Temporary plugging agent for drilling fluid

Abstract

The invention discloses a temporary plugging agent for drilling fluid, and belongs to the technical field of petroleum drilling. The temporary plugging agent is prepared from the following raw materials in percentage by weight: 60 to 70 percent of hexadecane, 0.5 to 1 percent of catalyst persulfate, 10 to 20 percent of phenol, 10 to 20 percent of formaldehyde, and 1 to 2 percent of cationic surface active agent. The preparation method comprises the following steps of: 1, adding the hexadecane liquid into a reaction kettle, heating the reaction kettle to 50+ / -5 DEG C, adding the phenol, stirring the mixture, controlling the temperature to be 80+ / -5 DEG C and the pressure to 2+ / -0.5MPa, slowly adding the catalyst, adding the formaldehyde solution after 2 hours, stirring the mixed solution for 2 hours while continuously controlling the temperature to 40+ / -5 DEG C, adding the surface active agent, and stirring the mixed solution for 2 hours; and 2, relieving the pressure in the reaction kettle to normal pressure, extracting the mixture, drying the mixture at the temperature of 100+ / -5 DEG C, and then grinding the dried mixture to obtain the temporary plugging agent. The softening point temperature of the temporary plugging agent is within a wide range from 70 to 140 DEG C, so that the temporary plugging agent can almost meet the needs of all layers of earth.

Description

technical field

[0001] The invention discloses a temporary plugging agent for drilling fluid, in particular to an oil-soluble resin temporary plugging agent and belongs to the technical field of petroleum drilling. Background technique

[0002] During the drilling operation, when the pressure of the fluid column in the wellbore of the oil layer is higher than the pressure of the oil layer, the drilling fluid will be lost to varying degrees, seriously affecting the normal process of the drilling operation, not only wasting the drilling fluid, but also causing damage to the oil layer. Therefore, it is necessary to temporarily block the formation that needs to be protected during the drilling process, and remove the plugging effect after the drilling operation is completed to restore the original state of the formation. The temporary plugging agent for drilling fluid is a treatment agent used in the drilling process to act as a temporary plugging agent. Drilling temporary plu...

Images