Comparison of Surface and Subsurface Fracture Patterns in the Front of Zagros Folding Belt, Ahwaz Anticline, Iran

Ahwaz anticline in the front of Zagros folding belt has created one of the giant oil fields of Iran with a production rate of 10 times more than the average world production rate. Due to the importance of fracture density and direction in the carbonate reservoirs, a research project with the support of National Iranian South Oil Company (NISOC) was fulfilled in 2 years. The main objective of this project was the comprehensive structural study and its final goal was application of all available data for comparison of fracture density and direction patterns in surface and subsurface horizons. For certainty, various methods were applied that most of them were initiative. One of the basic methods was axis transmission technique and in addition subsurface data of SVSL seismic profiles and FMS/FMI logs data were compared. Final results of this comparison lead surface and subsurface fractures in Ahwaz anticline have 90% agreement in direction and 75% in density.