Key points are not available for this paper at this time.
Abstract Field XX in North Oman has been the focus of many penetrations targeting deep formations such as the Haima and Amin reservoirs since 1994. The Upper Gharif interval was penetrated by many wells, but it was never considered a pay zone of interest and was left behind casing. Petroleum Development of Oman (PDO)'s Exploration team considered the Upper Gharif (HSGH-G3) sand as a miss pay and carried out a very successful drilling campaign focused on these sands. Six out of nine wells encountered sands making clear that additional work was needed to understand the sand geometries and the trapping mechanism. Several wells were fracked and tested delivering self-flow production of over 500 m3/day. Not all the wells showed the same response. This work focused on two techniques to help define the extend, channel geometry, connectivity, and reservoir behavior: Wide Angle Spectral Decomposition (WASD) and Pressure Transient Analysis (PTA). Detailed seismic mapping on a Wide Azimuth re-processed volume by PDO's processing team, allowed the use of WASD and the definition of sand geometries, orientation, and dimensions. These were calibrated using the existing well penetrations. PTA analysis of two key wells was performed and the model and results were tested against the geometries observed in the Spectral images. The PTA work clearly showed radial flow and the presence of barriers. It confirmed observations of the dynamic behavior (permeability, skin and storage) and was also used to test different models pertinent to the presence of potential micro-fracture networks or cross flow. The next phase of appraisal and development will continue using the WASD images for well placement and calibration and refinement will ensue in case of surprises.
Ardhi et al. (Mon,) studied this question.