Theory and application of DME enhanced waterflooding in low permeable heterogeneous reservoirs

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Abstract

Dimethyl Ether Waterflooding (DEW) is a promising water-soluble solvent-based EOR technique. Here, we study DEW mechanisms by developing a mathematical model taking into account the swelling and viscosity reduction of oil. Our analyses show that the swelling and viscosity reduction of oil cannot explain the observed increased recovery of DEW in the published core flooding data. Therefore, we define the residual oil saturation as a linear function of DME concentration in the oil phase to fit the model to the experimental data. After model validation against a 1D core flooding experiment, we utilize the model to study the effect of permeability heterogeneity and the injected DME slug size on the recovery of oil from a water-flooded chalk reservoir. We observe a sharp increase in the ultimate recovery when the DME slug size increases from 0.2 to 1.8 pore volume. For the DME slug sizes more than two pore volumes, no significant increase of the oil recovery is observed. Our net present value (NPV) calculations show that the highest profit of the DEW operation in the studied chalk reservoirs is achieved by injecting one pore volume of DME solution with a DME concentration of 10 wt%.
Original languageEnglish
Publication date2018
Publication statusPublished - 2018
Event80th EAGE Conference and Exhibition 2018 - Bella Center Copenhagen, Copenhagen, Denmark
Duration: 11 Jun 201814 Jun 2018

Conference

Conference80th EAGE Conference and Exhibition 2018
LocationBella Center Copenhagen
CountryDenmark
CityCopenhagen
Period11/06/201814/06/2018

Cite this

Mahdizadeh, M., Eftekhari, A. A., & Nick, H. M. (2018). Theory and application of DME enhanced waterflooding in low permeable heterogeneous reservoirs. Paper presented at 80th EAGE Conference and Exhibition 2018, Copenhagen, Denmark.