Pressure core is the gold standard of reservoir saturation determination retaining gas and oil in an enclosed container preventing hydrocarbon loss to the mud system during retrieval of the core to surface. The technique is underutilized in the oil industry due to safety concerns, short coring lengths (3 to 7 feet) per trip and small core diameters (1.6 to 2.6 inches). A new elevated pressure coring system addresses these concerns. The system does not maintain true formation pressure but reduces the core barrel pressure to less than 1,000 psia for safer working conditions on surface. Upon arrival at surface, the core barrel and accompanying gas/liquid collection canisters are blown down and gas/liquid volumes measured and analysed. Free oil is gathered and stored for later analyses. Core diameter is 4 inches and core length is 10 feet. Zakum Development Company (ZADCO) operates a gas injection pilot in a large carbonate oil reservoir. There was a need to determine field remaining oil saturation after gas flood (ROSg) in a gas injection pilot. Pressure coring was selected as the best technology to obtain this data. This paper covers the planning and implementation of a successful elevated pressure coring operation in the U.A.E., the operational aspects, special core handling techniques, issues encountered and solved. Recommendations are made for future pressure coring operations. A follow up paper will cover the core and fluid analyses aspects.

Objective/ Scope Production logging analysis is essential to understand and evaluate reservoir performance throughout the lifetime of an oil well. Data acquisition and analysis is known to be challenging in modern extended reach horizontal wells due to multiple factors such as conveyance difficulties, fluid segregation, debris, or open hole washouts. Advanced compact multiple array production logging tool (APLT) is proposed to minimize the uncertainties related to these challenges. Method, Procedure, and Process The proposed sensor deployment method provides a comprehensive borehole coverage, thus maximizing the amount of subsurface information collected to evaluate the production performance of a horizontal well. Essential measurements are combined on six individual arms. Each arm is independently deployed which guarantees the best borehole coverage in a variety of borehole condition. Robust mechanical arm design minimizes damage, allows tolerance to decentralization, and provides greater confidence in determining the sensor locations. Each arm utilizes two fluid holdup sensors (Resistance, Optical) and one velocity sensor (Micro-Spinner). Co-location of the sensors minimizes the uncertainty related to sensor spacing when compared with previous generation of APLT. Results, Observations, Conclusions The new sensor deployment method and analysis results are discussed showing the added value in barefoot completion as well as advanced ICD completion. The holdup sensors response from previous generation APLT is compared to the advanced tool and how it relates to better borehole coverage. The results also illustrate use of high frequency optical probes for phase holdup determination. In addition, the optical probes are used to confirm bubble point pressure at in situ conditions by confidently detecting the first gas indication in the tubular. The results clearly show how a compact APLT maximizes the borehole coverage in highly deviated and horizontal wells. This is critical in collecting representative data of all segregated fluids which enables more accurate interpretation of the flow profile in the well and better understanding of reservoir performance. Novel / Additive Information The novelty of the new instrument is the ability to maximize the amount of subsurface production logging information collected with low uncertainty and minimum operational risk.