First Multi-measurement Streamer Survey in Malaysia - Complimenting Acquisition Efficiency and Geophysical Sampling

During the decision making process for a new marine towed streamer seismic survey, the shooting direction depends on many factors like the structural dip, fault orientation, survey dimension and the location of the survey area relative to any exclusion zones. Generally, the data is acquired in the dip direction to enable finer inline sampling in the dominant dip direction and perpendicular to the faults. However, in many cases, economic factors override the geophysical issues and a survey is acquired in the most efficient direction. The case study presented here pertains to an area adjacent to a no-access zone, and the structural dip of interest is not aligned to the most efficient survey direction. 1D as well as 3D kinematic ray tracing were initially performed to estimate the sampling requirement for the steeply dipping fault zone and ray emergence angles at receiver locations. This was followed by 3D ray tracing based illumination analysis to evaluate the coverage at the target. This case study describes the analysis which led to the first survey in Malaysia to be acquired with multi-measurement streamers which facilitate the reconstruction of the wavefield sampled equally in both inline and crossline directions, thereby achieving operational efficiency without compromising on the geophysical integrity.