title: Rheological and Performance Research on a Regenerable Polyvinyl Alcohol Fracturing Fluid.
abstract: A regenerable polyvinyl alcohol/organic boron fracturing fluid system with 1.6 wt% polyvinyl alcohol (PVOH) and 1.2 wt% organic boron (OBT) was studied, and its main regeneration mechanism is the reversible cross-linking reaction between B(OH)4- and hydroxyl groups of PVOH as the change of pH. Results of rheology evaluations show that both the apparent viscosity and the thermal stability of the fracturing fluid decreased with the regeneration number of times increasing. In addition, the apparent viscosity of the fluid which was without regeneration was more sensitive to the shear action compared with that of the fluid with regeneration once or twice. When the fracturing fluid was without regeneration, the elasticity was dominating due to the three-dimensional network structure of the formed gel; the viscosity gradually occupied the advantage when the fracturing fluid was regenerated once or twice. The settling velocity of proppant was accelerated by both the regeneration process and the increasing temperature, but it was decelerated when the proppant ratio increased. Results of core damage tests indicate that less permeability damage was caused by the PVOH/OBT fracturing fluid compared with that caused by the guar gum fracturing fluid after gel breaking.
authors.affiliation: PetroChina Research Institute of Petroleum Exploration & Development-Langfang (RIPED-LF), Langfang, Hebei, 065007, P.R. China.|PetroChina Research Institute of Petroleum Exploration & Development, Beijing, 100083, P.R. China.
authors.forename: Xiaosen
authors.initials: X
authors.lastname: Shang
authors.affiliation: PetroChina Research Institute of Petroleum Exploration & Development-Langfang (RIPED-LF), Langfang, Hebei, 065007, P.R. China.
authors.forename: Yunhong
authors.initials: Y
authors.lastname: Ding
authors.affiliation: PetroChina Research Institute of Petroleum Exploration & Development-Langfang (RIPED-LF), Langfang, Hebei, 065007, P.R. China.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Wang
authors.affiliation: PetroChina Research Institute of Petroleum Exploration & Development-Langfang (RIPED-LF), Langfang, Hebei, 065007, P.R. China.
authors.forename: Lifeng
authors.initials: L
authors.lastname: Yang
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D004548:Elasticity; D005685:Galactans / Q000737:chemistry*; D008351:Mannans / Q000737:chemistry*; D053149:Plant Gums / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D012212:Rheology; D013696:Temperature; D014783:Viscosity
chemical_list: D001896:Boron Compounds; D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D011142:Polyvinyl Alcohol; C007894:guar gum