Hydrostatic pressures evaluation for effective benchmarking of basin's abnormal pressures

Abstract

The paper addresses a number of problematic issues that arise in the course of analysis of oil-and-gas bearing basins, their modelling and quantitative forecasting of some the most important parameters of its formation and development.

Researches carried out and described in the paper are focused on the problem of development of pore pressures in permeable rocks of the South-Caspian basin (SCB).

The paper also describes the problematic issues related to hydrostatic pressure in permeable rocks of the SCB. Hydrostatic pressure is a benchmark that allows one to draw conclusions about the presence of overpressure (OP) in the basin. The paper describes the technique of their correct calculation and forecasting dependent on the brine salinity, distinctive features of development in various stratigraphic units and zones of the basin. The quantitative variations and approaches that provide subsequent quantitative assessment of OP are given using proposed methodology, examples of their assessment in one or another part of the basin.

The issues studied and described in the paper are focused on the initial modules of the basin analysis and modelling. They covering such stages of lithogenesis as sediment deposition, subsidence, compaction, lithologic-facies characteristics and the heating associated with these processes, formation of overpressure and the evolution of reservoir properties formed as a result of the formation of different facies within the sedimentary rocks.