A kind of micro-nano anti-collapse plugging agent for drilling fluid and preparation method thereof

Abstract

The invention discloses a micro-nano anti-collapse plugging agent for drilling fluid and a preparation method thereof. The plugging agent is made of the following raw materials in proportions by weight: 5-20 parts of epoxy resin, 5-15 parts of itaconic acid 10-38 parts of acrylic acid, 15-35 parts of 2-acrylamido-2-methylpropanesulfonic acid, 2-10 parts of pH regulator, 1-6 parts of emulsifier, 0.2-1.0 parts of initiator, solvent 5‑15 parts, water 50‑150 parts. Compared with the prior art, the present invention has nano-scale and micron-scale deformable particles, reduces fluid loss, regulates rheology, has good temperature resistance, no fluorescence, and good compatibility; at the same time, the molecular chain of the plugging agent has A variety of adsorption groups can be adsorbed on the surface of clay particles to repair the filter cake formed by the particle filling in the drilling fluid; through the particle size and deformable characteristics, it can enter the pores and bedding of the shale formation and prevent the filtrate from entering The formation plays a role in stabilizing the well wall; the plugging agent has strong dispersion ability and high stability, and is suitable for hard and brittle mudstone with various micro-fractures.

Description

technical field [0001] The invention relates to the technical field of drilling fluid treatment agents, in particular to a micro-nano anti-collapse plugging agent for drilling fluid and a preparation method thereof. Background technique [0002] Wellbore stability is a common problem in many oilfields in the world, and it has been perplexing the development of the petroleum industry. At present, there are many ways and methods for water-based drilling fluid to protect walls and prevent collapse, which can be generally summarized into three directions, namely: density support, plugging and preventing collapse, and inhibiting hydration. The currently commonly used anti-slump agents such as asphalt, humic acid and other products are limited in application due to reasons such as fluorescence level and environmental protection performance; while the plugging agent emulsified paraffin is commonly used, but its temperature resistance is poor and its softening point Low, the applic...

AI Technical Summary

Problems solved by technology

The pore size of rocks in different formations is also different. The pore size of the shale formation prone to wellbore instability is mostly micro-nano level. Conventional particles cannot effectively seal and prevent the drilling fluid and its filtrate from affecting The erosion of the formation will cause the shale to hydrate and expand, resulting in complex accidents such as well wall collapse

During the drilling process, effective plugging of micro-fractures on the borehole wall is one of the effective means to avoid the instability of the borehole wall. However, asphalt and emulsified paraffin plugging materials have relatively large particle sizes, so for formations with large fractures and gaps The plugging effect is good, but it cannot form a good size match for nano-micro pores (fractures) such as mudstone mud micro-fractures and beddings, and its wellbore stability is greatly limited

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