Numerical Modeling of CO2 Sequestration within a Five-Spot Well Pattern in the Morrow B Sandstone of the Farnsworth Hydrocarbon Field: Comparison of the TOUGHREACT, STOMP-EOR, and GEM Simulators

Abstract

The objectives of this study were (1) to assess the fate and impact of CO2 injected into the Morrow B Sandstone in the Farnsworth Unit (FWU) through numerical non-isothermal reactive transport modeling, and (2) to compare the performance of three major reactive solute transport simulators, TOUGHREACT, STOMP-EOR, and GEM, under the same input conditions. The models were based on a quarter of a five-spot well pattern where CO2 was injected on a water-alternating-gas schedule for the first 25 years of the 1000 year simulation. The reservoir pore fluid consisted of water with or without petroleum. The results of the models have numerous broad similarities, such as the pattern of reservoir cooling caused by the injected fluids, a large initial pH drop followed by gradual pH neutralization, the long-term persistence of an immiscible CO2 gas phase, the continuous dissolution of calcite, very small decreases in porosity, and the increasing importance over time of carbonate mineral CO2 sequestration. The models differed in their predicted fluid pressure evolutions; amounts of mineral precipitation and dissolution; and distribution of CO2 among immiscible gas, petroleum, formation water, and carbonate minerals. The results of the study show the usefulness of numerical simulations in identifying broad patterns of behavior associated with CO2 injection, but also point to significant uncertainties in the numerical values of many model output parameters.

Field‐scale reactive transport assessment of CO2 storage in the Farnsworth unit through enhanced oil recovery practices

“…The results of the present field-scale study resemble in some ways those of Kutsienyo et al 42 carried out on a much smaller scale of a five-spot well pattern but with similar model parameter values. Kutsienyo et al's 42 study used not only the STOMP software used in the present study but also the GEM software for their three-phase (oil-water-CO 2 ) simulations.…”

“…Also listed are secondary minerals that are expected to have the potential to precipitate due to CO 2 injection, based on previous reaction path and reactive transport modeling studies. 37,39,42,48,49,70 Included in Table 3 are mineral-specific kinetic reaction data following Kutsienyo et al 42 The boundary conditions for the model were governed by the observation that the Morrow B Sandstone reservoir pinches out into adjacent shales…”

“…2.28 e 700 e Data sources: a Ampomah et al 30 ; b EPA 21 ; c Ampomah et al 50 ; d Sun et al 39 ; e Kutsienyo et al 42 ; f Geologic model; g Ahmmed et al 48 ; h Wilke and Lee method 65 ; i Wilke and Chang method 65 ; j Vignes method. 65 towards the edges of the FWU.…”

“…Subsequent numerical modeling studies attempted to include chemical processes to quantify changes to the mineral and pore fluid composition of the reservoir and to assess the importance of mineral trapping for CO 2 [35][36][37][38][39]43,48,49 . Limitations to the studies were as follows: (1) the model did not treat petroleum, 35,48,58 (2) the size of the model domains was very small, 37,39,42,43,49 (3) the reactive surface areas applied for the mineral reactions were not field-specific, [36][37][38][39]43,48,49 (4) the water alternating gas (WAG) schemes used did not represent well those used in the field, 35,48,49 (5) the model did not implement the actual regional pressure gradient occurring in the field, 48 (6) the injection temperature at the wells was not the same as the temperature in the field, [37][38][39]42,43,48,49 and (7) parts of the history matched model did not fit the production data well (i.e., less than 10% error). 37,39,43 In addition to these limitations, none of the studies accounted for capillary effects or fully quantified the field-scale response to the injected CO 2 by incorporating all four storage mechanisms.…”

Forecasting CO2 Sequestration with Enhanced Oil Recovery

“…Kutsienyo et al [13] assess the fate and impact of CO 2 injected into the Morrow B sandstone in the Farnsworth Unit (FWU) through numerical non-isothermal reactive transport modeling, and compare the performance of three major reactive solute transport simulators, TOUGHREACT, STOMP-EOR, and GEM, under the same input conditions. Model results show several broad similarities, such as the pattern of reservoir cooling caused by the injected fluids, a large initial pH drop followed by gradual pH neutralization, the long-term persistence of an immiscible CO 2 gas phase, the continuous dissolution of calcite, very small decreases in porosity, and the increasing importance over time of carbonate mineral CO 2 sequestration.…”