Controls on Spatial Structural Variability in Onshore Kuwait

Integrated analysis of well, seismic and gravity-magnetic data has provided new insights on the basement configuration and its controls on the tectonic evolution, structural styles and hydrocarbon entrapment.

2D gravity-magnetic modeling along regional seismic lines passing through deep wells has been carried out for working out basement and structural architecture.

Kuwait, located on the eastern edge of the Arabian Plate, has experienced a long and complicated structural history starting from Precambrian terrane accretion to continuing Zagros Orogeny. The broad structural framework of Onshore Kuwait is defined by three longitudinal tectonic domains. North aligned Kuwait Arch located in the east is the northern continuation of giant Khurais-Burgan Anticline. The arch is characterized by a steep eastern flank and gentle plunge to the north. Inheriting the Nabitah grain, the arch is segmented into a number of fault bound relatively narrow anticlines. To its west lies the Dibdibba Trough with a predominant northwest trending structural grain. The most visible feature in the trough is Minagish-Kra Almaru-Khabrat Ali High occurring in its central part. The structural grain is parallel to the regionally established Najd grain. The anticlines in the trough are relatively broad and gentle. Bordering the Dibdibba Trough in the west, Summan Platform gradually rises to the west with decreased sedimentary cover. The variations in the substratum underlying pre Khuff sediments have been observed to be coinciding with the tectonic interfaces. The meta-sediments of indeterminate age along with modeled basic volcanics forms the core of Kuwait Arch and structure formation appears to be primarily controlled re-activation of inherited lineaments by transpressional tectonics. In the Dibdibba Trough Precambrian Hormuz Salt provides the basement for the overlying sediments and salt intrusion appears to be responsible for triggering the structures. Over the Summan platform the Hormuz Salt is preserved with reduced thickness and has not impacted the structuration.

The tectonic model suggests distinctive mechanisms for structure formation in western and eastern Kuwait and has direct implications for timing of trap formation vis- a- vis hydrocarbon expulsion, influencing the trap geometry and its modifications during subsequent tectonic episodes.

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California