Dataset Information

Spectrophotometric Determination of Ca²⁺ and Ca-Complex Formation Constants: Application to Chemical Enhanced Oil Recovery.

ABSTRACT: Chemicals such as anionic surfactants and polymers often contain groups that complex divalent ions such as Ca²⁺. The formation of divalent ion complexes can decrease emulsifying or viscosifying power and lead to adsorption or precipitation. This is particularly relevant in chemical enhanced oil recovery, where high viscosities and low interfacial tensions are required for mobility control and the formation of oil-water microemulsions, respectively. In this work, we use a Ca²⁺-sensitive dye to determine the Ca²⁺ concentration and Ca-complex formation constants in solutions containing complexing agents. This method can be used to rapidly screen the affinity of different chemicals to form Ca-complexes in low-salinity solutions. The complex formation constants can be implemented into chemical flooding simulators to investigate the interplay with mineral dissolution and cation exchange and model adsorption processes.

SUBMITTER: Groenendijk DJ

PROVIDER: S-EPMC7905941 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Spectrophotometric Determination of Ca2+ and Ca-Complex Formation Constants: Application to Chemical Enhanced Oil Recovery.

Groenendijk Dirk J DJ Bouwmeester Ron R van Wunnik Johannes N M JNM

ACS omega 20210205 7

Chemicals such as anionic surfactants and polymers often contain groups that complex divalent ions such as Ca2+. The formation of divalent ion complexes can decrease emulsifying or viscosifying power and lead to adsorption or precipitation. This is particularly relevant in chemical enhanced oil recovery, where high viscosities and low interfacial tensions are required for mobility control and the formation of oil-water microemulsions, respectively. In this work, we use a Ca2+</su ...[more]

PMID: 33644611

Similar Datasets

Project description:The primary objective of this study is to develop a novel experimental nanofluid based on surfactant-nanoparticle-brine tuning, subsequently evaluate its performance in the laboratory under reservoir conditions, then upscale the design for a field trial of the nanotechnology-enhanced surfactant injection process. Two different mixtures of commercial anionic surfactants (SA and SB) were characterized by their critical micelle concentration (CMC), density, and Fourier transform infrared (FTIR) spectra. Two types of commercial nanoparticles (CNA and CNB) were utilized, and they were characterized by SBET, FTIR spectra, hydrodynamic mean sizes (dp50), isoelectric points (pHIEP), and functional groups. The evaluation of both surfactant-nanoparticle systems demonstrated that the best performance was obtained with a total dissolved solid (TDS) of 0.75% with the SA surfactant and the CNA nanoparticles. A nanofluid formulation with 100 mg·L-1 of CNA provided suitable interfacial tension (IFT) values between 0.18 and 0.15 mN·m-1 for a surfactant dosage range of 750-1000 mg·L-1. Results obtained from adsorption tests indicated that the surfactant adsorption on the rock would be reduced by at least 40% under static and dynamic conditions due to nanoparticle addition. Moreover, during core flooding tests, it was observed that the recovery factor was increased by 22% for the nanofluid usage in contrast with a 17% increase with only the use of the surfactant. These results are related to the estimated capillary number of 3 × 10-5, 3 × 10-4, and 5 × 10-4 for the brine, the surfactant, and the nanofluid, respectively, as well as to the reduction in the surfactant adsorption on the rock which enhances the efficiency of the process. The field trial application was performed with the same nanofluid formulation in the two different injection patterns of a Colombian oil field and represented the first application worldwide of nanoparticles/nanofluids in enhanced oil recovery (EOR) processes. The cumulative incremental oil production was nearly 30,035 Bbls for both injection patterns by May 19, 2020. The decline rate was estimated through an exponential model to be -0.104 month-1 before the intervention, to -0.016 month-1 after the nanofluid injection. The pilot was designed based on a production increment of 3.5%, which was successfully surpassed with this field test with an increment of 27.3%. This application is the first, worldwide, to demonstrate surfactant flooding assisted by nanotechnology in a chemical enhanced oil recovery (CEOR) process in a low interfacial tension region.

Project description:Throughout the application of enhanced oil recovery (EOR), surfactant adsorption is considered the leading constraint on both the successful implementation and economic viability of the process. In this study, a comprehensive investigation on the adsorption behaviour of nonionic and anionic individual surfactants; namely, alkyl polyglucoside (APG) and alkyl ether carboxylate (AEC) was performed using static adsorption experiments, isotherm modelling using (Langmuir, Freundlich, Sips, and Temkin models), adsorption simulation using a state-of-the-art method, binary mixture prediction using the modified extended Langmuir (MEL) model, and artificial neural network (ANN) prediction. Static adsorption experiments revealed higher adsorption capacity of APG as compared to AEC, with sips being the most fitted model with R2 (0.9915 and 0.9926, for APG and AEC respectively). It was indicated that both monolayer and multilayer adsorption took place in a heterogeneous adsorption system with non-uniform surfactant molecules distribution, which was in remarkable agreement with the simulation results. The (APG/AEC) binary mixture prediction depicted contradictory results to the experimental individual behaviour, showing that AEC had more affinity to adsorb in competition with APG for the adsorption sites on the rock surface. The adopted ANN model showed good agreement with the experimental data and the simulated adsorption values for APG and AEC showed a decreasing trend as temperature increases. Simulating the impact of binary surfactant adsorption can provide a tremendous advantage of demonstrating the binary system behaviour with less experimental data. The utilization of ANN for such prediction procedure can minimize the experimental time, operating cost and give feasible predictions compared to other computational methods. The integrated workflow followed in this study is quite innovative as it has not been employed before for surfactant adsorption studies.

