Experimental Study on the Synthesis of Nano Plugging Agent LAT for Shale Water-Based Drilling Fluid
The water in the drilling fluid will intrude into the shale interior through the nano-micron pores under the action of pressure difference and capillary force, so the effective sealing of micro and nano pores is an important measure to prevent shale hydration and swelling and maintain well wall stability. Conventional plugging agents are difficult to form an effective seal on shale microfractures due to particle size mismatch. In this paper, nano plugging agent LAT was prepared by using acrylamide, 2-acrylamide-2-methylpropanesulfonic acid and liquid paraffin as the main raw materials and azodiisoprenonitrile as the initiator, and the structure and morphology of LAT were characterized and analyzed by SEM, infrared spectroscopy and particle size analysis. and the plugging performance of plugging agent LAT was evaluated by microfracture simulation and shale tensile test. The experimental results show that the D50ofnano plugging agent LAT is 131 nm, and the plugging rate of the simulated mud cake reaches 87.35%, which shows a strong plugging performance.