Gas analysis system

Abstract

The invention relates to the technical field of detection of gas separated from well mouth drilling fluid, and provides a gas analysis system, electronic equipment and a computer readable storage medium. The system comprises a collection device, a gas mixing device, a combined monitoring device and an analysis unit. Wherein the gas mixing device is provided with a first mixing container and a second mixing container which are variable in volume, and the gas mixing device switches the working states of the two mixing containers according to the change of the internal pressure of the first mixing container or the second mixing container. According to the invention, the components and the concentrations of the to-be-detected gas received by the first detection equipment and the second detection equipment are ensured to be the same, and the accuracy of the detection result is greatly improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of gas detection of wellhead drilling fluid, and in particular to a gas analysis system. Background Art

[0002] Raman laser gas analyzer (hereinafter referred to as Raman instrument) has broad application prospects in the field of oil and gas exploration and development because it can detect more than ten kinds of hydrocarbon and non-hydrocarbon gases in real time and online non-destructively. In the early stage of Raman instrument promotion, it is necessary to carry out a series of on-site test experiments on oil and gas wells in different blocks. While testing various indicators such as instrument detection precision and accuracy, the measured value is compared with the true value of the detected gas concentration to further optimize the instrument hardware and software spectrum analysis algorithm, continuously improve the instrument performance, and meet the requirements of on-site detection.

[0003] Since field testing is different from laboratory testing, the composition and concentration of the detected gas are unknown. It is necessary to accurately obtain the true content value of the measured gas and compare it with the Raman detection value to determine whether the Raman instrument detection result is accurate. At present, in the process of oil and gas drilling, hydrogen flame ion chromatograph is usually used to detect the component type and content of each hydrocarbon gas in the drilling fluid returned from the wellhead. Its measurement results can be used as a reference for the Raman spectrometer. However, when the composition and concentration of the gas released from the wellhead drilling fluid continuously change, the construction site cannot guarantee the consistency of the composition and concentration of the gas entering the chromatograph and the Raman instrument, resulting in the inability to calibrate the detection indicators of the Raman instrument, resulting in low accuracy of the detection results. Summary of the invention

[0004] In view of this, the embodiments of the present disclosure provide a gas analysis system to solve the problem in the prior art that the composition and concentration of the gas entering the chromatograph and the Raman instrument cannot be guaranteed to be consistent, resulting in the inability to calibrate the detection indicators of the Raman instrument and causing low accuracy of the detection results.

[0005] The present disclosure provides a gas analysis system, including:

[0006] It includes a collection device for continuously collecting the gas to be tested which is released from the drilling fluid at the wellhead during oil and gas drilling and transmitting it to the gas mixing device;

[0007] A gas mixing device connected to the acquisition device is provided with a first mixing container and a second mixing container with variable volumes. The gas mixing device switches the working states of the two mixing containers according to the change of the internal pressure of the first mixing container or the second mixing container and records the switching time to generate a switching time set, wherein the working state includes an inflation state and a degassing state, the inflation state indicates that the mixing container receives the gas to be tested, and the degassing state indicates that the mixing container outputs the gas to be tested input therein to the joint detection device, wherein the working states of the first mixing container and the second mixing container are different at any time;

[0008] A combined detection device connected to the gas mixing device, comprising a gas distribution unit, a first detection device, and a second detection device, wherein a first end of the gas distribution unit is connected to the gas mixing device, a second end is connected to the first detection device, and a third end is connected to the second detection device, and the gas distribution unit is used to receive the gas to be tested, and distribute the received gas to be tested to the first detection device and the second detection device according to a preset ratio for analysis, so as to obtain first analysis data corresponding to the first detection device and second analysis data corresponding to the second detection device;

[0009] The analysis unit performs a joint analysis based on the switching time set, the first analysis data and the second analysis data.

[0010] In some embodiments, the step of switching the working state of the two mixing containers according to the change of the internal pressure of the first mixing container or the second mixing container comprises:

[0011] When negative pressure is generated inside the mixing container in the vacuum state, the working states of the first mixing container and the second mixing container are changed simultaneously.

[0012] In some embodiments, the step of the gas mixing device controlling the working states of the first mixing container and the second mixing container further comprises:

[0013] When the pressure inside the mixing container in the inflated state is not less than a preset pressure threshold, the subsequently received gas to be tested is vented.

[0014] In some embodiments, the gas mixing device includes an air inlet solenoid valve, an air outlet solenoid valve and a safety protection solenoid valve.

