Temperature-sensitive gel plugging agent

Abstract

The invention discloses a temperature-sensitive gel plugging agent, which consists of 40-50% curdlan gum, 40-50% bentonite for drilling fluid, 1-2% soda ash and 5-50% by mass fraction. Mixed with 15% viscosity enhancing agent, the viscosity enhancing agent is at least one of carboxymethyl starch and polyanionic cellulose; the temperature-sensitive gel plugging agent can form a solid gel at high temperature, free water It is completely fixed to achieve the purpose of pressure-bearing plugging, and can provide suitable viscosity and add suspended barite and other plugging materials to effectively ensure downhole safety while plugging, and is not easy to cause the risk of blowout; the on-site preparation is simple, and the plugging slurry It is only sensitive to temperature, there is no cross-linking agent and the second influencing factor caused by it, which reduces the risk of failure to gel downhole, and it is only sensitive to temperature, avoiding the risk of sudden accumulation during the transportation of plugging fluid.

Description

technical field [0001] The invention relates to the technical field of petroleum and natural gas, in particular to a temperature-sensitive gel plugging agent. Background technique [0002] Lost circulation is a worldwide problem, accounting for about 60% of the current drilling accidents, especially in fractured formations, which not only loses drilling time, but also easily causes engineering accidents such as well collapse and pipe sticking, and may also lead to out-of-control blowout. At present, cross-linked plugging gels mainly include cross-linked gels such as polyacrylamide, vegetable glue, polyvinyl alcohol, etc., but all cross-linked gels reported so far need to add cross-linking agents, which also leads to some gels being damaged. There is a risk of short cross-linking time and uncontrollable time. [0003] Curdlan gum, as a natural polysaccharide plant, has thermal gel properties and does not need to add a cross-linking agent, which effectively avoids the risk of...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a temperature-sensitive gel plugging agent that effectively solves the problem of insufficient strength of single curdlan gum at high temperature

Images