Modeling of Diagenesis in Relation to Coupled Mass and Heat Transport

Robert Ondrak

Pore fluid flow is an important factor influencing the diagenetic evolution of rocks, as has been shown by various diagenetic studies, especially in connection with fluid inclusion measurements. A 3D-computer model is presented, which allows to simulate coupled mass and heat transport in porous rocks.

The model is used to study the interaction of heat and mass transport with respect to the temporal and spatial evolution of sandstones. Mineral dissolution or precipitation change the mineralogical composition of rocks, and modify the physical properties at the same time. Altering the permeability of the rock affects the fluid flow system in the rock which determines the mass transport of the entire system. In addition to mass transport, fluid flow transports thermal energy, which may modify the temperature evolution of the rock.

The model will be used to examine the effect of convective heat and mass transport on temperature and diagenetic evolution of clastic rocks. Although the model cannot claim to simulate nature, it can be used to study the effect of different mechanisms, and their interaction within the coupled system. For practical applications, the model may be used to determine possible flow rates, which are necessary to explain the observed diagenetic and thermal history of sandstones.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California