Preparation and properties of a clean, low‐damage waterproof locking damage multifunctional integrated water‐based fracturing fluid

Abstract

In the wake of increasingly serious challenges in oilfield production and energy utilization, oil and gas reservoirs with ultra‐low permeability have gained tremendous importance for global energy supply. In such reservoirs, hydraulic fracturing is an important stimulation measure. Here, to develop a high‐performance fracturing fluid, a novel type of water‐based thickener named FPM‐2 was exploited based on low‐molecular weight alcohol and hydrophobically associating polymers, labeled as AAOS, and synthesized using acrylamide, acryloyl acid, octadecyl dimethyl allyl ammonium chloride, and octadecyl methacrylate. Dissolution rate and scanning electron microscope results showed the system to be a fast‐soluble thickener with a spatially cross‐linked network structure. The viscosity of 0.8 wt% FPM‐2 reached up to 216 mPa·s. Investigation of the rheological behavior showed that the thickener, 1.4 wt% FPM‐2, could withstand a temperature up to 180°C after being sheared for 80 min at 170 s−1, and its viscosity was up to 53 mPa·s. The 0.6 wt% FPM‐2 sample also displayed excellent shear recovery properties and high viscoelasticity. The most fascinating aspect of FPM‐2 was that its unique formula imparted the thickener with characteristics such as enhanced self‐association, waterproof locking, and prevention of wax formation. In this research, the recovery value of core permeability exceeded 80%, and wax was precipitated as small‐sized particles that prevented pipeline blockage. Therefore, the use of this multi‐effect cleansing thickener should set the trend for the development of oil and gas resources.

Fracturing Fluid Polymer Thickener with Superior Temperature, Salt and Shear Resistance Properties from the Synergistic Effect of Double-Tail Hydrophobic Monomer and Nonionic Polymerizable Surfactant

“…In addition, the repulsive forces of hydrophilic and hydrophobic segments of the polymer chains could promote the chain extension of polymers. [ 41 ] Although the presence of long hydrophobic chains had a negative impact on the water solubility of polymers, the polymers could be dissolved in less than 7 min, exhibiting rapid water solubility. The rapid-dissolving property of ASDM facilitated its preparation and application in hydraulic fracturing.…”