Preparation and Performance Evaluation of a Variable Viscosity Friction Reducer Suspension with High Salt Tolerance and Low Damage

Abstract

In view of challenges such as the long dissolution time of powder friction reducers in high-salinity water, poor environmental friendliness of water-in-oil (W/O) emulsion friction reducers, and the poor proppant-carrying capacity of conventional slickwater, a novel variable viscosity friction reducer suspension (EACM) with high salt tolerance, low damage, and strong proppant-carrying capacity was prepared by dispersing salt-tolerant polymer powder in alcohol solvents. The solubility, drag reduction ability, viscoelasticity, proppant-carrying capacity, temperature and shear resistance, and gel breaking ability of EACM were investigated. The results showed that the best solvent for the friction reducer suspension was polyethylene glycol 400, in which EACM exhibited a rapid dissolution rate with a thickening rate of 89.5% within 2 min. Due to the synergic effect between fumed silica and polyamide wax as antisedimentation agents, both at a concentration of 2.0 wt %, the EACM could remain stable for 60 days. EACM showed an excellent drag reduction performance at both low and high viscosities in 100 000 mg/L salt brine. Specifically, a drag reduction of up to 72.4% was obtained using 0.21 wt % EACM (4.65 mPa s), and a 60.8% drag reduction was achieved using 1.0 wt % EACM (35.5 mPa s). When the concentration increased from 0.13 to 1.0 wt %, the EACM solution changed from viscous to elastic; the spatial network structure of the solution became more compact, and the proppant-carrying capacity was enhanced. The viscosity of 1.6 wt % EACM solution could be maintained at 55.9 mPa s after shearing at 90 °C for 120 min at a shear rate of 100 s −1 . EACM solution also exhibited the advantages of easy breaking and low residue. This paper provides guidance for the design and selection of a novel friction reducer suspension in the oil and gas industry.

Preparation and Evaluation of Nanopolymer Microsphere Plugging Agents for Ultrahigh-Temperature Water-Based Drilling Fluids

“…The TSI reflects a combination of the magnitude of change in concentration and particle size of the sample throughout the placement time; the smaller the change, the smaller the kinetic instability index and the more stable the system, and vice versa. 31,32 In Figure 9, the TSI values for the 3 wt % PSDA suspension are in the range of 0.1 during the 4 h of the experiment. Nevertheless, the TSI values for the 3 wt % NP-1 suspension are in the range of 0.2.…”

pH-Switchable W/O Polymer Emulsion: A Promising Strategy for Rapid Dissolution of Drag Reducers

“…As water or slickwater flowed through a pipe, the pressure drop was recorded. The drag-reduction rate was calculated by the following eq , DR = normalΔ p 0 − normalΔ p 1 normalΔ p 0 × 100 % where DR is the drag-reduction rate of P(AM/AA/AMPS) aqueous solution (%), Δ P 0 is the pressure drop of water (kPa), and Δ P 1 is the pressure drop of P(AM/AA/AMPS) aqueous solution (kPa).…”

“…Drag reducer (DR) is the primary additive of slickwater fluids, which enhances pump discharge by reducing pump pressure and flow resistance. ,, Currently, polyacrylamides (PAMs) are the widely employed drag reducer that consists of powder and emulsion types. ,− PAMs powder is convenient for storage and transportation, but the slow dissolution performance that requires more than 20 min limits the continuous preparation of fracturing fluid on-site in the oil field . Besides, the inadequately dissolved polymer clusters are the leading cause of the blockage of shale gas formation. , Generally, PAM emulsion drag reducer, prepared by inverse emulsion polymerization, is introduced with hydrophilic surfactants for the adjustment of the HLB value before being used to formulate slickwater.…”

“…9 Drag reducer (DR) is the primary additive of slickwater fluids, which enhances pump discharge by reducing pump pressure and flow resistance. 5,6,10 Currently, polyacrylamides (PAMs) are the widely employed drag reducer that consists of powder and emulsion types. 5,10−13 PAMs powder is convenient for storage and transportation, but the slow dissolution performance that requires more than 20 min limits the continuous preparation of fracturing fluid on-site in the oil field.…”

“…Shale gas exploration is an inevitable channel for the growth of worldwide hydrocarbon resources. , Shale formation with extremely low permeability generally requires a hydraulic fracturing operation, which creates complex fracture networks with seepage capability. − Hydraulic fracturing fluids consist of cross-linked polymer fluids, viscoelastic surfactant fluids, and slickwater fluids. − Among these hydraulic fracturing fluids systems, slickwater fluid features drag-reduction capacity and low formation damage, which is admitted to be a desirable technology for the shale revolution …”