Title: Optimal well placement and brine extraction for pressure management during CO₂ sequestration

Abstract

Large-scale pressure increases resulting from carbon dioxide (CO₂) injection in the subsurface can potentially impact caprock integrity, induce reactivation of critically stressed faults, and drive CO₂ or brine through conductive features into shallow groundwater. Pressure management involving the extraction of native fluids from storage formations can be used to reduce such pressure increases. However, dealing with large volumes of extracted brine can be technically challenging and expensive. Selection of optimal well locations and pumping rates are critical for maximizing CO₂ storage and minimizing brine extraction during geologic CO₂ sequestration (GCS). Robust and efficient computerized algorithms combining reservoir models and optimization methods are needed to make proper decisions on well placement and pumping rates. This work presents a constrained differential evolution (CDE) algorithm for solving global optimization problems involving pressure management of GCS projects. Application of the CDE optimization methodology was demonstrated for a hypothetical CO₂ storage scenario in a deep sandstone reservoir in the Southern San Joaquin Basin in California, USA. Industrial-scale storage of CO₂ would generate significant pressure buildup in this formation, which in turn would raise concerns about induced seismicity due to presence of multiple faults surrounding the injection site. Through the CDE optimization algorithm coupled to amore » vertically-averaged reservoir simulator, we successfully estimated optimal solutions for brine extraction wells in the reservoir that would limit the local pressure along the faults to a prescribed threshold. Multiple realizations of the reservoir permeability field were created to understand the impact of reservoir heterogeneity on optimization results. Our results indicate that the reservoir slope and heterogeneity have significant impact on optimum extraction rates. Reservoir heterogeneity is also a significant factor for extraction well locations, suggesting that in practice decisions about extraction well placement through optimization should be made at later project stages when data from a few years of CO₂ injection have allowed iterative updating and refining of the reservoir forward models. Although the study focused on optimization of brine extraction, the CDE optimization methodology presented in this paper has also potential to solve other complex optimization problems related to GCS, such as increasing storage efficiency by enhancing injectivity and capillary and dissolution trapping.« less

Authors:

Cihan, Abdullah ^[1]; Birkholzer, Jens T. ^[1]; Bianchi, Marco ^[1]

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+ Show Author Affiliations

1. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Publication Date:

Sat Aug 22 00:00:00 EDT 2015

Research Org.:

Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Fossil Energy (FE), Clean Coal and Carbon Management

OSTI Identifier:

1474891

Alternate Identifier(s):

OSTI ID: 1251658

Grant/Contract Number:  

AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

International Journal of Greenhouse Gas Control

Additional Journal Information:

Journal Volume: 42; Journal Issue: C; Related Information: © 2015.; Journal ID: ISSN 1750-5836

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

58 GEOSCIENCES; 97 MATHEMATICS AND COMPUTING; geologic carbon storage; pressure management; brine extraction; optimization; differential evolution algorithm