Injection allocation volume automatic regulation method for marine oil-field water injection well

Abstract

The invention discloses a self-regulation method of injection allocation volume for an offshore oilfield, comprising following procedures: (1) a concentric water distribution device comprising a working barrel and a water distributor is installed in the flooding well; the water distributor is installed in a working barrel that is connected with an injection pipe column and connected with screw thread; a key slot is arranged on side wall; an aperture is arranged on the side wall of the working barrel that corresponds to the spout of the water distributor and communicated with an oil layer and a positioning step is arranged above the upper internal part of the working barrel; (2) a testing-adjusting instrument connected with a ground control instrument by cable is placed into the well and has end-to-end joint with the water distributor; and (3) the testing-adjusting instrument goes through the injection pipe column and chooses the water distributor of next injection allocation layer to measure flow rate or adjust injection allocation volume; or the testing-adjusting instrument is lifted out of the flooding well. The self-regulation method realizes the self-regulation layering injection allocation volume by a closed loop system, so work efficiency is high and labor intensity is low.

Description

technical field [0001] The invention relates to a method for automatically adjusting the distribution amount of water injection wells in an oil field, in particular to an automatic adjustment method for the distribution amount of water injection wells in offshore oil fields. Background technique [0002] In the middle and late stages of oilfield development, water injection is one of the main means to increase oilfield production. At this time, a water injection well needs to inject water into several strata at the same time to meet the geological requirements, and the injection volume of each water injection layer is generally different. At present, due to the relatively narrow wellbore space of oil wells in land oilfields, the eccentric water distribution method is mostly used. In order to improve the injection efficiency, the eccentric injection process is adopted while measuring and adjusting. Chinese patent specification CN1525041A disclosed such an automatic adjustmen...

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Problems solved by technology

In offshore oilfields, since water injection wells are mostly deviated wells, which are usually deeper than land oil wells, the well completion method is also different from that of land oilfields. If the eccentric injection technology of land oilfields is adopted, the injection volume cannot meet the requirements of offshore oilfields. Injection requirements, because the single-layer water distribution in offshore oil fields is often 500m 3 / d or so, while the single-layer injection volume of the eccentric injection process in land oilfields is generally only up to 200m 3 / d or so. Second, due to the large well deviation, the success rate of the eccentric injection process in onshore oilfields is too low to meet the actual production requirements.

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