The Application of Micro-Sized Crosslinked Polymer Gel for Water Control to Improve Zonal Isolation in Cement Sheath: An Experimental Investigation

Cementing is a major step in the construction and sealing of hydrocarbon wells. During the life cycle of the well, cement is prone to cracking due to change in downhole conditions. This research investigates the use of micro-sized cross-linked polymer gel as a sealant material to mitigate cracked cement sheaths. Two experimental setups were designed to investigate water leakage through cement. The impact of polymer gel strength on the gel's ability to seal cement cracks was investigated using four gel strengths including 500 pa, 1200 pa, 1450 pa, and 2440 pa. The impact of the width of the cement crack was also investigated using 0.5, 3.2, and 6.75 mm. Results show that polymer gel propagated across fractures like a piston with no gravity effect and with angle with gravity effect. Blocking efficiency to water flow is controllable and it can be increased if polymer gel with high strength is selected. To the authors’ knowledge, very little experimental work has been conducted to investigate the use of crosslinked micro-gel in cement zonal isolation. This study can provide the oil and gas industry with an innovative method to improve cement zonal isolation, thus reducing the impact of cement failure.