T89 Spatiotemporal Variations and the Role of Fluids in Fault-Zone Hydromechanical Processes (Posters)

Sunday, 22 October 2017
9:00 AM - 5:30 PM
Halls 4EF

NUMERICAL SIMULATION FOR CO2 MIGRATION, DISTRIBUTION, AND GEYSERING PROCESSES AT LITTLE GRAND WASH AND SALT WASH FAULTS IN UTAH

Paper number: T89-4
Program: Technical Sessions
Time: 9:00 AM – 5:30 PM

Authors

Abstract

Geologic CO2 sequestration is considered as one of means to reduce CO2 concentration. However, stored CO2 can leak from the targeted formation if there exist any unwanted pathways. Leaked CO2 can cause to secondary groundwater contamination and ultimately have potential to induce detrimental effects to the surrounding environment. In these reasons, many studies have been conducted to understand natural CO2 leakage process. Green River area, in eastern Utah, USA, is a well-known CO2 natural analogue site where CO2and brine leaked periodically through the abandoned wellbore and diffusively through east-west cutting normal faults such as Little Grand Wash (LGW) and Salt Wash (SW) fault.

Two-dimensional simulation models delineating the region containing both LGW and SW faults and Crystal geyser were developed. In these fault systems, supercritical CO2 and Paleozoic brine move via faults, and meteoric ground water which is recharged from San Rafael Swell flows with dissolved CO2 through the Navajo Sandstone. Since LGW fault acts vertically as a conduit (kv = 10-16 m2 ) and horizontally as a barrier (kh = 10-17 m2) (Jung at al., 2015) while confining formations and aquifers are interbedded each other, anticlinal CO2 trapping were developed adjacent to faults. Overall regional formations dip (4 degrees) to north and the LGW faults dip (70 degrees) to south made CO2 trapping zones develop not at the hanging wall but at footwall, and thus, at the hanging wall updip migration of CO2 occurred. Consequently, CO2 moved toward SW fault (the south). Due to this reason, CO2 trapping zone was developed at footwall of the northern SW fault. In two of southern faults, in spite of CO2 supply from northern fault, anticlinal CO2 trapping was not formed. Rather, most of CO2 directly diffused to the surface through faults. Additionally, eruption patterns for Crystal geyser simulated from this model were categorized to three processes including eruption, recharge and spring.

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-299825

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