Sand washing device applied to oil well to be repaired and capable of being driven by workover rig

Abstract

The invention relates to a sand washing device applied to a to-be-repaired oil well and driven by a workover rig, which comprises a sand washing head and a tubular column used for feeding the sand washing head into the bottom of the to-be-repaired oil well and arranging the sand washing head at the bottom of the to-be-repaired oil well, the pipe column comprises an inner pipe and an outer pipe, the radial size of the inner pipe is continuously or discontinuously reduced from top to bottom, the radial size of the outer pipe is continuously or discontinuously reduced from top to bottom, a core cavity exists in the inner pipe, an annular cavity exists between the inner pipe and the outer pipe, and the lower end of the inner pipe and / or the lower end of the outer pipe are / is connected with a sand washing head. The core cavity can receive and provide sand washing liquid for the sand washing head so that the sand washing head can carry out sand washing operation, and the annular cavity can receive and provide inert gas for the sand washing head so that the inert gas can be mixed with the sand washing liquid outside the sand washing head. According to the sand washing device, the requirements for the loading capacity, the output torque and the sand washing liquid pumping pressure of driving equipment can be lowered, and a workover rig with low cost is allowed to be used for driving the sand washing device to complete sand washing operation.

Description

technical field [0001] The invention belongs to the technical field of petroleum development, and in particular relates to a sand washing device which is applied in an oil well to be repaired and can be driven by a workover machine. Background technique [0002] During the production process of the oil well, the formation sand and fine particles are produced from the formation, blocking the oil outlet channel, causing the oil well production capacity to gradually decrease or even stop production, and at the same time, it will damage the downhole equipment and cause downhole stuck accidents. In order to restore the production of oil wells, it is necessary to use high-speed sand flushing fluid to disperse the sand plugging at the bottom of the well, and establish a fluid circulation through the inner space of the pipe string and the annular space of the pipe string-casing, and use the ability of the fluid circulation to return The scattered sand is brought out of the ground, t...

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Problems solved by technology

[0003] In the existing oil well sand washing operation, the sand washing device composed of hollow pipe string and sand washing head is often used, but as the well depth increases, the length of the pipe string required also increases, and the weight of the pipe string itself increases. The comprehensive requirements of driving equipment will also increase accordingly, which makes it difficult to apply workover rigs with low cost, low load capacity, low output torque and low sand washing fluid pumping pressure, and is forced to use high cost, high load capacity, Drilling rigs with high output torque and high sand flushing fluid pumping pressure are implemented

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