Linking Sequence Stratigraphy, Depositional Environment and Sedimentary Facies to Model the Sandstone 3D Architecture within Palaeozoic Clastic Reservoirs, Saudi Arabia (SPE-113733)

摘要

Palaeozoic clastic sediments comprising continental to transitional marine depositional environments, form excellent hydrocarbon reservoirs in SaudiArabia. In order to develop a realistic dynamic model that can be used in reservoir performance prediction, a robust geological model is required. Detailed modeling of sand accumulations, their lateral continuity and vertical stacking patterns is needed to capture reservoir heterogeneity at all wavelengths. To build up an understanding of the sandstone 'plumbing' within the reservoirs, Depositional Related EnvironmentArchitecture Modelling (DREAM) modelling workflow is invoked. Initially, the fabric of the medium-to-long wavelength gross depositional environments is described in 3D. The distribution resides within the envelope of a sequence stratigraphic structural framework that links the main time-correlative boundaries. This model captures the progradational and retrogradational depositional behaviour and employs a stochastic distribution process to address population uncertainties. With the broad-scale environments defined, a subsequent step involves the distribution of short-to-medium scale sedimentary facies conditioned to the environment model. Lateral probability distribution maps and vertical proportion curves, combined with geological templates, are invoked within each environment to ensure that the facies distributions conform to as many observable and analogue trend constraints as possible. In this paper, the DREAM workflow was applied for two case studies and the results are presented. The generated models combined the structural framework based on seismic and sequence stratigraphic interpretation principles with linked environment and facies distributions.