Reservoir Characterization. Группа авторов
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Название: Reservoir Characterization

Автор: Группа авторов

Издательство: John Wiley & Sons Limited

Жанр: Физика

Серия:

isbn: 9781119556244

isbn:

СКАЧАТЬ is complete without understanding rock properties and the corresponding rock physics. Furthermore, reservoir modeling could be considered as the last step for reservoir characterization during different stages of the life of the reservoir. Indeed, ideally, any reservoir simulation and could use reservoir models based on static and dynamic reservoir characterization to improve the process. 4D seismic data can help with the reservoir model updating process, thus enabling creation of a dynamic reservoir model.

      In what follows we describe rock physics and reservoir modeling briefly.

      1.6.1 Rock Physics

      Rock physics investigates reservoir rocks properties that affect transmission of seismic waves through the rocks. These physical properties are rigidity, compressibility, and porosity. This provides a connection between elastic properties measured at the surface of the earth, within the borehole environment or in the laboratory with the intrinsic properties of rocks, such as mineralogy, porosity, pore shapes, pore fluids, pore pressures, permeability, viscosity, stresses and overall architecture such as laminations and fractures.

      Rock physics uses sonic, density and dipole sonic logs to establish a relationship between the geophysical data and the petrophysical properties. In ‘80s and ‘90s many oil companies had their own rock physics laboratories. Because of the longer-range objectives and the need to assemble large databases, today such laboratories are found primarily within five or six universities and a few service companies. The focus of rock physics analysis started with estimating porosity and permeability of sandstones and carbonates. Today, much of the research is focused on unconventional reservoirs and on estimating rock strength or “fracability” and the presence of total organic carbon. For some detailed discussion on the value of rock physics analysis in various aspects of reservoir characterization and reservoir property estimation see Dvorkin and Nur [5] and Castagna et al. [4].

      Integration of 3D seismic interpretation with well measurements provides a powerful tool for characterization a reservoir for the 3D distribution of rock properties and the geometric framework of the reservoir. While the cores, wireline logs and outcrops provide the vertical resolution it is only geophysical data like 3D seismic data that can provide detailed spatial information between the wells for the geological model. Since 3D seismic is a measurement made at the surface of the earth, the subsurface interpretation using seismic data can be done only after proper calibration with available well information. Seismic reflection data provide the gross acoustic properties within a volume of rock and do not have the vertical resolution of wireline logs.

      1.6.2 Reservoir Modeling

      Reservoir fluid simulation is the quantification of fluid flow over time in the 3D reservoir model. The numerical model simulation and forecasts of reservoir performance is based on the geo-cellular static model. Reservoir simulation is performed to infer fluid flow behavior from a mathematical model. The forecast of reservoir performance is improved with increased accuracy in the geological model. Major decisions regarding the development and production plans for the reservoirs e.g., location and spacing of production and injector wells, depletion strategy, maximum production rates are based on the reservoir simulation. As hydrocarbons remaining in place become more difficult to recover, fluid movement in the reservoir needs to be more closely monitored. The location of remaining hydrocarbons must be known to plan injection schemes. Also, the manner in which injected fluids move and make contact with the target oil must be known in order to evaluate and, if necessary, correct the recovery project.