Challenges of seismic imaging in complex media around Iran, from Zagros overthrust in the southwest to Gorgan Plain in the northeast

Abstract

Seismic imaging is an old but immature technology in Iran. Several reasons for this act as obstacles in developing and applying newly introduced imaging methods for complex media. Ease of exploration of large reservoirs by geologic methods, dominance of petroleum geologists in seismic geologic interpretation, distrust between industrial technicians and academic researchers, and poor computational infrastructures are major reasons for the backwardness of seismic imaging methods in Iran. The high degree of complexity in the geologic condition of oil-field-bearing areas could be another reason for obtaining poor seismic images. In the general study of literature of seismic imaging in Iran, through time and over different geologic conditions, obstacles impeding the lack of development of seismic imaging can be classified in technical and nontechnical areas. In the first step, it is acknowledged that harsh topography and poor supervision of acquisition build the first and unfortunately irreversible ring in this chain. Subsequently, in processing as the second step, the application of very old-fashioned processing methods on data suffering from high levels of various noise and the application of simple and useless methods for migration prevent obtaining any appropriate final images for further realistic geologic interpretation. In the third step, interpretation is mostly performed on very low-quality images, which will result in an ambiguous interpretation with a large amount of uncertainty in defining geologic objects, location, and even correct and accurate recognition of geologic objects. The main challenge is to get rid of time imaging and geologic interpretation on time images, which is rather an unusual issue these days. Examples of the application of advanced imaging methods on data from different geologic conditions around Iran show that these obstacles could be removed if a proper imaging strategy were selected.