Petroleum reservoir

About: Petroleum reservoir is a research topic. Over the lifetime, 5403 publications have been published within this topic receiving 83535 citations. The topic is also known as: petroleum deposit.

Interpretation of Interference Tests in Reservoirs With Double Porosity BehaviorTheory and Field Examples

Abstract: A systematic approach for analyzing interference tests in reservoirs with double porosity behavior is presented; it applies to both naturally fractured reservoirs and multilayered reservoirs with sufficiently high permeability contrast between layers. Type curves are presented for the pressure response at an observation well, the active well being produced at either constant flow rate or constant pressure. They are derived from two models with the assumptions of pseudo-steady state or transient interporosity flow regime. The distinctive specific features they exhibit are clearly identified and quantitatively related to the model parameters. An interpretation method, based on type curve matching, is proposed: after selection of the most appropriate model, and identification of the successive flow regimes, the double porosity behavior of the reservoir is characterized and pertinent parameters are evaluated: flow conductivity kh, interporosity flow parameter ..lambda.., and storativity (/phi/Vc /SUB t/ )h segregation throughout the reservoir. Actual field examples are discussed to illustrate the method.

Hydrocarbons in Non-Reservoir-Rock Source Beds

Abstract: Distributions of ratios of odd- to even-carbon-numbered heavy n-paraffins (carbon preference indices) for shales and mudstones in oil provinces have been confirmed by a statistically significant number of examples. Thirty per cent of the shales and mudstones sampled contained petroleum-like mixtures of heavy n-paraffins; sixty per cent contained n-paraffins intermediate between oil and recent sediment n-paraffins; and ten per cent had n-paraffins similar to those in recent sediments, indicating that the freshly deposited sediments of the geologic past contained heavy n-paraffins with strong preferences for odd-carbon numbers. Carbon preference indices are inversely related to the proportion of hydrocarbon in the organic material of shales and mudstones and, consequently, may be indicative of conversion of organic material to hydrocarbons. Carbon preference indices also provide a unique clue for recognizing petroleum-like mixtures of heavy n-paraffins in non-reservoir rock. Petroleum-like mixtures occur more commonly in organic-rich and hydrocarbon-rich shales and mudstones which, from emprical observation, are inferred to be the source of oil. The heavy-saturated hydrocarbons of crude oils contain larger percentages of paraffins than do corresponding fractions from extracts of non-reservoir rock. Hypotheses for the primary migration and collection of finely disseminated oil from the source rocks should explain this difference. The variability of organic material in sediments complicates the search for source rock and presents problem in selection of sites as well as frequency of sampling. Analyses for hydrocarbons in outcrops should be preceded by geological study to determine if the outcropping sediments can be representative of the stratigraphic unit downdip. Outcrop samples must be unweathered; and depositional environment, lithology, and maximum depth of burial should be equivalent to the sediments of interest at depth.

Direct pore‐scale computation of material and transport properties for North Sea reservoir rocks

Abstract: [1] This work investigates two complex, heterogeneous sandstone lithofacies in a North Sea petroleum reservoir field. We compare samples acquired by X-ray microtomography with numerically reconstructed lithofacies, obtained from a geological process based reconstruction technique. Effective material and transport properties of these digitized rocks, such as electrical resistivity, elastic moduli, fluid permeability, and magnetic resonance (NMR), are computed. The comparison largely reveals an excellent agreement of calculated effective properties between the actual and reconstructed pore structures. A dependence of the effective properties on the specific mineralogy could be investigated in case of the reconstructed rocks. Our results allow for an interpretation of trends in effective medium properties and facilitate the construction of cross-property relations for the investigated lithofacies. The present study demonstrates the potential and feasibility of combining computer generated rocks with numerical calculations to derive material and transport properties for reservoir rocks.