Abstract:

Fluid dynamical fields in Damintun Depression, Liaohe Basin show that: the paleogeothermal gradient in the study area is greater than present one; the mudstone compaction could be classified into three types such as normal compaction-normal pressure, uncompaction-low overpressure in single interval, and uncompaction-high overpressure in double intervals. The present profile pressure system consists of normal pressure, slight overpressure and intense over-pressure from top to bottom. The fault systems, unconformity surfaces, interconnecting pore systems and diapir structures constitute the complex network system of vertical and horizontal transportation within the depression. Pressure evolution can be divided into two stages of initial overpressure accumulation and overpressure expulsion, and faults had an important controlling role to the formation, evoltution and distribution of the pressures. The fluid potential energy in profiles present a "double-layer" structure, and the depocenter was the fluid supply area whereas the slope was the main fluid dischareg area.

Key words: geothermal field, pressure field, potential energy field, Damintun Depression