Characteristics of Metal-Polymer Interactions in Fracturing Fluid Systems

Kramer, J.; Prud'homme, R.K.; Norman, L.R.; Sandy, J.M.

doi:10.2523/16914-ms

Cited by 10 publications

(1 citation statement)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The cis-hydroxyl, hydroxypropyl, and carboxymethyl groups attached to the CMHPG backbone or side chain and at least two ligands coordinated to zirconium center get involved in the cross-linking reaction of the zirconium-CMHPG gel system. Kramer et al 72 and Moorhouse et al 23 postulated three different possible mechanisms for cross-linking guar gum or its derivatives with zirconium. The mechanisms are described as hydrogen bonding, covalent bonding, and colloidal interactions based on variations in the pH values of the gel solutions.…”

Section: Energy and Fuelsmentioning

confidence: 99%

Laboratory Evaluation of a Low pH and Low Polymer Concentration Zirconium-CMHPG Gel System for Hydraulic Fracturing

Zhang¹,

Zhang²,

et al. 2019

Energy Fuels

View full text Add to dashboard Cite

Low pH fracturing fluids, such as the transition metal cross-linked guar derivative, can reduce the formation damage caused by clay swelling and fines migration in hydraulic fracturing treatments. However, a major disadvantage of the fluids is the uncontrollable rapid viscosity development, especially cross-linking under a pH below 3.0. In this paper, a novel delayed organic zirconium cross-linker with lactate and ethylene glycol as ligands was designed to overcome the shortcoming. Carboxymethyl hydroxypropyl guar (CMHPG), which results in a low gel residue after breaking, was used as the polymer at low concentration. The impact of gelation parameters on the properties of zirconium-CMHPG gel system was systematically investigated using a Sydansk bottle-testing method combined with a controlled stress rheometer. Desirable gelation time delay with agreeable rheological performance could be obtained by optimizing the polymer and cross-linker concentrations even at a pH as low as 2.0. Uniformly and compactly generated 3D network microstructures could firmly lock the free water within the gel, which further improved the thermostability and acid-resistance of the system. Meanwhile, the structures could also maintain the viscoelasticity of the fluid at a high level to ensure the efficient transportation of the proppants. Proppant settling and gel breaking tests demonstrated that the low pH and low polymer concentration gel system generated fewer insoluble residues with an uncompromised suspension performance. Moreover, the formation damage evaluation revealed that the low pH fracturing fluid system produced a better return permeability than the high pH system.

show abstract

Section: Energy and Fuelsmentioning

confidence: 99%

Laboratory Evaluation of a Low pH and Low Polymer Concentration Zirconium-CMHPG Gel System for Hydraulic Fracturing

Zhang¹,

Zhang²,

et al. 2019

Energy Fuels

View full text Add to dashboard Cite

show abstract

A Novel, Shear-Stable Fracturing Fluid for High-Temperature Applications

Kalgaonkar

Patil²

2012

SPE Oil and Gas India Conference and Exhibition

View full text Add to dashboard Cite

Hydraulic fracturing often employs crosslinked polymeric gels, which are pumped into a subterranean formation with sufficient viscosity properties to generate fracture geometry in the subterranean rock and transport solid proppants to hold the fracture open. Crosslinking of a polymeric gel can significantly contribute to the success or failure of a fracturing treatment. Crosslinking agents used in commercial fracturing applications include borate, titanium, and zirconium (Zr) complex ions. As the fracturing fluid is pumped downhole, it experiences different shears, such as high shear caused by tubulars, and low shear in the fracture. Typically, polymeric gels are shear thinning and will reduce in viscosity on application of high shear. The fracturing fluid's inability to shear recover as it transitions from a high shear regime in tubulars to a low shear regime as it enters the fracture can lead to compromising of near-wellbore (NWB) proppant transport and reduced fracture width, and treatment can screenout. Borate crosslinkers that are known to provide the shear recovery property to the fracturing gel typically have a temperature limitation of 300°F. Conversely, metal crosslinkers that have good temperature stability beyond 300°F are prone to irreversible shear degradation that does not reheal as the fluid passes from the high shear to a low shear regime, thus compromising efficient proppant transportation inside the fracture. This paper presents the development of a novel fracturing fluid for high-temperature applications with a delay of complete crosslinking until after the fluid is beyond the high shear environment. Rheological characterization was performed with a Model 50-type viscometer at temperatures greater than 300°F, including shear-history profiles. The fluid chemistry presented employs a zirconium crosslinker and buffer combination that controls the crosslinker kinetics to yield a viscoelastic gel crosslink after passing through the high shear-history profile. Additionally, regained-permeability results obtained using conventional breakers demonstrated the fracturing fluid's cleanup efficiency.

show abstract

Performance Evaluation of High Temperature Fracturing Fluid

Prakash

Achalpurkar

Uppuluri

2014

Abu Dhabi International Petroleum Exhibition and Conference

View full text Add to dashboard Cite

Hydraulic fracturing has remained a fundamental technique for stimulation of oil and gas reservoirs for enhanced or economic recovery of hydrocarbons from tight formations. Transporting proppant downhole without any interruption and maximum recovery of fracturing fluids are two important criteria for successful hydraulic fracturing. To achieve such objectives, the fracturing fluid should demonstrate good viscosity and complete cleanup of gelling agents. As wells are exploited at greater depths in environments of higher temperature and pressure, fracturing fluid selection is key. Fracturing fluids prepared by crosslinking guar, guar derivatives, and other naturally occurring polymers with borate or metal crosslinkers often exhibit instability at very high temperatures. The key reason for instability of the fracturing fluid is because strength of the bonds between the polymer chain and crosslinker decreases sharply in addition to breakdown of the glycosidic bonds between monomer units of the polymer chain beyond 375°F. Additionally, metal crosslinked bonds are prone to shear degradation, creating doubt for a successful job in high temperature long reach wells.To address these issues, a synthetic gelling-agent-based fracturing fluid that can work at temperatures greater than 400°F was developed. The gelling agent is a terpolymer, which can be crosslinked with a zirconium-based crosslinker. This paper discusses evaluation and performance of an extreme temperature fracturing fluid. This fracturing fluid system has sufficient proppant carrying viscosity and provides efficient cleanup using delayed oxidized breaker. Analysis of fluid stability and delayed oxidizing breaker usage is presented in addition to performance parameters, such as regained permeability and fluid loss. The study illustrates performance of the synthetic gelling-agent-based fracturing fluid at temperatures ranging from 380 to 420°F.

show abstract

Characteristics of Metal-Polymer Interactions in Fracturing Fluid Systems

Cited by 10 publications

References 5 publications

Laboratory Evaluation of a Low pH and Low Polymer Concentration Zirconium-CMHPG Gel System for Hydraulic Fracturing

Laboratory Evaluation of a Low pH and Low Polymer Concentration Zirconium-CMHPG Gel System for Hydraulic Fracturing

A Novel, Shear-Stable Fracturing Fluid for High-Temperature Applications

Performance Evaluation of High Temperature Fracturing Fluid

Contact Info

Product

Resources

About