A Novel Amphoteric Polymer as a Rheology Enhancer and Fluid-Loss Control Agent for Water-Based Drilling Muds at Elevated Temperatures

Abstract

Exploring deep and ultradeep wells has rapidly become more significant to meet the global demand for oil and gas. The study of rheological and filtration-loss properties is essential to designing drilling muds and determining their performance under operational conditions. Rheological and filtration-loss properties of drilling muds were found to have a negative impact when exposed to elevated temperatures in the wells. In this study, an amphoteric polymer (abbreviated to PEX) was synthesized and characterized using a combination of analyses: FTIR, SEM, 13 CNMR, and TGA. The synthesized PEX was used as an additive in water-based drilling muds to improve rheological properties and reduce fluid loss at elevated temperatures (180−220 °C). The experimental results demonstrated that inclusion of an optimal concentration of PEX (0.3 wt %) into the drilling mud formulation increased the rheological properties by 62.3% and decreased the filtration loss by 63.5% at an aging temperature of 180 °C. Moreover, PEX was found to perform superbly compared to polyanionic cellulose (PAC-LV) and polyacrylamide (PAM), the widely used drilling mud additives. PEX not only improved the rheological properties and reduced the filtration loss behavior but also bolstered the thermostability of the drilling mud formulation. It was concluded that the rigidity and amphoteric nature of PEX accounted for the exceptional performance and temperature resistance for PEX-drilling mud formulations. Succinctly, PEX exhibits admirable properties in smart drilling mud formulations for drilling operations under high-temperature geothermal conditions. Moreover, in terms of rheological models, the Herschel−Bulkley model adequately described the rheological properties of all the studied drilling mud formulations.

Formulation of cellulose using groundnut husk as an environment-friendly fluid loss retarder additive and rheological modifier comparable to PAC for WBM

“…The properties of mud are highly dependent on shear history and temperature; hence, it is of utmost significance to test the proposed mud cake composition in the laboratory prevailing the circumstances comparable to drilling a well. Many drilling mud additives degrade at high temperatures (Huang et al 2016;Hamad et al 2020). Consequently, the 250-297 Barite + XCP + husk 4 Water: 500 ml, barite: 110 g, XCP: 2 g, Husk: 4 g effect of temperature should be observed in all drilling fluid components and additives to corroborate their efficiency.…”

Experimental Study of Bentonite-Free Water Based Mud Reinforced with Carboxymethylated Tapioca Starch: Rheological Modeling and Optimization Using Response Surface Methodology (RSM)

“…These functions can be achieved with mud exhibiting significant rheological and filtration properties. Rheological properties are influenced by various factors including solid content, pH, and additives such as dispersants, surfactants, and polymers [ 1 , 2 , 3 , 4 ].…”

Nanomaterial-Based Drilling Fluids for Exploitation of Unconventional Reservoirs: A Review

“…Therefore, investigators have been consistently working to improve the characteristics of water-based drilling fluid system (WBDF) for unconventional reservoirs and drilling operation, where WBDF is inexpensive [27] and environmental friendly [28]. Eighty percent of oil and gas wellbore drilling operation uses WBDF [29]; however, WBDF possesses several problems related to drag and torque, pipe sticking, formation damage, lost circulation, and wellbore instability within HPHT downhole environments. However, researchers are currently working on improvements to WBDF systems using polymers to enhance rheology, reduce filtrate loss and shale inhibition, and to increase salt resistance [30][31][32].…”

“…Ternary copolymer reduced the fluid loss in the presence of high salt content of drilling fluid additives and resulted in better salt tolerance. Moreover, the copolymer produced better thermal stability within the drilling fluid system [29]. Nonetheless, some cellulose polymers have been shown to degrade at 483 to 533 K [47], where polyacrylamide was substantially lost at around 378 K in the presence of oxygen.…”