Impact of Hydrolysis at High Temperatures on the Apparent Viscosity of Carboxybetaine Viscoelastic Surfactant-Based Acid: Experimental and Molecular Dynamics Simulation Studies

Yu, Mengxi; Yan, M.; Wang, Guanqun; Nasr‐El‐Din, Hisham A.

doi:10.2118/142264-pa

Cited by 20 publications

(8 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chemical diverting agents are also available for acid diversion. Use of foamed fluids like foamed KCl solutions, foamed ammonium chloride solutions, and gelled pills were reported by Zerhbouh (1993), Zeilinger et al (1995), and Taylor and Nasr-El-Din (2001). The main limitation of these foamed and gelled systems is their instability at temperatures greater than 200 F and their ineffectiveness in plugging formations with permeabilities greater than 500 md (Alleman et al 2003).…”

Section: Discussionmentioning

confidence: 99%

Recent Advances in Viscoelastic Surfactants for Improved Production From Hydrocarbon Reservoirs

2016

View full text Add to dashboard Cite

Viscoelastic surfactants (VES) are used in upstream oil and gas applications, particularly hydraulic fracturing and matrix acidizing. A description of surfactant types is introduced along with a description of how they assemble into micelles, what sizes and shapes of micelles can be formed under different conditions, and finally how specific structures can lead to bulk viscoelastic-solution properties. This theoretical discussion leads into a description of the specific VES systems that have been used over the last 20 years in improved oil recovery for upstream applications.VES-based fluids have been used most extensively for hydraulic fracturing. They are preferred over conventional polymer-based fracturing-fluid systems because they are essentially solids-free systems that have demonstrated less damage to the reservoir-rock formation. In fact, approximately 10% of the fracturing treatments use VES-based fluids. Important advancements in VESs have been made by introducing "pseudocrosslinking agents," such as nanoparticles, to enhance the viscosity. Fracturing-fluid systems modeled after VES have also been improved recently by developing internal breakers to lower their viscosity to flow back the well. The flexibility of VES-based fluids has been demonstrated by their application as foamed fluids, as well as their incorporation with brine systems such as produced water.A second key area that has benefited from VES-based systems is matrix acidizing of carbonate-based reservoirs. The viscosity of these VES-based fluids is mostly controlled by pH; at low pH (low viscosity), the acid system flows easily and invades pore spaces in the formation. During acidizing, the acid is spent, and the pH and viscosity increase. Because the spent acid has higher viscosity, fresh acid is diverted to low-permeability, uncontacted zones and penetrates the rocks to form wormholes. A number of experimental studies and field applications to these effects have been performed and will be described in this study.In order for VES-based fluids to play a more-prominent role in the field, inherent limitations such as cost, applicable temperature range, and leakoff characteristics will need to continue to be addressed. If we can efficiently and economically overcome these issues, VES-based fluids offer the industry an excellent clean and nondamaging alternative to conventional polymer-based fluids.

show abstract

Section: Discussionmentioning

confidence: 99%

Recent Advances in Viscoelastic Surfactants for Improved Production From Hydrocarbon Reservoirs

2016

View full text Add to dashboard Cite

show abstract

“…This will help the acid plug the high permeability zones upon acid spending and divert the fresh acid to the low permeability zones. Yu et al (2012) studied the effect of hydrolysis on the rheology of VES-based acids systems. Under high temperature and in acidic environment, the CO-NH bond (peptide bond) is broken and the system is hydrolyzed.…”

Section: B1 Experimental Studiesmentioning

confidence: 99%

“…This resulted in a large decrease in the acid viscosity. Yu et al (2012) shows the VES-based acid phase separation as a function of hydrolysis time at 190°F for 4, 6, and 8 vol% VES concentration (Figures 3-5 of the manuscript). Similar behavior was noted at each surfactant concentration.…”

Section: B1 Experimental Studiesmentioning

confidence: 99%

Recent Advances in Viscoelastic Surfactants for Improved Production from Hydrocarbon Reservoirs

