Sabiriyah Mauddud is one of the largest carbonate reservoirs in North Kuwait on active water flood since last 20 years using sea water as the injectant. The reservoir is purely a depletion drive reservoir, responding to water flood quickly in terms of increase in reservoir pressure as well as preferential flow of injectant into the nearby producers, thus stressing the existing water handling capacities at the gathering centers. Almost 40% of the injected water re-circulated between the injectors & producers, thus disabling the complete benefit of the ongoing water flood activities. A new initiative has been tried at two of the injectors for cyclic injection for optimal balance between pressure requirements and water cut levels. While water flooding Sabiriyah Mauddud, surprises in terms of rock & fluid understanding influenced quick water cut build up, reaching to more than 90% in some wells. A comprehensive G&G; Reservoir engineering and surveillance data aided to understand the connection factors between the injectors and producers. A fit for purpose tool developed to evaluate the water re-circulation has been used to short list the wells with "bad" water, requiring attention to control. As such bad water had been mainly due to direct short circuiting with the nearby injectors, team decided to go for handling such water from injector management point of view rather than working over the well for conformance related isolation of water producing zone. Cyclic water injection is the best solution so as to minimize the water re-circulation and stay within the operating range of the ESP in the associated producers, with properly spaced cycles of closure & opening. The initiative has been implemented at two of the injectors recently with positive results. The cyclic injection has reduced the water cut at the associated producers up to 30%, thus improving the oil cut significantly. This has reduced the water handling requirements at the gathering centers. The closing action planned for few high water cut wells has been canceled as a result of this strategy. The concept is planned to be implemented in remaining injectors of Mauddud once there are evidences of bad water re-circulation in multiple wells associated with these injectors. Water flood & production efficiency using cyclic water injection approach is a proven way to manage undesirable water encroachment in producers in Sabiriyah Mauddud, the results of which are interesting & worth sharing with the global professionals.

The Sabiriyah Mauddud limestone is a super-giant depletion drive oil reservoir in North Kuwait. It is undergoing massive development efforts, with a planned enhancement in oil production through phased water flood development since 2000. The Phase1 development addresses the crestal area (60 km2) of the structure, which was the focus for development efforts in the past. 14 years of dynamic performance from producers and injectors located in the Ph1 area enhanced the understanding of the reservoir dynamics. Time lapsed monitoring of static reservoir pressures at key wells during the ongoing water flood, coupled with isochronal Pressure surveys during reservoir shut-downs and RFT data from newly drilled wells in the area during the post injection period, helped to confirm the pressure connectivity across the reservoir and the water flood response. As all the wells are on ESP, the live data on Pump-intake Pressures provided insights into response behavior. Production tests gave valuable insights into the well performance, specially water cut build-up and reservoir architecture. Integration of the dynamic data with Production logs & FMIs led to the identification of speed zones with high permeability. One of the limitations of the pattern water flood with a combination of vertical injectors & vertical producers perforated across the whole hydrodynamic unit was a quick water breakthrough via the high perm speed zones and re-circulation of the injected water, as evident from tracer surveys and PLT data. A comprehensive review and updated performance analysis led to the need of re-developing the reservoir with a paradigm shift using a combination of Horizontal injectors drilled & completed at bottom of the hydraulic unit and the horizontal producers drilled/ completed at upper part so that the water breakthrough is delayed and better sweep is achieved. A conformance plan has been taken up so as to switch over to the new strategy. The Phase2 development consists of all remaining peripheral acreage (250 km2), with immense reservoir rock & fluid uncertainties, leading to the identification of reservoir segments for re-appraisal through drilling & testing of new wells. Re-appraisal work, along with enhanced fluid description, led to the conclusion that a large segment within the Ph2 area, originally considered as a regime of light oil - turned out to be viscous oil with a high pressure ramp. In addition to helping the ongoing Full field dynamic modeling and development planning for this giant reservoir, this also led to the initiation of a peripheral Water flood with vertical wells initially, and switching over to Non-Conventional Wells in the poorer Ph2 area. This paper documents the case history of Waterflood management in a super-giant carbonate reservoir and the challenges that had to be met with a quick re-adjustment to the development plan as necessitated during the ongoing implementation & evaluation.

