Selection Criteria for Miscible Gases-Based EOR in Unconventional Liquid-Rich Reservoirs (ULR)


In this chapter, a two-step methodology is introduced to investigate the feasibility of using three different miscible gases in EOR from unconventional reservoirs: CO2, lean gases, and rich gases. The integrated procedure presented in this chapter includes reservoir simulation and history matching of some miscible-gases used in EOR projects. The objective is to provide a proper evaluation of the molecular diffusivity of such gases in the field level of unconventional liquid-rich reservoirs (ULR). First, numerical simulation methods of compositional models are introduced, which are incorporated into the local grid refinement of hydraulic fractures. This chapter also presents an analysis of diffusion effects using an LS-LR-DK (logarithmically spaced, locally refined, and dual permeability) model. Second, the history matching process is conducted by incorporating different molar-diffusivity rates to find the correct diffusivity level in the field scale by matching the simulation models with the EOR pilot tests conducted in the Bakken formation of North Dakota, Montana, and South Saskatchewan. The main purpose of this chapter is to provide selection criteria for the proper type of miscible gases in terms of EOR in ULR.


Geosciences and Geological and Petroleum Engineering


Chapter 8

Keywords and Phrases

CO -EOR 2; EOR methods simulation; natural gases-based EOR; selection criteria for miscible gases-based EOR in ULR; shale oil reservoir simulation

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Book - Chapter

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Publication Date

01 Jan 2020