Sustainable Success: Boosting Reservoir Performance Through Rapid Screening Technique, Case Studies from South and East Kuwait
Authors: Al-Dalal A. , Al-Watyan A. , Freire J. L. 
Published: September 2024

The supergiant Greater Burgan Field has been producing billions of commercial volumes since 1946 from the primary clastic sandstone Burgan and Wara reservoirs and from the secondary Burgan Marrat, Magwa Marrat and Burgan Minagish carbonate reservoirs. At present, a concerning rise in water influx is observed within the principal sandstone reservoirs with water cut levels approaching 60%. This threatens future production efficiency and recovery volumes. To maintain desired output levels, increased focus will be necessary on optimal management of the secondary carbonate reservoirs.

One of the main oil contributors is the Cretaceous Middle Minagish Oolite (MO) Formation, discovered in 1979, has been on production (primary depletion) for over 52 years due to the rapid pressure depletion in 2018 the reservoir management strategy changes to peripherical waterflood pressure support. MO is a structurally controlled field with unified oil water contact (OWC) with high H2S content, its development as of now considers the balance of dynamic pressures and flow rates behavior, completion effectiveness diagnosis and best practices in well intervention execution.

In order to maintain MO production target an accurate identification of performance outliers wells using normalization methods from time-based production data enables assessment of their potential. The methodology unlocks anomalous behavior at the macro level. Combining key reservoir properties facilitates a field-wide pattern analysis, aiding in the definition of well types and performance benchmarking. Visual analytics techniques were used to contextualize inter-well relationships and localized effects such as productivity index, water cut, drawdown, flowrate in a spatial framework. Nodal analysis was performed to evidence the impact of the expected production increase and rank the wells to include in the workover campaign for matrix stimulation. Coil tubing and bullheading were the methods selected to deploy the treatment, the candidates were ranked based on their expected production increase, detailed intervention job was planned, design and analyzed with rig and rigless, and crucial information like cased hole logs and production logs was obtained during the intervention to confirm the results of the methodology.

Nine wells were selected for acid-based stimulation treatments based on the methodology output. These treatments demonstrated successful results, with Fold of increase [FOI] ranging from a maximum of 37 to minimum of 3, reflecting the increase of productivity and effectiveness of the treatment. The drawdown required for production now is extremely low ranging from 20 psi to 700 psi in compared to the previous behavior, allowing to achieve sustainable recovery and stay away from the bubble point pressure while reducing the risk of the water breakthrough. The results obtained confirm and validate that the methodology generates opportunities for production optimization campaigns. After the campaign total oil production of 32,500 Bopd [15,840 Bopd Incremental] was achieved that represent 35% production increase from the wells that produce from MO reservoir.