Effect of Amphiphilic Polymer/Nano-Silica Composite on Shale Stability for Water-Based Muds

Abstract

Research on using nanotechnology to solve shale instability problems in drilling engineering has been increasing. The combination of amphiphilic polymer and silica nanoparticles may be a new way to improve shale stability. Herein, an amphiphilic polymer/nano-silica composite (poly(styrene-methyl methacrylate-acrylamide)/nano-SiO2) was introduced as a novel shale stabilizer SMA/SiO2 for water-based muds, which possessed the advantages of both physical plugging and chemical inhibition during the drilling operations. The SMA/SiO2 was prepared and characterized by Fourier transform infrared spectra (FT-IR), nuclear magnetic resonance (1H-NMR), transmission electron microscope (TEM), particle size distribution (PSD) and thermogravimetric analysis (TGA) experiments, which confirmed that SMA/SiO2 was regularly spherical with nano-scale and showed good high-temperature resistance. To evaluate the plugging capacity of SMA/SiO2, the pressure transmission test and BET analysis were applied. The results indicated SMA/SiO2 was capable of effectively plugging the pores and fractures in shale. To evaluate the hydration inhibition capacity of SMA/SiO2, the rolling dispersion experiment and contact angle test were adopted. The results demonstrated that SMA/SiO2 could reduce the tendency of shale hydration, which was better than potassium chloride (KCl) and polymeric alcohol (JHC). In addition, SMA/SiO2 only created slight variations on the rheological parameters of the water-based muds (WBMs) and showed a significant filtration control performance. Due to the outstanding performance of physical plugging and chemical inhibition, SMA/SiO2 was expected to be a novel shale stabilizer to solve shale instability problems.

Laponite: a promising nanomaterial to formulate high-performance water-based drilling fluids

“…Good plugging performance for nanoscale pores can affect the properties of shale itself, such as reducing the pore volume and specific surface area of shale (Li et al 2020a;Qiu et al 2018). The recovered shale fragments before and after the shale recovery test were used for the nitrogen adsorption experiment.…”

“…The hydration of shale would lead to increases in surface area and pore volume (Li et al 2020a;Qiu et al 2018), so water-treated shale samples obtained the largest surface area and pore volume. While laponite-treated shale samples had a lower surface area and pore volume than the water-treated shale, which was due to good inhibition property and plugging performances of laponite.…”

Special Issue on “Nanotech for Oil and Gas”

“…Three papers focus on nanomaterials in drilling operations. The paper by Qiu et al [3] applied amphiphilic (poly(styrene-methyl methacrylate-acrylamide)/nano-SiO 2 ) composite materials as a novel shale stabilizer for water-based muds, which possessed the advantages of both plugging capacity and hydration inhibition during the drilling operations. The nanocomposite only created slight variations on the rheological parameters of the water-based muds and showed a significant filtration control performance.…”

Synthesis and application of temperature‐sensitive polymer as a novel plugging agent for water‐based drilling fluids

“…Used in drilling fluid, nano‐SiO 2 can reduce the hygroscopicity, swelling rate and Young's modulus of shale through physical plugging effect, thus reducing the borehole instability of shale. However, the surface of unmodified SiO 2 nanoparticles contains a large number of active groups, which tend to aggregate in water‐based drilling fluid 35,36 . Therefore, SiO 2 needs to be modified.…”