Code intercomparison builds confidence in numerical simulation models for geologic disposal of CO2

doi:10.1016/j.energy.2004.03.077

Energy

Volume 29, Issues 9–10, July–August 2004, Pages 1431-1444

https://doi.org/10.1016/j.energy.2004.03.077 Get rights and content

Abstract

Numerical simulators were exercised on a suite of test problems for CO₂ disposal in saline aquifers and depleting oil and gas reservoirs. Intercomparison of results reveals broad agreement in most areas, but also points out sensitivities to fluid properties and discretization approaches that need further study. Currently available simulation codes were shown capable of modeling the complex phenomena accompanying geologic storage of CO₂ in a robust manner, and with quantitatively similar results.

Introduction

Different kinds of subsurface reservoirs have been proposed for geologic disposal of greenhouse gases, including saline aquifers (brine formations), depleted or depleting oil and gas reservoirs, and coalbeds. Injection of greenhouse gases into such formations will give rise to complex coupled processes of fluid flow, mechanical and chemical changes, and heat transfer. Mathematical models and numerical simulation tools will play an important role in evaluating the feasibility of geologic disposal of CO₂, and in designing and monitoring CO₂ disposal operations. To be credible, the models must accurately represent the major physical and chemical processes induced by injection of CO₂ into potential disposal reservoirs, such as miscible and immiscible displacement, partitioning of CO₂ among different fluid phases, chemical reactions, thermal effects, and geomechanical changes from increased pore pressures. It is essential to test and evaluate numerical simulation codes, to establish their ability to model these processes in a realistic and quantitative fashion. The code intercomparison study reported here is a first step in this direction.

Section snippets

Approach

The present study was initiated and coordinated by the Lawrence Berkeley National Laboratory [1]. It was decided to include only brine formation, oil, and gas reservoir problems, for which well-developed simulation capabilities are available. Coalbed simulators are less mature and are the subject of a separate study [2]. The test problems studied and reported here represent an initial set specifically designed to address basic processes in different potential disposal reservoirs. Hence, it was

Problem 1: Mixing of stably stratified gases

The main processes of interest for CO₂ storage in gas reservoirs are advection of a gas phase consisting of CO₂ and CH₄, interdiffusion of these two components, and gas dissolution in residual liquid. Problem 1 considers the mixing by molecular diffusion and advection of a stably stratified 1D column 100 m in height with the light gas (CH₄) on the top and the heavy gas (CO₂) on the bottom (Fig. 1). Problem specifications are given in a laboratory report [1], and a more detailed summary is

Concluding remarks

The study reported here has documented the capabilities of currently available numerical simulation codes to represent physical and chemical processes that would accompany CO₂ disposal into geologic formations, including oil and gas reservoirs, and brine aquifers. Codes from 10 participating groups have been exercised on a suite of eight test problems that probed advective and diffusive mass transport in multiphase conditions, with partitioning of CO₂ between gas and aqueous phases; two

Acknowledgements

This work was supported as part of the GeoSeq project by the National Energy Technology Laboratory (NETL) of the US Department of Energy under Contract No. DE-AC03-76SF00098. We are grateful to Christine Doughty and André Unger for a review of the manuscript and the suggestion of improvements.

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Published by Elsevier Ltd.

Code intercomparison builds confidence in numerical simulation models for geologic disposal of CO2

Abstract

Introduction

Section snippets

Approach

Problem 1: Mixing of stably stratified gases

Concluding remarks

Acknowledgements

Geochim Cosmochim Acta

Comput Geosci

Geochim Cosmochim Acta

An intercomparison study of simulation models for geologic sequestration of CO2

Code intercomparison builds confidence in numerical simulation models for geologic disposal of CO₂

An intercomparison study of simulation models for geologic sequestration of CO₂