Maximum Reservoir Contact Wells: Six Years of Performance-Lessons Learned and Best Practices

Abstract

This year marks the sixth year anniversary of the birth of the Maximum Reservoir Contact (MRC) wells in Saudi Aramco. The outstanding performance of 99 MRC wells drilled to date in different fields reflects the impact of MRC wells on improving well performance, enhancing recovery and reducing unit development costs. In view of this performance, the use of this technology will continue to be on the rise. This paper will highlight the drivers, selection criteria, and lessons-learned from the MRC wells. It will further highlight cases of how MRC wells became the cornerstone in optimizing the development of tight reservoirs and in re-engineering mature ones. In addition, the paper will highlight the impact of MRC wells on rate sustainability and on increasing off-take levels by up to five times when compared to vertical and single lateral well completions. MRC wells not only targeted new development wells, but also extended to workover programs where low performer and dead wells were converted to MRCs. Results were phenomenal in terms of improving well productivity and delaying water and gas breakthroughs-thereby improving sweep. Introduction An MRC well is defined as a well having an aggregate reservoir contact in excess of 5 km, through a single or multi-lateral configuration. The MRC well concept was developed to further improve well productivity and thereby lower drawdown pressures resulting in higher well potential and lower development costs. MRC wells have been mainly deployed, in Saudi Aramco, in reservoirs with low to medium rock permeability, and relatively thin oil columns. The first deployment of MRC technology took place in 2002. MRC wells have primarily been implemented in three fields: Shaybah, Haradh and Abqaiq fields. By year-end 2007, 99 MRC wells were completed in Saudi Aramco. Several publications were issued on this topic highlighting the succession of MRC wells in Saudi Aramco 1–7. Figure 1 illustrates the growth of MRC wells since 2002. The use of this technology will continue to be on the rise reaching several hundred MRC wells in the next four years. 31320337599200220032004200520062007Cumulative MRC Wells Year Results from the three fields have proven that MRC wells have significantly improved reservoir and well performance, minimized or eliminated water and gas production, and reduced development cost. The first MRC well drilled in Shaybah field was a tri-lateral well with a reservoir contact of 8.5 km. Initially, the MRC wells in Shaybah field were completed through open-hole completion. The MRC concept was not limited to new wells, it has also revolutionized the workover practices to maximize the value of existing wells (i.e., weak or dead conventional or single lateral wells). The effectiveness of MRC wells depends on the proper planning, design and placement of the laterals. This paper will capture the drivers, selection criteria and lessons-learned over the past six years of MRC implementation.

Justification of Applying Multilateral Wells in Samotlor Field

“…Main geologic criteria for MLT application were defined based on literature review of experience [1][2][3][4][5][6][7][8][9][10][11][12][13][14] of applying MLT in Russia and over the world. Resources are however always limited, and there is no sense in constructing models and calculating parameters for all development targets.…”

Justification of Applying Multilateral Wells in Samotlor Field (Russian)

“…На основе литературного обзора опыта [1][2][3][4][5][6][7][8][9][10][11][12][13][14] применения МЗС в России и в Мире были определены основные геологические критерии применения. Однако ресурсы всегда ограничены и нет смысла строить модели и рассчитывать показатели для всех объектов разработки.…”

“…С другой стороны, чем меньше проницаемость тем меньше дебит нефти и существует предел, когда МЗС становится нерентабельной [3,5,2,8,9,10,11,12,13]. С другой стороны, чем меньше проницаемость тем меньше дебит нефти и существует предел, когда МЗС становится нерентабельной [3,5,2,8,9,10,11,12,13].…”