Study on borehole temperature distribution when the well-kick and the well-leakage occurs simultaneously during geothermal well drilling

When the well-leakage or the well-kick occurs during drilling geothermal wells, the borehole temperature is redistributed. It causes the rheology and density of the mud to change, which in turn affects the borehole pressure control, borehole stability and cementing quality. In order to understand the distribution law of borehole temperature under complex working conditions in geothermal well drilling, this paper establishes a borehole temperature distribution model when well-leakage and well-kick occur simultaneously. The borehole temperature distribution law when well-leakage and well-kick occur simultaneously is obtained. When both the well-kick and the well-leakage exist in the drilling process, the temperature of the borehole and the formation fluctuates near the location where the well-kick and well-leakage occurs. Under the ordinary cycle condition, the highest temperature of annular drilling fluid is located at 5325 m; When the well-leakage occurs at the bot-tomhole and the well-kick occurs at a specific location in the borehole, the highest temperature of annular drilling fluid is at 5250 m; When the well-kick takes place at the bottomhole and the well-leakage occurs at a specific location in the borehole, the highest temperature of annular drilling fluid at 5286 m place. Compared with the ordinary cycle condition, when the well-leakage occurs at the bottom of the well and the well-kick occurs at a specific location in the borehole, the bottomhole mud temperature decreases after the same cycle time. And the temperature of the mud and the formations increases significantly near and above the position where the well-kick takes place. When the well-kick takes place at the bottom of the well, and the well-leakage occurs at a specific location in the borehole, compared with the ordinary cycle condition, the temperature of the bottom hole mud increases after the same cycle time and the mud temperature increases rather than decreases at the well-leakage location. Compared with other situations, it is found that when the well-kick occurs at the bottomhole, it has a more significant impact on the temperature distribution of the entire borehole.