Drew E. Hembling

Deployed Smart Technologies Enablers for Improving Well Performance in Tight Reservoirs-Case: Shaybah Field, Saudi Arabia

Intelligent 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. Shaybah field, a low permeability 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. A step development approach by increasing the reservoir contact to improve well productivity and performance was the basis for Maximum Reservoir Contact (MRC) concept. Maximizing reservoir contact through MRC wells was one of the measures taken in early 2002 to reduce gas coning and improve recovery. Results to date from 37 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. In addition, several advanced completion 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 setting 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 by 50% and improved well productivity. To date, over ten 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. Shaybah Field holds several world records in the area of technology implementation; one of which is for the first MRC window to exit from 5-1/2” expandable allowing the placement of 2-7/8” ICV for inflow control. This paper will highlight how smart technologies have positively impacted field performance. Introduction: The mid-1990s witnessed the development of the Shaybah field in southeastern Saudi Arabia utilizing horizontal drilling technology as the preferred development mechanism to drain, produce and sustain a targeted production rate. The field was initially developed with 106 horizontal wells, each with one km single lateral producing from the Shu’aiba reservoir characterized with an average reservoir permeability of 13 mD. The presence of a large gas cap and a relatively weak aquifer above and below the tight Shu’aiba reservoir (Figure 1) dictated the need to develop this field with horizontal technology to delay and minimize the potential for early gas breakthrough and/or water coning, and also economically produce the field at well rates in excess of critical coning rates for vertical completions. Figure 1Three-D View of Shu’aiba Reservoir Superimposed on a Picture of the Shaybah Field The performance of the initial development one km single lateral horizontal wells was as projected by in-house reservoir simulation studies. Assessing the performance of these wells