Original Article

Environmental Geology

, Volume 54, Issue 8, pp 1657-1665

First online:

Time-lapse crosswell seismic and VSP monitoring of injected CO2 in a brine aquifer

  • Thomas M. DaleyAffiliated withLawrence Berkeley National Laboratory Email author 
  • , Larry R. MyerAffiliated withLawrence Berkeley National Laboratory
  • , J. E. PetersonAffiliated withLawrence Berkeley National Laboratory
  • , E. L. MajerAffiliated withLawrence Berkeley National Laboratory
  • , G. M. HoverstenAffiliated withLawrence Berkeley National Laboratory

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


Seismic surveys successfully imaged a small scale CO2 injection (1,600 ton) conducted in a brine aquifer of the Frio Formation near Houston, Texas. These time-lapse borehole seismic surveys, crosswell and vertical seismic profile (VSP), were acquired to monitor the CO2 distribution using two boreholes (the new injection well and a pre-existing well used for monitoring) which are 30 m apart at a depth of 1,500 m. The crosswell survey provided a high-resolution image of the CO2 distribution between the wells via tomographic imaging of the P-wave velocity decrease (up to 500 m/s). The simultaneously acquired S-wave tomography showed little change in S-wave velocity, as expected for fluid substitution. A rock physics model was used to estimate CO2 saturations of 10–20% from the P-wave velocity change. The VSP survey resolved a large (∼70%) change in reflection amplitude for the Frio horizon. This CO2 induced reflection amplitude change allowed estimation of the CO2 extent beyond the monitor well and on three azimuths. The VSP result is compared with numerical modeling of CO2 saturations and is seismically modeled using the velocity change estimated in the crosswell survey.


CO2 Sequestration VSP Crosswell Seismic