WO-2026091265-A1 - GEOTHERMAL WELL CORROSION MEASUREMENT SYSTEM AND METHOD

WO2026091265A1WO 2026091265 A1WO2026091265 A1WO 2026091265A1WO-2026091265-A1

Abstract

The present application belongs to the technical field of corrosion measurement. Provided are a geothermal well corrosion measurement system and method. The system comprises: a well liquid level corrosion measurement mechanism, which is arranged on a height adjustment mechanism, wherein during measurement, the well liquid level corrosion measurement mechanism is partially located above a well liquid level and partially located below the well liquid level, and well liquid level corrosion data of a geothermal well is represented by means of a weight change amount; a downhole corrosion measurement mechanism, which is arranged below the well liquid level of the geothermal well and is used for measuring downhole corrosion data of the geothermal well; a wellhead corrosion measurement mechanism, which is arranged on the geothermal well and is used for measuring wellhead corrosion data of the geothermal well; and a processing apparatus, which is used for receiving and storing the downhole corrosion data and the wellhead corrosion data, and on the basis of an external control instruction, controlling the height adjustment mechanism to adjust the position height of the well liquid level corrosion measurement mechanism in the well, and is further used for generating the well liquid level corrosion data on the basis of an external input signal and storing the well liquid level corrosion data. The system in the present application has a simple structure and can comprehensively and accurately measure corrosion data of a geothermal well.

Inventors

YE, Xian
KONG, Dongliang
GAO, Qingchun
SUN, Liwei
SUN, Shaoliang
ZHANG, Xue
ZHANG, Tieming
LI, MIAO
Zhang, Xinran
LUO, Hua

Assignees

中国石油天然气集团有限公司
中国石油集团长城钻探工程有限公司

Dates

Publication Date: 20260507
Application Date: 20241220
Priority Date: 20241029

Claims (11)

