An Investigation of Overpressure Mechanisms: A Case Study of Offshore Turkmenistan

Abstract The main overpressure mechanisms identified in the South Caspian Basin are tectonic stress (rapid subsiding and sedimentation) and temperature (hydrocarbon generation). This paper will focus on the Block ABC located in the South Caspian Basin, Turkmenistan. The overpressure magnitude at the eastern part of the block is as high as close to 12000 psi whereas the western part of the block shows the magnitude of approximately 7000 psi at the same depth (3500m TVDss). In general, the formation pressure of this block shows an increasing in pressure from approximately in the RS-2 down to formation RS-8a. The formation pressure regressed down to RS-8b across the study area. This paper will try to investigate the main mechanism(s) that create different magnitude of overpressure in the eastern and western part of Block ABC. Once the overpressure mechanisms are identified, this paper will try to present an approach in predicting the pore pressure in this area.