Downhole gel slug and preparation method thereof

Abstract

The invention relates to a downhole gel slug and a preparation method thereof, which is characterized in that it consists of a monomer, a crosslinking agent, an initiator, a density modifier, a viscosity modifier and water; wherein the weight percentage of each component is: Monomer: 4.5-9%; Cross-linking agent: 0.1-0.14%; Initiator: 0.005-0.06%; Density modifier: 5-10%; Viscosity modifier: 0.1-1.0%; Ratio, dissolve the monomer and cross-linking agent in water, then add the viscosity modifier and stir to disperse evenly, then add the density modifier and stir to disperse evenly, and finally add the initiator before injection, and make the gel slug base after mixing evenly The gel slug base fluid is injected into the predetermined position of the wellbore to form the gel slug. The gel slug of the present invention can safely and effectively seal the wellbore downhole, realize snubbing tripping, and has the characteristics of high strength, good temperature resistance, simple preparation method and good economic benefit.

Description

Technical field: [0001] The invention relates to a downhole gel slug and a preparation method thereof, and belongs to the technical field of chemical agent application in petroleum drilling engineering. Background technique: [0002] Underbalanced drilling has been developed rapidly due to its advantages of increasing the rate of penetration, preventing differential pressure sticking, reducing wellbore circulation loss, reducing formation damage, and improving the level of oil and gas reservoir indications. At present, the main factor affecting the effect of underbalanced drilling is that it is often necessary to kill the well to balance the formation pressure before or during the drilling process. But killing wells has the potential to completely negate the benefits of underbalanced drilling, and may even cause more damage to the formation. Therefore, snubbing operation is the key point to implement underbalanced drilling technology. At present, there are two main types o...

AI Technical Summary

Problems solved by technology

[0004] However, in the process of deep well construction, the existing gel valve technology is difficult to meet the needs of high temperature and high pressure resistance. Therefore, the development of rubber plug sealing technology with better pressure resistance and temperature resistance will further expand the unsnubbing performance of underbalanced drilling. The technical route of down-drilling technology provides reliable technical support for underbalanced drilling