Offshore oilfield safe long-acting water injection tubular pile and construction method

Abstract

The invention discloses an offshore oilfield safe long-acting water injection tubular pile and a construction method. The offshore oilfield safe long-acting water injection tubular pile comprises a sand prevention tubular pile and a water injection tubular pile, and the water injection tubular pile is arranged in the sand prevention tubular pile; the sand prevention tubular pile comprises at least two sand filtering tubes which are arranged on a casing tube at intervals from top to bottom and correspond to different oil layers respectively, and Y341 packers are arranged between every two sand filtering tubes, above the uppermost sand filtering tube and below the lowermost sand filtering tube; the water injection tubular pile comprises at least two adjustable water distributors which are arranged on an oil tube at intervals from top to bottom and correspond to different oil layers respectively, the lower portion of each adjustable water distributor is connected with a setting switch, and hydraulic control layered packers are arranged above and below the corresponding setting switches respectively. One-time tripping-in of the sand prevention tubular pile and the water injection tubular pile can be achieved, the single-well construction time is saved, reliable independent overhauling of an offshore oil field can be achieved, and the service life of the sand control tubular pile is prolonged.

Description

technical field [0001] The invention relates to the technical field of downhole water injection tools for oil production, in particular to a safe and long-term water injection pipe string and a construction method for offshore oil fields. Background technique [0002] At present, water injection development is the dominant offshore development method. According to incomplete statistics, water flooding production accounts for more than 85% of the total output. Efficient water injection is of great significance to the stable production and increase of offshore oilfields. For sand-producing reservoirs, high-efficiency sand control is important to prolong the life of the water injection string and reduce the risk of later operations. Due to the short validity period of chemical sand control wells, sand plugging and sand burial are often caused after sand control failure, the water injection effect is poor, and the maintenance cost in the later period is high. Therefore, mechani...

AI Technical Summary

Problems solved by technology

When this type of string is overhauled in the later stage, it is necessary to turn the tubing forward to realize the separation of the upper joint of the through-type Y445 drop-off packer from the lower end of the string. There are two main problems: one is that an annular safety packer is generally installed in offshore water injection , because the packer has a locking structure, once the packer rubber tube is set, it can only be unsealed by lifting the string, so it is very difficult to rotate the string forward; Control the pipeline, which again increases the difficulty of forward rotation of the pipe string

Although the advantages of large well flushing channel and large displacement of the whole wellbore are taken into account, the construction is as in the above document, the sand control pipe string and the water injection pipe string need to be lowered twice, the construction process is cumbersome, and the construction success is relatively high.

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