Sand flushing method and sand flushing string for preventing leakage and loss

Abstract

The invention relates to the field of oil well sand flushing equipment, in particular to a sand flushing method for preventing leakage and loss and a sand flushing pipe string. In the leak-proof and sand flushing method of the present invention, a packer is connected to the outer oil pipe, the outer oil pipe is lowered into the well, and when the packer on the outer oil pipe is lowered to below the sand surface, the packer is set, so that the outer oil pipe and the casing are formed. The annular space of the casing oil pipe is separated from the inner space of the outer oil pipe, and the inner oil pipe with a diameter smaller than that of the outer oil pipe is lowered into the outer oil pipe, so that an annular space is formed between the inner oil pipe and the outer oil pipe, and the annular space between the outer oil pipe and the inner oil pipe is formed. It communicates with the inner space of the inner oil pipe to form a circulating sand flushing channel of the inner and outer oil pipes, and the sand flushing operation is carried out through the circulating sand flushing channel of the inner and outer oil pipes. The leak-proof and sand-washing method of the present invention prevents quicksand from entering the oil layer. Compared with the current sand washing process, the leak-proof and loss-proof sand washing method of the present invention solves the problem that the quicksand easily enters the oil layer and causes damage to the oil layer during the process of sand washing under the oil layer. .

Description

technical field [0001] The invention relates to the field of sand washing equipment for oil wells, in particular to a leakage prevention sand washing method and a sand washing pipe string. Background technique [0002] At present, after years of thermal recovery of heavy oil thermal recovery wells, the steam huff and puff production intensity is high, sand production is serious, the formation is generally severely deficient, and even the phenomenon of "big belly" appears near the bottom of the well, and the leakage during operation is serious. When conventional sand washing technology is used for sand washing, the phenomenon of sand washing without liquid return often occurs, and the sand at the bottom of the well leaks into the formation along with the well washing fluid. After the operation is completed, these "quick sands" enter the wellbore or pump barrel with the fluid production, causing the pump to get stuck and seriously affecting the production of heavy oil. [000...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a leak-proof sand washing method to solve the problem that quicksand easily enters the oil layer and causes damage to the oil layer during the sand washing process under the oil layer in the current sand washing process; in addition, the purpose of the present invention is also to provide a A sand washing pipe string for realizing the above method to solve the problem that quicksand easily enters the oil layer and causes damage to the oil layer during the sand washing process of the current sand washing pipe string under the oil layer

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