A geothermal well corrosion measurement system, characterized in that the system comprises: A well fluid surface corrosion measuring mechanism (1) is mounted on a height adjusting mechanism (2). The height adjusting mechanism (2) is used to adjust the position height of the well fluid surface corrosion measuring mechanism (1) in the geothermal well, so that during the measurement process, part of the well fluid surface corrosion measuring mechanism (1) is above the well fluid surface and part is below the well fluid surface. The well fluid surface corrosion measuring mechanism (1) is used to characterize the well fluid surface corrosion data of the geothermal well through weight change. The height adjusting mechanism (2) includes: A winding motor (21), the winding end of which is connected to a well fluid surface corrosion measuring mechanism (1) via a winding and unwinding cable; or The height adjustment mechanism (2) includes: The test tubing string (22) is provided with the well fluid surface corrosion measuring mechanism (1) mounted on the test tubing string (22). The lifting and adjusting mechanism (23) is connected to the test tubing (22) and is used to adjust the well depth of the test tubing (22); The downhole corrosion measuring mechanism (3) is set below the well fluid surface of the geothermal well and below the well fluid surface corrosion measuring mechanism (1) for measuring the in-well corrosion data of the geothermal well; Wellhead corrosion measurement mechanism (4) is set on the wellhead weir box of the geothermal well and is used to measure the wellhead corrosion data of the geothermal well; The processing device (5) is connected to the downhole corrosion measuring mechanism (3), the wellhead corrosion measuring mechanism (4), and the height adjustment mechanism (2). The processing device (5) is used to: receive and store in-well corrosion data and wellhead corrosion data; control the height adjustment mechanism (2) to adjust the position height of the well fluid surface corrosion measuring mechanism (1) in the well according to external control commands; and generate and store well fluid surface corrosion data based on external input signals; wherein the external input signals are determined by the weight change.
According to claim 1, the geothermal well corrosion measurement system is characterized in that the well fluid surface corrosion measurement mechanism (1) comprises: Support column (11), on the outer wall of the support column (11) are a plurality of corrosion plates (12) arranged at intervals from top to bottom.
According to claim 1, the geothermal well corrosion measurement system is characterized in that the downhole corrosion measurement mechanism (3) comprises: The outer shell (31) is hollow inside. The measuring end of the outer shell (31) is provided with a probe measuring test piece (33) and a probe compensation test piece (34) through a sealing mechanism (32). The sealing end of the outer shell (31) is provided with a sealing plug (35). The thermos bottle (311) is provided inside the outer shell (31). A power supply (36) is installed inside the thermos bottle (311) and connected to the probe measuring test piece (33) and the probe compensation test piece (34) for supplying power to the probe measuring test piece (33) and the probe compensation test piece (34); The data acquisition mechanism (37) is set inside the thermos bottle (311) and connected to the probe measuring test piece (33) and the probe compensation test piece (34) for collecting corrosion data in the well. A protective cover (38) has an internal accommodating space. The protective cover (38) is disposed at the measuring end of the outer shell (31). The probe measuring test piece (33) and the probe compensation test piece (34) are located in the internal accommodating space of the protective cover (38).
According to claim 3, the geothermal well corrosion measurement system is characterized in that a receiving groove (381) is provided on the outer wall of the protective cover (38); The downhole corrosion measurement device (3) also includes: Multiple corrosion plates (12) are set in the receiving groove (381) of the protective cover (38) through an isolation ring.
According to claim 1, the geothermal well corrosion measurement system is characterized in that the wellhead corrosion measurement mechanism (4) comprises: An inductive sensor (41) is used to collect induced electrical signals at the wellhead of a geothermal well; The collector (42) is connected to the inductive head (41) through the data transfer mechanism (43). The collector (42) is used to obtain wellhead corrosion data of geothermal wells based on induced electrical signals.
According to claim 5, the geothermal well corrosion measurement system is characterized in that the inductive sensing head (41) comprises: The probe mounting rod (411) has a hollow measuring test tube (412) sealed at its measuring end. The measuring end of the probe mounting rod (411) is also provided with a reference resistor (414) and multiple inductive probes (413). The multiple inductive probes (413) and the reference resistor (414) are located inside the measuring test tube (412). The connector end of the probe mounting rod (411) is provided with a first connector (415), which is connected to the data transfer mechanism (43). Multiple inductive probes (413) and the reference resistor (414) are connected to the first connector (415) via wires, and the inductive probes (413) are used to collect induced electrical signals.
According to claim 6, the geothermal well corrosion measurement system is characterized in that the data collector (42) comprises: The housing (421) is hollow inside, and a bottom plate (422) is provided at the open end of the housing (421) so that a sealed cavity is formed inside the housing (421). A data transmission socket (423) is provided on the bottom plate (422). A circuit board (424) is disposed in the cavity of the housing (421) and connected to the data transfer mechanism (43) via a data transmission socket (423) to obtain wellhead corrosion data of the geothermal well based on the induced electrical signal transmitted by the data transfer mechanism (43).
According to claim 7, the geothermal well corrosion measurement system is characterized in that the data transmission socket (423) is provided with an external thread, and the data transfer mechanism (43) includes: The support transmission rod (432) is hollow inside. A first socket (433) and a second socket (436) are respectively provided at both ends of the support transmission rod (432). The first socket (433) and the second socket (436) are connected to each other by wires. The first socket (433) is provided with external threads. The relay plug (431) has a first locking nut (434) and a second locking nut (435) rotatably provided at both ends. The first locking nut (434) is connected to the data transmission socket (423), and the second locking nut (435) is connected to the first socket (433) of the support transmission rod (432).
The geothermal well corrosion measurement system according to claim 8 is characterized in that a first connecting piece (61) is provided on the first joint (415); A second connecting piece (62) is provided on the second socket (436) of the supporting transmission rod (432); The first connecting piece (61) and the second connecting piece (62) are connected to each other by at least two bolts (63).
A method for measuring corrosion in geothermal wells, applied to the geothermal well corrosion measurement system according to any one of claims 1-9, characterized in that the method comprises: Confirm that the geothermal well washing process is complete; Install the downhole corrosion measurement device on the water pump of the test tubing, and lower the water pump into the geothermal well at a predetermined depth. The initial weight of the well fluid surface corrosion measurement mechanism is obtained, and the height of the well fluid surface corrosion measurement mechanism in the geothermal well is adjusted by the height adjustment mechanism so that during the measurement process, part of the well fluid surface corrosion measurement mechanism is above the well fluid surface and part is below the well fluid surface. The wellhead corrosion measurement device is installed on the wellhead weir box of the geothermal well; The geothermal well corrosion measurement begins. After a preset time, the actual weight of the well fluid surface corrosion measurement device is obtained. Based on the initial and actual weight of the well fluid surface corrosion measurement device, well fluid surface corrosion data is obtained. In addition, the well corrosion data of the downhole corrosion measurement device and the wellhead corrosion data of the wellhead corrosion measurement device are read.
According to the geothermal well corrosion measurement method of claim 10, the height adjustment mechanism includes: a winding motor, the winding end of which is connected to the well fluid surface corrosion measurement mechanism via a winding and unwinding cable; or it includes a test tubing and a lifting adjustment mechanism, wherein the well fluid surface corrosion measurement mechanism is mounted on the test tubing. The height of the well fluid surface corrosion measuring device within the geothermal well is adjusted using a height adjustment mechanism, including: If the geothermal well is in the open state, the well fluid surface corrosion measuring mechanism is connected to the winding end of the winding motor through the winding and unwinding cable, and the position height of the well fluid surface corrosion measuring mechanism in the geothermal well is adjusted by the winding and unwinding of the winding motor. If the geothermal well is not in operation, the well fluid corrosion measuring mechanism is set on the test tubing, and the position height of the well fluid corrosion measuring mechanism in the geothermal well is adjusted by adjusting the lowering depth of the test tubing through the lifting and adjusting mechanism.