[0015] The first air inlet end of the air inlet solenoid valve is connected to the collection device, the first air outlet end is connected to the first mixing container, and the second air outlet end is connected to the second mixing container, wherein the first air inlet end is only in a conducting state with one of the first air outlet end and the second air outlet end at the same time;

[0016] The third air inlet end of the air outlet solenoid valve is connected to the first mixing container, the fourth air inlet end is connected to the second mixing container, and the third air outlet end is connected to the joint detection device, wherein at the same time, the third air outlet end is only in a conducting state with one of the third air inlet end and the fourth air inlet end;

[0017] The fifth air inlet end of the safety protection solenoid valve is connected to the collection device, the fifth air outlet end is not connected, and the sixth air outlet end is connected to the atmosphere;

[0018] The gas mixing device controls the air inlet solenoid valve, the air outlet solenoid valve and the safety protection solenoid valve through a preset control circuit, thereby controlling the working states of the first mixing container and the second mixing container.

[0019] In some embodiments, the control circuit comprises:

[0020] A negative pressure detection switch, a first end of which is connected to a first power source, and a second end of which is connected to a first end of the single-key bistable module, wherein the initial state of the negative pressure switch is an off state, and when a negative pressure signal of the first mixing container or the second mixing container is detected, the off state is converted to an on state, and then restored to the off state;

[0021] A single-button bistable module, a second end of which is connected to the first end of the air inlet solenoid valve and the first end of the air outlet solenoid valve, a third end of which is connected to the second power supply, and a fourth end of which is grounded, and the single-button bistable module is used to change the level of the output of the second end when the negative pressure detection switch is turned on;

[0022] an air intake solenoid valve, the second end of which is grounded, and is used to change the conduction state between the first air intake end and the first air outlet end, and between the first air intake end and the second air outlet end when a level change is detected;

[0023] an air outlet solenoid valve, the second end of which is grounded, and is used to change the conduction state between the third air outlet end and the third air inlet end, and between the third air outlet end and the fourth air inlet end when a level change is detected;

[0024] A positive pressure detection switch, wherein the first end is connected to a power supply, and the second end is connected to the first end of the safety protection solenoid valve. The initial state of the positive pressure switch is an off state. When a high-voltage signal from the first mixing container or the second mixing container is detected, the off state is converted to an on state; when no high-voltage signal from the first mixing container or the second mixing container is detected, the off state is converted to an on state.

[0025] A safety protection solenoid valve, the second end of which is grounded, is used to connect the fifth air inlet end and the sixth air outlet end to discharge excess gas to be tested when the positive pressure detection switch is in the on state; and to connect the fifth air inlet end and the fifth air outlet end to pump the gas to be tested into the first mixing container or the second mixing container when the positive pressure detection switch is in the off state.

[0026] In some embodiments, the first mixing container and the second mixing container are both bidirectional movable cylinders or gas collection bags.

[0027] In some embodiments, the first mixing container and the second mixing container are both fluorine membrane gas collection bags or filter gas collection bags.

[0028] In some embodiments, the first detection device is a chromatograph, the second detection device is a Raman laser gas analyzer, and both the first analysis data and the second analysis data are data with time tags.

[0029] In some embodiments, performing a joint analysis based on the switching time set, the first analysis data, and the second analysis data includes:

[0030] Matching the switching time set, the first analysis data, and the second analysis data to generate a matching data set, wherein the matching data set includes matching data pairs having the same number as the switching times in the switching time set, and each matching data pair includes a corresponding switching time, a first analysis data, a second analysis data, and a spectrum graph, wherein the spectrum graph is obtained by matching based on the second analysis data;

[0031] A joint analysis is performed based on the matched data sets.

[0032] In some embodiments, matching the switching time set, the first analysis data, and the second analysis data to generate a matching data set includes:

[0033] Obtain the earliest target switching time in the switching time set;

[0034] Filter out the first target data having the smallest switching time difference with the target from the first analysis data;

[0035] Filter out the second target data having the smallest time difference with the first target analysis data from the second analysis data, and find out the spectrum graph corresponding to the second target data;

[0036] generating a target matching data pair according to the target switching time, the first target data and the second target data, and adding the pair to the matching data set;

[0037] The switching time with the smallest time difference after the target switching time is determined as the target switching time of the current time, and the step of filtering out the first target data with the smallest time difference with the target switching time of the current time from the first analysis data is repeated until there is no switching time after the last target switching time.

