Water-based fracturing fluid thickener and method for preparing same

The invention provides a water-based fracturing fluid thickener and a method for preparing the same. The water-based fracturing fluid thickener comprises acrylamide, 2-acrylamido-2-methyl-1-propanesulfonic acid, N-vinyl pyrrolidone, acrylic acid, a complexing agent, a chain transfer agent, sodium hydroxide solution, an initiator and water. The method comprises the following steps of: mixing the 2-acrylamido-2-methyl-1-propanesulfonic acid, the acrylic acid, water and the sodium hydroxide solution, wherein the pH value of a mixed solution is 3-11; adding the complexing agent to purify a solution of reaction, and adding the chain transfer agent at the same time to prevent cross-linking; adding the N-vinyl pyrrolidone and the initiator, and finally carrying out reaction to obtain the water-based fracturing fluid thickener. If the mass fraction of the water-based fracturing fluid thickener in a water-based fracturing fluid is 0.35%, the apparent viscosity is 140mPa.s. When being sheared continuously for 30 minute