Description: For representing reservoir heterogeneities, most of geological models need several tens of million of cells. Even though reservoir simulators are quicker and quicker, it is most of the time requested to average the properties representing these heterogeneities on larger cells for simulating the multi-phase flow. Methods to average reservoir simulation have been studied for several years by many authors. For averaging absolute permeabilities, two main approaches are met: 1) averaging first the permeabilities and using the averaged value when discretizing the equations, leading to average transmissivities, or 2) calculating directly the averaged transmissivities from the high resolution permeabilities. This paper is in line with the second approach. Compared to previous work, we combined the finite volume principles with algebraic methods providing upper and lower bounds of the upscaled transmissivities considering adjacent volumes on both sides of the boundaries between cells in a manner that the contrast of heterogeneities is better conserved. Comparisons with current upscaling approaches will confirm that this approach is more accurate than calculating transmissivities from upscaled permeabilities. The competitive advantages of the algebraic methods are that the upscaling step will be fast and the use of bounds provided by algebraic method allows controlling the quality of the upscaling and gridding. The main innovation of the presented method is that the calculations of transmissivities are performed on smaller local domain than those proposed in previous work. This approach increases contrast of transmissivity and thus gains in accuracy for field scale flow simulation in heterogeneous media.
Applications: This approach had been successfully implemented in an industrial E&P software platform and tested on actual fields.
Results and conclusions: This method calculating upscaled transmissivities is the natural end point of any workflow devoted to the geological modeling to determine the petrophysical parameters of the field scale simulation grid. Being based on algebraic method, this approach is fast and a control of its quality is possible.
Technical contributions: 1. An innovative method calculating on smaller domains the upscaled transmissivities is proposed to increase the accuracy of reservoir simulations. 2. This fast approach avoid calculation of local fluid flow simulation everywhere 3. This approach allows controlling the quality of upscaling and gridding.
|Title of host publication||14th European Conference on the Mathematics of Oil Recovery 2014, ECMOR 2014|
|Publisher||European Association of Geoscientists and Engineers, EAGE|
|Publication status||Published - 2014|
|Event||14th European Conference on the Mathematics of Oil Recovery 2014, ECMOR 2014 - Catania|
Duration: 8 Sep 2014 → 11 Sep 2014
|Other||14th European Conference on the Mathematics of Oil Recovery 2014, ECMOR 2014|
|Period||8/9/14 → 11/9/14|
ASJC Scopus subject areas
- Geochemistry and Petrology
- Geotechnical Engineering and Engineering Geology
- Energy Engineering and Power Technology