Development and Evaluation of the Nano Plugging Agent NF-1

Nano material has small particle size, is well dispersed and has stable properties, thus is always used in solving lost circulation and borehole collapse encountered in drilling operation. A nano material plugging agent, NF-1 was developed by adding SnCl₄·5H₂O and benzimidazole into a mixture of absolute alcohol and deionized water under certain conditions. The synthesis was done by combining hydrothermal method and solvothermalmethod, taking into account the effects of reaction solvent, molar ratio of reactants, reaction temperature, and surfactant used in the reaction. NF-1 has particle size of 91.4 nm. Laboratory evaluation showed that addition of 5% NF-1 into a base mud reduced the 30 min filter loss of the base mud to 12.8 mL at 105℃, 3.5 MPa, indicating that NF-1 had excellent plugging performance.