[0038] In some embodiments, the collection device is provided with a wellhead buffer tank, a degasser, a drying and filtering device and an air pump, wherein:

[0039] The wellhead buffer tank is used for buffering and placing drilling fluid;

[0040] The degasser is connected to the wellhead buffer tank and is used to separate the original gas from the drilling fluid;

[0041] The drying and filtering equipment is connected to the degasser and is used to dry and filter the raw gas to obtain the gas to be tested;

[0042] The air pump is connected to the drying and filtering equipment and is used to pump the gas to be tested into the gas mixing device.

[0043] In some embodiments, the maximum volumes of the first mixing container and the second mixing container are the same, and the maximum volumes are not less than the maximum detection volume in the chromatograph or the Raman laser gas analyzer, and the detection volume is the sum of the gas volume used by the chromatograph or the Raman laser gas analyzer in an analysis cycle, and the volume of the ventilation path of the gas to be tested transmitted from the first mixing container or the second mixing container to the chromatograph or the Raman laser gas analyzer.

[0044] In some embodiments, in any time period during the operation, the volume of the gas to be measured transmitted by the collection device to the gas mixing device is the same as the volume of the gas to be measured transmitted by the gas mixing device to the joint detection device.

[0045] Beneficial Effects

[0046] Compared with the prior art, the beneficial effects of the embodiments of the present disclosure include at least: by providing a first mixing container and a second mixing container with variable volumes, and cyclically switching the working states of the two mixing containers according to the internal pressures of the first mixing container and the second mixing container, it is ensured that the composition and concentration of the gas to be tested received by the first detection device and the second detection device are the same, thereby greatly improving the accuracy of the detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0048] Figure 1 is a simple structural schematic diagram of a gas analysis system provided according to an embodiment of the present disclosure;

[0049] Figure 2 It is a simple structural schematic diagram of some embodiments of a gas mixing device of a gas analysis system provided according to an embodiment of the present disclosure;

[0050] Figure 3It is a schematic diagram of some embodiments of a control circuit of a gas analysis system provided according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0051] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0052] It should also be noted that, for ease of description, only the parts related to the present disclosure are shown in the drawings. In the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other.

[0053] It should be noted that the concepts such as "first" and "second" mentioned in the present disclosure are only used to distinguish different systems, devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these systems, devices, modules or units.

[0054] It should be noted that the modifications of "one" and "plurality" mentioned in the present disclosure are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0055] The names of messages or information exchanged between multiple devices or equipment in the embodiments of the present disclosure are only used for illustrative purposes and are not used to limit the scope of these messages or information.

[0056] The present disclosure will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0057] Please refer to Figure 1 , shows a simple structural schematic diagram of a gas analysis system of the present disclosure in some embodiments. The gas analysis system includes:

[0058] The collection device is used to continuously collect the gas to be tested that is released from the wellhead drilling fluid during oil and gas drilling and transmit it to the gas mixing device. The gas to be tested may refer to hydrocarbon and non-hydrocarbon gases released from the wellhead drilling fluid during oil and gas drilling.

[0059] In some embodiments, the collection device is provided with a wellhead buffer tank, a degasser, a drying and filtering device and an air pump, wherein:

[0060] The wellhead buffer tank is used for buffering and placing drilling fluid;

[0061] The degasser is connected to the wellhead buffer tank and is used to separate the original gas from the drilling fluid;

[0062] The drying and filtering equipment is connected to the degasser and is used to dry and filter the raw gas to obtain the gas to be tested;

[0063] The air pump is connected to the drying and filtering equipment and is used to pump the gas to be tested into the gas mixing device.

[0064] The gas mixing device connected to the collection device is provided with a first mixing container and a second mixing container with variable volumes. The gas mixing device switches the working states of the two mixing containers according to the changes in the internal pressure of the first mixing container or the second mixing container and records the switching time to generate a switching time set, wherein the working state includes an inflation state and a vacuum state, the inflation state indicates that the mixing container receives the gas to be tested, and the vacuum state indicates that the mixing container outputs the gas to be tested input therein to the joint detection device, wherein the working states of the first mixing container and the second mixing container are different at any time.

