WO2024103233A1

WO2024103233A1 - Fluid leakage detection method and fracturing device

Info

Publication number: WO2024103233A1
Application number: PCT/CN2022/131780
Authority: WO
Inventors: 姚君磊; 姜一博; 王�锋
Original assignee: 烟台杰瑞石油服务集团股份有限公司; 烟台杰瑞石油装备技术有限公司
Priority date: 2022-11-14
Filing date: 2022-11-14
Publication date: 2024-05-23

Abstract

Disclosed are a fluid leakage detection method, applicable to a hydraulic end of a fracturing device. The hydraulic end comprises a valve assembly (100), and the valve assembly (100) comprises an upper valve (110) and a lower valve (120). The detection method comprises: collecting change parameters of a fluid and/or the structure within the hydraulic end to obtain a corresponding change parameter time domain curve; comparing the change parameter time domain curve with a preset change parameter time domain curve; and determining leakage of the upper valve and/or the lower valve according to the difference in phase change between the change parameter time domain curve and the preset change parameter time domain curve. Problems in current leakage detection means such as being unable to detect valve leakage in time can thus be solved. Also disclosed is a fracturing device using the detection method.

Description

Fluid leakage detection method and fracturing device

Technical Field

The present application belongs to the technical field of leakage detection, and specifically relates to a fluid leakage detection method and a fracturing device.

Background technique

Fracturing pumps are key production-increasing equipment commonly used in underground oil and gas extraction. In order to adapt to the development trend of future fracturing operations, fracturing pumps are developing towards hydraulic ends with characteristics such as high pressure, high power, large displacement and compact structure.

The hydraulic end is an important component of the fracturing pump system, and its main function is to pressurize low-pressure fluid (e.g., <1MPa) to high-pressure fluid (e.g., >10MPa). The structure of the hydraulic end includes a valve assembly, a packing assembly, a plunger, an end cover assembly, and other parts, wherein the valve assembly may include an upper valve, a lower valve, a valve seat, a valve spring, and the like. The valve assembly is the main hydraulic component of the hydraulic end, and its main function is to achieve unidirectional flow of the medium, wherein the lower valve is opened during the suction process of the hydraulic end and closed during the pressurized discharge process, and the upper valve is closed during the suction process of the hydraulic end and opened during the pressurized discharge process. The upper and lower valves are repeatedly opened and closed during the working process, which determines that they are vulnerable parts, and are prone to pits and cracks caused by impact and particle wear, which in turn causes seal failure and abnormal function of the hydraulic end.

There is a lack of means to monitor valve leakage in the current market. Usually, valves are replaced through regular inspection or after obvious abnormalities in the function of the hydraulic end are found. This may result in untimely replacement of valve leaks, abnormal wear or cracking of adjacent parts of the valve, and ultimately the entire hydraulic end being scrapped.

Summary of the invention

The purpose of the embodiments of the present application is to provide a fluid leakage detection method and a fracturing device, which can solve the problem that the current leakage monitoring means cannot detect valve leakage in time.

In order to solve the above technical problems, this application is implemented as follows:

The embodiment of the present application provides a method for detecting fluid leakage, which is applied to the hydraulic end of a fracturing device, wherein the hydraulic end includes a valve assembly, and the valve assembly includes an upper valve and a lower valve;

The detection method comprises:

Collecting the change parameters of the fluid and/or structure in the hydraulic end to obtain the corresponding change parameter time domain curve;

Comparing the time-domain curve of the variation parameter with a preset time-domain curve of the variation parameter;

The leakage of the upper valve and/or the lower valve is determined according to the difference in phase change between the time-domain curve of the changing parameter and the time-domain curve of the preset changing parameter.

The embodiment of the present application further provides a fracturing device, which uses the above-mentioned fluid leakage detection method, and the fracturing device includes: a hydraulic end, a first detection element and/or a second detection element, and a control element, wherein the hydraulic end includes a valve assembly, and the valve assembly includes an upper valve and a lower valve, the first detection element is used to collect the change parameters of the fluid in the hydraulic end, and the second detection element is used to collect the change parameters of the structure in the hydraulic end;

The control element is used to control and collect the change parameters of the fluid and/or structure in the hydraulic end to obtain the corresponding change parameter time domain curve;

In the embodiment of the present application, by collecting the fluid change parameters and/or structural change parameters in the hydraulic end, the corresponding change parameter time domain curve can be obtained, and compared with the preset change parameter time domain curve, the difference in phase change can be found, so as to determine the leakage location of the hydraulic end, so that the operator can repair or replace it in time. Therefore, the detection method in the embodiment of the present application can identify the failure of the valve in advance, so that the valve assembly and other components can be repaired or replaced in time before serious damage occurs, thereby ensuring the overall robustness of the hydraulic end and improving its service life, and to a certain extent, it can also reduce the maintenance cost of the valve assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of the hydraulic end of the fracturing device disclosed in an embodiment of the present application;

FIG2 is a schematic diagram showing a comparison of time domain curves of fluid pressure fluctuations in a high pressure area (such as inside a valve box, etc.) when a leak occurs in the upper valve disclosed in an embodiment of the present application;

FIG3 is a schematic diagram showing a comparison of time domain curves of fluid pressure fluctuations in a high pressure area (eg, inside a valve box, etc.) when a leak occurs in the lower valve disclosed in an embodiment of the present application;

FIG4 is a schematic diagram showing a comparison of time domain curves of fluid pressure fluctuations in a high pressure area (eg, inside a valve box, etc.) when leakage occurs in both the upper valve and the lower valve disclosed in an embodiment of the present application;

