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

Bahati Adnan Hamad; Miao He; Mingbiao Xu; Weihong Liu; Musa Mpelwa; Shanfa Tang; Lijun Jin; Jianjian Song

doi:10.1021/acsomega.9b03774

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

ACS Omega. 2020 Apr 7;5(15):8483-8495. doi: 10.1021/acsomega.9b03774. eCollection 2020 Apr 21.

Authors

Bahati Adnan Hamad¹, Miao He^{1

2}, Mingbiao Xu^{1

2}, Weihong Liu¹, Musa Mpelwa¹, Shanfa Tang^{1

2}, Lijun Jin¹, Jianjian Song¹

Affiliations

¹ School of Petroleum Engineering, Yangtze University, Wuhan 430100, China.
² Hubei Cooperative Innovation Center of Unconventional Oil and Gas in Yangtze University, Wuhan 430100, China.

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, ¹³CNMR, 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.