Patent ID: 10407608

Abstract:
The present invention relates to the field of drilling fluids, and discloses a strong plugging drilling fluid suitable for shale gas wells and a preparation method of the drilling fluid. The drilling fluid contains water, bentonite, a tackifier, a flow pattern regulator, a filtrate reducer, a plugging agent, and a weighting agent, wherein, based on 100 parts by weight of water, the content of the bentonite is 1-10 parts by weight, the content of the tackifier is 5-15 parts by weight, the content of the flow pattern regulator is 4-13 parts by weight, the content of the filtrate reducer is 4-13 parts by weight, the content of the plugging agent is 20-55 parts by weight, and the content of the weighting agent is 10-60 parts by weight; the drilling fluid provided in the present invention employs modified nano-silica as a plugging agent to improve dispersity and particle size distribution in the drilling fluid system. Therefore, the drilling fluid is especially suitable for well drilling in shale formations with developed micro-fractures (micro-fissures) and micro-pores, low porosity and low permeability (10−3-10−7 md), and prominent capillary effect.