Response and Recognition of Shuaiba Carbonate Reef-Shoal Body in Block A, Oman Basin

Block A of the Oman Basin is located on the western slope of the Fahud Salt Sub-basin in northwest Oman, and Lower Cretaceous limestones of the Shuaiba Formation are one of the most important oil reservoir in Oman. Because of thin thickness, strong heterogeneity and relatively developed faults, it is quite difficult to identify and predict the reef-shoal of Shuaiba Formation in Block A. Based on logging and seismic data, the comprehensive seismic and geological research were carried out in this study area, including forward modeling, identification of reservoir seismic facies, etc. A set of effective seismic and geological evaluation techniques such as formation thickness interpretation and discontinuous seismic attribute extraction are formed, which can determine the spatial distribution characteristics of reef-shoal reservoir in the study area. The results show that the reef-shoal body is characterized by dome-shape, medium-strong amplitude and medium-high continuity in the envelope surface, with medium-weak amplitude and medium-low continuity inner reflection. The combination of seismic facies recognition and seismic multi-attribute analysis technology can effectively predict the distribution range of reef-shoal reservoirs, improve the success rate of drilling in the study area, and help to find favorable targets for the further exploration.