Circulating drilling-free blind plate cementing device

Abstract

The invention relates to a circulating drilling-free blind plate cementing device for semi-stroke cementation and plug-free cementation of a horizontal well for oil drilling. In particular, the circulating drilling-free blind plate cementing device comprises a diverting short joint, a circulating short joint and a sealing rubber ring and is characterized in that the circulating short joint is arranged in the diverting short joint and is fixedly connected with the diverting short joint through a fixing bracket and a fixing shear pin; a seat sealing rubber cylinder is arranged in the circulating short joint and is fixedly connected with a fishing short joint; a seat sealing flange is arranged outside the seat sealing rubber cylinder; and a sealing protective cover is arranged outside the diverting short joint, a closing spring and a seat sealing slide sleeve are arranged in the sealing protective cover, and the lower end of the diverting short joint is linked with a casing packer hoop through a threaded buckle and is sealed by the sealing rubber ring. The casing wear, window opening and borehole rejection caused by drilling blockage during cementation can be avoided.

Description

technical field [0001] The patent of the present invention relates to a circulating drilling-free blind cementing device for oil drilling horizontal well half-process cementing and plug-free cementing, especially a circulating drilling-free blind cementing device. Background technique [0002] At present: Half-stage cementing of horizontal wells is mostly used 1. Drilling blind plate cementing technology: cementing plug is a cementing technology commonly used at home and abroad; drilling blind plate is easy to open the casing window, causing new wells to be scrapped; Due to the wear and thinning of the drilling blind casing, it is prone to breakage and leakage during gas injection; the production life of the oil well is shortened, and there are many hidden dangers. 2. Non-circulation and drilling-free blind cementing technology: This technology also has many defects and deficiencies, such as: easy drilling during salvage, causing downhole accidents; in addition: experiments ...

AI Technical Summary

Problems solved by technology

[0002] At present: Half-stage cementing of horizontal wells is mostly used 1. Drilling blind plate cementing technology: cementing plug is a cementing technology commonly used at home and abroad; drilling blind plate is easy to open the casing window, causing new wells to be scrapped; Due to the wear and thinning of the drilling blind casing, it is prone to breakage and leakage during gas injection; the production life of the oil well is shortened, and there are many hidden dangers

2. Non-circulation and drilling-free blind cementing technology: This technology also has many defects and deficiencies, such as: easy drilling during salvage, causing downhole accidents; in addition: experiments have proved that the diameter of the open hole packer rubber tube currently used expands by 70-80mm , when the pressure is 4-6MPa, the vulcanized parts at both ends of the rubber cylinder will break, so the conventional open hole packer is prone to seal not tight, resulting in cement slurry stringing and cement plug; also: when the lower casing is blocked, the pump cannot be turned on and circulated in time to solve the problem. In addition, the salvage tonnage is large and the maximum salvage tonnage exceeds 80 tons, which has potential safety hazards in operation; due to low safety performance, the circulation channel is likely to be closed during operation, resulting in ash plugging, perforation and cementing drilling plugs Wait for downhole accidents; the final experimental data proves that for shallow horizontal wells with a vertical depth of less than 1000m without drilling blind cementing, most of the packers do not work, and the probability of cement slurry stringing is less when the pressure difference is small, and the formation is loose and deep. Non-circulation drill-free blind cementing device, due to the defects of the packer and the tool itself, the phenomenon of cement slurry interlayering is easy to occur

In recent years, there have been half-cementing processes in various oil fields at home and abroad every year; Drilling blinds scrapped new wellbore and non-drilling blinds failed, causing huge economic losses

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