Spatial Stochastic Modeling of Sedimentary Formations to Assess CO₂Storage Potential

Abstract

Carbon capture and sequestration (CCS) is a technology that provides a near-term solution to reduce anthropogenic CO2 emissions to the atmosphere and reduce our impact on the climate system. Assessments of carbon sequestration resources that have been made for North America using existing methodologies likely underestimate uncertainty and variability in the reservoir parameters. This paper describes a geostatistical model developed to estimate the CO2 storage resource in sedimentary formations. The proposed stochastic model accounts for the spatial distribution of reservoir properties and is implemented in a case study of the Oriskany Formation of the Appalachian sedimentary basin. Results indicate that the CO2 storage resource for the Pennsylvania part of the Oriskany Formation has substantial spatial variation due to heterogeneity of formation properties and basin geology leading to significant uncertainty in the storage assessment. The Oriskany Formation sequestration resource estimate in Pennsylvania calculated with the effective efficiency factor, E=5%, ranges from 0.15 to 1.01 gigatonnes (Gt) with a mean value of 0.52 Gt of CO2 (E=5%). The methodology is generalizable to other sedimentary formations in which site-specific trend analyses and statistical models are developed to estimate the CO2 sequestration storage capacity and its uncertainty. More precise CO2 storage resource estimates will provide better recommendations for government and industry leaders and inform their decisions on which greenhouse gas mitigation measures are best fit for their regions.

Statistical performance of CO2 leakage detection using seismic travel time measurements

“…When applied at actual sites, the framework will require consideration of reservoir heterogeneity, with spatially varying (and uncertain) distributions of porosity, permeability and other features at the site. Methods to simulate uncertain subsurface spatial fields conditioned on partial observations of permeability and other measurements are available using approaches that rely on knowledge of subsurface processes and statistical techniques such as Sequential Gaussian Simulation . We look forward to using methods such as these to evaluate seismic monitoring and other leak detection methods at a test site at some time in the future.…”

“…Methods to simulate uncertain subsurface spatial fi elds conditioned on partial observations of permeability and other measurements are available using approaches that rely on knowledge of subsurface processes and statistical techniques such as Sequential Gaussian Simulation. [56][57][58] We look forward to using methods such as these to evaluate seismic monitoring and other leak detection methods at a test site at some time in the future. In this work, the power of CO 2 leakage detection using a statistical analysis and test of P-wave travel times is assessed with a simplifi ed rock physics model for the monitoring zone.…”

A probabilistic assessment of geomechanical reservoir integrity during CO2sequestration in flood basalt formations

“…As a result, geomechanical reservoir integrity has become an important criterion for numerical model‐based risk assessment in CCS reservoir siting . In order to address this problem, stochastic methods have been increasingly deployed to understand how spatial, parametric, and geologic uncertainty affects CCS reservoir performance . For example, Pollyea et al .…”

“…15 In order to address this problem, stochastic methods have been increasingly deployed to understand how spatial, parametric, and geologic uncertainty affects CCS reservoir performance. [16][17][18][19][20][21][22] For example, Pollyea et al 19 develop and implement ensemble simulation methods to quantify spatially variable sealing behavior within the low-volume Snake River Plains basalts. Jayne et al 23 extend these methods into flood basalt formations to show how permeability uncertainty affects the injectivity and leakage during CCS in flood basalt formations.…”

Storing and Securing Carbon Dioxide in Depleted Shale Formations

“…Perhaps the most comprehensive methodology for estimating sequestration capacity comes from the US Department of Energy (US DOE), which developed a model for calculating CO2 sequestration capacity in saline aquifers, coal seams, and depleted oil and gas fields. 15,66 This model is based on volumetric estimates but provides considerable detail regarding the effective pore space that CO2 can flow into. The DOE model also considers water saturation, porosity and an effective storage efficiency factor which considerably increases the data requirements of the model.…”