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.

Impact of Poroelastic Response of Sandstones on Geothermal Power Production

Abstract: During geothermal power production using a borehole doublet consisting of a production and injection well, the reservoir conditions such as permeability k, porosity π and Skempton coefficient B at the geothermal research site Gross Schoenebeck/Germany will change. Besides a temperature decrease at the injection well and a change of the chemical equilibrium, also the pore pressure Pp will vary in a range of approximately 44 MPa ±10 MPa in our reservoir at −3850 to −4258 m depth. This leads to a poroelastic response of the reservoir rocks depending on effective pressure P eff (difference between mean stress and pore pressure), resulting in a change in permeability k, porosity π and the poroelastic parameter Skempton coefficient B. Hence, we investigated the effective pressure dependency of Flechtinger sandstone, an outcropping equivalent of the reservoir rock via laboratory experiments. The permeability decreased by 21% at an effective pressure range from 3 to 30 MPa, the porosity decreased by 11% (P eff=6 to 65 MPa) and the Skempton coefficient decreased by 24% (p eff=4 to 25 MPa). We will show which mechanisms lead to the change of the mentioned hydraulic and poroelastic parameters and the influence of these changes on the productivity of the reservoir. The most significant changes occur at low effective pressures until 15 to 20 MPa. For our in situ reservoir conditions p eff=43 MPa a change of 10 MPa effective pressure will result in a change in matrix permeability of less than 4% and in matrix porosity of less than 2%. Besides natural fracture systems, fault zones and induced hydraulic fractures, the rock matrix its only one part of geothermal systems. All components can be influenced by pressure, temperature and chemical reactions. Therefore, the determined small poroelastic response of rock matrix does not significantly influence the sustainability of the geothermal reservoir.

Fluid–fluid and solid–fluid interfacial interactions in petroleum reservoirs

Abstract: The distribution and flow behavior of crude oil, gas and brine in the porous rock medium of petroleum reservoirs are controlled largely by the interactions occurring at the interfaces within the various fluids and by the interactions between the fluids and the rock surface. With an objective to correlate the macroscopic multiphase flow behavior with fundamental interfacial interactions, the recent developments in the field of fluid–fluid and solid–fluid interactions and their applications in petroleum engineering are presented in this contribution. A computerized drop shape analysis technique and its application to the measurement of fluid–fluid interfacial tension at elevated pressures and temperatures are discussed. A recently developed technique that is capable of measuring dynamic (advancing and receding) contact angles at realistic conditions encountered in petroleum reservoirs is presented. Its effectiveness in making reproducible and rapid measurements relative to the conventional techniques is dem...

The Role of Geology in Reservoir Simulation Studies

Abstract: Reservoir simulation models are becoming more and more sophisticated as a result of improved technology and in response to the need to reduce costs and improve hydrocarbon recovery. The improved technology has resulted in part from the development of capabilities for more precise reservoir description, including both the geological and engineering aspects of description. Increased precision in the geological contribution results from (1) improved knowledge of the geologic controls on reservoir rock properties, (2) better methods for synthesizing and quantifying geologic data, and (3) the experience gained from joint engineering-geologic projects. (11 refs.)

Comparison of Permeability from NMR and Production Analysis in Carbonate Reservoirs

Abstract: Several issues come to mind in the pursuit of log-derived permeability. Two of them, often referred to in recent publications, are the accuracy of the parameter and the representative of this permeability. Permeability from nuclear magnetic resonance (NMR) logs is often compared to core, wireline formation tester mobility, drillstem test and production data. The variation in vertical and lateral extent of these different measurements can give valuable insight into reservoir behavior. Average matrix permeability can be estimated from wireline NMR measurements while the other methods can more accurately evaluate the directional reservoir permeability as it varies with heterogeneities such as vugs, fractures, maximum horizontal stress and stylolites. Determining matrix permeability in carbonates from NMR data has been considered more difficult than in typical sandstone reservoirs. Recent developments in NMR carbonate analysis have provided insight as to how the permeability estimation from NMR logs can be improved. A method will be presented that overcomes some of the limitations of using NMR permeability in carbonates and will be compared with conventional NMR permeability estimation, core, wireline formation tester and drillstem test analysis in three Middle East carbonate reservoirs.