Emulsion leaking stopping agent and preparing method thereof

Abstract

The invention relates to an emulsion leaking stopping agent in oil-and-gas-field well-drilling leaking stopping operation and a preparing method thereof, in particular to a gel-expansion leaking stopping agent with molecules containing functional groups capable of enhancing the interaction with the stratum. The leaking stopping agent is prepared from four monomers in a copolymerized mode; the first monomer supplies hydrophilia to the leaking stopping agent and promotes water expansion of materials; the second monomer is a cationic monomer, supplies groups with positive charges and improves attraction between the charges of the leaking stopping agent and charges of the leakage hole way well wall; the third monomer is a un-saturation organosilicone-coupling-agent monomer and can improve the retention capability of the leaking stopping agent in a leakage layer; the fourth monomer is a polyunsaturated bond functional monomer and enables the leaking stopping agent to form chemical crosslinking. According to the emulsion leaking stopping agent, aqueous solution polymerization is adopted, the technology is simple, and operation is convenient. The prepared leaking stopping agent has the advantages that water expansion capacity is high; as the leaking stopping agent contains the multiple functional groups capable of mechanically interacting with the leakage layer, the retention capability of the leaking stopping materials in the leakage layer can be improved.

Description

technical field [0001] The invention relates to an emulsion plugging agent in oil and gas field drilling plugging operations and a preparation method thereof, in particular to an emulsion plugging agent capable of cementing formations. Background technique [0002] Lost circulation is a complex problem in drilling operations. It causes drilling fluid to leak from the wellbore into the lost channel, which not only consumes a lot of mud and plugging materials, but also may cause well collapse, pipe sticking, blowout, and even lead to the scrapping of the wellbore, etc. Major accidents cause huge economic losses. Plugging material is an essential substance in the process of drilling leak prevention and plugging, and its performance directly affects the success rate of plugging construction. [0003] In the 1960s, the country began to apply the plugging material to deal with lost circulation, and carried out some basic research work. During the entire period before the 1970s, ...

AI Technical Summary

Problems solved by technology

During the entire period before the 1970s, high-viscosity drilling fluid plus bridge plugging materials (sawdust, mica, straw, mud balls, bricks, etc.) and cement plugs were mainly used. The plugging materials and methods were single, often resulting in Failure of lost circulation treatment

However, in the case of severe lost circulation, the composite lost circulation agent has problems such as the separation of components and the inability to provide synergistic effect, the swelling amount of the expansion plugging agent when absorbing water is small, and the plugging agent is not easy to be stably retained in the lost zone under external force, etc. Therefore, it is easy to cause poor plugging effect and repeated leakage after plugging

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