Al Nasr field
Conducted a petrophysical evaluation of 14 wells to determine the volumetric reserves within the Upper Alif sandstone. The reserves were based on a log-calculated oil-water contact and a seismic structural model. The Lower Alif is productive below the Upper Alif and reserves were evaluated on two separate four-way structural closures. Reviewed the feasibility of future water injection and recommended the establishment of a reservoir maintenance program to improve overall recovery.
Al Roidhat field
Evaluated the volumetrics by building a static geological model on the Qishn sandstone S1, S2, and S3 sub-unit reservoirs and estimated the developed and undeveloped reserves using dynamic reservoir simulation on this heavy oil field. Well tests were also part of the dynamic simulation history-matching process. Studied several reserves forecast scenarios to optimize the oil field recovery and field economics.
Evaluated the proved producing reserves of this one-well oil field that produces from the Sean sandstone. Reserves were based on well performance.
Atuf Northwest field
This field had three producing oil wells within the Upper Biyad formation. Original mapping had the No. 1 and No. 2 wells within separate, adjacent fault blocks. Ryder Scott evaluated the performance of those wells and reworked the petrophysics to determine that the wells were within a common fault block. Remapping gave a correct initial volumetric estimate of reserves. An initial volumetric estimate of reserves for the No. 3 well fault block was also completed.
Volumetrically mapped the Shuqra carbonate reservoir and estimated reserves based on the available well tests.
Evaluated multiple wells within the Alif sandstone to determine the volumetric reserves. Dhabab is an elongated four-way structural closure that trends northwest-southeast. Petrophysical review showed a common oil-water contact within the field and this formed the lowest known hydrocarbon base for the proved volumetric reserves. In addition, detected bypassed reserves in an undeveloped area of the reservoir and made recommendations to facilitate recovery.
The Upper Alif reservoir within this field is composed of an oil rim with an associated gas cap. Volumetric reserves for various wells were estimated down to a common oil-water contact. No gas reserves or production forecasts were estimated because of the lack of a gas market in the area.
Determined the field volumetrics by using a static geological model. Water saturations were distributed using J-functions for the Saar reservoir. Evaluated well tests and the development plan, including facilities schedules, capital expenditures and operating costs that were used in the determination of reserves.
Based upon geology and well performance, this field is divided into three, separate production areas. The Upper Biyad sandstone is the major oil producer with minor additional production coming from the Sarr carbonate. Ryder Scott evaluated well performance and well-log data to estimate in-place and recoverable reserves for each area. In areas of unstable or new production, the primary reserves-estimation technique was volumetric reserves based on geologic mapping. In areas of stable production, volumetric reserves served as a check and balance to the performance estimate.
Wadi Taribah field
Evaluated the proved producing reserves of this one-well field that produces from fractured basement rock. Reserves were based on well performance.