Method for eliminating sand plug in brine well sleeve

Abstract

The invention discloses a method for eliminating sand plug in a brine well sleeve. The method comprises sequential steps as follows: 1), 100 m<3> of water is injected into a smooth water injection well, then water is returned from the water injection well, and the returning flow is not lower than 60 m<3> / h; 2), after 20 min, a tank building pump is utilized for injecting water into a brine returnwell provided with a plugged sleeve and communicating with the water injection well horizontally, the flow is not lower than 50 m<3> / h, and after at least two hours, grit in the sleeve is flushed intoa dissolving cavity. According to the principle that a certain amount of water can be injected into the underground dissolving cavity when the underground dissolving cavity is larger, a certain amount of water is injected into the water injection well, under the condition that one-way water injecting production of the water injection well can be realized, water with large displacement is discharged from the plugged sleeve, so that the grit in the sleeve is dispersed, reverse water injection is performed on the brine return well, the grit in the sleeve sequentially enters the dissolving cavityunder certain pressure, and the purpose of plug removal of the brine well is achieved.

Description

technical field [0001] The invention relates to the technical field of petroleum drilling, and more specifically relates to a method for solving sand plugging in casing pipes of brine wells. Background technique [0002] For the brine wells mined by water solution method, due to the large amount of sand in the brine well solution cavity, during the production process, the roof will collapse and the sand will be raised, and the sudden power failure will lead to reverse flow of water injection and large flow rate. Sand plugging in the casing is a common downhole accident due to other reasons. [0003] After the casing is blocked by sand, the usual solutions are pressure-suppressed blowout method and high-pressure blowout method. However, the pressure-suppressed blowout method can only inject water from the water injection well, and the brine-returning well can return brine. The water injection flow rate of the brine-returning well cannot exceed 4.5 m 3 / h, otherwise it will ...

AI Technical Summary

Problems solved by technology

[0003] After the casing is blocked by sand, the usual solutions are pressure-suppressed blowout method and high-pressure blowout method. However, the pressure-suppressed blowout method can only inject water from the water injection well, and the brine-returning well can return brine. The water injection flow rate of the brine-returning well cannot exceed 4.5 m 3 / h, otherwise it will be blocked again, that is, the success rate of deblocking by the pressure-holding and spraying method and the high-pressure pressure-holding method is low, only about 25%. cost

If the above method is unsuccessful, only workover equipment can be used for repair, but the workover costs incurred are relatively large, especially when repair operations such as casing milling, undercutting, and milling are required, the cost is even greater, and at the same time, due to repair The cycle is long and affects the normal production of brine wells