[0065] If the first mixing container and the second mixing container are containers of fixed volume, as the gas to be tested is input, the container will generate an increasingly greater pressure to produce an obstructive effect, making it increasingly difficult to input the gas to be tested, so that it is impossible to ensure the introduction of a sufficient amount of the gas to be tested. Therefore, it is necessary to select a container with a variable volume. Since the gas molecules move at a high speed and have a certain initial speed when input into the first mixing container or the second mixing container (for example, they can be pumped in by an air pump), the gas to be tested is considered to be uniformly mixed at the same time or within a short period of time when it is input into the first mixing container or the second mixing container.

[0066] The first mixing container and the second mixing container work alternately. As an example, when the working state of the first mixing container is the inflation state, it means that the gas to be tested input by the acquisition device is inflated into the first mixing container, and at the same time, the gas to be tested in the second mixing container is extracted to the joint detection device. Conversely, when the working state of the second mixing container is the inflation state, it means that the gas to be tested input by the acquisition device is inflated into the second mixing container, and at the same time, the gas to be tested in the first mixing container is extracted to the joint detection device. That is, the working states of the first mixing container and the second mixing container are different at any time.

[0067] When the gas in the mixing container in the evacuation state is extracted, its internal pressure gradually decreases, and when the gas is filled into the mixing container in the filling state, its internal pressure gradually increases. When the pressure inside the mixing container in the evacuation state is less than or equal to the set threshold, or the pressure inside the mixing container in the filling state is greater than or equal to the set threshold, the working states of the two mixing containers can be switched.

[0068] In some embodiments, when negative pressure is generated inside the mixing container in the evacuation state, the working states of the two mixing containers are switched. Negative pressure is generated inside the mixing container in the evacuation state, indicating that the gas residual amount inside is 0 or close to zero, which can be used as a trigger to switch the working states of the two mixing containers at the same time.

[0069] In some optional implementations of some embodiments, when the pressure inside the mixing container in the inflated state is not less than a preset pressure threshold, the gas to be tested received subsequently is emptied. The pressure threshold may refer to a preset high pressure limit value. When the pressure inside the mixing container in the inflated state is too high, and the mixing container in the evacuated state has not yet reached a negative pressure, if the inflation continues, the mixing container may be damaged. At this time, a pressure threshold may be set. When the pressure inside the mixing container in the inflated state is greater than the pressure threshold, the input gas to be tested is no longer received, and the gas to be tested is emptied to avoid damage to the mixing container. By venting the gas to be tested received subsequently when the pressure inside the mixing container is not less than the preset pressure threshold, the safety and stability of the system in long-term operation can be greatly improved.

[0070] In some embodiments, the first mixing container and the second mixing container can both be bidirectional movable cylinders or gas collection bags. In principle, both bidirectional movable cylinders and collection bags can meet the requirement of variable volume, but since the cylinder is heavy and the reciprocating motion of the piston in the cylinder requires lubrication of lubricating oil, the lubricating oil will enter the instrument with the gas and pollute the gas path of the equipment, so the collection bag is a better choice.

[0071] In some optional implementations of some embodiments, the first mixing container and the second mixing container are both fluorine membrane gas collection bags or filter gas collection bags. Fluorine membrane gas collection bags or filter gas collection bags are relatively cheap and meet the requirements of practicality, so they are the better choice.

[0072] A combined detection device connected to the gas mixing device comprises a gas distribution unit, a first detection device and a second detection device, wherein the first end of the gas distribution unit is connected to the gas mixing device, the second end is connected to the first detection device, and the third end is connected to the second detection device, and the gas distribution unit is used to receive the gas to be tested, and distribute the received gas to be tested to the first detection device and the second detection device according to a preset ratio for analysis, so as to obtain first analysis data corresponding to the first detection device and second analysis data corresponding to the second detection device.

[0073] Since the switching time is used as a reference point to match the data in the subsequent gas analysis, the time of each switching needs to be recorded. After recording the time of each switching, the switching time set can be obtained.

[0074] In some embodiments, the gas mixing device is provided with an IO module for recording a switching signal when the gas mixing device switches the mixing container. The IO module can transmit the recorded switching signal to a wired or wirelessly connected storage structure for subsequent analysis.

[0075] Since the first detection device and the second detection device are different devices, the amount of gas to be tested required is also inconsistent. Therefore, when allocating the two, the preset ratio can be set according to the ratio of the gas volume required by the two. The gas distribution unit may refer to a unit used to distribute different ratios or different quantities of gas to be tested to the first detection device and the second detection device. When distributing the gas to be tested, the gas to be tested can be divided into two parts according to the preset ratio and introduced into the first detection device and the second detection device respectively, and then analyzed. The first analysis data may refer to the data obtained by the first detection device based on the detection of the gas to be tested input therein. The second analysis data may refer to the data obtained by the second detection device based on the detection of the gas to be tested input therein.