In 2009, the Kuwait Integrated Digital Field (KwIDF) project was established in the Sabriyah field in north Kuwait to boost production and reserves (Al-Jasmi et al. 2014). The goal was to help realize the vision of sustained oil production in Kuwait of four million barrels of oil equivalent per day (BOE/D) by 2030 . The project involved the creation of 11 integrated, automated workflows, and a real-time collaborative environment to help optimize production, reduce downtime, and improve reservoir management:• Reservoir visualization and analysis, and subsurface waterflood optimizer-helps enable the monitoring of subsurface health during the waterflooding process, and provides predictive reservoir optimization analysis and actions (Ranjan et al. 2013).By 2012, KwIDF had been deployed on 49 wells, representing a pilot that served as a proof of concept. By 2013, cumulative production gains of 756,000 barrels of oil were reported (Singh et al. 2013). While the gains were impressive, and management wanted to expand KwIDF, it was recognized that full deployment would pose significant challenges and, without a set of necessary changes, the value of KwIDF would not be realized.The key challenge facing management was to identify the appropriate operating model to deliver on the KwIDF vision and scale the program to accommodate future expansion across the rest of the organization. A transition and deployment assessment team was established by management to address this challenge.The transition and deployment assessment project produced a recommended operating model, a transition road map, change management strategy, risk and mitigation plan, and project charters to assist the program team and steering group in the deployment of KwIDF across the rest of North Kuwait.

By using Persistent and Daily Digital Oil Field Diagnostics techniques a KOC FD team transformed a 5 year closed well, into a 2000 mdb Oil Gain with a remarkable 0% water cut also been achieved. Historically wells completed in Complex & heterogeneous carbonate reservoirs always surprised the NOC NK FD team with distinctive behavior and anomalies, noting also that the NOC's North Kuwait field is on the threshold of embarking upon a strategic ambitious water flood expansion and a systematic increase in injection volumes. Within this process of increasing WI volumes the team realized that it is essential that producing wells are continuously analyzed with the latest Digital Field dynamic data and tangible decisions are made to manage the Voidage-Replacement Ratio. It was during this review process that Well-M was recognized to have a potential added value opportunity This paper outlines both DOF technical review and management process's used in transforming what was seen as a DEAD and closed well into a daily valuable contributor to the NK asset and assist KOC meeting its production goals. The paper closes in lessons learned and the next steps to embed this process into KOC's management processes.

North Kuwait is an active asset with Sabiriyah Mauddud as the largest reservoir undergoing development using water flood. Initially with inverted 5 spot; followed by inverted 9 spot and ultimately with Produce High-Inject Low (PHIL) concept, Mauddud had witnessed a continuous testing of as to what is the best strategy to maximize sweep & recovery. The current focus is on striking a balance between production and injection so as to beat the impact of delays in water injection projects. Several techniques for evaluation of rock, pressure-production; fluid/ PVT; injection water quality; segment reviews; network modelling for producer as well injection network have been either matured to top class stature or initiated with the help of IOC consultants. Out of box solutions to have more injection in needy segments; deferment of drilling of new producers in pressure sink areas; ESP upsizes in segments with excellent pressure support or inversely ESP downsizing in low pressure areas had been the tested options without significantly impacting the trajectory of production build up. Due diligence was conducted to have comprehensive integration & optimization of resources and setting up associated priorities based on the depletion indices, injection efficiency and Voidage replacement trend. Exercise was done to assess the volume of water being re-circulated without sweep benefits so as to mitigate via conformance actions. MOCs have been initiated to fast track injection into the reservoir, even before the major project for water injection facility comes up. Opportunities for aggressive dump flood have been investigated and action plan under implementation. Change in scope from producers to injectors in the drilling plan for 2017/18 & 2018/19 have been proposed for the health of the reservoir. Sabiriyah Mauddud is the single largest producer of oil in North Kuwait since last 2 years as a result of effective water flood management. Grey areas and gaps, as evident from the present performance and upcoming challenging production targets are quickly being bridged so as to encash the subsurface booty of STOOIP in Sabiriyah Mauddud - SAMA.