3-D Approach on CO2-Rich Fluid Circulation Impact on Reservoir and Cyclic Fault Permeability Changes along Moab-Green River Segmented Fault System

Ellouz Zimmermann, Nadine ¹; Faure, J-luc ¹; Frery, Emanuelle ¹; Deschamps, Remy ¹
(1)Geology, IFPenergies nouvelles, Rueil malmaison cedex, France.

The Moab as well as Green River fault system and their hosted rocks have been extensively investigated : datings (some), structural and sedimentological evaluation are available on Jurassic reservoirs like Navajo , Entrada and Carmel sandstones, as well as in some of the Pensylvanian reservoirs. Using integrated methodology allowing to link tectonics and the reservoirs properties changes evolution and fault leakage/sealing cycles, we analyzed and modeled in 3D, one of the connecting small segment between the two well-known Moab and Green River faults. Boundary conditions have been carefully collected from field sample analyses and measurements, fine petrography, diagenetic stage, paleomagnetism on in-situ (gouge and damaged zone) and ex-situ (travertines) fault mineralisation have been done. Fluid circulation modeling implies the use of 3D models at basin and detailed scale, as Temis Flow, CO2-rich or agressive fluid circulation, constrains to associate reactive transfer modeling with classic basin one (we use Coores software). The reservoir properties evolution between primary, early and late diagenetic stages (resulting from CO2-rich fluid circulation, coupled or not with HC), as well as fluid and gas composition knowledge, are two strong pre-requisits for reactive transfer modeling. The main result of our study evidenced the disconnection of the fluid pathways through time and vertically, between the Mesozoic system and the -Paleozoic to Permo-Triassic one.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.