Coal-bed gas producing well flowing bottom hole pressure control system and control method

Abstract

The invention discloses a coal-bed gas producing well flowing bottom hole pressure control system and control method. The coal-bed gas producing well flowing bottom hole pressure control system comprises a wellhead device, a data collection system, a control system, a gas exhaust control valve, a gas injection control valve and a gas injection system; the wellhead device comprises a first oil pipehead, a second oil pipe head and a third oil pipe head which are correspondingly connected with a gas exhaust pipeline, a production pipeline and a gas injection pipeline; the gas exhaust control valve is positioned on the gas exhaust pipeline and used for adjusting a gas exhaust quantity; the gas injection control valve is positioned on the gas injection pipeline and used for adjusting a gas injection quantity; the data collection system is mounted at the coal-bed gas producing well bottom and used for collecting flowing bottom hole pressure actual value; and the control system controls opening values of the gas exhaust control valve and / or the gas injection control valve according to the flowing bottom hole pressure actual value and a preset flowing bottom hole pressure reference valueso as to adjust the flowing bottom hole pressure of the coal-bed gas producing well bottom. According to the coal-bed gas producing well flowing bottom hole pressure control system and control method,the flowing bottom hole pressure control capacity and flexibility are enhanced, and the technical effect that the flowing bottom hole pressure is effectively, stably and reliably controlled in time can be realized.

Description

technical field [0001] The invention relates to the technical field of coalbed methane development, in particular to a bottomhole flow pressure control system and control method of a coalbed methane production well. Background technique [0002] This section is intended to provide a background or context to embodiments of the invention that are recited in the claims. The descriptions herein are not admitted to be prior art by inclusion in this section. [0003] Coalbed methane refers to the hydrocarbon gas stored in coal seams and their surrounding rocks, with methane as the main component, mainly adsorbed on the surface of coal matrix particles, and partially free in coal pores or dissolved in coal seam water. It is an associated mineral resource of coal. , an unconventional natural gas. As an efficient and clean energy, coalbed methane has huge resource potential and broad development prospects. [0004] The storage and production mechanism of coalbed methane is signifi...

AI Technical Summary

Problems solved by technology

[0012] The embodiment of the present invention provides a bottomhole flow pressure control system of a coalbed methane production well, which is used to solve the problem of poor timeliness and accuracy in the existing bottomhole flow pressure control system of a coalbed methane production well by controlling the discharge of the liquid drainage pump to adjust the bottomhole flow pressure. low stability, unreliable technical problems, the system includes: wellhead device, data acquisition system, control system, exhaust control valve, gas injection control valve and gas injection system; wellhead device includes: connected to the exhaust pipeline The first oil pipe head, the second oil pipe head connected to the production pipeline, and the third oil pipe head connected to the gas injection pipeline; the exhaust control valve is located on the exhaust pipeline to adjust the exhaust volume of the exhaust pipeline; The gas injection control valve is located on the gas injection pipeline, and is used to adjust the gas injection volume of the gas injection system; wherein, the data acquisition system is installed at the bottom of the coalbed methane production well, and is used to collect the bottom hole flow pressure at the bottom of the coalbed methane production well Actual value: the control system controls the opening value of the exhaust control valve and / or gas injection control valve according to the actual value of the bottom hole flow pressure collected by the data acquisition system and the preset reference value of the bottom hole flow pressure, so as to adjust the coalbed methane production well bottom hole pressure

[0013] The embodiment of the present invention also provides a bottomhole flow pressure control method of a coalbed methane production well, which is applied to the above-mentioned bottomhole flow pressure control system of a coalbed methane production well to solve the problem of passing control of the bottomhole flow pressure control system of an existing coalbed methane production well. The adjustment of the bottomhole flow pressure is realized by the drainage of the liquid drainage pump, which has technical problems of poor timeliness, low accuracy, and unreliable stability. The method includes: obtaining the current production stage of the coalbed methane production well, wherein the production stage is at least Including: drainage stage and unstable gas production stage; according to the production system of each production stage, set the reference value of the bottom hole flowing pressure at the bottom of the coalbed methane production well; obtain the actual value of the bottom hole flowing pressure at the bottom of the coalbed methane production well, and The actual value of the bottom flow pressure and the reference value of the bottom hole flow pressure generate the first command and / or the second command, wherein the first command is used to control the exhaust control valve to perform the exhaust operation, and the second command is used to control the gas injection control valve to perform Gas injection operation, the first command contains the opening value of the exhaust control valve, and the second command contains the opening value of the gas injection control valve

[0014] The embodiment of the present invention also provides a bottomhole flow pressure control method of a coalbed methane production well, which is applied to the above-mentioned bottomhole flow pressure control system of a coalbed methane production well to solve the problem of passing control of the bottomhole flow pressure control system of an existing coalbed methane production well. There are technical problems of poor timeliness, low accuracy, and unreliable stability when the drainage pump is used to adjust the bottom hole flow pressure. The method includes: when the coalbed methane production well is in the drainage stage, obtain the The actual bottomhole flowing pressure at the bottom of the well; when the actual bottomhole flowing pressure drops to the preset bottomhole flowing pressure value range, the first reference value of the bottomhole flowing pressure at the bottom of the coalbed methane production well is obtained, and according to the actual bottomhole flowing pressure value and the first bottomhole flowing pressure reference value, and control the opening value of the gas injection control valve so that the bottomhole flowing pressure value at the bottom of the coalbed methane production well meets the first bottomhole flowing pressure reference value

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