Fault and Fractures within Jurassic Petroleum System in Kuwait, with Special Reference to Hydrocarbon Habitat

By

 Salah Abdulla AbdulMalek¹, Sunil Kumar Singh¹, Fahed Al-Medhadi¹, Ahmad Jaber Al-Eidan¹, Nikhil Chandra Banik¹, Abdulaziz Sager Al-Anezi¹

(1) Kuwait Oil Company, Ahmadi, Kuwait

 This paper is representing an ongoing study for fault and fracture systems within Jurassic Petroleum System in Kuwait. The study aims at detailed description of faults and fracture systems and discusses the specific characteristics of these. So far the Structural elements of Jurassic Formations were inferred on the basis of gravity, magnetic and old vintage regional 2D seismic data.

The newly acquired high quality seismic data (2D and 3D) coupled with wealth of information in the form of core, thin section, image log and specially designed VSP data from drilled wells form the basic ingredients for this study. These have been integrated with regional stress regime. This has resulted in the understanding of fault and fracture systems from regional to microscopic scale. The key controls for faults and fractures were established. The faults have been categorized on the basis of genesis, age, reactivation history, trends, extent and throw etc. Image log data and seismic attribute (coherency, Edge detection, etc) have been used to decipher sub seismic faults and associated fracture systems.

An attempt has been made to see the relationship with oil habitat. The fracture systems associated with certain fault trends have facilitated the flow of Jurassic reservoirs while the others played a key role in compartmentalization of these reservoirs. The reactivation of Jurassic faults affected the seal integrity of Gotnia Formation at few places, laterally as well as vertically. The positive influence of reactivation had been on fracturing, which is key for Najmah/Sargelu reservoir productivity. While Fault related digenesis have adversely affected the reservoir properties of nearby wells.