{"id":{"repo_id":"salford","oai_identifier":"oai:salford-repository.worktribe.com:1369312"},"canonical_url":"https://search.dev.ndltd.org/etd/salford/oai:salford-repository.worktribe.com:1369312","repository":{"repo_id":"salford","name":"U. of Salford","base_url":"https://salford-repository.worktribe.com/oaiprovider"},"display":{"title":"Role of connate water salinity in gas dispersion during enhanced gas recovery by carbon dioxide injection and sequestration","abstract":"A better understanding of the factors that influence mixing between CO2 and CH4 in naturalgas reservoirs can provide an avenue to minimise the gas dispersion during Enhanced GasRecovery (EGR). This highlights EGR’s field scale adoption as a potential method forsimultaneously reducing CO2 emissions through sequestration and enhancing natural gasrecovery and, thus, showcases it economic viability. An important aspect of the reservoir isconnate water. So, what is the role of its connate water salinity on mixing during EGR? In this investigation, three (3) different sandstone core samples (Grey Berea, Buff Berea, andBandera Grey) with different petrophysical properties were used in this research. Phase I ofthis study entailed the cleaning and the characterisation of the core samples usingexperimental core analyses to determine the petrophysical properties. A novel practicalapproach to grain diameter determination of the core samples using image analysis wasdeveloped. The measurement showed that Buff Berea had the largest average grain size of165.70 μm amongst the core samples used, followed by Grey Berea with 94.66 μm, and lastlyBandera Grey with 57.15 μm. This facilitated the determination the Peclet number during thedisplacement which helped develop a robust injection strategy for displacement of the CH4with minimum contamination by providing an optimum injection rate ranges for thisapplication. Phase II involved core flooding process to simulate the displacement of CH4 by CO2 that wascarried out at 1300 psig and 50oC with varying injection rates of 0.2, 0.3, 0.4, and 0.5 ml/min.This was performed on dry core samples at different injection orientations –horizontal andvertical - to ascertain the effects of these variations on the displacement efficiency. Theoptimum injection rate was determined based on the dispersion coefficient and the CH4recovery efficiency obtained from testing individual core samples. Grey Berea at 0.3 ml/minin the vertical orientation gave the best results based on the criteria adopted and provided thebenchmark for subsequent sensitivity analyses. The Phase III of the study focused on the impact of connate water salinity of the mixing anddispersion of CO2 into CH4 during the displacement at the simulated reservoir conditionsduring EGR with different brine salinities (0, 5, 10 wt% NaCl) using the optimum conditionsdetermined in Phase II for consistent results. The results from the core flooding processindicated that the dispersion coefficient decreases with increasing salinity, hence the higherthe density of the immobile phase (connate water) the lower the dispersion of CO2 into CH4.This is the first investigation into the relationship between the connate water salinity and thedispersion coefficient in EGR. Consequently, feasibility of the solubility trapping as asecondary mechanism for CO2 storage during EGR was experimentally investigated throughcore flooding process. Solubility trapping was found to increase the CO2 storage capacity ofnatural gas reservoir by about 60% during EGR and the higher the connate water salinity thehigher the sequestration potential of CO2 but lower the CH4 recovery was realised. With this new information, the effect of connate water salinity on EGR is substantial and itsinclusion in simulations studies will be helpful for field scale applications of EGR technique.","abstract_html":"A better understanding of the factors that influence mixing between CO2 and CH4 in naturalgas reservoirs can provide an avenue to minimise the gas dispersion during Enhanced GasRecovery (EGR). This highlights EGR’s field scale adoption as a potential method forsimultaneously reducing CO2 emissions through sequestration and enhancing natural gasrecovery and, thus, showcases it economic viability. An important aspect of the reservoir isconnate water. So, what is the role of its connate water salinity on mixing during EGR? In this investigation, three (3) different sandstone core samples (Grey Berea, Buff Berea, andBandera Grey) with different petrophysical properties were used in this research. Phase I ofthis study entailed the cleaning and the characterisation of the core samples usingexperimental core analyses to determine the petrophysical properties. A novel practicalapproach to grain diameter determination of the core samples using image analysis wasdeveloped. The measurement showed that Buff Berea had the largest average grain size of165.70 μm amongst the core samples used, followed by Grey Berea with 94.66 μm, and lastlyBandera Grey with 57.15 μm. This facilitated the determination the Peclet number during thedisplacement which helped develop a robust injection strategy for displacement of the CH4with minimum contamination by providing an optimum injection rate ranges for thisapplication. Phase II involved core flooding process to simulate the displacement