Study on Well Control Technology of High Temperature Geothermal Drilling

With the rapid development and research of geothermal resources, the number, drilling depth and formation temperature of high temperature geothermal wells increases year by year. But, so far the well control technology of high temperature geothermal drilling has not been paid attention to by relative person, the serious shortage of related technology and equipments retards the development of geothermal resources. This article describes the calculating methods of formation pressure, collapse pressure, circulating temperature, saturation vapor pressure and mud circulating temperature in high temperature geothermal wells, it can offer reference data for the design of drilling fluid, bottom hole assembly (BHA), well control equipment. High temperature geothermal drilling depends on the formation pressure and collapse pressure, the safe mud window is very narrow, suitable for pressure balance or underbalanced drilling, we design a simple structure, high speed, good heat resistance rotary blowout preventer (RBOP), which can increase the operability of geothermal wells balanced drilling.