FIG5 is a schematic diagram of measured values of fluid pressure fluctuations in a high-pressure area (such as inside a valve box, etc.) when a leak occurs in the upper valve disclosed in an embodiment of the present application;

FIG6 is a schematic diagram of measured values of fluid pressure fluctuations in a high-pressure area (such as inside a valve box, etc.) when a leak occurs in the lower valve disclosed in an embodiment of the present application;

FIG7 is a schematic diagram of measured values of fluid pressure fluctuations in a high-pressure area (eg, inside a valve box, etc.) when both the upper valve and the lower valve disclosed in the embodiment of the present application leak;

FIG8 is a schematic diagram showing a comparison of time domain curves of fluid pressure fluctuations in a low pressure area (eg, at the entrance of a lower valve, etc.) when a leak occurs in the upper valve disclosed in an embodiment of the present application;

9 is a schematic diagram showing a comparison of time domain curves of fluid pressure fluctuations in a low pressure area (eg, at the entrance of the lower valve, etc.) when a leak occurs in the lower valve disclosed in an embodiment of the present application;

FIG10 is a schematic diagram showing a comparison of time domain curves of fluid pressure fluctuations in a low pressure area (eg, at the entrance of the lower valve, etc.) when leakage occurs in both the upper valve and the lower valve disclosed in the embodiment of the present application;

FIG11 is a schematic diagram showing a comparison of time domain curves of fluid flow fluctuation at the inlet of the lower valve when leakage occurs in the upper valve disclosed in the embodiment of the present application;

FIG12 is a schematic diagram showing a comparison of time domain curves of fluid flow fluctuation at the inlet of the lower valve when leakage occurs in the lower valve disclosed in the embodiment of the present application;

13 is a schematic diagram showing a comparison of time domain curves of fluid flow fluctuation at the inlet of the lower valve when leakage occurs in both the upper valve and the lower valve disclosed in the embodiment of the present application.

Description of reference numerals:

100-Valve assembly; 110-Upper Valve; 120-Lower Valve;

200-valve box;

300- plunger;

400-end cap;

500-upper liquid manifold;

610-pressure sensor; 620-flow sensor; 630-stress strain sensor.

Detailed ways

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and/or" in the specification and claims represents at least one of the connected objects, and the character "/" generally indicates that the objects associated with each other are in an "or" relationship.

The embodiments of the present application are described in detail below through specific embodiments and their application scenarios in conjunction with the accompanying drawings.

With reference to FIGS. 1 to 13 , the embodiment of the present application discloses a method for detecting fluid leakage, which is applied to the hydraulic end of a fracturing device, so as to detect the leakage of a part of the structure of the hydraulic end. The hydraulic end may include a valve assembly 100, which includes an upper valve 110 and a lower valve 120. In addition, the hydraulic end may also include a valve box 200, a plunger 300, an end cover 400, a packing, an upper liquid manifold 500 and other structures, wherein the valve box 200 may include a cavity, a liquid inlet channel and a liquid outlet channel, the plunger 300 may be movably arranged in the cavity, the packing is installed at the end of the cavity, the upper valve 110 is arranged in the liquid outlet channel, and the lower valve 120 is arranged in the liquid inlet channel. Specifically, during the pressurized liquid discharge process, the lower valve 120 is closed and the upper valve 110 is opened, so that the pressurized liquid in the valve box 200 can be discharged through the liquid outlet pipe; during the liquid inlet process, the upper valve 110 is closed and the lower valve 120 is opened, so that the liquid can enter the valve box 200 through the upper liquid manifold 500 and the liquid inlet channel, so as to pressurize the liquid through the plunger 300.

The upper valve 110 and the lower valve 120 are constantly opened and closed during the operation of the fracturing device, which determines that they are vulnerable parts. After working for a long time, at least one of the upper valve 110 and the lower valve 120 may be damaged, causing sealing failure and abnormal function of the hydraulic end.

Based on the above situation, an embodiment of the present application provides a method for detecting fluid leakage, by detecting at least one of the upper valve 110 and the lower valve 120, so as to lay a foundation for repairing or replacing the valve assembly 100.

The disclosed detection methods include:

Collecting the changing parameters of the fluid and/or structure in the hydraulic end to obtain the corresponding changing parameter time domain curve;

Comparing the time-domain curve of the changing parameter with the preset time-domain curve of the changing parameter;

The leakage of the upper valve 110 and/or the lower valve 120 is determined according to the difference in phase change between the time-domain curve of the changing parameter and the preset time-domain curve of the changing parameter.

In the embodiment of the present application, by collecting the fluid change parameters and/or structural change parameters in the hydraulic end, the corresponding change parameter time domain curve can be obtained, and compared with the preset change parameter time domain curve, the difference in phase change can be found, so as to determine the leakage location of the hydraulic end, so that the operator can repair or replace it in time. Therefore, the detection method in the embodiment of the present application can identify the failure of the valve in advance, so that the valve assembly 100 and other components can be repaired or replaced in time before serious damage occurs, thereby ensuring the overall robustness of the hydraulic end and improving its service life, and to a certain extent, it can also reduce the maintenance cost of the valve assembly 100.

It should be noted here that in the embodiment of the present application, the corresponding time domain curve is obtained by actually detecting the fluid change parameters and/or structural change parameters in the hydraulic end, and by comparing the limit change difference with the preset time domain curve under normal circumstances, the leakage of the valve assembly 100 is judged by a certain threshold.

Various implementation methods for determining and detecting leakage of the valve assembly 100 will be described in detail below.

