Gel System for Water Shut-Off Operations in Oil Wells

Abstract

AbstractThis study presents a new approach to creating a cost-effective thermally active formulation using readily available raw materials, including a gelation initiator and a gel-forming agent solution, designed for water shut-off applications. The innovation lies in the ability to customize the gelation time to match the well's specific conditions by adjusting the molar ratio and temperature. The proposed method involves introducing a thermally active blend of gel-forming initiator and gelling agent solutions to prevent water inflow into wells. Optimal concentrations for the mixture components were identified as 10-12% for the gel initiator and 9-10% for the gel-forming agent. Furthermore, the research revealed that escalating the temperature from 20 °C to 60 °C led to a remarkable 5-6-fold reduction in gelation time. At temperatures surpassing 60 °C, gel formation was achieved within 1-2 hours. Experiments conducted on both carbonate and sandstone reservoir models unveiled that the highest displacement efficiencies (%) were attained with the injection of a freshly prepared mixture (12.2% and 14.3% respectively). Notably, oil sweeping trials highlighted the superior efficiency of the newly devised method for water shut-off, using the thermally active gelling agent, surpassing the performance of established compositions in terms of technological effectiveness.