(7go) Screening Improved Recovery Methods in Tight-OIL Formations By Injecting and Producing through Fractures

Tight-oil reservoirs exhibit two characteristic behaviors that limit potential for improved recovery: i) limited fluid movement from the unfractured matrix limits the potential to sweep additional oil towards the production wells with injection of a displacing fluid, ii) the wettability of these reservoirs tend to be oil-wet which holds oil in relatively smaller pores, as compared to gas or water, making it difficult to mobilize that trapped oil. Primary oil production from these formations can decline to half of initial rates in the first year due to low permeability in the unfractured reservoir matrix, and a large amount of unrecovered oil remains in smaller pores that is not able to move out. Declining oil rates and low ultimate recoveries from oil-rich shale formations could benefit from application of secondary fluid injection schemes.

To address these challenges, this study investigates the potential to improve oil recovery from tight-oil reservoirs by a method that includes injecting a fluid into the fractured reservoir to produce hydrocarbons from adjacent fractures intersecting the same wellbore. We study the injection of three different fluids (water, immiscible CO₂, and surfactant flooding) in a single wellbore having three injection-fractures and three recovery-fractures. We compare the estimates of oil recovery obtained by injecting water, immiscible CO2, and surfactant with the oil recovered by primary depletion (from all six fractures) with no injection. This injection/production scheme has a potential economic advantage over huff-n-puff scheme such that there is no lag-period between injection and production. This study may help motivate further research in this area that will benefit the shale industry by enhancing oil rates in an economically competitive way.

Research Interests:

1) My primary research interest is solving multiphase flow problems for shale oil and gas reservoirs, storage of CO2, and gas hydrates.
2) Extensive experience in full-physics multiphase numerical simulations for conventional and unconventional fractured reservoirs.
3) Extensive experience in reservoir and fluid characterization using conventional and geostatistical approaches.

Teaching Interests:

1) Reservoir engineering (conventional and unconventional)

2) Transport phenomena in porous media

3) Reservoir modeling (stochastic and well-log based)