[0076] In some embodiments, the first detection device may be a chromatograph, the second detection device may be a Raman laser gas analyzer, and the first analysis data and the second analysis data are both data with time tags. Since subsequent analysis requires summarizing and analyzing the first analysis data and the second analysis data, the first analysis data and the second analysis data must be provided with time tags.

[0077] The analysis unit performs a joint analysis based on the switching time set, the first analysis data and the second analysis data.

[0078] The analysis unit may refer to a unit with computing functions, which may be a computing device connected to a field device, a computing device based on a wired or wireless network connection, a wirelessly connected cloud computing center, or other types of units with computing functions, and no specific restrictions are made here.

[0079] In some embodiments, the joint analysis based on the switching time set, the first analysis data and the second analysis data includes: matching the switching time set, the first analysis data and the second analysis data to generate a matching data set, wherein the matching data set includes the same number of matching data pairs as the switching time in the switching time set, each matching data pair includes the corresponding switching time, the first analysis data, the second analysis data and the spectrum, wherein the spectrum is obtained based on the matching of the second analysis data; and performing a joint analysis based on the matching data set. The spectrum is a commonly used data spectrum involved in the Raman instrument analysis process, which will not be described in detail here.

[0080] In some optional implementations of some embodiments, the switching time set, the first analysis data and the second analysis data are matched to generate a matching data set, including: obtaining the earliest target switching time in the switching time set; filtering out the first target data with the smallest time difference with the target switching time from the first analysis data; filtering out the second target data with the smallest time difference with the first target analysis data from the second analysis data, and finding the spectrum corresponding to the second target data; generating a target matching data pair according to the target switching time, the first target data and the second target data, and adding it to the matching data set; determining the switching time with the smallest time difference after the target switching time as the target switching time of the current time, and repeating the step of filtering out the first target data with the smallest time difference with the target switching time of the current time from the first analysis data until there is no switching time after the last target switching time.

[0081] As a specific example, the interval for saving a piece of data of the first target analysis data obtained by the chromatograph analysis can be 90 seconds, and the interval for saving a piece of data of the second target analysis data obtained by the Raman instrument analysis can be 6 seconds. Assume that the starting time is 0 seconds, the first switching time is 166 seconds, and the second switching time is 338 seconds. First, taking the 166th second as the benchmark, the first target analysis data closest to 166 seconds is the first target analysis data of the 180th second; the second target analysis data closest to 180 seconds is the second target analysis data of the 180th second, and then obtaining the spectrum corresponding to the second target analysis data of the 180th second, then the matching data pair corresponding to the 166th second can be obtained. Then, taking the 338th second as the benchmark, the first target analysis data closest to 338 seconds is the first target analysis data of the 360th second; the second target analysis data closest to 360 seconds is the second target analysis data of the 360th second, and then obtaining the spectrum corresponding to the second target analysis data of the 360th second, then the matching data pair corresponding to the 338th second can be obtained. By analogy, a matching data pair corresponding to each switching time can be obtained, and then the matching data set can be obtained for subsequent analysis.

[0082] When analyzing the gas to be tested, a large amount of spectral data is required to provide data support for the optimization and improvement of the Raman instrument spectrum analysis model. Since the Raman spectrum peak is easily disturbed by noise, background and overlapping of the spectrum peaks of each component, the spectrum generated by the mixed gas with different concentration ratios is very complex. It is difficult to quantitatively calculate the concentration value through the traditional peak height and peak area calibration technology. It is necessary to use artificial intelligence algorithms to establish a streamlined and reliable Raman spectrum qualitative and quantitative model, and use spectral analysis algorithms and data analysis methods to ensure the accuracy of the spectrum analysis results. The improvement of the model algorithm requires the acquisition of a large number of known detection gas components and corresponding spectral data. Laboratory sampling not only does not conform to the characteristics of continuous changes in on-site gas samples, but also requires a large amount of C1-C5 standard gases. Through the technical solution disclosed in this disclosure, the spectrum and detection data of various gases can be collected on-site in different oil and gas blocks for spectrum analysis, which greatly saves the cost of purchasing gas samples.

