MRC Wells Performance Update: Shaybah Field, Saudi Arabia

Abstract

This paper is an update of previous SPE technical papers1,2 highlighting the results of 25 Maximum Reservoir Contact (MRC) wells drilled in the Shaybah Field either as new wells or part of a workover strategy to convert existing weak 1-km single lateral wells to MRC wells with reservoir contacts ranging from 5 to 9 km. Shaybah field, a low permeability reservoir overlain by a huge gas cap was initially developed in 1996 with 1-km single lateral horizontal wells to effectively drain the hydrocarbon while reducing gas coning. A step development approach by increasing the reservoir contact to improve well productivity and performance was the basis for the MRC concept. Results to date from 25 MRC wells have indicated a four-fold increase in well productivities and a three-fold decrease in unit development cost when compared to the one-km single lateral wells. A useful by-product of MRC drilling is the enhancement achieved in reservoir characterization. In addition to MRC wells, smart technologies such as downhole flow control systems (smart completions), expandable liners, and production equalizers were deployed in Shaybah Field. These technologies have shown major improvements to well performance and recovery. Smart controls assisted in optimizing production from each lateral in a multi-lateral well in the event of premature gas or water coning. In addition, downhole smart completions improved well productivity in multi-lateral wells through an improved well cleanup process. Production equalizers when deployed in high GOR wells reduced gas coning and improved well productivity. To date over 21 expandable liners have been deployed as enablers to a workover strategy to convert single lateral wells to Multi-lateral/MRC wells thereby providing the platform for installation of downhole flow control systems. Introduction MRC well concept initiated in early 2002 by Saudi Aramco was based on the horizontal well technology as a disruptive technology1 to challenge the current practice with the objectives of improving well performance and ultimate recovery. An MRC well is defined as a well with an aggregate reservoir contact of 5 km or more either as a single lateral or multi-lateral configuration. The concept that was first tested in the Shu'aiba carbonate reservoir of the Shaybah field (Saudi Arabia) has been extended to cover several fields and rock types in both onshore and offshore environments. The majority of MRC wells were initially drilled as tri-lateral configuration. This configuration is now being challenged; quad and penta-lateral well types are being drilled to further improve well performance by increasing well productivity index and thereby lowering the drawdown pressures resulting in high well potentials and improved long term performance in terms of recovery and sweep. As in the mid-90s where the oil and gas industry was moving to horizontal well applications as the norm, today Saudi Aramco is leading the way in deploying MRC wells, where applicable, across most of its fields to ensure improved well performance and ultimate recovery. This paper will reflect on the performance of Saudi Aramco MRC wells over the past four years and the different technologies implemented, and highlight the way forward. Background Shaybah field, dominated by the low permeability Shu'aiba reservoir overlain by a huge gas cap, was initially developed in 1996 with one-km single lateral horizontal wells to effectively drain the hydrocarbon while reducing gas coning. Following the initial development and based on wells and field performance, reservoir contact was gradually increased by drilling 2 km and 3+ km single lateral wells. From 1998–2001 this step approach resulted in significant improvements to well performance in terms of increased PI, lower drawdown, and further delays in gas coning. This success led to the birth of the MRC well concept.

Geomechanical assessment of the Lower Turonian AR-F limestone Member, Abu Gharadig Field, Egypt: Implications for unconventional resource development

“…Horizontal well drilling through the AR-F with a slotted liner completion strategy is an effective way to ensure maximum reservoir contact (Salamy et al, 2008), as these perforated liners also provide increased accessibility for coil tubing (CT) as well as acid jobs. The studied vertical well indicates around 0.52 PSI/ft shear failure gradient (SF) against the AR-F carbonate interval (Figure 3), which is very close to the drilling mud pressure.…”

“…A similar approach can be taken up for AR-F as well. Referring to the Middle Eastern tight carbonate reservoir development strategies (Salamy et al, 2008;Chimmalgi et al, 2013;Alyan et al, 2015;Sen et al, 2021) we recommend that coil tubing (CT) carried a gun and acid stimulation will be helpful to activate this tight reservoir. Saleri et al (2004) discussed the utility of MRC (maximum reservoir contact) wells to achieve optimum reservoir performance and economic production rates from tight carbonate reservoirs in the Shaybah field of Saudi Arabia.…”

Horizontal Wells: Applications, Considerations, and Case Histories

“…(29). The development of Shaybah Field in Saudi Arabia (12)(13)(14) and Saih Rawl in Oman (15) are for pressure transient analysis were published (19) , and commercial software are now available that can handle the analyses. However, the analytical solutions published so xii-Cost sensitive projects whereas reducing the well count is vital.…”

Expandable Tubulars Facilitate Improved Well Stimulation and Well Production

“…Solid expandable liners deployed as enablers in a workover strategy to convert single lateral wells to multi-lateral/MRC wells provided the platform for installation of downhole flow control systems. (Salamy 2007) …”