Oil well pipe cleaning and sand flushing integrated device and pipe cleaning and sand flushing method

Abstract

The invention discloses an oil well pipe cleaning and sand flushing integrated device. The device comprises a shunt nipple, a shunt packer, a double-layer pipe body, a pipe scraper and a sand flushing nipple which are mutually communicated and are each of a double-layer pipe structure; the pipe cleaning and sand flushing method comprises the steps that the pipe scraper is opened, the shunt packer is recovered, the device is placed down in an oil well casing, a well cleaning fluid is injected into casing annulus, and pipe cleaning and well cleaning are completed; after the sand surface position is determined, the pipe scraper is recovered, and the shunt packer is subjected to setting; a sand cleaning fluid is injected into the casing annulus, and the bottom of a well is flushed through positive pressure sand flushing or negative pressure sand flushing; finally, the shunt packer is upset, and pulling out of the hole is conducted. According to the oil well pipe cleaning and sand flushing integrated device, pipe cleaning and sand flushing operation can be achieved at a time, for formation leakage, both positive pressure sand flushing and negative pressure sand flushing can be conducted, the risk of sticking operation is reduced, the pipe cleaning and sand flushing operation efficiency is improved, the well-completion operation cycle is shortened, and the well-completion operation cost is reduced.

Description

technical field [0001] The invention relates to an oil well scraper and sand washing, in particular to an oil well scraper sand washing integrated device and a scraper sand washing method. Background technique [0002] Scratching operation is the basic operation step in the well completion stage, and it is the key to ensure the normal operation of the follow-up operation steps of well completion. Appropriate scratching tube technology can not only improve the quality of scraping tube, avoid complex situations and even downhole accidents in the follow-up operation of well completion, but also improve the operation efficiency of the entire well completion stage, shorten the completion cycle, and reduce the cost of well completion. job cost. [0003] Especially for oil and gas fields that are loose and easy to produce sand, there will often be more sand settling in the wellbore after perforation. In order not to affect the subsequent well completion operations, it is usually n...

AI Technical Summary

Problems solved by technology

Since the impact force of the annular liquid flow on the sand settling is relatively small, the efficiency of reverse circulation sand washing is relatively low. In some cases, it cannot be washed at all. The drill pipe string is used for positive sand flushing, so two strings increase the completion cycle

Due to the relatively high pressure in the annular space during reverse circulation sand washing, for low-pressure wells, because the liquid column pressure is greater than the formation pressure, the liquid will leak into the formation, resulting in low sand washing efficiency or sand sinking. Formation pollution caused by incompatibility will not only increase the cost of completion fluid, but also increase pollution to the reservoir, and there are technical defects

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