Annular Pressure-Volume Interaction Analysis for HPHT Well Based on Multi-scale

Abstract

Annulus pressure build-up is a potentially serious issue with high-pressure and high-temperature wells created by annuli which maybe heated up during production. Considering the mass conservation, energy conservation, and heat stability of fluid, the pressure-volume interaction models of multi-scale annulus are established based on PVT and the matrix of micro-annular temperature fields. Results indicate that the pressure-volume interaction moves the balance point of adjacent annulus early, which is a potentially serious issue for well integrity. The relationship between annulus temperature and pressure is linear. Moreover, at the same production, annulus pressure rapidly rises as the temperature increases, and the change rate of temperature increases at a negative exponential function. After the same production time, the relationship among temperature, pressure, and production is a quadratic function.