In some embodiments, the leakage of the valve assembly 100 can be determined based on the characteristics of the fluid in the hydraulic end, wherein the characteristics of the fluid may include pressure fluctuations, flow fluctuations, etc. of the fluid. Specifically, the following are included:

The first embodiment: the changing parameters of the fluid may include a fluid pressure fluctuation value, a fluid pressure fluctuation time domain curve is obtained according to the fluid pressure fluctuation value, and the leakage of the upper valve 110 and/or the lower valve 120 is judged according to the difference in phase change between the fluid pressure fluctuation time domain curve and a preset fluid pressure fluctuation time domain curve.

The hydraulic end has a high-pressure area, and the pressure fluctuation value of the fluid in the high-pressure area can be detected. For example, the high-pressure area can be located in the cavity of the valve box 200, the inner wall of the valve cover 400, the end surface of the plunger 300, etc. Of course, it can also be other locations, and the embodiments of the present application do not specifically limit this.

When the fluid pressure fluctuation time domain curve at the high-pressure area has a rising advance angle and a falling lag angle compared to the preset fluid pressure fluctuation time domain curve, it is determined that the upper valve 110 has a leak, as shown in Figures 2 and 5.

Furthermore, the aperture of the leakage area of the upper valve 110 is positively correlated with the increase of the rising advance angle and the falling lag angle, respectively.

Specifically, when there is a leak in the upper valve 110, the detected fluid pressure fluctuation time domain curve will have a rising advance angle and a falling lag angle compared to the normal fluid pressure fluctuation time domain curve (i.e., the preset fluid pressure fluctuation time domain curve), and as the aperture of the leakage area of the upper valve 110 increases, the pressure rise advance angle and the falling lag angle increase respectively, that is, the larger the aperture of the leakage at the upper valve 110, the larger the pressure rise advance angle and the falling lag angle respectively. Therefore, the leakage of the upper valve 110 and the aperture size of the leakage area can be determined by the difference between the fluid pressure fluctuation time domain curve and the preset fluid pressure fluctuation time domain curve.

When the fluid pressure fluctuation time domain curve at the high pressure area has a rising lag angle and a falling advance angle compared to the preset fluid pressure fluctuation time domain curve, it is determined that the lower valve 120 has leakage, as shown in FIGS. 3 and 6 .

Furthermore, the aperture of the leakage area of the lower valve 120 is positively correlated with the increase of the rising lag angle and the falling advance angle, respectively.

Specifically, when there is a leak in the lower valve 120, the detected fluid pressure fluctuation time domain curve will have a rising lag angle and a falling advance angle compared to the normal fluid pressure fluctuation time domain curve (i.e., the preset fluid pressure fluctuation time domain curve), and as the aperture of the leakage area of the lower valve 120 increases, the pressure rise lag angle and the falling advance angle increase respectively, that is, the larger the aperture of the leakage at the lower valve 120, the larger the pressure rise lag angle and the falling advance angle respectively. Therefore, the leakage of the lower valve 120 and the aperture size of the leakage area can be determined by the difference between the fluid pressure fluctuation time domain curve and the preset fluid pressure fluctuation time domain curve.

When the fluid pressure fluctuation time domain curve at the high pressure area has a rising advance angle and a falling advance angle compared to the preset fluid pressure fluctuation time domain curve, it is determined that both the upper valve 110 and the lower valve 120 are leaking, as shown in Figures 4 and 7.

Further, the aperture of the leakage area of the upper vane 110 is positively correlated with the increase of the rising advance angle and the falling advance angle, respectively, and the aperture of the leakage area of the lower vane 120 is positively correlated with the increase of the rising advance angle and the falling advance angle, respectively.

Specifically, when both the upper valve 110 and the lower valve 120 leak, the detected fluid pressure fluctuation time domain curve will have a rising advance angle and a falling advance angle compared to the normal fluid pressure fluctuation time domain curve (i.e., the preset fluid pressure fluctuation time domain curve), and, as the aperture of the upper valve 110 leakage area increases, the pressure rise advance angle and the falling advance angle both increase, that is, the larger the aperture of the leakage at the upper valve 110, the larger the pressure rise advance angle and the falling advance angle; and, as the aperture of the leakage area of the lower valve 120 increases, the pressure rise advance angle and the falling advance angle both increase, that is, the larger the aperture of the leakage at the lower valve 120, the larger the pressure rise advance angle and the falling advance angle. Therefore, the difference between the fluid pressure fluctuation time domain curve and the preset fluid pressure fluctuation time domain curve can be used to determine whether the upper valve 110 and the lower valve 120 are leaking at the same time and the aperture size of each leakage area.

In the embodiment of the present application, the hydraulic end may also have a low-pressure area, and the pressure fluctuation value of the fluid in the low-pressure area is detected. For example, the low-pressure area may be located at the entrance of the lower valve 120, in the upper liquid manifold 500, etc. Of course, it may also be other locations, and the embodiment of the present application does not specifically limit this. Among them, the pressure of the fluid in the above-mentioned low-pressure area is the total pressure of the fluid in the area, that is, the sum of the dynamic pressure of the fluid and the static pressure of the fluid.

When the fluid pressure fluctuation time domain curve in the low-pressure area has a rising advance angle and a falling lag angle compared to the preset fluid pressure fluctuation time domain curve, and there is a sudden change in the falling section, it is determined that the upper valve 110 has a leak, as shown in FIG8 .

