Abstract
In this paper, chelating agents were introduced as standalone fluids for enhancing the oil recovery from carbonate and sandstone reservoirs. Chelating agents such as glutamic acid di-acetic acid (GLDA), ethylene-diamine-tetra acetic acid (EDTA), and hydroxyl-ethylethylene-diamine-tri-acetic acid (HEDTA) were used. Chelating agents can be found in different forms such as sodium, potassium, or calcium salts. There is a significant gap in the literature about the influence of salt type on the hydrocarbon recovery from carbonate and sandstone reservoirs. In this study, the impact of the salt type of GLDA chelating agent on the oil recovery was investigated. Potassium-, sodium-, and calcium-based high-pH GLDA solutions were used. Coreflooding experiments were conducted at high-pressure high-temperature (HPHT) conditions using carbonate and sandstone cores. The used samples had porosity values of 15–18%, and permeability values were between 10 and 75 mD. Seawater was injected as a secondary recovery process. Thereafter, a GLDA solution was injected in tertiary mode, until no more oil was recovered. In addition to the recovery experiments, the collected effluent was analyzed for cations concentrations such as calcium, magnesium, and iron. Moreover, dynamic adsorption, interfacial tension, and contact angle measurements were conducted for the different forms of GLDA chelating agent solutions. The results of this study showed that incremental oil recovery between 19% and 32% of the Original Oil in Place (OOIP) can be achieved, based on the salt type and the rock lithology. Flooding carbonate rocks with the calcium-based GLDA chelating agent yielded the highest oil recovery (32% of OOIP), followed by that with potassium-based GLDA chelating agent, and the sodium-based GLDA chelating agent yielded the lowest oil recovery. The reason behind that was the adsorption of the calcium-based GLDA on the rock surface was the highest without reducing the rock permeability, which was indicated by the contact angle, dynamic adsorption, and flooding experiments. The outcome of this study will help in maximizing the oil recovery from carbonate and sandstone reservoirs by suggesting the most suitable salt type of chelating agents.
Highlights
Enhanced Oil Recovery (EOR) techniques are applied to enhance hydrocarbon recovery utilizing several methods such as gas injection, thermal treatments, and chemical flooding [1,2]
Various chemicals are injected into a reservoir to enhance the hydrocarbon flow by controlling the oil movement and minimizing interfacial tension (IFT) [3,4,5,6]
In both the sandstone and carbonate samples, Na4GLDA and K4GLDA showed faster breakthrough compared to Ca2GLDA, indicating that higher oil rtotGeocaLoCDpvaoeA2roG.yrALewrDfosaAwus,tleedienrpbdbeeircefaafacitckhinitiehegnvrctoehyudaagtunhhsdiicngathhgnueclrseaoalwcdiiliulrtlmoercea-odbvpaueoscreoeydrtewhGreosLouwDilldeAreeb.pceAoeavffficaehcsriityeee.vnrIecnbdyjreeaucantskiidntnhgtgrhCocuaausl2gcGwhiuLiclmDlarAn-ebdlaienusatecdode tthhthheuigescho,aeihrlsbitrgoevhcnoeoalrvtueeomriaylen.rdItenocsjoebavcrnteeidarnsykgttowhCnraoeo2uuGslagdLmhDb,peAalneaisdcnhsttohiheoutvhwsee,dehcdauigrtsbhhinoeegnrhaoCitigelahr2aGeenscdLtoDvvsaeoAnrl.uydTmswthoeoenutieonldsjbearbcmeetaepadklcethhfsliruseohivudoegwdshpe,urdaseintanhddge aaConlofadno2gGbile,tLthrDteeesArruoo.lctiTilknhrsgeeuciiornnfvjaeleaccrettyeead.bnrfldeuadikdisthpsprlaorcueeagddhaaalhnoidngghbeethrtteveorroloucikml rseeucoroffvaoceierl,yar.nesdudltiisnpglainceldatae hbirgehaekrthvrooluugmhe
Summary
Enhanced Oil Recovery (EOR) techniques are applied to enhance hydrocarbon recovery utilizing several methods such as gas injection, thermal treatments, and chemical flooding [1,2]. They concluded that an injection of a 5 wt % chelating agent can enhance the oil recovery by around 20% for carbonate and sandstone rocks. The highest oil recovery was obtained using GLDA as the chelating agent.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