[0083] The beneficial effects of one of the above-mentioned embodiments of the present disclosure include at least: by setting a first mixing container and a second mixing container with variable volumes, and cyclically switching the working states of the two mixing containers according to the internal pressure of the first mixing container and the second mixing container, it is ensured that the composition and concentration of the sample gas entering the chromatograph and the Raman instrument at the same time during the field test are completely consistent, so that the chromatographic measurement value can be used as the true value to calibrate various indicators of the Raman instrument, thereby greatly improving the accuracy of the Raman instrument detection results.

[0084] Please refer to Figure 2 , shows a simple structural diagram of the gas mixing device. The gas mixing device includes an air inlet solenoid valve, an air outlet solenoid valve and a safety protection solenoid valve, wherein:

[0085] The first air inlet end of the air inlet solenoid valve is connected to the collection device, the first air outlet end is connected to the first mixing container, and the second air outlet end is connected to the second mixing container, wherein at the same time, the first air inlet end is only in a conducting state with one of the first air outlet end and the second air outlet end.

[0086] The third air inlet end of the air outlet solenoid valve is connected to the first mixing container, the fourth air inlet end is connected to the second mixing container, and the third air outlet end is connected to the joint detection device, wherein at the same time, the third air outlet end is only in a conductive state with one of the third air inlet end and the fourth air inlet end.

[0087] The fifth air inlet end of the safety protection solenoid valve is connected to the collection device, the fifth air outlet end is not connected, and the sixth air outlet end is connected to the atmosphere.

[0088] The gas mixing device controls the air inlet solenoid valve, the air outlet solenoid valve and the safety protection solenoid valve through a preset control circuit, thereby controlling the working states of the first mixing container and the second mixing container.

[0089] Continue to refer Figure 3 , shows a simple circuit diagram of the above control circuit. The control circuit includes:

[0090] A negative pressure detection switch, wherein the first end is connected to the first power supply, and the second end is connected to the first end of the single-key bistable module. The initial state of the negative pressure switch is the off state. When a negative pressure signal of the first mixing container or the second mixing container is detected, the off state is converted to the on state, and then restored to the off state.

[0091] A single-button bistable module with its own power supply has a second end connected to the first end of the air inlet solenoid valve and the first end of the air outlet solenoid valve, a third end connected to the second power supply, and a fourth end grounded. The single-button bistable module is used to change the level of the second end output when the negative pressure detection switch is turned on. It should be pointed out that the power supply of the single-button bistable module can be a power supply outside the circuit (not shown in the circuit diagram), or it can be a self-contained power supply unit, and no specific limitation is made here.

[0092] The single-button bistable module is used to provide a signal when detecting that the negative pressure detection switch is turned on, and change the output level value, for example, changing the previously maintained high level to a low level and maintaining it, or changing the previously maintained low level to a high level and maintaining it.

[0093] The air inlet solenoid valve has a second end connected to the ground, and is used to change the conduction state between the first air inlet end and the first air outlet end, and between the first air inlet end and the second air outlet end when a level change is detected. That is, when a level change is detected, the original conduction between the first air inlet end and the first air outlet end is changed to the conduction between the first air inlet end and the second air outlet end, or the original conduction between the first air inlet end and the second air outlet end is changed to the conduction between the first air inlet end and the first air outlet end.

[0094] The second end of the air outlet solenoid valve is grounded, and is used to change the conduction state between the third air outlet end and the third air inlet end, and between the third air outlet end and the fourth air inlet end when a level change is detected. Similar to the air inlet solenoid valve, no further details are given here.

[0095] A positive pressure detection switch, whose first end is connected to a power source, and whose second end is connected to a first end of the safety protection solenoid valve. The positive pressure switch is initially in an off state. When a high-voltage signal of the first mixing container or the second mixing container is detected, the off state is converted to an on state; when no high-voltage signal of the first mixing container or the second mixing container is detected, the on state is converted to an off state. It should be noted that the high-voltage signal can be a continuous signal.

[0096] The safety protection solenoid valve, whose second end is grounded, is used to connect the fifth air inlet end and the sixth air outlet end to discharge the excess gas to be tested when the positive pressure detection switch is in the on state; when the positive pressure detection switch is in the off state, connect the fifth air inlet end and the fifth air outlet end to pump the gas to be tested into the first mixing container or the second mixing container. When the positive pressure detection switch is in the off state, the fifth air inlet end and the fifth air outlet end are in the on state, that is, the gas to be tested introduced by the collection device cannot pass through here and is all input into the gas mixing device. On the contrary, when the positive pressure detection switch is in the on state, the fifth air inlet end and the sixth air outlet end are in the on state, indicating that the air pressure in one of the mixing containers in the gas mixing device is higher at this time, and the gas to be tested transmitted by the collection device is discharged through the sixth air outlet end to prevent damage to the mixing container.

