Method for increasing and stabilizing injection and application thereof

Abstract

The invention discloses a method for increasing and stabilizing injection. The method comprises the following steps of: injecting acid liquor into a water injection well at the maximum construction displacement of 20-40%, and rapidly increasing the displacement of the injected acid liquor to the maximum construction displacement after the wellhead pressure is reduced by 10-30%; and injecting displacement liquid into the water injection well at the maximum construction displacement. The method can be used for manufacturing large-diameter multi-branch earthworm holes. The method can be used for obtaining large-diameter multi-branch earthworm holes, and compared with small-diameter single-branch main earthworm holes in the original traditional acidification process, the large-diameter multi-branch earthworm holes are not easily blocked by suspended particles of injected water, and the blocking time is greatly prolonged, so that the acidification validity period of the water injection well is greatly prolonged.

Description

technical field [0001] This article involves but is not limited to a technology for increasing and stabilizing injection of water injection wells, especially relates to but is not limited to a method for increasing and stabilizing injection and its application. Background technique [0002] In the long-term water injection process of water injection wells, due to various factors, the reservoir pores will be gradually blocked, and the acidified wormholes will be gradually blocked after the acidizing operation. The main reasons for the clogging of reservoir pores and acid-eroded wormholes in water injection wells are solid particles, Fe 3+ Sedimentation, crude oil and bacteria, etc. These impurities suspended in the injected water will gradually deposit on the inner wall of the injection pipe string and near the wellbore, and gradually accumulate at the bottom of the well, resulting in the gradual deterioration of the water quality from the wellhead to the bottom of the well,...

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Problems solved by technology

[0004]However, for injection wells acidified by this conventional acidification process, on the one hand, due to the small Reservoir acidification method has low displacement and small liquid volume, the displacement is usually about 1m3 / min, and the liquid volume is 1m3 to 2m per meter of perforation section >3acid liquid, the small acidizing radius cannot remove the special deep formation blockage of the water injection well, resulting in high bottomhole pressure of the water injection well after acidification, and a low degree of improvement in the water absorption index

On the other hand, due to the small diameter and short length of the acid-etched main wormhole after the construction of this ordinary acidification process, it is easy to be blocked by the solid-phase suspended matter injected into the water, resulting in a short acidification period.

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