Specifically, when there is a leak in the upper valve 110, the detected fluid pressure fluctuation time domain curve will have a rising advance angle and a falling lag angle compared to the normal fluid pressure fluctuation time domain curve (i.e., the preset fluid pressure fluctuation time domain curve), and there will be a sudden change in the descending section, and as the aperture of the leakage area of the upper valve 110 increases, the pressure rise advance angle and the falling lag angle increase respectively, that is, the larger the aperture of the leakage at the upper valve 110, the larger the pressure rise advance angle and the falling lag angle. Therefore, the leakage of the upper valve 110 and the aperture size of the leakage area can be determined by the difference between the fluid pressure fluctuation time domain curve and the preset fluid pressure fluctuation time domain curve. It should be noted here that when the aperture of the upper valve 110 is greater than a certain threshold, the obtained fluid pressure fluctuation time domain curve will have a sudden change in pressure.

When the fluid pressure fluctuation time domain curve in the low-pressure area has a rising advance angle compared to the preset fluid pressure fluctuation time domain curve, and the falling lag angle is zero or close to zero, it is determined that the lower valve 120 has a leak, as shown in FIG9 .

Furthermore, the aperture of the leakage area of the lower valve 120 is positively correlated with the increase in the rising advance angle.

Specifically, when there is a leak in the lower valve 120, the detected fluid pressure fluctuation time domain curve will have a rising advance angle compared to the normal fluid pressure fluctuation time domain curve (i.e., the preset fluid pressure fluctuation time domain curve), and the falling lag angle is zero or close to zero, and, as the aperture of the leakage area of the lower valve 120 increases, the pressure rise advance angle will increase, while the falling lag angle will not change significantly, that is, the larger the aperture of the leakage area of the lower valve 120, the larger the pressure rise advance angle (the mean value of the pressure rise section), and the pressure drop lag angle will not change significantly. Therefore, the difference between the fluid pressure fluctuation time domain curve and the preset fluid pressure fluctuation time domain curve can be used to determine whether the lower valve 120 has a leak and the aperture size of the leakage area.

When the fluid pressure fluctuation time domain curve at the low pressure area has a rising advance angle and a falling lag angle compared to the preset fluid pressure fluctuation time domain curve, it is determined that both the upper valve 110 and the lower valve 120 are leaking, as shown in FIG. 10 .

Further, the aperture of the leakage area of the upper valve 110 is positively correlated with the increase of the rising advance angle and the falling lag angle, respectively, and the aperture of the leakage area of the lower valve 120 is positively correlated with the increase of the rising advance angle and the falling lag angle, respectively.

Specifically, when the upper valve 110 and the lower valve 120 leak at the same time, the detected fluid pressure fluctuation time domain curve will have a rising advance angle and a falling lag angle compared to the normal fluid pressure fluctuation time domain curve (that is, the preset fluid pressure fluctuation time domain curve), and, as the aperture of the upper valve 110 leakage area increases, the pressure rise advance angle and the falling lag angle will both increase, that is, the larger the aperture of the leakage at the upper valve 110, the larger the pressure rise advance angle and the falling lag angle; and, as the aperture pair of the leakage area of the lower valve 120 increases, the pressure rise advance angle and the falling lag angle will both increase, that is, the larger the aperture of the leakage at the lower valve 120, the larger the pressure rise advance angle and the falling lag angle. Therefore, the difference between the fluid pressure fluctuation time domain curve and the preset fluid pressure fluctuation time domain curve can be used to determine whether the upper valve 110 and the lower valve 120 are leaking at the same time and the aperture size of each leakage area.

Second implementation mode: The change parameter of the fluid may include a fluid flow fluctuation value, and a fluid flow fluctuation time domain curve is obtained according to the fluid flow fluctuation value, and the leakage of the upper valve 110 and/or the lower valve 120 is judged according to the difference in phase change between the fluid flow fluctuation time domain curve and the preset fluid flow fluctuation time domain curve. Exemplarily, the fluid flow fluctuation value at the inlet of the lower valve 120 can be detected to obtain the fluid flow fluctuation time domain curve. Of course, it can also be other locations, such as in the upper liquid manifold 500, and the embodiment of the present application does not specifically limit this.

When the fluid flow fluctuation time domain curve has a rising lag angle and a falling advance angle compared to the preset fluid flow fluctuation time domain curve, it is determined that the upper valve 110 has a leak, as shown in FIG11 .

Furthermore, the aperture of the leakage region of the upper valve 110 is positively correlated with the increase of the rising lag angle and the falling advance angle, respectively.

When there is leakage in the upper valve 110, it will be found that the flow at the entrance of the lower valve 120 increases with the increase of the aperture of the upper valve 110 leakage area, and the instantaneous flow at the entrance lags and rises and falls in advance during the opening process of the lower valve 120, that is, there is a rising lag angle and a falling advance angle, and as the aperture of the upper valve 110 leakage area increases, the flow rise lag angle and the falling advance angle increase respectively, that is, the larger the aperture, the larger the instantaneous flow rise lag angle and the falling advance angle respectively, and at the same time, the mean of the entire process section of the inlet instantaneous flow increases. Therefore, the leakage of the upper valve 110 and the aperture size of the leakage area can be determined by the difference between the fluid flow fluctuation time domain curve and the preset fluid flow fluctuation time domain curve.

When the fluid flow fluctuation time domain curve has a rising advance angle compared to the preset fluid flow fluctuation time domain curve, and when there is reverse leakage, it is determined that the lower valve 120 has leakage, as shown in FIG. 12 .

Furthermore, the aperture of the leakage area of the lower valve 120 is positively correlated with the absolute value of the rising advance angle and the reverse leakage flow rate.

