Theoretical analysis of steam-assisted gravity drainage process.

摘要

The steam-assisted gravity drainage (SAGD) process is one of the latest and the most advanced techniques in enhanced oil recovery processes. The determination of the swept volume in a steam chamber process provides an early means to evaluate the project's progress. The pseudo-steady state method has been used to estimate the swept volume, from pressure falloff testing, of horizontal wells. This method is easy to use and is similar in form to the well-known productivity equation for a vertical well.; To improve one's understanding of pressure transient behaviour of a horizontal well under steam injection, an analytical study was conducted. This study uses the Green Function with successive integration to evaluate the transient pressure response of a horizontal well in an anisotropic, closed, box-shaped reservoir.; Accuracy and applicability of the pseudo-steady state method in estimating the swept volume for steam injection through a horizontal well is thoroughly investigated. A commercial thermal numerical simulator (CMG, STARS) is used to generate pressure falloff data. More than 31 simulated pressure falloff tests are analyzed. (Abstract shortened by UMI.)