of CH4 by CO2 that wascarried out at 1300 psig and 50oC with varying injection rates of 0.2, 0.3, 0.4, and 0.5 ml/min.This was performed on dry core samples at different injection orientations –horizontal andvertical - to ascertain the effects of these variations on the displacement efficiency. Theoptimum injection rate was determined based on the dispersion coefficient and the CH4recovery efficiency obtained from testing individual core samples. Grey Berea at 0.3 ml/minin the vertical orientation gave the best results based on the criteria adopted and provided thebenchmark for subsequent sensitivity analyses. The Phase III of the study focused on the impact of connate water salinity of the mixing anddispersion of CO2 into CH4 during the displacement at the simulated reservoir conditionsduring EGR with different brine salinities (0, 5, 10 wt% NaCl) using the optimum conditionsdetermined in Phase II for consistent results. The results from the core flooding processindicated that the dispersion coefficient decreases with increasing salinity, hence the higherthe density of the immobile phase (connate water) the lower the dispersion of CO2 into CH4.This is the first investigation into the relationship between the connate water salinity and thedispersion coefficient in EGR. Consequently, feasibility of the solubility trapping as asecondary mechanism for CO2 storage during EGR was experimentally investigated throughcore flooding process. Solubility trapping was found to increase the CO2 storage capacity ofnatural gas reservoir by about 60% during EGR and the higher the connate water salinity thehigher the sequestration potential of CO2 but lower the CH4 recovery was realised. With this new information, the effect of connate water salinity on EGR is substantial and itsinclusion in simulations studies will be helpful for field scale applications of EGR technique.","abstract_has_math":false,"creators":["Abba, MK"],"institution":null,"degree_name":null,"degree_level":"Doctoral (Level 8)","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2026,"date_issued":"2026","date_published":"2026","updated_at":"2026-07-24T04:26:23Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:salford-repository.worktribe.com:1369312"],"render_values":[{"text":"oai:salford-repository.worktribe.com:1369312","href":null,"code":true}]}]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.sponsor","label":"Sponsor","values":["University of Salford"]},{"key":"dc:creator","label":"Author","values":["Abba, MK"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2026-07-24"]},{"key":"dc:date.issued","label":"Date","values":["2026"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://salford-repository.worktribe.com/output/1369312"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral (Level 8)"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:salford-repository.worktribe.com:1369312"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://salford-repository.worktribe.com/1369312/1/Thesis%20Final%202.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A better understanding of the factors that influence mixing between CO2 and CH4 in naturalgas reservoirs can provide an avenue to minimise the gas dispersion during Enhanced GasRecovery (EGR). This highlights EGR’s field scale adoption as a potential method forsimultaneously reducing CO2 emissions through sequestration and enhancing natural gasrecovery and, thus, showcases it economic viability. An important aspect of the reservoir isconnate water. So, what is the role of its connate water salinity on mixing during EGR? In this investigation, three (3) different sandstone core samples (Grey Berea, Buff Berea, andBandera Grey) with different petrophysical properties were used in this research. Phase I ofthis study entailed the cleaning and the characterisation of the core samples usingexperimental core analyses to determine the petrophysical properties. A novel practicalapproach to grain diameter determination of the core samples using image analysis wasdeveloped. The measurement showed that Buff Berea had the largest average grain size of165.70 μm amongst the core samples used, followed by Grey Berea with 94.66 μm, and lastlyBandera Grey with 57.15 μm. This facilitated the determination the Peclet number during thedisplacement which helped develop a robust injection strategy for displacement of the CH4with minimum contamination by providing an optimum injection rate ranges for thisapplication. Phase II involved core flooding process to simulate the displacement of CH4 by CO2 that wascarried out at 1300 psig and 50oC with varying injection rates of 0.2, 0.3, 0.4, and 0.5 ml/min.This was performed on dry core samples at different injection orientations –horizontal andvertical - to ascertain the effects of these variations on the displacement efficiency. Theoptimum injection rate was determined based on the dispersion coefficient and the CH4recovery efficiency obtained from testing individual core samples. Grey Berea at 0.3 ml/minin the vertical orientation gave the best results based on the criteria adopted and provided thebenchmark for subsequent sensitivity analyses. The Phase III of the study focused on the impact of connate water salinity of the mixing anddispersion of CO2 into CH4 during the displacement at the simulated