Specifically, when the lower valve 120 leaks, it is found that there is a reverse leakage at the entrance of the lower valve 120 before the lower valve 120 is opened. As the aperture of the leakage area of the lower valve 120 increases, the absolute value of the leakage flow increases. After the lower valve 120 is closed, there is a reverse flushing flow at the entrance of the lower valve 120. As the aperture of the leakage area of the lower valve 120 increases, the absolute value of the leakage increases. At the same time, during the opening process of the lower valve 120, the instantaneous flow at the entrance of the lower valve 120 rises in advance, that is, the larger the leakage aperture of the lower valve 120, the larger the advance angle of the instantaneous flow rise. Therefore, the leakage of the lower valve 120 and the aperture size of the leakage area can be determined by the difference between the fluid flow fluctuation time domain curve and the preset fluid flow fluctuation time domain curve.

When the fluid flow fluctuation time domain curve has a descending advance angle compared to the preset fluid flow fluctuation time domain curve, and there is reverse leakage, it is determined that both the upper valve 110 and the lower valve 120 are leaking, as shown in FIG. 13 .

Furthermore, the aperture of the leakage area of the upper vane 110 is positively correlated with the increase in the absolute values of the descent advance angle and the reverse leakage flow rate, and the aperture of the leakage area of the lower vane 120 is positively correlated with the increase in the absolute values of the descent advance angle and the reverse leakage flow rate.

Specifically, when the upper valve 110 and the lower valve 120 leak at the same time, a reverse leakage is found near the entrance of the lower valve 120 before the lower valve 120 is opened, and a reverse leakage also exists at the entrance of the lower valve 120 after the lower valve 120 is closed, and when the lower valve 120 is opened, the instantaneous flow rate drops with lag. Therefore, it can be determined that both the upper valve 110 and the lower valve 120 are leaking and the aperture size of the leakage area by the difference between the fluid flow rate fluctuation time domain curve and the preset fluid flow rate fluctuation time domain curve.

A third implementation method: The change parameters of the structure may include a structural stress fluctuation value, a structural stress fluctuation time domain curve is obtained according to the structural stress fluctuation value, and the leakage of the upper valve 110 and/or the lower valve 120 is judged according to the difference in phase change between the structural stress fluctuation time domain curve and a preset structural stress fluctuation time domain curve.

Among them, the hydraulic end has a high-pressure area, and the structural stress fluctuation value of the high-pressure area can be detected. For example, the high-pressure area can be located at the inner wall of the cavity of the valve box 200, the end face of the plunger 300, the inner wall of the end cover 400, etc. Of course, it can also be other positions, and the embodiments of the present application are not specifically limited to this.

When the structural stress fluctuation time domain curve at the high-pressure area has a rising advance angle and a falling lag angle compared to the preset structural stress fluctuation time domain curve, it is determined that the upper valve 110 has a leak.

Specifically, when there is a leak in the upper valve 110, the detected structural stress fluctuation time domain curve will have a rising advance angle and a falling lag angle compared to the normal structural stress fluctuation time domain curve (i.e., the preset structural stress fluctuation time domain curve), and as the aperture of the leakage area of the upper valve 110 increases, the stress rise advance angle and the falling lag angle increase respectively, that is, the larger the aperture of the leakage at the upper valve 110, the larger the stress rise advance angle and the falling lag angle respectively. Therefore, the leakage of the upper valve 110 and the aperture size of the leakage area can be determined by the difference between the structural stress fluctuation time domain curve and the preset structural stress fluctuation time domain curve.

When the structural stress fluctuation time domain curve at the high-pressure area has a rising lag angle and a falling advance angle compared to the preset structural stress fluctuation time domain curve, it is determined that the lower valve 120 has a leak.

Specifically, when there is a leak in the lower valve 120, the detected structural stress fluctuation time domain curve will have a rising lag angle and a falling advance angle compared to the normal structural stress fluctuation time domain curve (i.e., the preset structural stress fluctuation time domain curve), and as the aperture of the leakage area of the lower valve 120 increases, the stress rising lag angle and the falling advance angle increase respectively, that is, the larger the aperture of the leakage at the lower valve 120, the larger the stress rising lag angle and the falling advance angle respectively. Therefore, the leakage of the lower valve 120 and the aperture size of the leakage area can be determined by the difference between the structural stress fluctuation time domain curve and the preset structural stress fluctuation time domain curve.

When the structural stress fluctuation time domain curve at the high-pressure area has a rising advance angle and a falling lag angle compared to the preset structural stress fluctuation time domain curve, leakage occurs simultaneously in the upper valve 110 and the lower valve 120 .

Specifically, when both the upper vane 110 and the lower vane 120 leak, the detected structural stress fluctuation time domain curve will have a rising advance angle and a falling lag angle compared to the normal structural stress fluctuation time domain curve (i.e., the preset structural stress fluctuation time domain curve). As the aperture of the upper vane 110 leakage area increases, the stress rise advance angle and the falling lag angle both increase, that is, the larger the aperture of the leakage at the upper vane 110, the larger the stress rise advance angle and the falling lag angle; and, as the aperture of the leakage area of the lower vane 120 increases, the stress rise advance angle and the falling lag angle both increase, that is, the larger the aperture of the leakage at the lower vane 120, the larger the stress rise advance angle and the falling lag angle. Therefore, the difference between the structural stress fluctuation time domain curve and the preset structural stress fluctuation time domain curve can be used to determine whether the upper vane 110 and the lower vane 120 are leaking at the same time and the aperture size of each leakage area.

In the embodiment of the present application, the hydraulic end may also have a low-pressure area, and the structural stress fluctuation value at the low-pressure area is detected. For example, the low-pressure area may be located at the entrance of the lower valve 120, and of course, it may also be other locations, which is not specifically limited in the embodiment of the present application.

