f Fracture Characteristics of a Carbonate Platform, Kashagan Field, Kazakhstan

The Paleozoic reservoir at Kashagan field is characterized by a relatively porous carbonate platform interior surrounded by a highly-cemented margin called the rim. Most of the faults and fractures are concentrated near the rim. Despite low matrix porosity and permeability, rim wells experience lost circulation, bit drops, and high Kh, suggesting a well-developed secondary porosity system. Understanding the role of fractures in this secondary porosity system will be key to reservoir quality prediction. At the seismic scale, faults commonly strike parallel to the rim boundary. At the borehole-scale, image logs also show a fracture set striking parallel to the rim, with secondary sets at high angles to the rim. Rim parallel features are consistent with their formation during early syndepositional margin collapse and differential compaction of the platform and rim.