Enhanced reservoir understanding is critical for the development program of a mature field. This understanding will optimize petrophysical data gathering requirements, wells construction costs, and overall reservoir management strategy to maximize the asset value.

Logging while drilling (LWD) technologies were used in multiple wells to provide an integrated petrophysical and geomechanical interpretation. The bottomhole assembly (BHA) included LWD gamma ray, resistivity, bulk density, thermal neutron, acoustic, high-resolution imaging, and formation pressure sensors. A deterministic multimineral petrophysical model was used for formation volumetrics and fluid analysis.

Geomechanical interpretation used high-resolution microresistivity imaging and acoustic slownesses together with caliper data.

Historical data were also evaluated to determine sweep efficiency and residual fluid saturations.

LWD sensors have proven to provide robust geological, petrophysical, and geomechanical data, as compared to previous traditional wireline data acquisition.

High-resolution images facilitated fracture evaluation and the determination of the reservoir facies, leading to the identification of flow units.

Integrated interpretation has enabled the identification of the completion intervals. Well test results and the production profiles facilitated the reevaluation of the petrophysical cutoffs for the calculation of the oil in place and remaining oil saturations. Reservoir petrophysical attributes were updated in correlation with other data, including the identified pressure depletion intervals honoring history matching.

The interpreted results, based on LWD data, have facilitated the benchmarking of future data- gathering requirements to optimize the overall reservoir management strategies.

This pilot case study prompted a feasibility study to evaluate various well construction and completion design options, including high-angle and horizontal wells, for the future development program.

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