It should be noted here that according to the Navier-Stokes vector equation

When describing the flow of fluid around the column, the dynamic pressure of the fluid is converted into static pressure, that is, the dynamic pressure fluctuation can be converted into stress-strain fluctuation. By arranging the stress-strain sensor 630, the stress-strain fluctuation of the local dynamic pressure at the inlet of the lower valve 120 is detected, so as to lay a foundation for judging the leakage of the valve assembly 100.

When the structural stress fluctuation time domain curve at the low-pressure area has a stress change advance angle and a stress change lag angle compared to the preset structural stress fluctuation time domain curve, it is determined that there is a leak in the upper valve 110.

Specifically, when there is leakage in the upper valve 110, according to the time domain curve of fluid flow fluctuation, there are stress change advance angle and stress change lag angle, and as the aperture of the leakage area of the upper valve 110 increases, the stress change advance angle and stress change lag angle increase respectively.

When the structural stress fluctuation time domain curve at the low-pressure area has a stress change advance angle compared to the preset structural stress fluctuation time domain curve, and there is a stress fluctuation value when the lower valve 120 is closed, it is determined that the lower valve 120 has a leak.

Specifically, when the lower valve 120 leaks, according to the time domain curve of the fluid flow fluctuation, when the lower valve 120 is closed, stress fluctuations occur and there is a stress change advance angle, and as the aperture of the leakage area of the lower valve 120 increases, the stress change advance angle increases, and the stress change lag angle does not change.

When the structural stress fluctuation time domain curve at the low-pressure area has a stress change lag angle compared to the preset structural stress fluctuation time domain curve, and there is a stress fluctuation value when the lower valve 120 is closed, it is determined that both the upper valve 110 and the lower valve 120 are leaking.

Specifically, when leakage occurs in both the upper valve 110 and the lower valve 120, when the lower valve 120 is closed, stress fluctuation occurs and there is a stress change lag angle. As the aperture of the leakage area of the upper valve 110 and the lower valve 120 increases, the stress change advance angle remains unchanged, while the stress change lag angle increases.

Based on the above fluid leakage detection method, the embodiment of the present application further discloses a fracturing device, which applies the above fluid leakage detection method to detect and judge the leakage of the hydraulic end of the fracturing device through the above detection method.

The disclosed fracturing device includes a hydraulic end, a first detection element and/or a second detection element, and a control element, wherein the hydraulic end includes a valve assembly 100, the valve assembly 100 includes an upper valve 110 and a lower valve 120, the first detection element is used to collect the change parameters of the fluid in the hydraulic end, and the second detection element is used to collect the change parameters of the structure in the hydraulic end.

The control element is electrically connected to the first detection element and/or the second detection element. The control element is used to control the collection of the change parameters of the fluid and/or structure in the hydraulic end, and draw a change parameter time domain curve; to compare the change parameter time domain curve with the preset change parameter time domain curve; to judge the leakage of the upper valve 110 and/or the lower valve 120 according to the difference in phase change between the change parameter time domain curve and the preset change parameter time domain curve.

Specifically, the control element can receive the changing parameters of the fluid in the hydraulic end collected by the first detection element, such as the fluid stress changing parameters, the fluid flow changing parameters, etc., and draw a time domain curve of the fluid changing parameters, compare it with the preset fluid changing parameter time domain curve, determine the difference in phase changes of the two curves, and judge the leakage of the upper valve 110 and/or the lower valve 120 based on the difference.

Of course, the control element can also receive the change parameters of the structure in the hydraulic end collected by the second detection element, such as the structural stress change parameters, and draw a time domain curve of the structural change parameters, compare it with the preset time domain curve of the structural change parameters, determine the difference in phase changes of the two curves, and judge the leakage of the upper valve 110 and/or the lower valve 120 based on the difference.

In some embodiments, the first detection element may be a pressure sensor 610 , and the pressure sensor 610 may be disposed in a high-pressure area or a low-pressure area of the hydraulic end.

Specifically, the hydraulic end may include a valve box 200 and an end cover 400, wherein a plunger 300 is disposed in the valve box 200. During operation of the fracturing device, the inner wall of the cavity of the valve box 200, the end face of the plunger 300, and the inner wall of the end cover 400 are all in contact with the compressed high-pressure fluid and are in the high-pressure area. Based on this, the pressure sensor 610 may be disposed in at least one area such as the inner wall of the cavity of the valve box 200, the inner wall of the end cover 400, and the end face of the plunger 300, so as to detect the fluctuation of the fluid pressure at the high-pressure area of the hydraulic end.

In addition, the fluid enters the hydraulic end through the inlet of the lower valve 120, and the inlet is separated from the cavity of the valve box 200 by the lower valve 120. Therefore, the inlet of the lower valve 120 is a low-pressure area, and the pressure sensor 610 can also be set at the inlet of the lower valve 120 to facilitate the detection of fluid pressure fluctuations in the low-pressure area of the hydraulic end.

In other embodiments, the first detection element may also be a flow sensor 620, and the flow sensor 620 may be disposed in a low-pressure area of the hydraulic end.

Specifically, the fluid enters the hydraulic end through the inlet of the lower valve 120, and the inlet is separated from the cavity of the valve box 200 by the lower valve 120. Therefore, the inlet of the lower valve 120 is a low-pressure area, and the flow sensor 620 can also be set at the inlet of the lower valve 120 to detect the fluctuation of the fluid flow in the low-pressure area of the hydraulic end.

In some embodiments, the second detection element may be a stress strain sensor 630 , and the pressure sensor 610 may be disposed in a high pressure region or a low pressure region of the hydraulic end.