reservoir conditionsduring EGR with different brine salinities (0, 5, 10 wt% NaCl) using the optimum conditionsdetermined in Phase II for consistent results. The results from the core flooding processindicated that the dispersion coefficient decreases with increasing salinity, hence the higherthe density of the immobile phase (connate water) the lower the dispersion of CO2 into CH4.This is the first investigation into the relationship between the connate water salinity and thedispersion coefficient in EGR. Consequently, feasibility of the solubility trapping as asecondary mechanism for CO2 storage during EGR was experimentally investigated throughcore flooding process. Solubility trapping was found to increase the CO2 storage capacity ofnatural gas reservoir by about 60% during EGR and the higher the connate water salinity thehigher the sequestration potential of CO2 but lower the CH4 recovery was realised. With this new information, the effect of connate water salinity on EGR is substantial and itsinclusion in simulations studies will be helpful for field scale applications of EGR technique."]},{"key":"dc:title","label":"Title","values":["Role of connate water salinity in gas dispersion during enhanced gas recovery by carbon dioxide injection and sequestration"]}]}],"canonical_facts":{"dc:contributor.sponsor":["University of Salford"],"dc:creator":["Abba, MK"],"dc:date":["2026-07-24"],"dc:date.issued":["2026"],"dc:description.abstract":["A better understanding of the factors that influence mixing between CO2 and CH4 in naturalgas reservoirs can provide an avenue to minimise the gas dispersion during Enhanced GasRecovery (EGR). This highlights EGR’s field scale adoption as a potential method forsimultaneously reducing CO2 emissions through sequestration and enhancing natural gasrecovery and, thus, showcases it economic viability. An important aspect of the reservoir isconnate water. So, what is the role of its connate water salinity on mixing during EGR? In this investigation, three (3) different sandstone core samples (Grey Berea, Buff Berea, andBandera Grey) with different petrophysical properties were used in this research. Phase I ofthis study entailed the cleaning and the characterisation of the core samples usingexperimental core analyses to determine the petrophysical properties. A novel practicalapproach to grain diameter determination of the core samples using image analysis wasdeveloped. The measurement showed that Buff Berea had the largest average grain size of165.70 μm amongst the core samples used, followed by Grey Berea with 94.66 μm, and lastlyBandera Grey with 57.15 μm. This facilitated the determination the Peclet number during thedisplacement which helped develop a robust injection strategy for displacement of the CH4with minimum contamination by providing an optimum injection rate ranges for thisapplication. Phase II involved core flooding process to simulate the displacement of CH4 by CO2 that wascarried out at 1300 psig and 50oC with varying injection rates of 0.2, 0.3, 0.4, and 0.5 ml/min.This was performed on dry core samples at different injection orientations –horizontal andvertical - to ascertain the effects of these variations on the displacement efficiency. Theoptimum injection rate was determined based on the dispersion coefficient and the CH4recovery efficiency obtained from testing individual core samples. Grey Berea at 0.3 ml/minin the vertical orientation gave the best results based on the criteria adopted and provided thebenchmark for subsequent sensitivity analyses. The Phase III of the study focused on the impact of connate water salinity of the mixing anddispersion of CO2 into CH4 during the displacement at the simulated reservoir conditionsduring EGR with different brine salinities (0, 5, 10 wt% NaCl) using the optimum conditionsdetermined in Phase II for consistent results. The results from the core flooding processindicated that the dispersion coefficient decreases with increasing salinity, hence the higherthe density of the immobile phase (connate water) the lower the dispersion of CO2 into CH4.This is the first investigation into the relationship between the connate water salinity and thedispersion coefficient in EGR. Consequently, feasibility of the solubility trapping as asecondary mechanism for CO2 storage during EGR was experimentally investigated throughcore flooding process. Solubility trapping was found to increase the CO2 storage capacity ofnatural gas reservoir by about 60% during EGR and the higher the connate water salinity thehigher the sequestration potential of CO2 but lower the CH4 recovery was realised. With this new information, the effect of connate water salinity on EGR is substantial and itsinclusion in simulations studies will be helpful for field scale applications of EGR technique."],"dc:identifier":["oai:salford-repository.worktribe.com:1369312"],"dc:identifier.uri":["https://salford-repository.worktribe.com/1369312/1/Thesis%20Final%202.pdf"],"dc:language":["en"],"dc:relation.isreferencedby":["https://salford-repository.worktribe.com/output/1369312"],"dc:title":["Role of connate water salinity in gas dispersion during enhanced gas recovery by carbon dioxide injection and sequestration"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral (Level 8)"]},"updated_at":"2026-07-24T04:26:23Z"}