[0097] The beneficial effects of one of the above-mentioned embodiments of the present disclosure include at least: through the setting of the above-mentioned gas mixing device, a high degree of automation is achieved, so that the gas mixing device can operate stably and continuously for a long time. Through the automatic monitoring and control of the pressure of the sample gas sample bag, the automatic switching of the sample gas pumping in, pumping out and sampling cycle is realized to ensure the consistency of the sample gas volume in each sampling cycle. After the device is installed and debugged, it automatically switches and controls according to the gas bag pressure and gas volume, alternately changes the air intake and exhaust modes of the two gas sample bags, and continuously collects the sample gas from the wellhead in sections according to the time interval, without manual operation and on-duty, reducing labor and maintenance costs.

[0098] The above descriptions are only some preferred embodiments of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present disclosure is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the above-mentioned inventive concept. For example, the above-mentioned features are replaced with the technical features with similar functions disclosed in the embodiments of the present disclosure (but not limited to) and the technical solutions formed.

Claims

1. A gas analysis system, characterized in that: include: It includes a collection device for continuously collecting the gas to be tested which is released from the drilling fluid at the wellhead during oil and gas drilling and transmitting it to the gas mixing device; A gas mixing device connected to the acquisition device is provided with a first mixing container and a second mixing container with variable volumes. The gas mixing device switches the working states of the two mixing containers according to the change of the internal pressure of the first mixing container or the second mixing container and records the switching time to generate a switching time set, wherein the working state includes an inflation state and a degassing state, the inflation state indicates that the mixing container receives the gas to be tested, and the degassing state indicates that the mixing container outputs the gas to be tested input therein to the joint detection device, wherein the working states of the first mixing container and the second mixing container are different at any time; A combined detection device connected to the gas mixing device, comprising a gas distribution unit, a first detection device, and a second detection device, wherein a first end of the gas distribution unit is connected to the gas mixing device, a second end is connected to the first detection device, and a third end is connected to the second detection device, and the gas distribution unit is used to receive the gas to be tested, and distribute the received gas to be tested to the first detection device and the second detection device according to a preset ratio for analysis, so as to obtain first analysis data corresponding to the first detection device and second analysis data corresponding to the second detection device; The analysis unit performs a joint analysis based on the switching time set, the first analysis data and the second analysis data.

2. The system according to claim 1, characterized in that The step of switching the working state of the two mixing containers according to the change of the internal pressure of the first mixing container or the second mixing container comprises: When negative pressure is generated inside the mixing container in the vacuum state, the working states of the two mixing containers are switched.

3. The system according to claim 2, characterized in that The steps also include: When the pressure inside the mixing container in the inflated state is not less than a preset pressure threshold, the subsequently received gas to be tested is vented.

4. The system according to claim 3, characterized in that The gas mixing device includes an air inlet solenoid valve, an air outlet solenoid valve and a safety protection solenoid valve. The first air inlet end of the air inlet solenoid valve is connected to the collection device, the first air outlet end is connected to the first mixing container, and the second air outlet end is connected to the second mixing container, wherein the first air inlet end is only in a conducting state with one of the first air outlet end and the second air outlet end at the same time; The third air inlet end of the air outlet solenoid valve is connected to the first mixing container, the fourth air inlet end is connected to the second mixing container, and the third air outlet end is connected to the joint detection device, wherein at the same time, the third air outlet end is only in a conducting state with one of the third air inlet end and the fourth air inlet end; The fifth air inlet end of the safety protection solenoid valve is connected to the collection device, the fifth air outlet end is not connected, and the sixth air outlet end is connected to the atmosphere; The gas mixing device controls the air inlet solenoid valve, the air outlet solenoid valve and the safety protection solenoid valve through a preset control circuit, thereby controlling the working states of the first mixing container and the second mixing container.

