Temperature-sensitive hydrogel leak-plugging agent and preparation method and application thereof

Abstract

The invention discloses a temperature-sensitive hydrogel leak-plugging agent. The leak-plugging agent is composed of the following raw materials in parts by weight: 3-8 parts of natural starch, 5-10 parts of a nonionic monomer, 1-3 parts of an anionic monomer, 0.06-0.10 part of a cross-linking agent, 0.1-0.3 part of an initiator, 4-8 parts of a pH adjuster, and 85 parts of deionized water. Meanwhile, the invention also discloses a preparation method of the leak-plugging agent and a leak-plugging application of the leak-plugging agent in leakage formations. The provided temperature-sensitive hydrogel leak-plugging agent can be subjected to a reaction in response to temperature to realize phase transformation, the leak-plugging agent is a flowable liquid before being injected into a formation, and after the leak-plugging agent is injected into a formation of 60-150 DEG C, the formation has a certain temperature, the leak-plugging agent is subjected to a reaction to becomes a solid leak-plugging agent with strong adhesion and elastic characteristics when reaching a bottom temperature, the effective plugging of a leakage channel is realized, and the bearing pressure is relatively high,a pressure of a pore and crack pressure-bearing test can reach 5 MPa or more, and thus the repeated leakage of the formation is prevented.

Description

technical field [0001] The invention belongs to the technical field of oil drilling plugging agents, and in particular relates to a temperature-sensitive hydrogel plugging agent and a preparation method and application thereof. Background technique [0002] Lost circulation is one of the common downhole complex situations in the drilling process. With the deepening of oil and gas exploration and development, the formation conditions encountered become more and more complex. When drilling broken or weakly cemented formations, fractured formations and multiple sets of pressure formations Lost circulation is very easy to occur, which will not only waste drilling time and loss of mud, but also may cause a series of complex situations such as pipe sticking, blowout, well collapse, etc., and even lead to the scrapping of the wellbore, resulting in major economic losses. In recent years, high-performance gel plugging agents have been developed to solve fracture leakage and malignan...

AI Technical Summary

Problems solved by technology

However, polymer lost circulation plugging agent itself also has certain disadvantages: on the one hand, the strength of the plugging agent is not high, the pressure bearing capacity is low, and it cannot effectively block the malignant leakage channel; Due to the influence of other factors, the performance of the plugging agent is greatly affected, which makes it difficult to control the performance of the plugging agent and achieve the plugging effect during on-site construction.

[0003] At present, there have been many achievements in the research and invention of leak-stopping agents, but the functions and effects of various products are different.

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