A device and method for layered water injection and sand prevention and backwashing in one trip string

Abstract

The invention discloses a one-pass pipe string layered water injection sand control backwashing device, comprises a reservoir casing which is inserted into the first injection layer, the second injection layer, the third injection layer and the fourth injection layer in turn, wherein the reservoir casing is provided with an inner layer setting sealing water injection backwashing integrated pipe string which has water injection function and is compatible with backwashing well function, and an outer layer sand control pipe string which has independent screen pipe type sand control function; Theinner-layer set seal inspection and backwashing integrated pipe string is arranged in the blind pipe of the outer sand control pipe string, and the upper part of the screen pipe is connected with thestandard oil pipe, and the outer part is connected with the release packer of the outer sand control pipe string, and the release packer and the release packer form an integral whole through the cablesuspension release sealing device. The invention realizes setting and checking seal, ensures sealing effect of packers at all levels, realizes water injection and backwashing function after setting,integrates setting and backwashing operation mode, reduces risk of later operation, and improves workover efficiency.

Description

Technical field [0001] The present invention relates to the technical field of offshore oilfield development, and in particular to a one-time pipe string layered water injection and sand control backwashing device and method that can meet the requirements of the offshore oilfield for layered water injection and sand control well washing technology. Background technique [0002] As oilfield development enters the middle and late stages, the pressure for stabilizing and increasing production is increasing, and there is an urgent need for sand control and sub-layer injection technology to increase productivity and reduce costs. At present, the conventional layered sand control technology is mainly divided into two types: one adopts a layer-by-layer construction technology, that is, one layer is completed, one layer is inspected and sealed, and then the construction is carried out step by step. The diameter is small, which is not conducive to the development of the later layered oil ...

AI Technical Summary

Problems solved by technology

At present, there are mainly two types of conventional layered sand control technology: one adopts the layer-by-layer construction technology, that is, the construction of one layer is completed, the seal of the first layer is completed, and then the construction is carried out step by step. The diameter is small, which is not conducive to the development of later layered oil recovery or water injection technology; the other one uses a string setting to seal all the sand control tools, but this process does not have the function of seal inspection, and it needs to be run separately for seal inspection tools. In many cases, the construction period is longer and the operation cost is higher

Both of the above two processes adopt anchored packer layering, and the unsealing method is forced lifting and unsealing, which is difficult to unsealing and increases risks for subsequent workover operations. After unsealing failure, it often leads to overhaul operations, which greatly Increased workover costs

The conventional water injection technology also needs to be implemented on the basis of the layered sand control completion technology. Therefore, the conventional layered sand control completion technology cannot meet the needs of fast and safe production in offshore oilfields, and a safer and more effective method is needed. Layered sand control technology, with a large internal diameter, can provide sufficient completion channels for later oil production and water injection

Images