.944 ~ 4.154 ℃ by increasing the drilling fluid density;2) The surface cooling method can reduce the inlet temperature of drilling fluid and indirectly reduce the bottom hole circulating temperature by 5 ℃. It is recommended to adopt the surface cooling method to reduce the circulating inlet temperature of drilling fluid as an engineering method to reduce the bottom hole circulating temperature.