Acidifying liquid capable of sand stabilization and plug removal, and preparation method thereof

Abstract

The invention discloses an acidifying liquid capable of sand stabilization and plug removal and a preparation method thereof, which belongs to the technical field of oil exploitation. The acidifying liquid comprises, by weight, 6 to 15% of hydrochloric acid, 3 to 10% of fluorboric acid, 0.5 to 5% of hydrofluoric acid, 0.5 to 5% of an anti-swelling agent, 0.5 to 5% of an IS-130 corrosion inhibitor, 0.5 to 5% of an SCA iron ion stabilizing agent, 0.5 to 5% of an XT-05 cleanup additive, 0.5 to 5% of glycol monobutyl ether and 5 to 15% of an XT-23 sand control stabilizing agent, with the balance being water. The acidifying liquid is mainly used for strata with loose sandstone reservoirs, can remove inorganic obstruction of strata, forms a bonding covering on points and surfaces where silty-fine sandstone contacts with clay particles, strengthens skeleton gravels, inhibits migration of particles and reduces damage to reservoirs caused by formation sand production and particle migration obstruction due to loosening of a rock skeleton during various operations of an oil-water well; thus, the effective period of each measure is prolonged, construction procedures are simplified, operation cost is reduced, and the comprehensive effects of exploitation of oil reservoirs in loose sandstone are improved.

Description

technical field [0001] The invention specifically relates to a sand-stabilizing and plugging-removing acidification fluid for unconsolidated sandstone reservoirs and a preparation method thereof, belonging to the technical field of petroleum exploitation. Background technique [0002] In the process of oil well development and production, some unconsolidated sandstone reservoirs with good physical properties will cause pollution and plugging after years of development and frequent downhole operations. Acidification is often used to remove plugging. sand. In addition, in the middle and late stages of oilfield development, long-term water injection or gas injection production and multiple rounds of acidification also greatly damaged the reservoir framework, resulting in sand production in oil and water wells. In some oilfields, because the reservoir is mainly composed of muddy cement and loose rock skeleton, after long-term water injection and acidification measures, the loss...

AI Technical Summary

Problems solved by technology

For example, acidification in the early stage will easily lead to the destruction of the rock skeleton, aggravate the sand production in the formation, reduce the success rate of sand control in the later stage, and shorten the effective period of sand control, and conventional acidification will lead to the migration of fine particles in the formation, which will easily cause blockage in the near wellbore zone and sand retaining layer, affecting Well Productivity and Water Well Injection

Although some oilfields have studied related sand stabilizer formulations, most of them use polymer polyacrylamide and cross-linking agent, which not only has poor compatibility with acid liquid, but also has poor field test results.

[0004] The patent (publication number: CN 101067078A) discloses a sandstone matrix acidizing solution, which is composed of organic polyphosphonic sulfonic acid, ammonium bifluoride, phosphonic acid corrosion inhibitor, NTS-2 iron ion stabilizer, JS-7 clay stabilizer, ethylene glycol Composed of alcohol monobutyl ether, XBS-919 drainage aid and water, the main function is to retard and increase the action distance. It is a typical retarded acid, but it is suitable for the acidification of unconsolidated sandstone reservoirs or high shale sand production reservoirs. There are many deficiencies in sand control technology

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