ARRA Research

Geologic Sequestration Site Characterization (GSSC) -


Recovery Act: Characterization of Pliocene and Miocene Formations in the Wilmington Graben, Offshore Los Angeles, for Large Scale Geologic Storage of CO2


Performer: Geomechanics Technologies, Inc.

Project No: FE0001922


Accomplishments


  • Terralog has acquired 175 km of new 2-D seismic lines and completed drilling of the first characterization well into the Pliocene Repetto Formation.
  • Rock properties have been obtained from the Pliocene Pico and Repetto formations and used to supplement existing data to develop 3-D geologic structure maps.
  • Both the existing and newly acquired site data have been integrated into a 3-D CO2 migration model (TOUGH2) and a geomechanical model (FLAC3D). These models allow for additional quantification and analysis of storage targets and seals and have the ability to simulate long-term CO2 injection, migration and storage.
  • A 5 year injection and 50 year CO2 gas plume migration model for the northern and central portions of the Wilmington Graben have been completed. The CO2 has migrated 550 m horizontally and 350 m vertically in the northern portion and 1100 m horizontally and 400 m vertically in central portion of the basin. Based on our simulation on various injection rates, we recommend injecting 250,000 MT/Y of CO2 per well to ensure the pressure does not exceed the fracture gradient. We further recommend placing the well a minimum distance of 1000 m (3280 ft) away from any existing un-cemented wells and all other injection wells to avoid extensive CO2 plume interference.
  • The top 20 industrial sources of CO2 emissions in the LA Basin have been identified. Furthermore, sinks such as oil and gas fields, saline aquifer reservoirs and gas storage fields plus existing oil and gas pipelines have been identified and digitized. An interactive map is now available online at www.socalCARB.org where these CO2 sources, sinks and potential pipelines can be viewed. This data has also been submitted to NATCARB.
  • Terralog is continuing work on targeting the Miocene Puente Formation by drilling, coring, and testing a second characterization well in the western Wilmington Graben area from an offshore platform.
  • The integrated 3-D CO2 migration and geomechanical models will be refined with lithologic properties as new well data are acquired.
  • A risk analysis regarding large scale CO2 injection into a subaqueous saline aquifer is currently underway. The report will identify specific risks such as induced seismicity and seismic hazards, caprock integrity, lateral CO2 migration and existing well leakage paths.

Project Details