TECHNICAL ARTICLE
A Systematic Multidisciplinary Approach for Optimization in Brownfield SAGD Projects - Part 1 of 2 BY SHAHBAZ MASIH, P. ENG. AND MARK SAVAGE P. L. GEO. This article is the first half of a paper that focuses on a multidisciplinary optimization approach for brownfield SAGD development, i.e., optimization at existing SAGD production operations. This part of the article addresses optimization of existing pads by modifications in well completions and operational strategies. The article’s second part, planned for the CHOA Journal’s next issue, will discuss how a multidisciplinary approach can be used for adding infill wells, pad extension wells and/or farmer wells based on updated reservoir characterization, heat transfer and other observations from operational performance data.
INTRODUCTION Operators of oil sands projects need to be prudent about capital intensity and focus on operational efficiencies in all oil price environments. Optimized capital intensity is equally important for new projects (greenfield) and projects in operation (brownfield). Steam oil ratio (SOR) and oil production rate are the main parameters that determine the economics of a steam assisted gravity drainage (SAGD) project. Both are influenced by reservoir characteristics, well placement, design, completions, and surface and subsurface operational practices. Optimization of greenfield and brownfield projects in any of these parameters can improve the SOR, oil production rate, and GHG intensity of production. Improvement in oil production and SOR of brownfield projects can be attained by either optimization of existing wells or adding more wells, e.g., infill wells, extension wells, farmer wells (new horizontal wells above base of pay and below the horizontal production well), and sustaining well pads. Previous studies have examined parameters that could impact optimization of SAGD performance at different stages of the process, e.g., by Gittins et al2, have evaluated modification of SAGD process by using solvent co-injection, e.g., by Gupta et al3, and proposed improvement of the process mechanism, e.g., by Edmunds et al1. In this article, the SAGD process is divided into surface and subsurface systems to ensure a systematic approach across disciplines to look for suitable optimization solutions. The systems approach facilitates root cause analysis by identifying the critical parameters and the disciplines involved. This systematic approach also helps form a multidisciplinary methodology to address operational issues
33 CHOA JOURNAL — February 2022
“Operators of oil sands projects need to be prudent about capital intensity and focus on operational efficiencies in all oil price environments. Optimized capital intensity is equally important for new projects (greenfield) and projects in operation (brownfield).”
