Computational Science Issues in Oil and Gas Production: Upscaling, Geologic Uncertainty and Economic Models

Wednesday, January 9, 2002 - 11:00am - 12:00pm
Keller 3-180
Mary Wheeler (The University of Texas at Austin)
In oil and gas production, the major objective is maximize return on investment. The challenges involve the ability to treat large detailed flow models, geologic uncertainty, and operational flexibility since infinitely many production strategies are possible. These challenges clearly point to the requirement of accurate and efficient parallel simulators which can be coupled to geostatatistical and economic models within a flexible and friendly computational infrastructure.

In this presentation we first describe a methodology called mortar space upscaling for treating computationally intense porous media simulations. This approach has been implemented in the the Center for Subsurface Modeling's (CSM) multiphysics multiblock simulator IPARS (Integrated Parallel Accurate Reservoir Simulator). Here a reservoir is decomposed into a series of subdomains (blocks) in which independently constructed numerical grids and possibly different physical models and discretization techniques can be employed in each block. Physically meaningful matching conditions are imposed on block interfaces in a numerically stable and accurate way using mortar finite element spaces. Coarse mortar grids and fine subdomain grids provide two-scale approximations. In the resulting effective solution flow is computed in subdomains on the fine scale while fluxes are matched on the coarse scale. In addition the flexibility to vary adaptively the number of interface degrees of freedom leads to more accurate multiscale approximations. Unlike most upscaling approaches the underlying systems can be treated fully implicitly.

We demonstrate computational experiments that show the mortar upscaling method is scalable in parallel as well as showing that it can be applied to non-matching grids across the interface, multinumerics and multiphysics models, and mortar adaptivity.

Geologic uncertainty and production strategies need to be evaluated simultaneously. This involves multiple realizations of multiple geostatistical models and the number and local of wells as well as the coupling to economic models which are functions of production data, cost/ price parameters, rate of return on investment, etc., From a computational point of view, one must be able to treat these uncertainties in a seamless fashion and to test variations on production strategies, evaluate sweep efficiency, and bypassed oil. Here we present results showing the coupling of computational tools:

- IPARS for reservoir simulation

- DataCutter for terascale data management/interrogation

- DISCOVER for collaborative interactive simulation

The above work on mortar upscaling methods was done in collaboration with Malgorzata Peszynska (UTAustin) and Ivan Yotov (University of Pittsburg). The coupling of IPARS with advanced computational tools involves Steven Bryant, Ryan Martino, Peszynska, and Wheeler (CSM), the DataCutter team, Joel Saltz and Tahsin Kurc (Ohio State University) and Alan Sussman (University of Maryland) and DISCOVER, Manish Parashar (Rutgers University).