ISSN: 2578-4846
Authors: Gang L, Chunzhi L and Baijing W*
In order to improve the film-blocking and anti-collapse of water-based drilling fluid, a polymer emulsion polymer filmforming plugging agent LWFD containing multiple adsorption groups was synthesized by emulsion polymerization. The effects of the agent on the rheological properties of polysulfonate and cationic drilling fluids, API fluid filter loss, lubricity, film-forming plugging properties, and their temperature and salt resistance are evaluated in the laboratory. The experimental results show that the agent has little effect on the rheological property and fluid filter loss of polysulfonate and cationic drilling fluids, and can improve lubricity by more than 30%. It has good film-forming and plugging property for sand discs with different permeability and its temperature resistance is 130 ° C, salt resistance is 10%. When the agent is combined with the inorganic nano-blocking agent NMFD, it can improve its film-forming and plugging property. Having been tested in an oil field in Fuling, Chongqing, the results show that the rheological property of the drilling fluid is basically unchanged after adding LWFD and NMFD in polymer drilling fluid during vertical well section, and API fluid loss and filter loss of the sand disc are significantly reduced. It shows that the film-forming blocking agent LWFD has good film-forming and plugging property.
Keywords: Film-forming plugging agent; Emulsion polymerization; Rheology; Lubrication coefficient; Sand filter loss
