High-temperature annular protection sealing liquid for water injection well

Abstract

The invention discloses a high-temperature annular protection sealing liquid for a water injection well. A base fluid is prepared from the following compositions in percentage by weight: 3.5-10% of gelatinizing agent, 0.5-3% of crosslinking agent A, 0.3-1.0% of crosslinking agent B, 0.006-0.015% of initiator, 0.001-0.006% of modifier, and the balance of water, wherein the gelatinizing agent is acrylamide, the crosslinking agent A is formaldehyde, the crosslinking agent B is phenol, the initiator is azodiisobutyronitrile, and the modifier is potassium ferricyanide. The sealing liquid is prepared by the step of crosslinking the base fluid at 70-90DEG C for 4-8 hours or at 100-130DEG C for 1.5-3 hours. According to the high-temperature annular protection sealing liquid for the water injection well, the manufacture and usage cost is low, the construction is safe and reliable, the annular protection effect for the water injection well is obvious, and the oilfield exploitation production cost can be greatly lowered.

Description

technical field [0001] The invention relates to an annulus protection technology for oilfield water injection wells, in particular to an amide high-temperature annulus [0002] The air protection sealing fluid specifically relates to a high-temperature annular space protection sealing fluid for water injection wells, which is mainly used in water injection wells. Background technique [0003] During the water injection process in the oil field, due to the long-term injection of unqualified water quality, the near-wellbore area, especially the annular space of the oil casing, can easily cause serious deterioration of the water quality, causing a large number of SRB bacteria, iron bacteria and saprophytic bacteria to multiply, resulting in serious damage to the casing. Corrosion, various products increase sharply, causing damage to oil and gas layers, and reducing the service life of water wells. Since the value of a well is several million yuan, in order to prevent the well...

AI Technical Summary

Problems solved by technology

Aiming at the problem of limited use of packers, many oilfields in China have carried out research on replacing packers with chemical gels and made great progress. However, in the actual production process, the existing technologies still have many shortcomings and limitations, such as If the well depth is more than 1500m, the effect is poor, and the operating temperature is lower than 60°C. It is necessary to prepare liquid 1-3 days in advance, and special equipment is required for liquid preparation on the ground.

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