Author : Dayo A. Akindipe
Publisher :
ISBN 13 :
Total Pages : 244 pages
Book Rating : 4.4/5 (387 download)
Book Synopsis Pore-scale Investigations of Carbon Dioxide Applications for Enhanced Oil Recovery and Geological Sequestration by : Dayo A. Akindipe
Download or read book Pore-scale Investigations of Carbon Dioxide Applications for Enhanced Oil Recovery and Geological Sequestration written by Dayo A. Akindipe and published by . This book was released on 2022 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon dioxide (CO2) capture, utilization, and storage (CCUS) is becoming a major climate change mitigation strategy. Some key issues that have limited accelerated development are injectivity losses due to near-wellbore salt precipitation during geological sequestration and poor displacement efficiency during utilization for enhanced oil recovery. To understand and mitigate these challenges, a pore-scale approach that combines flow tests with digital rock physics is proposed. This was implemented to visualize, quantify, and assess CO2/oil/brine/rock interactions that culminate in salt precipitation. It was also used to evaluate the pore morphology changes and the oil recovery performance encountered during carbonated water injection (CWI). In the studies on salt precipitation, three evolution stages—advection-dominated, transition, and diffusion-dominated evaporative drying—were observed. A new mechanism that occurs during the transition from advection to diffusion-limited flow termed reverse solute diffusion was also delineated. This mechanism was typified by upward solute diffusion from regions of lower concentration within the aqueous phase to a highly concentrated evaporating front. The time required for precipitation initiation was shorter in an intermediate-wet carbonate than in a weakly oil-wet carbonate. Higher amounts of salt deposits were formed in the more hydrophilic (intermediate-wet) carbonate, leading to an intensification of porosity reduction in this rock. In addition, the presence of oil within the pore space did not hinder the precipitation process but suppressed the reverse flow of solutes toward the evaporation front, thereby creating localized precipitation at the front. Mineral dissolution via CWI-induced reactive transport is one way to increase near-wellbore injectivity. In experiments involving oil/carbonated water/carbonate rock systems, flow channeling resulted in significant mineral dissolution. This led to the formation of high-conductivity wormholes with two distinct patterns. The first was a conical wormhole formed at a low flow rate where diffusion was significant. Whereas, the second was a dominant wormhole developed at a higher injection rate where advection controlled the transport of reactive species to the flow boundaries. Experiments performed to determine the underlying oil recovery mechanisms during CWI in oil-wet carbonate rocks revealed that carbonated low salinity seawater containing definite amounts of potential determining ions (Ca2+, Mg2+, and SO42−) promotes superior oil recovery compared to other brine samples. This enhanced performance was evidenced by the dominance of wettability reversal to near-neutral states, which created a more favorable capillary pressure required for pore-level displacements. Wettability alteration originated from the reduction in electrostatic attraction between oil/brine and brine/rock interfaces through the surface adsorption of SO42− ions in low-pH environments.
