Geophysical interpretation and static reservoir modeling of structurally complex reservoir, RG oil field area, Sirte Basin, Libya

Cambrian-Ordovician and Upper Cretaceous reservoir formations are found in the central western Sirte Basin, the main oil producing region in the Sirte Basin, Libya. As a result of changes in sedimentary environments and structural activities, a number of irregularities in reservoir continuity have developed, which negatively affected the overall performance of the reservoir. Effective simulation of such complex reservoirs can be achieved by integrating geophysical, geological, and petrophysical data to construct a reliable full-field static model, which has the potential to simulate the vertical and lateral variations in the reservoir formations. In this study, 2D and 3D seismic data acquired in the central western Sirte Basin are used to construct a fault and structural model which is an important component of the static model. The median filter and spectral whitening are applied to enhance the data quality and remove noise resulted from acquisition and processing effects. Spectel whitening is used to enhance the resolution of the data while median filter is used as noise filter. Coherence and curvature attributes are used to delineate faults and fracture zones. Coherence adequately detect major faults and minor faults. Most positive and most negative curvatures are used to define upthow and downthrow faults blocks. Curvatures attributes are also used to define fracture zones in reservoir formations. The most common fracture zone are identified in the northwest and southeast in the Cambrian-Ordovician reservoir formation in the study area. Well data are incorporated with core data to construct a property model that integrates a range of reservoir properties including facies, porosity, permeability, and net-to-gross ratio. A fine-scale geo-cellular model is created by integrating the fault, structural, and property models for the entire field --Abstract, page iv