Rheological behaviors of fluorinated hydrophobically associating cationic guar gum fracturing gel

Abstract

Fracturing gel has been applied widely in oil production. Therefore, more and more people pay attention to the new studies about gel rheological properties. In this research, a new cationic guar gum gel was prepared and the rheological properties of guar gum (GG) gel, cationic guar gum (CGG) gel, and fluorinated hydrophobically associating cationic guar gum (FCGG) gel including the shear resistance properties, heat resistance properties, dynamic moduli and viscosity behavior were investigated. We found that GG, CGG and FCGG gels behave as a shear thinning pseudoplastic behavior and the flow behavior of gels can be described by Ostwald-Dewael model. In contrast to GG or CGG gel, the FCGG gel had improvement in heat resistance properties and the shear resistance properties owing to its associative properties, which was conducive to let the system possess strong fracture-making ability and sand-carrying. In addition, the apparent viscosity of FCGG gel increases with the increased shear rate at low shear rates. FCGG gel system has good viscoelasticity and its proppant suspension property is the best. Besides, gel-out properties test described that FCGG gel broken fluid has low content fracturing fluid residue and little formation damage. In addition, FCGG can decrease obviously surface tension of gel breaking liquid, improve fluid flowing back rate, so fluid flowing back additives are unnecessary. Therefore, FCGG gel has a good application foreground during the oil field production.