Specifically, the fracturing device may include a driving mechanism, which may include a crankshaft, a first connecting rod, a crosshead, a second connecting rod and a plunger 300 connected in sequence. During the operation of the fracturing device, the crankshaft, the first connecting rod, the crosshead, the second connecting rod and the plunger 300 will all bear a large load, so that each will produce a relatively large deformation. Based on this, the stress strain sensor 630 can be set on at least one of the crankshaft, the first connecting rod, the crosshead, the second connecting rod and the plunger 300, so as to detect the structural stress fluctuation changes at the high pressure area of the hydraulic end.

In addition, the fluid enters the hydraulic end through the inlet of the lower valve 120, and the inlet is separated from the cavity of the valve box 200 by the lower valve 120. Therefore, the inlet of the lower valve 120 is a low-pressure area, where the load is small, so that the area will produce a relatively small deformation. Based on this, the stress strain sensor 630 is set at the inlet of the lower valve 120 to detect the structural stress fluctuation changes in the low-pressure area of the hydraulic end.

In the embodiment of the present application, the fracturing device may further include an upper liquid manifold 500, the outlet of which is connected to the inlet of the lower valve 120, so that the upper liquid manifold 500 is also in a low pressure area. Based on this, at least one of the pressure sensor 610, the flow sensor 620 and the stress strain sensor 630 may also be disposed in the upper liquid manifold 500 to detect at least one of the fluid pressure, fluid flow and structural stress therein.

It should be noted here that the detection of the changing parameters of the fluid pressure, fluid flow, and structural stress in the hydraulic end of the fracturing device in the embodiment of the present application and the comparative analysis principle of the time domain curves of each changing parameter, and the judgment of the leakage of the upper valve 110 and/or the lower valve 120 can all refer to the corresponding contents in the above-mentioned fluid leakage detection method, which will not be repeated here.

In summary, by collecting the fluid change parameters and/or structural change parameters in the hydraulic end, the time domain curve of the change parameters can be obtained, and compared with the preset time domain curve of the change parameters to find the difference, so as to determine the leakage location of the hydraulic end, so that the operator can repair or replace it in time. Based on this, the detection method in the embodiment of the present application can identify the failure of the valve in advance, so that the valve assembly 100 and other components can be repaired or replaced in time before serious damage occurs, thereby ensuring the overall robustness of the hydraulic end and improving its service life, and to a certain extent, it can also reduce the maintenance cost of the valve assembly 100.

The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

A method for detecting fluid leakage is applied to the hydraulic end of a fracturing device, wherein the hydraulic end comprises a valve assembly, and the valve assembly comprises an upper valve and a lower valve, wherein the detection method comprises:

Collecting the change parameters of the fluid and/or structure in the hydraulic end to obtain the corresponding change parameter time domain curve;

Comparing the time-domain curve of the variation parameter with a preset time-domain curve of the variation parameter;

The leakage of the upper valve and/or the lower valve is determined according to the difference in phase change between the time-domain curve of the changing parameter and the time-domain curve of the preset changing parameter.
The detection method according to claim 1 is characterized in that the change parameter of the fluid in the hydraulic end includes a fluid pressure fluctuation value, and a fluid pressure fluctuation time domain curve is obtained according to the fluid pressure fluctuation value;

The leakage of the upper valve and/or the lower valve is determined based on the difference in phase change between the fluid pressure fluctuation time domain curve and a preset fluid pressure fluctuation time domain curve.
The detection method according to claim 2, characterized in that the hydraulic end has a high pressure area;

When the fluid pressure fluctuation time domain curve at the high pressure area has a rising advance angle and a falling lag angle compared with the preset fluid pressure fluctuation time domain curve, it is determined that the upper valve has leakage;

When the fluid pressure fluctuation time domain curve at the high pressure area has a rising lag angle and a falling advance angle compared with the preset fluid pressure fluctuation time domain curve, it is determined that the lower valve has leakage;

When the fluid pressure fluctuation time domain curve at the high-pressure area has a rising advance angle and a falling advance angle compared to the preset fluid pressure fluctuation time domain curve, it is determined that both the upper valve and the lower valve are leaking.
The detection method according to claim 3 is characterized in that the aperture of the leakage area of the upper valve is positively correlated with the increase amplitude of the rising advance angle and the falling lag angle respectively;

Alternatively, the aperture of the leakage area of the lower valve is positively correlated with the increase range of the rising lag angle and the falling advance angle respectively;

Alternatively, the aperture of the leakage area of the upper valve is positively correlated with the increase amplitude of the rising advance angle and the falling advance angle, and the aperture of the leakage area of the lower valve is positively correlated with the increase amplitude of the rising advance angle and the falling advance angle.
The detection method according to claim 2, characterized in that the hydraulic end has a low pressure area;

When the fluid pressure fluctuation time domain curve at the low pressure area has a rising advance angle and a falling lag angle compared to the preset fluid pressure fluctuation time domain curve, and there is a sudden change in the falling section, it is determined that the upper valve has a leak;

When the fluid pressure fluctuation time domain curve at the low pressure area has a rising advance angle compared to the preset fluid pressure fluctuation time domain curve, and the falling lag angle is zero or close to zero, it is determined that the lower valve has leakage;

When the fluid pressure fluctuation time domain curve at the low-pressure area has a rising advance angle and a falling lag angle compared to the preset fluid pressure fluctuation time domain curve, it is determined that both the upper valve and the lower valve are leaking.
The detection method according to claim 5 is characterized in that the aperture of the leakage area of the upper valve is positively correlated with the increase amplitude of the rising advance angle and the falling lag angle respectively;

Alternatively, the aperture of the leakage area of the lower valve is positively correlated with the increase amplitude of the rising advance angle;

