CO2 Sequestration

SEAM CO2 Project- Understanding the value of geophysical information in CO2 capturing and storage

Introduction

This project aims to develop realistic models representing classes of field location where CO2 might be sequestered. The models will be allowed to evolve in time as CO2 is injected into the subsurface reservoir and migrates within the subsurface in either a contained reservoir or one that does not contain the injected fluid. Finally, geophysical models will be constructed from the temporal sequence of reservoir states during fluid injection. Geophysical simulation will be conducted on the models that help to evaluate the 4D geophysical response of the subsurface. The simulated data will be used to construct images of the earth’s subsurface that will then be interpreted to infer the state of the reservoir, the locations of CO2 and the reliability of the reservoir seal. The interpretation will be done in a way to allow project participants to evaluate the benefits of the various geophysical acquisition and processing approaches for characterizing reservoirs undergoing CO2 sequestration.

Objectives, Features, and Benefits

  • Multiple earth models representing classes of CO2 injection sites
  • Reservoir simulation output and geophysical simulations and imaging data ready for interpretation
  • Value of information report for different monitoring techniques (not sure about this one)
  • Partnership with public organizations regarding challenges and findings

Technical Specifications

Reservoir Description: The main reservoir in the ongoing model (onshore pilot) consists of a sequence of stacked turbidites located below a shale caprock. Two reservoirs exist at different depths above the caprock that are potential locations for CO2 that have migrated through the caprock by various mechanisms. Additional reservoir scope of work is currently underway.

Simulations: Reservoir modeling has provided good information about the containment and migration of CO2 within the reservoir and through the leakage pathways. This information has led to a refinement of the model to make it more appropriate for participants’ interests. Coupled reservoir flow/geomechanical simulations provide the most realistic model for the distribution of CO2 within the model. Several scenarios have been tested and include one where CO2 is fully contained within the main reservoir and scenarios where CO2 leaks into the upper siliciclastic reservoirs by passing through the reservoir caprock and along a fault.

CO2 Program Geophysical Simulation Products (Onshore pilot)

Geophysical simulations are being conducted on 4 models of the reservoir. One is the baseline model prior to injection of CO2, one is a scenario where all CO2 is contained within the main reservoir, and to are conducted on a model where CO2 migrates above the caprock. One of the sets of simulations will be conducted on a geophysical model constructed from reservoir simulation output at 30 years after the initiation of CO2 injection. Two simulations are conducted on output from a reservoir simulation at 9 and 30 years after the start of injection in a scenario where CO2 leaks through the shale caprock into a middle reservoir immediately above the caprock and along a fault that penetrates the reservoir and has continuity up to a shallow reservoir at 500 m where CO2 migrates.

3D migration imaging will be conducted on 3D seismic datasets, 2D imaging will be conducted on the 2D datasets. Imaging will also be conducted on the VSP data (approach TBD).

We define 2D seismic to be 3D simulations where sources and receivers all fall along lines passing through one or two wellbores. These data will be processed using 2D imaging algorithms.

4D Controlled-source EM simulations will be conducted on the baseline and at least one monitor model. 4D gravity simulations have been conducted on 3 monitor models.

Products Summary

  1. 3D Seismic on the  Baseline model and are conducted on 3D seismic monitormodels
  2. 2D Seismic (more often than 3D) conducted on the three models used for 3D simulation plus one additional monitor model
  3. VSPs (2 injectors, observation well) on the same models as used for 2D seismic
  4. CSEM (4D)
  5. Gravity (4D)
  6. Data to calculate surface and Downhole DAS (4D) using a suite of user-selected gauge lengths
  7. Induced seismicity
  8. Natural and anthropogenic noise for interferometry (to be confirmed)

Use Cases/Applications

The model is meant to be representative of a class of reservoirs where CO2 may be injected for sequestration. It does not represent any real-world reservoir.

Get the Best Technical Modeling While Saving Money

Guide the formation of the project and tailor it to your specific needs while sharing the cost effort of substantial model design and generation. Get exposure to diverse expertise supplied by each participating company and access to the data two years before the industry.

Participants