Hull

Sayed

Al-Muntasheri

2015

SPE International Symposium on Oilfield Chemistry

View full text Add to dashboard Cite

Viscoelastic surfactants (VES) are used in upstream oil and gas applications, particularly hydraulic fracturing and matrix acidizing. A description of surfactant types is introduced along with a theoretical description of how they assemble into micelles, what sizes and shapes of micelles can be formed under different conditions, and finally how specific structures can lead to bulk viscoelastic solution properties. This theoretical discussion leads into a description of the specific VES systems that have been used over the last twenty years or so in improved oil recovery for upstream applications.VES-based fluids have been used most extensively for hydraulic fracturing. They are preferred over conventional polymer-based fracturing fluid systems because they are essentially solids-free systems which have demonstrated less damage to the reservoir rock formation. Important advancements in VES have been made by introducing "pseudo-crosslinking agents" such as nanoparticles to enhance the viscosity. Fracturing fluid systems based on VES have also been improved recently by developing internal breakers to lower their viscosity in order to flow back the well. The flexibility of VES-based fluids has been demonstrated by their application as foamed fluids as well as their incorporation with brine systems such as produced water.A second key area that has benefited from VES-based systems is matrix acidizing carbonated-based reservoirs. The viscosity of these VES-based fluids is mostly controlled by pH where, at low pH (low viscosity), the acid system flows easily and invades pore spaces in the formation. During acidizing, the acid is spent, and the pH and viscosity increase. Because the spent acid has higher viscosity, fresh acid is diverted to low permeability un-contacted zones and penetrates the rocks to form wormholes. A number of experimental studies and field applications to these effects have been performed and will be described here.In order for VES-based fluids to play a more prominent role in the field, inherent limitations such as cost, applicable temperature range, and leak-off characteristics will need to continue to be addressed. If we can efficiently and economically overcome these issues, VES-based fluids offer the industry an excellent clean, non-damaging alternative to conventional polymer-based fluids.

show abstract

“…Carboxybetaine viscoelastic surfactants have been used in acid diversion and fracturing treatments in which high temperatures and low pH are usually involved [43]. These surfactants are often subjected to hydrolysis under such conditions because of the existence of a peptide group −CO−NH− in their molecules, leading to changes in the rheological properties of the acid.…”

Section: Viscoelastic Formulationsmentioning

confidence: 99%

Fracturing fluids

2015

Petroleum Engineer's Guide to Oil Field Chemicals and Fluids

View full text Add to dashboard Cite

Hydraulic fracturing is a technique to stimulate the productivity of a well. A hydraulic fracture is a superimposed structure that remains undisturbed outside the fracture. Thus the effective permeability of a reservoir remains unchanged by this process. The increased productivity results from the increased wellbore radius, because in the course of hydraulic fracturing, a large contact surface between the well and the reservoir is created.The literature from 2004 to 2014, more than 100 references concerning waterbased fracturing fluids for fracturing ultralow-to moderate-permeability reservoirs has been reviewed [1].Guar-based polymers are still used in fracturing at temperatures less than 150 • C. To minimize the damage associated with this class of polymers, several approaches are known. These include the use of a lower polymer concentration in formulating these fluids and the use of different crosslinking agents. Higher viscosities with lower polymer loadings can be achieved. In addition, cleaner guar-based polymers are used now, because commercial guar contains some 5% of residues, which may cause a damage of proppant packs.It has been found that shear and pressure effects on the rheological behavior of borate crosslinked gels are important. Although these fluids recover their viscosity after shear, they have been observed to lose a significant portion of their viscosity under high pressures.When fracturing is done in deeper wells, i.e., in hotter reservoirs, a new class of thermally stable polymers became relevant. These are poly(acrylamide)-based polymers. These synthetic polymers show a sufficient viscosity at temperatures up to 230 • C [1]. Examples are 2-acrylamido-2-methylpropanesulfonic acid and copolymers of partially hydrolyzed acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, and vinyl phosphonate. High-density brines have been used to increase the hydrostatic pressure by 30% for high-pressure pumping.Also, new breaker materials emerged [1]. These breakers destroy the gel by a reaction with the crosslinking agent. They form ligands with the metallic crosslinking agents and displace them from the crosslinking moieties of the guar-based polymers. Examples of these breakers include poly(succinimide) derivates and lignosulfonate derivates.To minimize the environmental impact of using massive amounts of fresh water and to minimize costs associated with treating produced water, the use of produced water in hydraulic fracturing treatments has been reported. Petroleum Engineer's Guide to Oil Field Chemicals and Fluids. http://dx.567 568 CHAPTER 17 Fracturing fluids B HO 17.3 Types of hydraulic fracturing fluids 571 TYPES OF HYDRAULIC FRACTURING FLUIDSGenerally, a hydraulic fracturing treatment involves pumping a proppant-free viscous fluid, or pad, usually water with some fluid additives to generate high viscosity, into a well faster than the fluid can escape into the formation so that the pressure rises and the rock breaks, creating artificial fractures or enlarging existing fractures.After fracturing...

show abstract

Impact of Hydrolysis at High Temperatures on the Apparent Viscosity of Carboxybetaine Viscoelastic Surfactant-Based Acid: Experimental and Molecular Dynamics Simulation Studies

Cited by 20 publications

References 35 publications

Recent Advances in Viscoelastic Surfactants for Improved Production From Hydrocarbon Reservoirs

Recent Advances in Viscoelastic Surfactants for Improved Production From Hydrocarbon Reservoirs

Recent Advances in Viscoelastic Surfactants for Improved Production from Hydrocarbon Reservoirs

Fracturing fluids

Contact Info

Product

Resources

About