Fracture-cavern type oil reservoir filtrate reducer composition and fracture-cavern type oil reservoir filtrate reducing method

The invention provides a fracture-cavern type oil reservoir filtrate reducer composition. The fracture-cavern type oil reservoir filtrate reducer composition is prepared from the following components including a slick water fracturing fluid containing a dispersion suspension concentrate and modified styrene-butadiene rubber particles, wherein the concentration of the dispersion suspension concentrate is 0.2-1.0 wt%; the modified styrene-butadiene rubber particles are prepared by carrying out emulsion free radical polymerization on 1, 3-butadiene monomer and styrene monomer to obtain a polymer with a repetitive unit structural formula shown as -(CH2-CH=CH-CH2)m-(CH-C6H5-CH2)n-, and then carrying out vulcanization treatment on the polymer to obtain the modified styrene-butadiene rubber particles, and the ratio of m to n is 70 to 30. The invention also provides a fracture-cavern type oil reservoir filtrate reducing method. The fracture-cavern type oil reservoir filtrate reducing method comprises the following steps: pouring the slick water fracturing fluid containing the dispersion suspension concentrate into a formation to form a fissure, wherein the concentration of the dispersion suspension concentrate in slick water is 0.2-1.0 wt%; and with the slick water fracturing fluid containing the dispersion suspension concentrate as a carrier, pouring the modified styrene-butadiene rubber particles into the formation in a segmented adding mode, wherein in the pouring process, the concentration of the modified styrene-butadiene rubber particles is sequentially and progressively increased from 3wt% to 5wt% and 8wt%. The fracture-cavern type oil reservoir filtrate reducer composition and the fracture-cavern type oil reservoir filtrate reducing method are obvious in effect and can also obtain good acid fracturing transformation effect.