Offshore snubbing electric pump lifting process string

Abstract

The invention discloses an offshore no-killing electric pump lifting process pipe string. The pipe string comprises a control pipe string and a production pipe string which are mutually connected and matched, wherein the control pipe string comprises a sand preventing and filtering pipe, a pressure measuring and transferring cylinder and a no-coupling casing which are connected sequentially from bottom to top; the production pipe string is arranged in the no-coupling casing and comprises an electric pump unit, a check valve, a cable conversion device and a coiled tubing which are connected sequentially from bottom to top; a filling packer is connected between the sand preventing and filtering pipe and the pressure measuring and transferring cylinder, a densely inserting device is nested to the upper end part of the filling packer, and a guide step is arranged at the bottom of the densely inserting device; and a subsurface safety valve is connected between the pressure measuring and transferring cylinder and the no-coupling casing, and a variable-diameter guide step is arranged at the bottom of the no-coupling casing. According to the offshore no-killing electric pump lifting process pipe string, opening and closing of a flow path from the stratum to a wellhead of a down-hole are controlled through a mode that pressurization is performed by a ground hydraulic pump and pressure is transferred through a pilot-controlled pipeline, and operation such as no-killing pump inspection, pump change, downhole cable inspection and the like are performed on an offshore producing well.

Description

technical field [0001] The invention relates to an oil recovery pipe string, in particular to an offshore snubbing electric pump lifting process pipe string. Background technique [0002] Offshore oil and gas development is affected by the characteristics of the "high-tech, high-intensity, and high-risk" operating environment, and the technical requirements for well control operations are relatively high. At present, well killing and workover are basically adopted in domestic offshore oil and water well operations, that is, killing fluid with reasonable well fluid density is injected into the annulus of the oil and water well casing through a high-pressure pump truck, so that the pressure of the wellbore fluid column of the oil and water well is greater than the formation pressure, avoiding Blowout occurs when the tubing string is tripped, but the method of killing the well has the following defects: 1. It is required to accurately grasp the data such as the geological press...

AI Technical Summary

Problems solved by technology

At present, well killing and workover are basically adopted in domestic offshore oil and water well operations, that is, killing fluid with reasonable well fluid density is injected into the annulus of the oil and water well casing through a high-pressure pump truck, so that the pressure of the wellbore fluid column of the oil and water well is greater than the formation pressure, avoiding Blowout occurs when the tubing string is tripped, but the method of killing the well has the following defects: 1. It is required to accurately grasp the data such as the geological pressure of the reservoir in the operating well, and the well control design must be absolutely accurate, which prevents the design from killing the well. If the liquid density is too small, it will cause blowout accidents, and it is necessary to prevent the designed killing fluid from entering the formation if the density of the designed killing fluid is too high, causing the formation to be polluted and the production to drop or even not produce oil; 2. During the well killing operation, the formation energy For larger wells, the formation energy will continuously accumulate pressure with the time of the killing force. When the pressure accumulates to a certain extent higher than the liquid column pressure produced by the wellbore killing fluid, blowout will occur. At this time, by increasing the killing fluid It is too late to restore the pressure balance at the bottom of the well, and the well must be shut down to stop the operation, and the operation progress is also greatly affected

However, this technology cannot adapt to the special marine environmental characteristics of offshore operations, platform working conditions, and the existing offshore wells are equipped with cable packers, safety valve strings, etc., which affects the promotion of snubbing technology in offshore oil wells. Technical problems to be solved in offshore oil and water well operations

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