3D seismic acquisition for Petroleum Exploration in the Artic Region is typically restricted to four operational months during the winter season. The area of the survey and the acquisition parameters need to be optimized and constrained to match the narrow time frame. Seismic operations must follow environmental regulations to avoid adverse impacts to the wildlife and sensitive terrains, including lakes, rivers, abandoned meanders, and the flora able to grow in the region. No vehicles or seismic equipment is allowed to operate above them in winter regardless of their protection by the snow cover. Furthermore, only vehicles and machinery are allowed to work on the frozen tundra or over frozen lakes and rivers with grounded ice. However, the ice thickness in the frozen lakes and rivers is not capable of supporting the heavy seismic vibrator. Therefore, many source points must be relocated which finally results in irregular source point distribution over the survey acquisition area.
The conventional method to recover source points around obstructions causes a concentrated redistribution of source points in the vicinity around the obstructions. An alternative operational method to recover source positions is presented in this paper. We used different types of geophysical analysis to evaluate the proposed optimized method for source recovery including traditional geophysical attribute analysis, illumination studies and attribute analysis of seismic data acquired in the Horse Shoe 3D project.
The proposed method can be implemented in areas with significant surface obstructions, either due to environmental restrictions, population, industrial or oilfield areas, or natural obstructions, etc.
An important conclusion is that the improvement in S/N and attributes obtained by the implementation of the proposed method for source recovery did require only a marginal increase in the work volume or resources for the project and so the cost and time of execution were not affected.