Validation and development of multiphase reservoir simulations with controlled source electromagnetics
Abstract
Multiphase subsurface flow models are critical management tools for enhanced oil and gas recovery, wastewater disposal, geothermal, and water resource applications. These models may involve multiple fluids including water, oil, and gases of varying pressure- and temperature-dependent miscibility. Fluids such as carbon dioxide (CO2) may be near their critical point transitioning in and out of a supercritical state. Out of necessity, reservoir models are often generated and calibrated using sparse data and the resulting model uncertainty is both high and difficult to quantify. These are complex and evolving systems, and often wells and other infrastructure are installed throughout the long life of a project. As such, it is not uncommon for wells to be temporarily or permanently abandoned.
Geophysical characterization can be an important tool in improving reservoir simulation properties. In most multiphase systems, the detection of phase saturation is of critical importance in order to validate existing models. Electromagnetic methods are often sensitive to changes in brine saturation vs resistive phases such as gas or oil. However, electromagnetic methods often suffer from low resolving power, and also may fail to image the depths of interest. Legacy infrastructure such as abandoned well casings can be leveraged to help alleviate both of these shortcomings. We investigate the use of legacy wellbore casings as long deep electrodes in controlled source electromagnetic (CSEM) surveys. Electrical and magnetic field data are measured using distributed nodal acquisition technology. Transient EM and MT soundings are also collected in order to develop a complete picture of subsurface conductivity from the surface to the underburden. When the data are integrated with possible permutations of reservoir flow model states, it becomes possible to reduce the associated reservoir model uncertainty. To illustrate we present data from an active CO2 enhanced oil recovery field in addition to synthetics.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMNS13A..08I
- Keywords:
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- 0920 Gravity methods;
- EXPLORATION GEOPHYSICSDE: 0925 Magnetic and electrical methods;
- EXPLORATION GEOPHYSICSDE: 0935 Seismic methods;
- EXPLORATION GEOPHYSICSDE: 0999 General or miscellaneous;
- EXPLORATION GEOPHYSICS