Surfactant Prefloods During Carbon Dioxide Foam Injection for Integrated Enhanced Oil Recovery in Fractured Oil-Wet Carbonates

SPE Journal ◽  
2019 ◽  
Vol 24 (03) ◽  
pp. 1139-1153 ◽  
Author(s):  
S. B. Fredriksen ◽  
Z. P. Alcorn ◽  
A.. Frøland ◽  
A.. Viken ◽  
A. U. Rognmo ◽  
...  

Summary An integrated enhanced-oil-recovery (EOR) (IEOR) approach is used in fractured oil-wet carbonate core plugs where surfactant prefloods reduce interfacial tension (IFT), alter wettability, and establish conditions for capillary continuity to improve tertiary carbon dioxide (CO2) foam injections. Surfactant prefloods can alter the wettability of oil-wet fractures toward neutral/weakly-water-wet conditions that in turn reduce the capillary threshold pressure for foam generation in matrix and create capillary contact between matrix blocks. The capillary connectivity can transmit differential pressure across fractures and increase both mobility control and viscous displacement during CO2-foam injections. Outcrop core plugs were aged to reflect conditions of an ongoing CO2-foam injection field pilot in west Texas. Surfactants were screened for their ability to change the wetting state from oil-wet using the Darcy-scale Amott-Harvey index. A cationic surfactant was the most effective in shifting wettability from an Amott-Harvey index of –0.56 to 0.09. Second waterfloods after surfactant treatments and before tertiary CO2-foam injections recovered an additional 4 to 11% of original oil in place (OIP) (OOIP), verifying the favorable effects of a surfactant preflood to mobilize oil. Tertiary CO2-foam injections revealed the significance of a critical oil-saturation value below which CO2 and surfactant solution were able to enter the oil-wet matrix and generate foam for EOR. The results reveal that a surfactant preflood can reverse the wettability of oil-wet fracture surfaces, lower IFT, and lower capillary threshold pressure to reduce oil saturation to less than a critical value to generate stable CO2 foam.

ICIPEG 2016 ◽  
2017 ◽  
pp. 205-215
Author(s):  
Shehzad Ahmed ◽  
Khaled Abdalla Elraies ◽  
Isa M. Tan ◽  
Mudassar Mumtaz

SPE Journal ◽  
2013 ◽  
Vol 19 (02) ◽  
pp. 249-259 ◽  
Author(s):  
Yunshen Chen ◽  
Amro S. Elhag ◽  
Benjamin M. Poon ◽  
Leyu Cui ◽  
Kun Ma ◽  
...  

Summary To improve sweep efficiency for carbon dioxide (CO2) enhanced oil recovery (EOR) up to 120°C in the presence of high-salinity brine (182 g/L NaCl), novel CO2/water (C/W) foams have been formed with surfactants composed of ethoxylated amine headgroups with cocoalkyl tails. These surfactants are switchable from the nonionic (unprotonated amine) state in dry CO2 to cationic (protonated amine) in the presence of an aqueous phase with a pH less than 6. The high hydrophilicity in the protonated cationic state was evident in the high cloudpoint temperature up to 120°C. The high cloud point facilitated the stabilization of lamellae between bubbles in CO2/water foams. In the nonionic form, the surfactant was soluble in CO2 at 120°C and 3,300 psia at a concentration of 0.2% (w/w). C/W foams were produced by injecting the surfactant into either the CO2 phase or the brine phase, which indicated good contact between phases for transport of surfactant to the interface. Solubility of the surfactant in CO2 and a favorable C/W partition coefficient are beneficial for transport of surfactant with CO2-flow pathways in the reservoir to minimize viscous fingering and gravity override. The ethoxylated cocoamine with two ethylene oxide (EO) groups was shown to stabilize C/W foams in a 30-darcy sandpack with NaCl concentrations up to 182 g/L at 120°C and 3,400 psia, and foam qualities from 50 to 95%. The foam produces an apparent viscosity of 6.2 cp in the sandpack and 6.3 cp in a 762-μm-inner-diameter capillary tube (downstream of the sandpack) in contrast with values well below 1 cp without surfactant present. Moreover, the cationic headgroup reduces the adsorption of ethoxylated alkyl amines on calcite, which is also positively charged in the presence of CO2 dissolved in brine. The surfactant partition coefficients (0 to 0.04) favored the water phase over the oil phase, which is beneficial for minimizing losses of surfactant to the oil phase for efficient surfactant usage. Furthermore, the surfactant was used to form C/W foams, without forming stable/viscous oil/water (O/W) emulsions. This selectivity is desirable for mobility control whereby CO2 will have low mobility in regions in which oil is not present and high contact with oil at the displacement front. In summary, the switchable ethoxylated alkyl amine surfactants provide both high cloudpoints in brine and high interfacial activities of ionic surfactants in water for foam generation, as well as significant solubilities in CO2 in the nonionic dry state for surfactant injection.


