A composite bridge plug and its central tube

Abstract

The invention relates to a composite bridge plug and a central tube of the composite bridge plug. The composite bridge plug comprises the central tube, wherein the axis of the central tube extends in the vertical direction and the central tube is made of a composite material,a setting press ring and a plug component that are arranged upwards and downwards are arranged on the central tube in a sleeved manner, the setting press ring is connected with the central tube through a setting pin, a mounting hole is formed in a tube body of the central tube above the setting press ring in the radial direction, a pin sleeve made of a metal material is fixedly arranged in the mounting hole along the same axis, and the pin sleeve is provided with an inner hole used for mounting a shearing pin released by the composite bridge plug in a penetrating manner. The invention provides the central tube which can guarantee both reliable connection of the shearing pin and reliable clipping of the shearing pin.

Description

technical field [0001] The invention relates to an oil field downhole plugging tool, in particular to a composite bridge plug and a center pipe thereof. Background technique [0002] In the process of oil and gas well testing, in order to correctly evaluate and understand the target layer, when there are multi-layer formations, there are differences between the layers of oil, gas and water layers, and it is necessary to perform layered testing, layer-by-layer stimulation measures, and multi-layer well completion for production , Temporary sealing layer, etc., all need to use the bridge layering tool. The bridge plug is a kind of oil and gas well separation device widely used at home and abroad. The existing composite bridge plug is "a composite bridge plug" disclosed in the Chinese patent CN103046896A. The pipe is fitted with a setting pressure ring, a plugging assembly and a stop ring in order from top to bottom. The sealing assembly includes an upper slip, an upper cone, ...

AI Technical Summary

Problems solved by technology

[0003] The problem with the existing composite bridge plug is that the center pipe is made of composite material, and the setting tool is connected to the center pipe through a shear pin, which means that one end of the shear pin is inserted into the center pipe. In composite materials, due to the characteristics of the composite material, the connection between the shear pin and the central tube is not reliable, and one end of the shear pin in the central tube is prone to shake, and the shear pin is easy to be released from the central tube during the insertion of the bridge plug. The smooth delivery of the bridge plug cannot be achieved due to the upper protruding out of the bridge plug. At the same time, the shear pin is also easy to come out of the center tube during the process of dropping the hand, so the smooth release of the bridge plug cannot be realized. Even if the shear pin does not come out of the center tube, the composite material The finished central tube is not easy to cut off the shear pins, and failures often occur because the shear pins are not cut; in addition, due to the limited steps provided on the central tube, the setting pressure ring of the existing bridge plug, The upper slip, upper cone, rubber tube, lower cone, lower slip and stop ring can only be fitted on the center tube from bottom to top. The assembly method of each part is single, which is inconvenient to assemble and low in assembly efficiency; the center tube The outer contour of the center tube is cylindrical, and the components such as the setting pressure ring, upper slip, upper cone, rubber tube, lower cone, lower slip and stop ring are all set on the cylindrical outer peripheral surface of the central tube. When the plug is drilled and ground after use, each component will rotate relative to the central tube and it will be difficult to drill out, especially for the flexible material of the rubber tube, the rubber tube will rotate relative to the central tube, making the rubber tube difficult to drill out; It can only be sent to the ball seat at the upper end of the center tube after the throw is over, which increases the construction time

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