Project description:BackgroundPseudomonas aeruginosa, the rhamnolipids-producer, is one of dominant bacteria in oil reservoirs. Although P. aeruginosa strains are facultative bacteria, the anaerobic biosynthesis mechanism of rhamnolipids is unclear. Considering the oxygen scarcity within oil reservoirs, revealing the anaerobic biosynthesis mechanism of rhamnolipids are significant for improving the in-situ production of rhamnolipids in oil reservoirs to enhance oil recovery.ResultsPseudomonas aeruginosa SG anaerobically produced rhamnolipids using glycerol rather than glucose as carbon sources. Two possible hypotheses on anaerobic biosynthesis of rhamnolipids were proposed, the new anaerobic biosynthetic pathway (hypothesis 1) and the highly anaerobic expression of key genes (hypothesis 2). Knockout strain SGΔrmlB failed to anaerobically produce rhamnolipids using glycerol. Comparative transcriptomics analysis results revealed that glucose inhibited the anaerobic expression of genes rmlBDAC, fabABG, rhlABRI, rhlC and lasI. Using glycerol as carbon source, the anaerobic expression of key genes in P. aeruginosa SG was significantly up-regulated. The anaerobic biosynthetic pathway of rhamnolipids in P. aeruginosa SG were confirmed, involving the gluconeogenesis from glycerol, the biosynthesis of dTDP-L-rhamnose and β-hydroxy fatty acids, and the rhamnosyl transfer process. The engineered strain P. aeruginosa PrhlAB constructed in previous work enhanced 9.67% of oil recovery higher than the wild-type strain P. aeruginosa SG enhancing 8.33% of oil recovery.ConclusionThe highly anaerobic expression of key genes enables P. aeruginosa SG to anaerobically biosynthesize rhamnolipids. The genes, rmlBDAC, fabABG, rhlABRI, rhlC and lasI, are key genes for anaerobic biosynthesis of rhamnolipid by P. aeruginosa. Improving the anaerobic production of rhamnolipids better enhanced oil recovery in core flooding test. This study fills the gaps in the anaerobic biosynthesis mechanism of rhamnolipids. Results are significant for the metabolic engineering of P. aeruginosa to enhance anaerobic production of rhamnolipids.

Project description:Low salinity waterflooding (low salinity-EOR) has attracted great interest from many giant oil producers and is currently under trial in some of the oil fields of the United States, Middle Eastern countries, and North Sea reservoirs. Most of the reported studies on this process were carried out for medium to relatively heavy oil with significant polar contents. In this work, we have investigated low salinity waterflooding performance for light paraffinic crude oil with a low acid number. This study has been performed using crude oil from an Indian offshore oilfield and Indian offshore seawater. Oil recovery efficiencies of seawater and its diluted versions (low salinity seawater) were evaluated through core-flooding experiments performed on a silica sand pack containing small amounts (2 wt %) of bentonite clay saturated with crude oil. Interfacial tension and wettability studies were performed to understand the associated low salinity effects on the crude oil/brine/rock properties. Effluent brine produced during the flooding experiments was also analyzed to obtain a clearer insight into the low salinity-enhanced oil recovery (EOR) mechanism. The results showed that injection of low salinity seawater can significantly increase the waterflood recovery in comparison with high salinity seawater injection. Interfacial tension and contact angle studies revealed that there is an optimum dilution level at which the interfacial tension and wettability are the most favorable for enhanced oil recovery even in the case of light paraffinic crude. These results are in line with the results obtained from the core-flooding experiments. The possible reason behind recovery improvement based on the interfacial tension and wettability studies in conjugation with the effluent brine analysis has been discussed in detail. In this study, we have observed that the enhanced oil recovery efficiency could be achieved by applying low salinity seawater flooding even in the case of light paraffinic oil with a low acid number.

Dataset Information

Spectrophotometric Determination of Ca²⁺ and Ca-Complex Formation Constants: Application to Chemical Enhanced Oil Recovery.

Publications

Spectrophotometric Determination of Ca<sup>2+</sup> and Ca-Complex Formation Constants: Application to Chemical Enhanced Oil Recovery.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets