Self-healing gel leakage-proof agent while drilling under covalent bond-non-covalent bond composite action and preparation method and application thereof

Abstract

The invention relates to a self-healing gel leakage-proof agent while drilling under covalent bond-non-covalent bond composite action and a preparation method and application thereof. The self-healing gel leakage-proof agent while drilling comprises the following raw materials in parts by weight: 20-40 parts of a first comonomer, 10-20 parts of a second comonomer, 0.01-1 part of an initiator, 1-4 parts of a first cross-linking agent, 1-3 parts of a second cross-linking agent, 1-3 parts of a hydrogen bond enhancer and the balance of an acetic acid aqueous solution, and the sum of the raw materials is 100. The material is injected into a stratum fracture in a form of particles, and can be healed into integral gel with good mechanical strength in the stratum fracture, so that good plugging of fracture pores is realized, and due to the self-healing characteristic of the material, micro cracks generated by a plugging layer can be self-repaired, so that good and stable plugging is formed, and the bearing capacity is high, and the applicable temperature is high.

Description

technical field [0001] The invention relates to a covalent bond-non-covalent bond compound self-healing gel while drilling anti-leakage agent and its preparation method and application, belonging to the technical field of drilling fluid leakage prevention and plugging. [0002] technical background [0003] Whether it is in land or sea drilling engineering, lost circulation is one of the most common and difficult engineering complex accidents. During drilling, when drilling into fractured, fractured, fractured and poorly cemented formations, leakage is prone to occur, and during deepwater drilling of offshore drilling, a riser with a long The pressure pump carries the drilling rock, which is prone to lost circulation. However, due to the "breathing effect" of deep-water drilling, it is difficult to detect early lost circulation. After the lost circulation is strengthened, it will cause overflow or even blowout, which will bring huge losses. Appropriate anti-leakage / plugging ...

AI Technical Summary

Problems solved by technology

[0004] Chinese patent document CN104987856A provides a pressure-bearing plugging agent for marine drilling fluid and its application method. The pressure-bearing plugging agent is based on aluminum ore powder, sodium soil, fly ash, wood fiber powder, composite salt It is formulated with polymer, furfural slag powder, and cross-linking agent. Although the plugging agent has a strong pressure bearing capacity, it does not have intelligent healing properties

However, the above two plugging materials are both based on metal coordination bonds and hydrogen bonds. The obtained self-healing gel plugging materials have weak pressure bearing capacity and low applicable temperature due to weak bonding.

[0006] Chinese patent document CN105504158A provides a re-crosslinkable smart gel particle under formation conditions and its preparation method and application. The smart gel particle is composed of acrylamide, anionic monomer, cationic monomer, N,N -Vinylpyrrolidone, pH adjuster, initiator, cross-linking agent I, cross-linking agent II, stabilizer, nano particle material and water, after the gel particles enter the formation, under the formation conditions, the Re-cross-link between them to form a high-strength gel to achieve effective plugging. The above method is to inject pre-cross-linked gel particles into the formation through the cross-linking agent I. Cross-linking forms an overall gel, although the strength is high, but the formula of the gel particles is complicated, and its preparation process is relatively complicated

[0007] The research on self-healing gel plugging materials currently used is still in its infancy. In view of the defects of the existing plugging material formula, complex preparation process, weak pressure bearing capacity, and low applicable temperature, it is necessary to develop new self-healing gel plugging materials based on different healing mechanisms. Healing gel plugging material

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