Integrated rod-free lifting tubing string

Abstract

The invention provides an integrated rodless lifting string, which includes: an outer cylinder and an oil pipe pierced in the outer cylinder; a screw pump, which is arranged in the outer cylinder, and the screw pump is connected to the Below the oil pipe, and includes a screw and a screw pump stator sleeved outside the screw, an oil delivery chamber communicated with the oil pipe is formed between the screw pump stator and the screw; the submersible motor is located at In the outer cylinder, it includes a motor rotor connected to the stator of the screw pump, and a motor stator sleeved outside the motor rotor and connected to the outer cylinder, and the motor rotor can drive the screw pump The stator rotates; the flexible shaft is arranged in the outer cylinder and connected under the screw rod; the thrust device is fixed in the outer cylinder and connected under the flexible shaft. The invention can reduce the length of the tool string of the lifting pipe string and improve the passability of the inclined well section.

Description

technical field [0001] The invention relates to the technical field of oil production, in particular to an integrated rodless lifting string. Background technique [0002] With the deepening of oilfield development, in order to increase the drainage area and single well production, the number of inclined wells and horizontal wells has been increasing. In low-yield and low-permeability oil fields such as Changqing Oilfield, the number of new wells and inclined wells accounts for more than 60%. Due to the low production rate of a single well, the system efficiency is low when the conventional pumping unit is lifted, the energy consumption is high, and the eccentric wear of the rod and tube is serious, and the maintenance cost is high. Rodless lifting technology can solve this problem very well. [0003] In the current rodless lifting process, the electric submersible pump lifting requires oil well production not less than 30m 3 / d, it is difficult to meet the application req...

AI Technical Summary

Problems solved by technology

[0003] In the current rodless lifting process, the electric submersible pump lifting requires oil well production not less than 30m 3 / d, it is difficult to meet the application requirements of low-yield single wells; gas lift needs sufficient gas sources, complex ground equipment, and difficult implementation

The Chinese patent with the application number 201320650324.0 introduces an electric submersible screw pump pumping device, which is a rodless lifting system. The system includes an underground low-speed motor, a protector, an eccentric damping system, and a screw pump. It can meet the needs of downhole rodless lifting, but its tool string is too long. For inclined wells, too long tool string combination will affect the downhole passability, especially in places where the dogleg degree is relatively large, it may occur The complex working conditions of the jamming will affect the depth of the pump hanging

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