Alternatively, the aperture of the leakage area of the upper valve is positively correlated with the increase amplitude of the rising advance angle and the falling lag angle, and the aperture of the leakage area of the lower valve is positively correlated with the increase amplitude of the rising advance angle and the falling lag angle.
The detection method according to claim 1 is characterized in that the change parameter of the fluid in the hydraulic end includes a fluid flow fluctuation value at the inlet of the lower valve, and a fluid flow fluctuation time domain curve is obtained according to the fluid flow fluctuation value;

The leakage of the upper valve and/or the lower valve is determined based on the difference in phase change between the fluid flow fluctuation time domain curve and the preset fluid flow fluctuation time domain curve.
The detection method according to claim 7 is characterized in that when the fluid flow fluctuation time domain curve has a rising lag angle and a falling advance angle compared to the preset fluid flow fluctuation time domain curve, it is determined that the upper valve has leakage;

When the fluid flow fluctuation time domain curve has a rising advance angle compared to the preset fluid flow fluctuation time domain curve, and there is reverse leakage, it is determined that the lower valve has leakage;

When the fluid flow fluctuation time domain curve has a descending advance angle compared to the preset fluid flow fluctuation time domain curve, and there is reverse leakage, it is determined that both the upper valve and the lower valve are leaking.
The detection method according to claim 8 is characterized in that the aperture of the leakage area of the upper valve is positively correlated with the increase amplitude of the rising lag angle and the falling advance angle respectively;

Alternatively, the aperture of the leakage area of the lower valve is positively correlated with the absolute value of the rising advance angle and the reverse leakage flow rate respectively;

Alternatively, the aperture of the leakage area of the upper valve is positively correlated with the increase in the absolute values of the descent advance angle and the reverse leakage flow rate, and the aperture of the leakage area of the lower valve is positively correlated with the increase in the absolute values of the descent advance angle and the reverse leakage flow rate.
The detection method according to claim 1 is characterized in that the change parameter of the structure in the hydraulic end includes a structural stress fluctuation value, and a structural stress fluctuation time domain curve is obtained according to the structural stress fluctuation value;

The leakage of the upper valve and/or the lower valve is determined based on the difference in phase change between the structural stress fluctuation time domain curve and a preset structural stress fluctuation time domain curve.
The detection method according to claim 10, characterized in that the hydraulic end has a high pressure area;

When the structural stress fluctuation time domain curve at the high-pressure area has a rising advance angle and a falling lag angle compared to the preset structural stress fluctuation time domain curve, it is determined that the upper valve has a leak, or both the upper valve and the lower valve have a leak;

When the structural stress fluctuation time domain curve at the high-pressure area has a rising lag angle and a falling advance angle compared to the preset structural stress fluctuation time domain curve, it is determined that the lower valve has a leak.
The detection method according to claim 11 is characterized in that the aperture of the leakage area of the upper valve is positively correlated with the increase amplitude of the rising advance angle and the falling lag angle respectively;

Alternatively, the aperture of the leakage area of the lower valve is positively correlated with the increase amplitude of the rising lag angle and the falling advance angle respectively;

Alternatively, the aperture of the leakage area of the upper valve is positively correlated with the increase amplitude of the rising advance angle and the falling lag angle, and the aperture of the leakage area of the lower valve is positively correlated with the increase amplitude of the rising advance angle and the falling lag angle.
The detection method according to claim 10, characterized in that the hydraulic end has a low pressure area;

When the structural stress fluctuation time domain curve at the low pressure area has a stress change advance angle and a stress change lag angle compared with the preset structural stress fluctuation time domain curve, it is determined that the upper valve has a leak;

When the structural stress fluctuation time domain curve at the low-pressure area has a stress change advance angle compared to the preset structural stress fluctuation time domain curve, and there is a stress fluctuation value when the lower valve is closed, it is determined that the lower valve has a leak;

When the structural stress fluctuation time domain curve at the low-pressure area has a stress change hysteresis angle compared to the preset structural stress fluctuation time domain curve, and there is a stress fluctuation value when the lower valve is closed, it is determined that both the upper valve and the lower valve are leaking.
A fracturing device, using the fluid leakage detection method according to any one of claims 1 to 13, characterized in that the fracturing device comprises: a hydraulic end, a first detection element and/or a second detection element, and a control element, wherein the hydraulic end comprises a valve assembly, the valve assembly comprises an upper valve and a lower valve, the first detection element is used to collect the change parameters of the fluid in the hydraulic end, and the second detection element is used to collect the change parameters of the structure in the hydraulic end;

The control element is used to control and collect the change parameters of the fluid and/or structure in the hydraulic end to obtain the corresponding change parameter time domain curve;

Comparing the time-domain curve of the variation parameter with a preset time-domain curve of the variation parameter;

The leakage of the upper valve and/or the lower valve is determined according to the difference in phase change between the time-domain curve of the changing parameter and the time-domain curve of the preset changing parameter.
The fracturing device according to claim 14, characterized in that the hydraulic end comprises a valve box and an end cover, and a plunger is provided in the valve box;

The first detection element is a pressure sensor, and the pressure sensor is arranged on at least one of the inner wall of the cavity of the valve box, the inner wall of the end cover, the end surface of the plunger, or the inlet of the lower valve.
The fracturing device according to claim 14 is characterized in that the first detection element is a flow sensor, and the flow sensor is arranged at the entrance of the lower valve.
The fracturing device according to claim 14, characterized in that the fracturing device further comprises a driving mechanism, wherein the driving mechanism comprises a crankshaft, a first connecting rod, a crosshead, a second connecting rod and a plunger connected in sequence;

The second detection element is a stress strain sensor, and the stress strain sensor is disposed at at least one of the crankshaft, the first connecting rod, the crosshead, the second connecting rod, the plunger, or the entrance of the lower valve.