Novel Acrylamide/2-Acrylamide-2-methylpropanesulfonic Acid/4-Vinylpyridine Terpolymer as an Anti-calcium Contamination Fluid-Loss Additive for Water-Based Drilling Fluids

Abstract

A novel terpolymer of acrylamide (AM), 4-vinylpyridine (VP), and 2-acrylamide-2-methylpropanesulfonic acid (AMPS) was synthesized through free radical polymerization and characterized by proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, elemental analysis, and static light scattering measurement. The monomer ratio was shown to be the predominant factor to the fluid-loss control performance of this polymer in drilling fluids. The terpolymer under optimal polymerization conditions (PAAV) was prepared, and the dipolymer of AM and AMPS (PAA) was synthesized as a contrast sample. In an American Petroleum Institute (API) filtration test of bentonite-based mud with 10% CaCl 2 contamination after a 16 h aging at 150 °C, mud with 1% PAAV maintained an API filtrate volume (FL API ) of 4.8 mL, whereas mud with 1% PAA reached a FL API of 96.0 mL. The fluid-loss control mechanism of PAAV was investigated through adsorption experiments, ζ potential measurements, and particle size distribution analysis. The results illustrate that the introduction of VP units into a polymer molecule greatly improves the temperature resistance performance of the polymer and enhances the interaction between the polymer and bentonite, which improves colloidal properties of bentonite particles, and these make PAAV a pronounced fluidloss control agent in deep gypsum drilling operations.

A polymer microsphere emulsion as a high-performance shale stabilizer for water-based drilling fluids

“…2 (a) FT-IR spectrum of PME. (b) 1 H NMR spectrum of PME. were not observed in the TEM image due to the small number present in PME.…”

“…They have a variety of functions, such as transporting and suspending rock cuttings, balancing formation pressure, preventing wellbore collapse, and cooling and lubricating drilling bits. [1][2][3][4] Based on their composition, drilling uids are divided into three categories: water-based drilling uids (WDFs); oil-based drilling uids; and synthetic-based drilling uids. Among these, WDFs are considered the drilling uids with the most potential, because of their environmental friendliness, low cost and convenient preparation.…”

Effect of molecular flexibility on the rheological and filtration properties of synthetic polymers used as fluid loss additives in water-based drilling fluid

“…They reduce the attractions between bentonite particles by electrostatic stabilization, strengthen the bentonite structure, and help to plug the lter cake holes. 17,18 Therefore, recent efforts to modify polymeric uid loss additives have mainly been focused on adsorption and hydration groups. However, it is worth noting that the temperature resistance of a polymeric uid loss additive obtained by changing the types and proportions of adsorbed and hydrated groups in the molecule rarely exceeds 230 C. In order to further improve the temperature resistance of polymeric uid loss additives, other molecular modication methods must be considered.…”

Shale inhibition by low-molecular-weight cationic polymer in water-based mud

“…Over 75% of the formations drilled for petroleum exploration and production are comprised of shale and it causes about 70% of the wellbore instability problems across the world (Aftab et al 2017), as the shale swell rapidly on absorption of water. Shales are essentially fine-grain sedimentary rocks composed of different clay minerals like kaolinite, illite, montmorillonite, and other minerals like quartz and calcite (Caenn et al 2011;Feng et al 2018). Due to absorption of water by clay minerals in shale, the shale swells that drastically changes the stress regime and the mechanical strength of shale formation decreases.…”

“…A base mud was prepared by dispersion of bentonite in water with some other additives used in drilling fluids such as sodium silicate and xanthan gum. Bentonite is a major additive for most water-based muds, and it contains sodium montmorillonite (a dioctahedral smectite) as a major component which gives unique colloidal and rheological properties (Cao et al 2017). These polymers are added in the base mud formulation, to evaluate the effect of synthesized additives on rheological and filtration characteristics and most importantly on shale stabilization.…”