Analysis of Fractures in the Rag-E-Safid Oil Field Using Static and Dynamic Data

The study of fractures and their analysis has been conducted using the interpretation of graphic diagrams in one of the southwestern oil fields of Iran, called Reg Sefid. A total of 6.677 layers and fractures, including 8.333 continuous or discontinuous open fractures and 7.929 resistance or closed fractures, were selected in the image diagram of wells after interpretation and analyzed using Fracaflow software developed by Beicip-Franlab ( https://www.beicip.com/software/fracaflow/ ). The analysis of the fractures, based on the interpretation of the diagrams, identified three categories of fractures. The N30°E category can be classified as transverse fractures, the N150°E category as longitudinal fractures, and the E–W fracture category as oblique fractures. Analyses show that Asmari Zone No. 2 has a lower fracture potential compared to other zones of the Asmari Formation. The fracture density map in Asmari indicates that the density of open fractures in the White Rag anticline is higher in the northern, central, and bent sections of the anticline, respectively. In the wells adjacent to the main drifts, the fractures are located on the southern edge and in the western part of the field. In addition to the change in the direction of the axial surface of the White Rag anticline, the Izeh transverse fault has caused the development of longitudinal and transverse fractures in the western part of the White Rag anticline. Moreover, the increase in the density of fractures in the northwestern promontory indicates the effect of the Izeh fault on the concentration of fractures in this region of the anticline. From a structural perspective, the role of old elevations in changing the thickness and type of sedimentary facies has led to different behaviors of the sedimentary formations located in the Dezful Depression. Such activities have profoundly impacted the changes in the thickness and distribution of the source, reservoir, and cover rocks, creating discontinuities, forming fractures and porosity in the reservoir rocks, and influencing the distribution and migration of hydrocarbons in the region. Structural evidence shows that the bending of the anticline and the displacement of the axial surface of fold in controlled the movements of the transverse faults and bedrock with the Arabian trend, which was effective in determining the location and quantity of hydrocarbons.