Poly-l-arginine as a High-Performance and Biodegradable Shale Inhibitor in Water-Based Drilling Fluids for Stabilizing Wellbore

Abstract

The hydration and swelling of shale formations are serious problems for well drilling. The use of an efficient shale inhibitor is one of the most important methods for overcoming the wellbore instability issue. In this work, poly-L-arginine (PArg) was synthesized and used as an efficient and biodegradable shale inhibitor. This inhibitor was systematically evaluated through measuring the swelling degree of the bentonite (Bent) pellet, the rheological behavior of the Bent suspensions, and the recovery percentage of shale cuttings. The results demonstrated that 2.0 wt % PArg could reduce the swelling degree of Bent to 70.53%, improve the shale recovery percentage to 71.40% at 180 °C, and inhibit 12.0 wt % Bent mud-making. The PArg displayed a highly inhibitive performance and excellent high-temperature resistance property, better than common inorganic KCl and organic polyether diamine. The underlying inhibition mechanism was also proposed based on measuring the variation of the interlayer spacing of the Bent, observing the exterior morphologies of Bent particles, and assessing the particle size distribution and electrokinetic potential. The results indicated that the PArg displayed its inhibitive effect mainly by adsorbing onto the Bent, encapsulating the Bent particles efficiently, and decreasing the interlayer spacing in a certain degree with 0.9 Å. This study can contribute to designing highly inhibitive water-based drilling fluids containing PArg.

Graphene with Covalently Grafted Amino Acid as a Route Toward Eco‐Friendly and Sustainable Supercapacitors

“…An absorption band at approximately 1571 cm −1 was suggested to be related to C=C skeleton vibrations in aromatic graphene regions in FG/Boc‐48 h and also N−H bending vibration of the primary amine in FG/Arg‐48 h [24,26] . A band at around 1400 cm −1 was assigned to either C−O−H bending due to a carboxylic group and/or C−N stretching vibration and −CH 2 deformation [27–29] . A band at approximately 1451 cm −1 was also attributed to −CH 2 bending vibration [25] .…”

Utilization of Eco-Friendly Waste Generated Nanomaterials in Water-Based Drilling Fluids; State of the Art Review

“…These additives must also address issues such as circulation loss control, wellbore integrity, wellbore completion, and inhibition of corrosion to ensure a smooth drilling operation [ 54 ]. However, at present, the chemicals used for these purposes are non-biodegradable and can cause significant negative effects on the environment [ 55 ]. A sustainable solution would use chemicals that are biodegradable and do not cause any environmental damage, while simultaneously providing the desired properties of a good drilling fluid, as presented in Figure 4 .…”

Technical Progress on Environmental-Friendly, High-Performance Water-Based Drilling Fluids

“…The main additives are cellulose viscosfier and high-temperature synthetic polymers filtrate reducers. During field application, the maximum temperature at the bottom of the well reaches 215℃ and the density reaches 1.86 g/cm 3 . Based on the newly developed 175℃ high temperature polymer viscosfier and rheological modifier, Halliburton successfully developed a 180℃ high temperature bentonitefree drilling fluid, breaking through the technical bottleneck of high temperature stability of bentonite-free drilling fluid [17].…”

“…The research and development of highperformance drilling fluids has always been the research focus and hotspot in the drilling engineering industry. With the increasing difficulty of oil and gas exploration and the constant pursuit of economic and environmental benefits, "safe, fast, quality, environmental friendly and efficient" have become higher goals for the development of drilling engineering technology, which will inevitably put forward more comprehensive and higher technical requirements for drilling fluids [1][2][3].…”