TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractIntelligent wells are becoming the buzz word in the oil and gas industry. Today the development and deployment of smart technologies are important drivers for improving well productivity and delaying early water or gas breakthrough in tight and challenging reservoirs.

Summary This paper is an update on previous SPE technical papers (Saleri et al. 2003; Saleri et al. 2004) highlighting the results of 25 maximum-reservoir-contact (MRC) wells drilled in the Shaybah field either as new wells or as 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 in Saudi Arabia, a low-permeability reservoir overlain by a large gas cap, was developed initially in 1996 with 1-km single-lateral horizontal wells to drain hydrocarbon while reducing gas coning effectively. A step-development approach of increasing reservoir contact to improve well productivity and performance was the basis for the MRC concept. To date, results 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 1-km single-lateral wells. A useful byproduct 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 improved well performance and recovery greatly. Smart controls assisted in optimizing production from each lateral in a multilateral (ML) well in the event of premature gas or water coning. In addition, downhole smart completions improved well productivity in ML wells with a better well-cleanup process. Production equalizers that were deployed in high-gas/oil-ratio (GOR) wells reduced gas coning and improved well productivity. To date, more than 21 expandable liners have been deployed as enablers to a workover strategy to convert single-lateral wells to ML/MRC wells, thereby providing a platform for installation of downhole-flow-control systems. Introduction The MRC-well concept that was started in early 2002 by Saudi Aramco was based on the horizontal-well technology as a disruptive technology (Saleri et al. 2003) to challenge the current practice with the objective of improving well performance and ultimate recovery. An MRC well is defined as a well with a minimum aggregate reservoir contact of 5 km either as a single-lateral or ML configuration. The concept that was first tested in the Shu'aiba carbonate reservoir of the Shaybah field has been extended to cover several fields and rock types in both onshore and offshore environments. The majority of MRC wells were drilled initially as trilateral configurations; this configuration is now being challenged. Quad- and pentalateral well types are being drilled to improve well performance further by increasing well productivity index (PI) and, thus, lowering the drawdown pressures, resulting in high well potentials and improved long-term performance of sweep and recovery. Just as in the mid-1990s the oil and gas industry began using horizontal-well applications as the norm; today, Saudi Aramco is leading the way in deploying MRC wells across several of its fields to ensure improved well performance and ultimate recovery. In this paper, we discuss the performance of Saudi Aramco MRC wells over the past 4 years, including the different implemented technologies, and assess future uses of smart completions.

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.