2D Seismic Acquisition Undershoot : 2D Seismic OBN PHE WMO Case Study
Author: Agung Ardiyanto, Ferdy, Husein Asy’ari, Rizqi Wahyu Nurcahyo, Yukha Ariadmana
yukha.ariadmana@pertamina.com
In mapping the subsurface structure of the earth, is a challenge in seismic survey operations. One of the challenges in the transition area in the 2D seismic survey PHE WMO is silting up to a depth of 1 meter on the northwest side of the survey area. Bathymetric data shows that in the northwest area of the survey, the depth of the seabed is shallow up to 1 meter in the transition zone so that the vibration source using only gun boat cannot pass that depth because the draft of the ship is only able to pass a depth of 3 meters. While the receiver used is nodal with a very flexible ability to the environment, both land and sea. In order to maintain data in the prospect zone area on the northwest side of the survey, the source line on the northwest side is offset or shifted to a depth of more than 3 meters where the seismic source (air gun) on the gun boat can still pass through. This method is known as undershoot, which is doing 2D seismic data acquisition where the source line and receiver line are not in the same line, resulting in a CDP that is not right under the acquisition line. The effectiveness of this method is quite capable of maintaining full fold coverage and describes a good layer to be interpreted starting from the shallowest depth of about 700 miliseconds.
Keywords: Seismic data acquisition, silting, undershoot
View Full ManuscriptDownload