The role of CO2 and ion type in the dynamic interfacial tension of acidic crude oil/carbonated brine

Mostafa Lashkarbolooki,Shahab Ayatollahi,Ali Zeinolabedini Hezave

doi:10.1007/s12182-019-0310-1

Abstract

The effects of CO2 and salt type on the interfacial tension (IFT) between crude oil and carbonated brine (CB) have not been fully understood. This study focuses on measuring the dynamic IFT between acidic crude oil with a total acid number of 1.5 mg KOH/g and fully CO2-saturated aqueous solutions consisting of 15,000 ppm of KCl, NaCl, CaCl2 and MgCl2 at 30 °C and a wide range of pressures (500–4000 psi). The results of IFT measurements showed that solvation of CO2 into all the studied aqueous solutions led to an increase in IFT of acidic crude oil (i.e., comparison of IFT of crude oil/CB and crude oil/brine), while no significant effect was observed for pressure. In contrast, the obtained results of studied salts indicated a positive effect on the IFT reduction of acidic crude oil/carbonated water (CW) (i.e., comparison of IFT of crude oil/CB and crude oil/CW).

Highlights

In recent years, severe environmental problems and global warming, due to the accumulation of carbon dioxide (CO2) in the atmosphere, lead to the development of various technologies for the capturing and storage of C O2 (Abbaszadeh et al 2016; Ahmadi et al 2016a; Godec et al 2013; Li et al 2008; Zhao et al 2010)
Based on the results reported by Johnson et al (1952), Yang et al (2005), Riazi and Golkari (2016) and Honarvar et al (2017), it can be shown that the interfacial tension (IFT) of crude oil/CO2-enriched water is lower than that of crude oil/water which makes the IFT reduction a property of carbonated brine (CB) injection (Ahmadi et al 2016b; Foroozesh et al 2016; Mosavat and Torabi 2014)
4.1 Evaluation of dynamic IFT of acidic crude oil (ACO)/carbonated brine consisting of monovalent cation

Summary

Introduction

Severe environmental problems and global warming, due to the accumulation of carbon dioxide (CO2) in the atmosphere, lead to the development of various technologies for the capturing and storage of C O2 (Abbaszadeh et al 2016; Ahmadi et al 2016a; Godec et al 2013; Li et al 2008; Zhao et al 2010). The poor sweep efficiency of direct C O2 injection indicates a lower C O2 storage capacity as well as economically inefficient enhanced oil recovery process To diminish these problems, an alternative scenario is the injection of CO2-enriched brine, i.e., carbonated brine (CB) (Lashkarbolooki et al 2018; Riazi and Golkari 2016). Since IFT of carbonated water/acidic crude oil has demonstrated unusual and confusing behavior, this study was designed as the continuation of our previous systematic procedure to find the effect of salt type on the dynamic IFT of ACO/CB In this regard, the dynamic IFTs of ACO/CO2-enriched solutions consisting of 15,000 ppm of NaCl, KCl, CaCl2 and MgCl2 were measured and results were compared to those obtained for unadulterated brine without any C O2 content (Lashkarbolooki and Ayatollahi 2017). The adsorptions of the mentioned cases which were obtained based on the mono-exponential decay model were compared

Methods and materials

Mono‐exponential decay model

Results and discussion

Conclusions