Description

Geothermal Well Corrosion Measurement System and Method Cross-reference of related applications This application claims the benefit of Chinese Patent Application No. 202411519997.1, filed on October 29, 2024, the contents of which are incorporated herein by reference. Technical Field This application relates to the field of corrosion measurement technology, specifically to a geothermal well corrosion measurement system and a geothermal well corrosion measurement method. Background Technology Geothermal energy is gaining increasing attention due to its unique advantages such as stability, high efficiency, pollution-free operation, and the ability to provide combined heat and power (CHP). The geothermal energy industry is experiencing rapid growth and is currently in a period of relatively rapid development. However, a serious problem commonly found in geothermal systems is corrosion caused by the contact between corrosive components in geothermal water, such as Cl- , O2 , and H2S , and the materials of equipment within the system. This corrosion has a significant negative impact on the normal operation and economic efficiency of geothermal systems. Statistics show that perforated pipe fittings and sewage pipelines include elbows, horizontal pipes, risers, and welds. The perforation locations are diverse and widely distributed. Scaling in pipes reduces water flow and heat transfer efficiency, exacerbating corrosion. Corrosion accounts for approximately 11% of the annual losses in geothermal wells, and every 1mm of scale buildup reduces heat exchange efficiency by 5%. While current anti-corrosion and anti-scaling measures have shown some effectiveness, they have not completely solved the problem and seriously affect the subsequent development of geothermal wells. In geothermal development, especially in newly developed areas where the area is unfamiliar, pilot tests are necessary to measure corrosion data and provide parameters for subsequent large-scale development. Therefore, corrosion rates need to be tested and analyzed during pilot tests of geothermal wells. Currently, the main method for geothermal well pilot tests involves collecting geothermal water during pumping tests and analyzing it indoors, while simultaneously incorporating field test parameters for indoor circulation simulation to analyze the corrosivity of the water sample. The drawback of this method is that the parameters used in the indoor tests are not the actual parameters of the geothermal water at the site, leading to discrepancies between the simulated results and the actual field results. This results are inaccurate and cannot guide subsequent large-scale geothermal development. Application content The purpose of this application is to provide a geothermal well corrosion measurement system and method to solve the problem that the parameters added during indoor testing are not the actual parameters of the geothermal water on site, and the results of indoor simulation deviate from the actual results on site, resulting in inaccurate test results and failing to guide subsequent large-scale geothermal development. To achieve the above objectives, embodiments of this application provide a geothermal well corrosion measurement system, the system comprising: A well fluid surface corrosion measuring mechanism is installed on a height adjustment mechanism. The height adjustment mechanism is used to adjust the position height of the well fluid surface corrosion measuring mechanism in the geothermal well, so that during the measurement process, part of the well fluid surface corrosion measuring mechanism is above the well fluid surface and part is below the well fluid surface. The well fluid surface corrosion measuring mechanism is used to characterize the well fluid surface corrosion data of the geothermal well through the weight change. The downhole corrosion measurement mechanism is installed below the well fluid level in the geothermal well and below the well fluid surface corrosion measurement mechanism, and is used to measure the corrosion data inside the geothermal well. The wellhead corrosion measurement device is installed on the wellhead weir box of the geothermal well and is used to measure the wellhead corrosion data of the geothermal well. A processing device is connected to the downhole corrosion measurement mechanism, the wellhead corrosion measurement mechanism, and the height adjustment mechanism. The processing device is used to: receive and store downhole corrosion data and wellhead corrosion data; control the height adjustment mechanism to adjust the position and height of the well fluid surface corrosion measurement mechanism in the well according to external control commands; and generate and store well fluid surface corrosion data based on external input signals; wherein the external input signals are determined by the weight change. Optionally, the well fluid surface corrosion measuring mechanism includes: A support column,