Abstract:

In deep wells, the safe window between pore pressure and fracture pressure is extremely narrow, and the pressure and temperature are very high at the bottom holes. The characteristics make it more difficult to control the pressure balance of hole in deep wells than in conventional wells. Aiming at the characteristics, a circulating and shut – in temperature distribution model, a HTHP density model and a HTHP rheologic model .This paper is presented based on the basic principles of Rheology ,Heat Transfer and Fluid Mechanics. With these models and the PVT properties of formation fluid, some kick phenomena in several deep wells are analyzed. The results show that the models presented by this paper are very important to control the pressure balance in deep wells.

Key words: Deep well, High temperature, High pressure