Highly effective utilization of vinyl copolymer as filtrate reducer of water‐bentonite drilling fluid under ultrasonic oscillations

Abstract

The water-bentonite drilling fluids incorporating the terpolymer of acrylic acid, acrylamide, and 2-acrylamide-2-methyl propane sulfonic acid were prepared by common mechanical agitation of industrial community with superposition of ultrasound. Various performances of the drilling fluids in the absence and presence of ultrasonic oscillations were evaluated, including fluid loss, rheology, mud cake thickness, and surface appearance, adsorptive capacity of terpolymer on bentonite clay as well as clay particle size and distribution. The results showed that the filtrate volume and mud cake thickness as well as rheological values presented downtrend with the increase of ultrasonic time or power. Scanning electron microscope showed that the more smooth-faced and compact mud cake was formed after ultrasonic oscillations. The analysis of clay particle size confirmed that ultrasonic oscillations could reduce the average particle diameter and broaden the particle size distribution, along with the appearance of ultra-tiny clay particle components. Adsorbed amount of terpolymer on bentonite was enhanced with introduction of ultrasonic oscillations (as confirmed by total organic carbon analysis). The ultrasound-induced dispersion and adsorption stemmed from acoustic cavitation and could cooperate with each other, together improving filtration properties.

Properties of Bentonite Slurry Drilling Fluid in Shallow Formations of Deepwater Wells and the Optimization of Its Wellbore Strengthening Ability While Drilling

“…Chao et al 14 studied the improving effects of vegetable gum, sodium polyacrylate, and grafted starch on the stability and filtration loss properties of bentonite retaining wall mud and prepared polymer-modified bentonite slurry with stable viscosity, low filtration loss, and little applied admixture, which can be used to solve technical problems such as the shrinkage and collapse of holes in the construction of water-sensitive geology. Guo et al 15 prepared terpolymer water–bentonite drilling fluids using mechanical stirring and ultrasonic superimposition, which are commonly used in industry. The mud cake formed by the terpolymer water–bentonite drilling fluid had a smooth and dense surface.…”

Investigation on Filtration Control of Zwitterionic Polymer AADN in High Temperature High Pressure Water-Based Drilling Fluids

“…As an indispensable additive of WBDFs, a filtration loss reducer can inhibit the aggregation of bentonite particles and maintain reasonable particle size distribution by adsorbing on the surface of bentonite, thus forming a thin and dense mud cake on the sidewall to reduce filtrate loss [ 2 ]. Therefore, the filtration loss reducer plays a significant role in controlling the loss of drilling fluids, ensuring wellbore stability, and protecting reservoirs [ 15 , 16 , 17 ], and has become the current research’s focus. Polymers are the primary filtrate reducers, including natural polymers, modified natural polymers, and synthetic polymers.…”