Case Studies - Environmental

Enhanced 3D Seismic Surveys Using a New Airborne Pipeline Mapping System

During June and July of 1997, a detailed airborne pipeline detection survey was flown under contract to COMESA and PEMEX over an active oil field in Mexico. The objective of the survey was to locate and map the oil field pipelines and well heads, as well as other potential hazards, prior to COMESA shooting a large 3D survey over the entire field. The survey was flown in advance of the 3D shoot, and the results were used to ensure seismic crew safety, and to enhance seismic data quality. This was accomplished by the use of the PDS (Pipeline Detection System) data to relocate shot holes to safer, most advantageous positions.

The entire survey area covered roughly 340 square kilometers. The topography was flat and swamp covered over half of the area, and rolling hills and farmland over the remainder. The PDS system was flown using a flight line spacing of 50 meters over the densest parts of the oil fields, and at 200 meters over the rest of the seismic shoot area. Flight lines were flown using real-time differential GPS so as to exactly overfly the planned seismic shot pattern. The elevation of the PDS sensor was a nominal 30 meters above ground.

The survey was completed in 43 days (including roughly 10 days where flying was not possible due to weather and other factors), using 97 flying hours with a Bell B-206 helicopter. Infrastructure maps were delivered to the client on a progressive basis during the survey. A complete area map was presented fifteen days after all flying was completed.