The Vertical Seismic Profile (VSP) in AZ-03 Injection Well, Los Azufres Geothermal Field, México

Abstract

The application of borehole seismic technology has been developed mainly in the oil industry, but this time it has been applied in geothermal wells in order to obtain information from structural data speeds and the area surrounding the well. The development requires log as an initial step of feasibility assessment of the acquisition under the specific conditions of the well and the geological conditions of the area. The second step is log design in which the geometry is determined using the number of sensors and source parameters by using vibro-seismic truck. The last step is the processing and interpretation of the results. This case was the vertical seismic profile (VSP) run by two logs (the first ZVSP and second OVSP) in AZ-03 injection well geothermal field of Los Azufres, Mich. The objective was to obtain a lateral image of the well and map geological structure known as El Chino. The ZVSP log was constructed based on the model of the structural section and the measured velocities of the P wave to \"illuminate\" the below of well. For the OVSP log the source was located on the platform of the well AZ-54, obtaining an image of the north side AZ-03 injection well, with a coverage of 500 m in the area of interest. Lateral discontinuities were identified close to the well AZ-03: between 600 m and 1350 m depth shows a system is northbound, from 1350 m to 1950 m depth showed presence of fracturing, and from 2000 m to 2600 m depth identified the fault structural system named El Chino. The results obtained indicate that the VSP log is a support in the exploration stage that identifies faults and fractures and geothermal fields in areas that lack structural features visible on the surface. It is also an additional technique in developing geothermal conceptual models and the proposal of producing and injection wells.