Method for acidification to dispel block

Abstract

The present invention discloses an acidizing plugging removal method which comprises steps of: injecting liquid gas as energy increased slug into target layer before traditional acidification process, the liquid gas is liquid nitrogen or liquid carbon dioxide, the injection rate is 1-1.5 stere each meter oil layer, optimal selection is 1.2 stere, the injection speed is 100-250L / min, optimal selection is 200L / min. The method of present invention can relieve zone blocking, improve yield of oil well, successful rate of plugging removal is above 98%, the average base increase production of single well is above 1.5ton / day.

Description

technical field [0001] The invention relates to a method for acidizing and plugging removal, in particular to a method for acidizing and plugging removal of oil wells in oil fields. Background technique [0002] For low-permeability oilfields, with the prolongation of production time, the blockage of the zone will continue to increase, and the seepage resistance will increase, resulting in a continuous decline in production. , the recovery degree of the high-permeability layer is relatively high, or the high-permeability layer generally has high water content, while the low-permeability layer has relatively high seepage resistance due to low permeability, and the recovery degree is low, so it is the target of stimulation measures. [0003] The purpose of acidizing is mainly to remove plugging, and at the same time increase the permeability of the low-permeability potential layer as much as possible, and increase the oil well production. The over-acidification of the layer c...

AI Technical Summary

Problems solved by technology

[0002] For low-permeability oilfields, with the prolongation of production time, the blockage of the zone will continue to increase, and the seepage resistance will increase, resulting in a continuous decline in production. , the recovery degree of the high-permeability layer is relatively high, or the high-permeability layer generally has high water content, while the low-permeability layer has relatively high seepage resistance due to low permeability, and the recovery degree is low, so it is the target of stimulation measures

[0003] The purpose of acidizing is mainly to remove plugging, and at the same time increase the permeability of the low-permeability potential layer as much as possible, and increase the oil well production. Excessive acidification of the layer cannot achieve the purpose of increasing production or a large amount of water will flow out after acidification, while the low-permeability layer is the target layer for acidification and plugging removal, relatively less acid inflow, and the purpose of acidification and production increase cannot be achieved

[0004] In addition, for reservoirs with low formation energy, although conventional acidification can be used to remove plugging, due to the serious shortage of formation energy, it is difficult to flow back the residual liquid, and the purpose of increasing production cannot be achieved after taking measures