Author(s):  
Gabe Nahas ◽  
Mo. Mohitpour

Pipeline transportation of carbon dioxide (CO2) dates back to the early 1970’s with the construction of the Canyon Reef Carriers & Val Verde pipeline in Texas USA. Since that time about 7200 kilometers of CO2 pipeline have been built in North America (mostly in the USA), some in Asia (Turkey) and Africa and one offshore Europe. The experience of such pipelines is predominantly for the transportation of naturally occurring and relatively pure CO2 for the purpose of enhanced oil recovery (EOR).


SPE Journal ◽  
2017 ◽  
Vol 22 (05) ◽  
pp. 1416-1423 ◽  
Author(s):  
Jingshan San ◽  
Sai Wang ◽  
Jianjia Yu ◽  
Ning Liu ◽  
Robert Lee

Summary This paper reports the study of the effect of different ions (monovalent, bivalent, and multiple ions) on nanosilica-stabilized carbon dioxide (CO2) foam generation. CO2 foam was generated by coinjecting CO2/5,000 ppm nanosilica dispersion (dispersed in different concentrations of brine) into a sandstone core under 1,500 psi and at different temperatures. A sapphire observation cell was used to determine the foam texture and foam stability. Pressure drop across the core was measured to estimate the foam mobility. The results indicated that more CO2 foam was generated as the sodium chloride (NaCl) concentration increased from 1.0 to 10%. In addition, the foam bubble became smaller and foam stability improved with the increase in NaCl concentration. The CO2-foam mobility decreased from 13.1 to 2.6 md/cp when the NaCl concentration increased from 1 to 10%. For the bivalent ions, the generated CO2-foam mobility decreased from 19.7 to 4.8 md/cp when CaCl2 concentration increased from 0.1 to 1.0%. Synthetic produced water with total dissolved solids (TDS) of 18,583 ppm was prepared to investigate the effect of multiple ions on foam generation. The results showed that stable CO2 foam was generated as the synthetic produced water and nanosilica dispersion/CO2 flowed through a porous medium. The lifetime of the foam was observed to be more than 2 days as the foam stood at room temperature. Mobility of the foam was calculated as 5.2 md/cp.


2017 ◽  
Vol 114 ◽  
pp. 6950-6956 ◽  
Author(s):  
Ken Allinson ◽  
Dan Burt ◽  
Lisa Campbell ◽  
Lisa Constable ◽  
Mark Crombie ◽  
...  

2021 ◽  
Author(s):  
Qichao Lv ◽  
Tongke Zhou ◽  
Xing Zhang ◽  
Xinshu Guo ◽  
Zhaoxia Dong

Abstract CO2 foams have been used for a long time for enhanced oil recovery (EOR) and carbon capture, utilization, and storage. Note that conventional CO2 foam focuses on mobility control and storage of bare CO2. However, this technology has suffered from low storage efficiency and EOR because of foam instability. In this study, the geological storage of CO2 and coal fly ash (CFA) using Pickering foam for EOR was explored. The aim is to obtain an inexpensive method for EOR and storage of greenhouse gases and atmospheric pollutants. The Pickering foam was prepared using Waring blender method. The experiments were conducted to evaluate CO2/liquid interface enhancement by measuring the interfacial tension and interfacial viscoelastic modulus. As per the heterogeneous sandpack flooding experiments, the profile control capacity and the performance of oil displacement using CO2 foam enhanced by CFA were investigated. The amount of storage from dynamic aspects of CO2 and CFA was measured to demonstrate the storage law. The stability of aqueous foam was improved significantly after the addition of CFA. The half-life time of foam stabilized by CFA particles increased by more than about 11 times than that of foam without CFA particles. The interfacial dilatational viscoelastic modulus of CO2/foaming solution increased with CFA particle concentration increasing, indicating the interface transformed from liquid-like to solid-like. Flooding experiments in heterogeneous porous media showed that more produced fluid was displaced from the relatively low-permeability sandpack after the injection of CO2 foam with CFA. The oil recovery by CFA stabilized foam was improved by ~28.3% than that of foam without CFA particles. And the sequestration of CO2 in heterogeneous porous media was enhanced with the addition of CFA to CO2 foam, and the CFA stabilized foam displayed a strong resistance to water erosion for the storage of CO2 and CFA. This work introduces a win–win method for EOR and storage of CO2 and atmospheric pollutant particles. CFA from coal combustion was used as an enhancer for CO2 foam, which improved the interfacial dilatational viscoelasticity of foam film and the dynamic storage of CO2. Furthermore, the storage of CO2 and CFA contributed to improvement in sweep efficiency, and thus EOR.


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