5. The system according to claim 4, characterized in that The control circuit comprises: A negative pressure detection switch, a first end of which is connected to a first power source, and a second end of which is connected to a first end of the single-key bistable module, wherein the initial state of the negative pressure switch is an off state, and when a negative pressure signal of the first mixing container or the second mixing container is detected, the off state is converted to an on state, and then restored to the off state; A single-button bistable module with its own power supply, the second end of which is connected to the first end of the air inlet solenoid valve and the first end of the air outlet solenoid valve, the third end is connected to the second power supply, and the fourth end is grounded, and the single-button bistable module is used to change the level of the second end output when the negative pressure detection switch is turned on; an air intake solenoid valve, the second end of which is grounded, and is used to change the conduction state between the first air intake end and the first air outlet end, and between the first air intake end and the second air outlet end when a level change is detected; an air outlet solenoid valve, the second end of which is grounded, and is used to change the conduction state between the third air outlet end and the third air inlet end, and between the third air outlet end and the fourth air inlet end when a level change is detected; A positive pressure detection switch, wherein the first end is connected to the power supply, and the second end is connected to the first end of the safety protection solenoid valve. The initial state of the positive pressure switch is an off state. When a high-voltage signal of the first mixing container or the second mixing container is detected, the off state is converted to an on state; when no high-voltage signal of the first mixing container or the second mixing container is detected, the on state is converted to an off state; A safety protection solenoid valve, the second end of which is grounded, is used to connect the fifth air inlet end and the sixth air outlet end to discharge excess gas to be tested when the positive pressure detection switch is in the on state; and to connect the fifth air inlet end and the fifth air outlet end to pump the gas to be tested into the first mixing container or the second mixing container when the positive pressure detection switch is in the off state.

6. The system according to any one of claims 1 to 5, characterized in that: The first mixing container and the second mixing container are both bidirectional movable cylinders or gas collection bags.

7. The system according to claim 6, characterized in that The first mixing container and the second mixing container are both fluorine membrane gas collection bags or filter gas collection bags.

8. The system according to claim 6, characterized in that The first detection device is a chromatograph, the second detection device is a Raman laser gas analyzer, and both the first analysis data and the second analysis data are data with time tags.

9. The system according to claim 8, characterized in that The performing joint analysis according to the switching time set, the first analysis data and the second analysis data includes: Matching the switching time set, the first analysis data, and the second analysis data to generate a matching data set, wherein the matching data set includes matching data pairs having the same number as the switching times in the switching time set, and each matching data pair includes a corresponding switching time, a first analysis data, a second analysis data, and a spectrum graph, wherein the spectrum graph is obtained by matching based on the second analysis data; A joint analysis is performed based on the matched data sets.

10. The system according to claim 9, characterized in that The step of matching the switching time set, the first analysis data, and the second analysis data to generate a matching data set includes: Obtain the earliest target switching time in the switching time set; Filter out the first target data having the smallest switching time difference with the target from the first analysis data; Filter out the second target data having the smallest time difference with the first target analysis data from the second analysis data, and find out the spectrum graph corresponding to the second target data; generating a target matching data pair according to the target switching time, the first target data and the second target data, and adding the pair to the matching data set; The switching time with the smallest time difference after the target switching time is determined as the target switching time of the current time, and the step of filtering out the first target data with the smallest time difference with the target switching time of the current time from the first analysis data is repeated until there is no switching time after the last target switching time.

11. The system according to claim 1, characterized in that The collection device is provided with a wellhead buffer tank, a degasser, a drying and filtering device and an air pump, wherein: The wellhead buffer tank is used for buffering and placing drilling fluid; The degasser is connected to the wellhead buffer tank and is used to separate the original gas from the drilling fluid; The drying and filtering equipment is connected to the degasser and is used to dry and filter the raw gas to obtain the gas to be tested; The air pump is connected to the drying and filtering equipment and is used to pump the gas to be tested into the gas mixing device.

12. The system according to claim 8, characterized in that The maximum volumes of the first mixing container and the second mixing container are the same, and the maximum volumes are not less than the maximum detection volume of the chromatograph or the Raman laser gas analyzer, and the detection volume is the sum of the gas volume used by the chromatograph or the Raman laser gas analyzer in an analysis cycle, and the volume of the ventilation path of the gas to be tested transmitted from the first mixing container or the second mixing container to the chromatograph or the Raman laser gas analyzer.

13. The system according to claim 12, characterized in that In any time period during the operation, the volume of the gas to be measured transmitted from the collection device to the gas mixing device is the same as the volume of the gas to be measured transmitted from the gas mixing device to the combined detection device.

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