On Improving Water-Based Drilling Mud Swelling Control Using Modified Poly(Vinyl Alcohol)s

Danielle Poungui; Yuichi Sugai; Ronald Nguele; Kyuro Sasaki

doi:10.1021/acsomega.3c08317

On Improving Water-Based Drilling Mud Swelling Control Using Modified Poly(Vinyl Alcohol)s

ACS Omega. 2024 Apr 26;9(18):19732-19740. doi: 10.1021/acsomega.3c08317. eCollection 2024 May 7.

Authors

Danielle Poungui¹, Yuichi Sugai¹, Ronald Nguele², Kyuro Sasaki³

Affiliations

¹ Department of Earth Resources Engineering, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan.
² Institute of Northern Engineering, University of Alaska Fairbanks,1764 Tanana Loop Fairbanks, Alaska 99775, United States.
³ Institute for Future Engineering, 2-6-11 Fukagawa, Tokyo 135-8473, Japan.

Abstract

One of the most challenging issues when drilling under high-temperature, high-pressure (HT/HP) conditions is wellbore instability caused by clay swelling and fluid loss of the drilling mud. One of the most difficult issues when drilling under high-temperature, high-pressure (HT/HP) conditions is wellbore instability caused by clay swelling and fluid loss in drilling mud. Two modified PVOHs, nonionic and cationic polymers made from sodium bentonite clay and deionized water at concentrations of 0.08, 0.28, and 0.49 wt.%, were introduced to WBM percent. A series of specific gravity and mud rheology experiments at 25, 55, and 85 °C indicated that both values drop monotonically with increasing temperature, regardless of PVOH addition or concentration. A temperature increase of 30 °C decreases the mud viscosity of WBM (without PVOH) by 18% from its starting value, on average. Only 0.1% of cationic and nonionic polymer reduces viscosity by 10% and 0%, respectively. Experimenting with mud samples for 5 h revealed that adding nonionic polymers enhances mud filtration by up to 34.7%, 1.25 times more than that achieved from cationic polymers under the same filtration circumstances. Increasing the filtration temperature moderately affects mud cake generation due to increased mud swelling index and preferential adsorption by nonionic polymer. The latter observation was corroborated by determining the polymer content of the filtrates. Therefore, it was shown that nonionic polymers adsorbed more (118.9 mg/g) than cationic polymers (84.51 mg/g). Increased filtration temperature moderately affects mud cake generation due to increased mud swelling index and preferential adsorption by nonionic polymer. The latter observation was corroborated by testing the filtrates for the polymer content. As a result, it was discovered that nonionic polymer adsorbed more (118.9 mg/g) than cationic polymer (84.51 mg/g). Thermogravimetry analysis (TGA) finally tested the thermal stability of polymers.

Publication types

Review