Majority of the oil and gas fields in the UAE are mature multi-layered carbonates reservoirs, which determines complex vertical heterogeneity and challenging development of those reservoirs. Conventional methodology to measure sublayer pressure is to utilizing different wireline formation testers for any new well or worked over well before commissioning for production. Once well is completed and put on production; usually the average reservoir pressure is measured at the depth of perforation using conventional pressure build up (PBU) or bottomhole closed-in pressure (BHCIP) methods. Using conventional approach it is always difficult to understand which layers are more depleted than others, as only average reservoir pressure is recorded in the wellbore. In case of the heterogeneous multi-layer reservoirs, pressure measured conventionally in the wellbore will be at most of the times, inadequate for sublayer pressure estimation. This paper will describe new methodology of formation pressure evaluation, as well as real case study done in one of the developed offshore carbonate field in the UAE. This method allows measuring each sublayer pressure for producing wells without interruption of the production and properly defining any differential pressure between sublayers. This will help when applying any gas shut-off or water shut-off techniques and prolong the life of producing wells, as well as to help future development of the field. The determined reservoir pressure for each layer has been compared with recent formation pressure tester measurements obtained for this well. The pressure measurement is in the range of 20 psi tolerance. Identification of sublayer reservoir pressure for each producing interval is vital for highly heterogeneous multi-layered reservoirs. This technique is important for gas and water production management when one or several sublayers become depleted. Appropriate action for gas/water shut-off technique can be applied in the right time which will help to manage reservoir efficiently, as well as reducing the cost for conventional pressure measurements and eliminating the loss of production due to shut in time for pressure stabilization during conventional BHCIP or PBU.

The formation pressure testing data is widely used in the oil & gas industry to understand the reservoir vertical heterogeneity and the fluid movement within the reservoir. With the recent advances in formation testing technology, now the subsurface engineers are able to visualize the rock and fluid characteristics beyond the conventional few centimeters into the formation without putting the well on production. A study for integrating all available formation pressure data was carried out in a field scale level. The holistic analysis of the data enabled the reservoir engineers to deduce critical information, such as, reservoir compartmentalization, reservoir depletion trend and the injectors’ efficiency. The aim of this paper is to demonstrate a novel approach of analyzing formation testing data on a field scale from a complex reservoir that enabled ADMA-OPCO subsurface team to make informed decisions for better reservoir management. Certainly, the replication of this analysis approach could benefit the petroleum community in the similar field development scenarios.

The importance of an optimum well placement cannot be over-emphasized, because well location is one of the key factors that dominate the success of a field development plan. Well placement is a challenging and complicated process due to the complexity of reservoir, especially for a mature reservoir. The process of determining the optimized well location requires multi-disciplinary input and collaboration. In order to optimize the analysis process, this paper presents an innovative and interactive tool, which utilizes a 2-D map format to visualize the multi-disciplinary data, including reservoir management, reservoir simulation, geology, geophysics, and petrophysics. Following the analysis workflow, well target and risks can be optimized and identified by engineers through analyzing various maps, including well status map, well trajectory map, pressure map, production map, net oil thickness map, simulation confidence map, productivity index map, rock facies map, etc. The data that cannot display into map format can be accessed through links integrated in the tool.This ADMA-OPCO offshore field is a giant field, which has been producing for almost 50 years. As a current Mid-term development plan, more than 40 new wells and 90 existing wells will be drilled or worked over from the multi-layer reservoirs. The well placement is a critical activity to achieve a sound field development plan. By utilizing the novel tool and workflow, all the planned wells have been reviewed and optimized based on current reservoir situation. Prioritization has been evaluated based on the risks and reservoir requirements. Opportunities of quick wins have been identified during the process as well. Successful completions of wells after optimization have confirmed the value of the new tool. Besides, since reservoir condition is dynamic, the tool would be utilized frequently to capture the new updated information.