Improving Plugging Performance during Conformance Control in Waterflood using Novel Carbon Nanocomposite-based Pickering Emulsion for Malaysian Formation

Abstract Low sweep efficiency during water injection besets the oil production from matured Malaysian fields undergoing waterflood operations. The water conformance issue might cause premature breakthrough in heterogeneous reservoir leading to low oil recovery. In this study, we described comprehensive experimental work to evaluate emulsion stabilized by Pickering particles as conformance control agent considering the reservoir characteristics in offshore Malaysian fields. The Pickering emulsion offers better stability in terms of resistance against mechanical and thermal changes during propagation under reservoir conditions compared to surfactant-based emulsions. In addition, emulsion due to its rheology in comparison to foam and gel have low pumping requirements with minimum chances of formation damage, providing better selective placement and ability to maneuver to deep levels of the reservoir under high temperature, salinity, and pressure conditions. In the case of conformance control applications, the particle-based emulsions provide better pore throat plugging in the high permeability thief zones mostly due to the better adsorption of Pickering particles on to the rock surface. This study investigated an ecofriendly novel carbon nanocomposite-based Pickering emulsion designed for conformance control in harsh environments of high-temperature and salinity typical of reservoirs in Malaysian fields. The research evaluated the thermal stability, rheological behavior of the emulsion under different temperatures, and salinities. Adsorption behavior of the emulsion on sandstone rock surface was analyzed based on rock-fluid interaction via contact angle measurements. We performed core flooding test to evaluate plugging performance by determining permeability reduction stimulated by the emulsion closely mimicking reservoir conditions. A permeability reduction of 98.2% was observed showing promising plugging performance with single pill injection and maintaining colloidal stability under dynamic conditions. The insights from this study can be beneficial to optimize emulsion design during the development phase, leading to improved performance of the conformance control agent with the reservoir. Moreover, the newly developed, ecofriendly emulsion due to its low volume consumption and superior plugging performance can potentially enhance conformance control performance in Malaysian reservoirs by reduction excess water production and consumption, thereby reducing operational costs and increasing oil production from untapped low permeable zones.