Universal Breakers with Broad Polymer Specificity for Use in Alkaline, High-Temperature Fracturing Fluids

Abstract

Increased interest in minimizing environmental risk from chemicals has sparked the innovation of new universal breakers for use in high-temperature fracturing fluids. Enzymes have been used for many years in fracturing applications with great success, but their use could be limited due to polymer specificity and thermal stability.A novel type of breaker system, derived from biological sources and displaying catalytic, polymer degrading activity similar to that of enzymes, was obtained and tested for its ability to reduce the viscosity and molecular weight of polymers used in hydraulic fracturing applications. The universal breakers (UB) are miscible, catalytic, renewable, biodegradable and are not polymer-specific. Additionally, these breakers do not display the thermal denaturation limitations of enzyme breakers, and can thus be used over a much wider temperature range.Three novel universal breakers were tested for their ability to break the viscosity of various oilfield polymers (guar, carboxymethyl guar, and xanthan) at temperatures of 175, 200, and 225 °F. UB-1 and UB-3 showed rapid catalytic activity at 175, 200, and 225 °F, and reduction in viscosity. UB-2 was more effective at temperatures equal to and greater than 200 °F. Additionally, all UB breakers showed activity against xanthan, with UB-1 and UB-3 being the most effective. This paper will describe the testing program for the viscosity-reducing ability of three novel universal breakers against both linear and crosslinked high-yield guar, guar, carboxymethyl guar, and xanthan in alkaline and high-temperature conditions. Comparisons of the UB breakers to conventional polymer-specific enzymes and oxidative breaker systems will be discussed. Finally, this paper will include recommendations for field applications, including economic impacts on fracturing fluid systems.

Supramolecular dynamic binary complexes with pH and salt-responsive properties for use in unconventional reservoirs

“…After the fluid injection step is completed and the proppant is deposited in the fractures, the fracturing fluid must attain a lower viscosity to allow flow back and efficient cleanup [ 70 ]. The use of oxidizers and enzymes have sometimes been utilized for this purpose in linear and crosslinked gels, but their incompatibility towards certain fracturing fluids and additives prompted the search for alternatives [ 71 , 72 ]. The dynamic binary complex presented in this paper, which can be switched down to a lower viscosity by decreasing the pH has the potential to address the gel breaking requirements of industry in a facile manner.…”

Improving Fracture Conductivity by Developing and Optimizing Channels within the Fracture Geometry: CFD Study

“…Enhancing crosslinker chemistry Ainley et al 1993, Putzig and St. Clair 2007, Sun and Qu 2011, and Legemah et al 2013 Enhancing breaker chemistry Brannon 1994, Sarwar et al 2011, Gunawan et al 2012, and Patil et al 2013 Fracture fluid additives Bang et al 2008, andKim et al 2015 Foamed fluids Hutchins and Miller 2005, Gupta et al 2005, Chen et al 2005, Friehauf and Sharma 2009, and Gupta and Carman 2011 Viscoelastic surfactant systems Samuel et al 1999, Gomaa et al 2011, and Gomaa et al 2015 Polymer chemistry Cramer et al 2004, and Gomaa et al 2014Proppant Technology Brannon et al 2004 These improvements contributed incrementally toward the goal of attaining the maximum theoretical conductivity that can be achieved in a homogeneous proppant pack.…”

A review of fracturing fluid systems used for hydraulic fracturing of oil and gas wells

“…Delayed release systems capable of delaying the activity of breakers or crosslinking of guar during the injection are another important focus of the oil and gas industry. 34,35,69,70 Slickwater Fluids The current focus of the industry is on the following items: Development of a system that can use less or no water, in order to address the concerns regarding high water volumes being used and also other concerns regarding near fracture damage. Development of gas-based fracturing systems and efficient fluid loss additives for smaller pore size formations are currently being pursued for this purpose.…”

“…Moreover, the industry is focused on development of environmentally‐ and equipment‐friendly breakers that can be applied at high temperatures and extremely low or high pH conditions. Delayed release systems capable of delaying the activity of breakers or crosslinking of guar during the injection are another important focus of the oil and gas industry …”