Compositional Modeling to Analyze the Effect of CH4 on Coupled Carbon Storage and Enhanced Oil Recovery Process

Jinhyung Cho,Kun Lee,Baehyun Min,Seoyoon Kwon,Hye Lee,Gayoung Park

doi:10.3390/app10124272

Jinhyung Cho, Kun Lee + Show 4 more

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https://doi.org/10.3390/app10124272

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Abstract

The present study is aimed at the development of compositional simulation models of the co-injection of CO2 and CH4 during the water-alternating-gas (WAG) process in order to assess the efficiency of carbon capture and storage in combination with enhanced oil recovery (CCS-EOR). The co-injection of CO2 and CH4 occupies more reservoir pore volume and causes higher reservoir pressure than CO2 WAG, thus leading to an enhanced early EOR performance. However, the overall EOR performance of the co-injection method becomes lower than that of CO2 WAG due to the reduced miscibility and sweep efficiency upon further CH4 addition. The decrease in gas displacement and sweep efficiency weaken the hysteresis effects upon the residual trapping mechanism. However, the solubility trapping mechanism takes effect because the co-injection generates higher average reservoir pressure than does the CO2 WAG. The index of global warming potential (GWP) in a mole unit is employed to quantify the carbon storage effects of CO2 and co-injection WAG cases. According to the index, 1 mole of CH4 sequestration has the same effects as that of 10 moles of CO2 for global warming mitigation. In conclusion, the carbon storage effects are enhanced as CH4 concentration in the WAG increases.

Highlights

Carbon capture and storage (CCS) has become well-known as a technology for reducing the emission of greenhouse gases from fossil fuels during power generation and industrial processes [1].Projects involving the injection of carbon dioxide (CO2 ) for enhanced oil recovery (EOR) have been operating worldwide since the early 1970s [2] and EOR is expected to be a major driver for CCS by providing an additional revenue stream
The fluid composition of W3 experimental data and corresponding input equation of state (EOS) parameters used for fluid modeling are summarized in Table 1, while Table 2 presents the oil properties calculated via a regression method using the Peng-Robinson Equation of State (PR-EOS) and matched against the experimental data to increase the reliability of the compositional reservoir simulation [37,38]
A compositional numerical simulation was conducted to investigate the effects of CH4 additions upon the coupled CO2 -enhanced oil recovery (EOR) and carbon storage process

Summary

Introduction

Carbon capture and storage (CCS) has become well-known as a technology for reducing the emission of greenhouse gases from fossil fuels during power generation and industrial processes [1]. Projects involving the injection of carbon dioxide (CO2 ) for enhanced oil recovery (EOR) have been operating worldwide since the early 1970s [2] and EOR is expected to be a major driver for CCS by providing an additional revenue stream. Combining the CO2 -EOR and CCS into a coupled. CCS-EOR approach provides a synergistic effect towards business and environmental protection by offering commercial opportunities to oilfield operators. Almost 80 million tons (Mt) of CO2 are already being used for CCS-EOR each year [3,4]. As CH4 is a potent greenhouse gas (GHG), the operator often chooses to flare this by-product instead of releasing it directly to the atmosphere if there is little commercial opportunity or

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