Span-type oil testing and re-fracturing tool system

Abstract

The invention discloses a spanning oil testing and repeated fracturing tool system, which is formed by connecting a lift-and-release ball valve type setting tool, an upper packer, a spanning central pipe tool, and a lower packer. The present invention connects the upper and lower high-performance expandable packers by means of lifting and releasing ball valves and pressure transmission pipes, which can realize multiple setting / unsealing, and can control the two packers to always be in / maintain the setting state and unsealing state. The simple lifting / lowering of the string without ball throwing combined with the wellhead pressure / pressure relief operation can realize the sealing of the span and maintain the full diameter of the working channel. Conventional perforated pipes, fracturing ports and other instruments and tools can be used between the two packers, which is highly combinable.

Description

technical field [0001] The invention relates to the technical field of well testing and completion and repeated acidizing fracturing in multi-layer oil and gas fields, in particular to a span-type oil testing and repeated fracturing tool system that can be set and maintained multiple times through oil pipes. Background technique [0002] Oil testing or acid fracturing in multi-layer oil and gas wells is an important means to achieve efficient development of oil fields, and can understand and utilize each reservoir section more effectively. This process technology is widely used in the oil and gas development process, mainly: temporary or permanent isolation of specific production layers, adjustment or plugging of oil production / water production / water injection layer profiles, suction and sampling testing of specific production layers, for Temporary cross-bridge plugging during workover operations, squeeze injection operations, temporary production packers when seeking produc...

AI Technical Summary

Problems solved by technology

[0003] In order to achieve the above purpose, the known process and tool system need to be lowered into a multi-stage packer and control sliding sleeve system, and the corresponding sliding sleeve of each layer is controlled layer by layer by means of ball throwing, steel wire or coiled tubing operation. For multi-layer oil and gas wells, the number of running tools is relatively high, the construction work volume is large, and the construction operation period is long, and there are too many drilling tools that are prone to sand sinking and sticking. Not suitable, nor suitable for use in open hole sections

[0004] There are known techniques that use layer-by-layer cable bridge plugs or mechanical bridge plugs. However, each layer of operation requires at least two pipe strings. The workload is extremely high, the construction cost is extremely high, and the construction of horizontal wells is difficult or Unable to construct, not suitable for use in open hole sections

[0005] There is also known related technology that adopts the coiled tubing dragging method to realize multiple straddling operations layer by layer, but the setting pressure can only be provided for the packers through the throttle valve between the straddling packers, and the movement between tools Poor compatibility, prone to interference and misoperation, and can only be used for pump injection operations such as fracturing and acidification, and cannot be used for cross-separation mining. It is not suitable for layer-by-layer production test oil testing

Choke valves are prone to erosion for high sand volume operations, resulting in packer failure and pipe string breakage

[0006] There is also known related technology that uses two-way paired rubber cup packers to straddle the compartment, which can realize layer-by-layer spanning operations. It is always larger than the inner diameter of the casing, and is severely worn during the tripping operation. It is not suitable for deep wells and wells with complex structures, and it is also not suitable for tubing operations.

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