Well Control Technology of High Temperature and High Pressure with Different Well Shapes

摘要

Well control safe is the prerequisite of safety drilling, especially for high temperature and high pressure horizontal wells. However, there are few papers about well control of horizontal well drilling, which mostly learn from vertical well control process. By means of analysis of the theory of gas kick, we conclude that underbalance, the bottom hole pressure is less than the formation pressure is the main means of gas invasion. During balance period, the gas also intrudes into wellbore through the way of direct invasion, diffusion invasion and replacement invasion, but the amount of gas kick is less, so the risk of well control is small. This paper also anlyses the kick tolerance, the kick tolerance decreases with the increasing of drilling fluid density when the formation pressure and drilling equipment is constant.