Characterization of cm-Scale Heterogeneities in a Tight Oil Reservoir Using X-ray Computed Tomography, Profile Permeability Measurements and 3-D Image Analysis

摘要: Summary The permeability reported for many tight-oil reservoirs is often affected by bedding and sub-bedding scale lithological heterogeneities (microlithofacies, μLFs). These are usually caused the combined effects of physical biogenic processes occurring during shortly after sediment deposition, resulting in local changes reservoir properties which must be accounted to properly assess potential these reservoirs. We have developed a comprehensive methodology evaluating geometry, volumetric distribution individual μLFs highly heterogeneous rocks. workflow relies on an innovative combination x-ray computed tomography, pressure decay profile permeability, image analysis techniques; interpretation datasets allows separate evaluation quality their connectivity. This approach particularly applicable detailed characterization bioturbated lithofacies (e.g., shoreface offshore deposits), including those with selective diagenetic imprints (i.e., biogenicinfluenced dolomitization carbonates). illustrated using core samples comprising siliciclastic lower transition deposits from Upper Cretaceous Cardium Fm. Western Canada Sedimentary Basin. Four dominant were identified: SS1 (sandy litharenite), SS2 (litharenitic wacke), SH1 (shale), PB (siderite/pyrite-filled burrows). Porosity values average 13.2% 7.7%, relatively high (SS1) intermediate (SS2) clusters, whereas corresponding geometric 4 mD, 0.56mD, respectively. Connectivity rather limited compared that SS2, ratio SS2:SS1 ranges between 3 5 most instances. In rocks connectivity abundance prevents this rock type dominating fluid flow process. abundances elemental types ρb, ∅, k) identified valuable input experimental flow/simulation models at scale. Significantly, data necessary morphological topological structures established methodology.