Synthesis and investigation of a graphene oxide grafted with copolymer of acrylic acid and acrylamide for shale hydration inhibition

Wellbore instability is often caused by chemical interactions between clay stabilizer fluids and shales; therefore, selecting the proper hydration inhibition fluid is essential for effective clay inhibition treatment. Thus, it is crucial to develop a high-temperature stabilizing inhibitor that prevents clay hydration. Using free radical polymerization, a copolymer of acrylic acid and acrylamide graphene oxide composite was synthesized to provide a high thermal stability inhibitor for clay hydration. With graphene oxide added, the inhibitor will be more thermally stable, preventing polymer degradation at high temperatures. The Composite inhibitory properties at high temperature were investigated using standard methods such as anti-swelling ratio, and shale recovery test. The pristine copolymer, poly (acrylic acid-co-acrylamide) was also synthesized, and its inhibitory properties were compared to the polymer graphene oxide composite. Pure polymer and the polymer composite showed shale recovery of 82 % and 85 %, respectively, demonstrating that both inhibitors prevented shale-cutting disintegration and improved the rheology of shale formations. Pure polymer and polymer composite inhibit expansion and hydration with anti-swelling ratios of 80 and 82 %, suggesting that the inhibitors are effective at suppressing bentonite swelling. Contact angle, Fourier transform infrared spectroscopy, Scanning electron microscope, and X-ray diffraction results indicate that the polymer forms a protective film, adsorbed onto the surface of the bentonite by electrostatic attraction, thereby making the surface more hydrophobic. Therefore, both Pure polymer and polymer composite prevent hydration and swelling of bentonite by preventing water molecules from invading the interlayer spacing. According to Thermogravimetric Analysis results, the polymer composite is highly stable at 200 °C, making it an excellent clay hydration inhibitor at high temperatures. The prepared materials exhibit similar inhibitory properties since their chemical compositions are identical.