Subdivision water injection, ball-off and profile control integrated tubular column for water injection well of oilfield and process of tubular column

Abstract

The invention relates to a subdivision water injection, ball-off and profile control integrated tubular column for a water injection well of an oilfield. A plurality of special water distributors for subdivision water injection, ball-off and profile control of the water injection well are serially connected to form the integrated tubular column, packers are arranged among the special water distributors, and a ball valve is disposed at the bottom end of the integrated tubular column; the special water distributors for subdivision water injection, ball-off and profile control of the water injection well comprise water distributor bodies, and a ball containing basket is hermetically sleeved on the outer side of each water distributor body along the axial direction of the water distributor body and corresponds to a water outlet of the water distributor body; each ball containing basket is in the shape of an annular barrel, the upper end of each ball containing basket is hermetically connected to the outer wall of the corresponding water distributor body while an annular opening at the lower end of each ball containing basket is hermetically closed by an annular baffle plate, and each annular baffle plate is connected with the lower end of the corresponding ball containing basket via a shear pin; an inner cavity of each ball containing basket is communicated with the water outlet of the corresponding water distributor body; and subdivision water injection, ball-off and profile control selective plugging balls are arranged in the ball containing baskets. The profile control balls are fed in a subdivision water injection section to plug shot holes so as to adjust uneven interlayer water absorption, a water injection effect is improved, and accordingly crude oil production yield and oil production efficiency are improved.

Description

technical field [0001] The invention relates to a subdivided water injection process for oil field water injection wells, in particular to an oil field water injection well subdivided water injection and profile control integrated pipe string and its process. Background technique [0002] Most of the thin oil reservoirs in the oil field are developed by water injection. In the later stage of water injection development, due to the heterogeneity of the reservoir and the existence of interlayer contradictions in the reservoir, general water injection is likely to cause unbalanced water absorption between layers, so the water flooding effect cannot be achieved. , the conventional solution is to use subdivided water injection or chemical profile control to adjust the water absorption profile of the injection well, increase the sweep coefficient of the injected water, reduce the injection water breaking into the oil well along the high permeability layer, and give full play to the...

AI Technical Summary

Problems solved by technology

[0006] In recent years, due to the problems of many small layers and thin interlayers in some water injection blocks, the water injection string cannot be divided into thinner layers, which leads to the problem of uneven water absorption between layers in the small layers that have been injected. , and it is not easy to adopt chemical profile control technology for the section that has already been injected because of throttling of the water injection nozzle; Figure 4 As shown, the existing conventional eccentric water distributor 9 is composed of an upper joint 91, an upper connecting pipe 92, a centralizer 93, a working cylinder main body 94, a lower connecting pipe 95, a bracket 96, and a guide body 97. There is a water injection channel 99, the main body 94 of the working cylinder is formed with a plug bias hole 98, and the outer wall of the water distributor is provided with a water outlet A that communicates with the plug bias hole 98

However, the function of the conventional eccentric water distributor is single, and it can only distribute the required dispensing amount to each layer according to the design requirements. Since there is no external ball holding device, it is impossible to bring the dispensing ball, profile control, blocking ball to the water injection layer to realize delivery. Separate injection and ball injection for profile control and blocking ball selection, let alone the implementation of ball profile control in stratified well sections

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