Novel drilling fluid nano-plugging agent and preparation method thereof, and water-based drilling fluid containing plugging agent

Abstract

The invention discloses a novel drilling fluid nano-plugging agent and a preparation method thereof, and a water-based drilling fluid containing the plugging agent. The nano-plugging agent comprises the following components in parts by weight: 10-20 parts of a mixture of SiO2 and SiO<x> microcrystalline particles, 60-70 parts of a sulfonated styrene and butadiene copolymer emulsion, 10-20 parts ofa modified asphalt powder, and 5-10 parts of amorphous soil, wherein the mixture of SiO2 and SiO<x> microcrystalline particles is prepared by mixing silica with a particle size of 100-300 nm and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane in a weight ratio of 20:1, and then performing uniform stirring, and a value range of x in SiO<x> is 0<x<2. The mixture of SiO2 and SiO<x> microcrystalline particles in the nano-plugging agent can be wrapped by the sulfonated styrene and butadiene copolymer, and a relatively good continuous-dispersion plugging film can be formed in a drilling fluid. The drilling fluid prepared by using the nano-plugging agent has good plugging performance, and the effective support for a drilling wellbore is formed.

Description

technical field [0001] The invention belongs to the technical field of water-based drilling fluid, and in particular relates to a novel drilling fluid nano-sealing agent, a preparation method thereof, and a water-based drilling fluid containing the sealing agent. Background technique [0002] At present, in the drilling of conventional and unconventional oil and gas (such as shale oil (gas)) directional wells and horizontal wells, when the drilling process encounters mud shale formations, there are many micro-fractures in brittle shale, and the pore size is very small. It is difficult for water-based drilling fluid to form an effective plug, so it often causes complex and accidents such as well wall instability, blockage and collapse, lost circulation, pressure difference adhesion sticking, damage to oil and gas production reservoirs, etc., resulting in Serious downhole and equipment safety accidents cause huge economic losses. Therefore, in order to solve these problems, o...

AI Technical Summary

Problems solved by technology

Traditional nano-blocking agents include polymers or rigid blocking agents, such as iron oxide, calcium carbonate, etc. Such blocking agents either cannot form effective supports, or cannot form continuous dispersed films, all of which have certain limitations

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