Intelligent degassing system and method for drilling fluid

Abstract

The application discloses an intelligent degassing system and method for drilling fluid, and relates to the field of degassing of drilling fluid, and is applied to mud degassing. The system comprises an electrical control system and a degasser. The electrical control system collects state data acquired by sensors arranged on a path of mud flow or / and equipment flowed through, or / and collects state data in a drilling control system, and controls opening and closing of the degasser according to the state data. The method is to arrange sensors on the path of mud flow or / and equipment flowed through, acquire state data detected by the sensors or / and acquire state data in the drilling control system, and control opening and closing of the degasser according to the state data. The application automatically controls opening and closing of the degasser by monitoring state data of gas and the like in mud or equipment flowed through by mud and making analysis, so that the purpose of discovering gas invasion as early as possible and timely opening the degasser is achieved, unmanned operation of the degasser is realized, and over-opening of the degasser is avoided.

Description

Technical Field

[0001] This invention relates to the field of drilling fluid degassing, and in particular to an intelligent degassing system and method for drilling fluid. Background Technology

[0002] Gas intrusion is one of the main causes of well control accidents. It reduces drilling fluid density and alters its properties, thus affecting drilling safety and efficiency. If gas intrusion is not controlled in time, the gaseous drilling fluid entering subsequent processing will deteriorate its properties and cause wellbore problems. Furthermore, the presence of acidic gases lowers the pH value of the drilling fluid, reducing the lifespan of subsequent equipment. Gas-intruded drilling fluid can also interfere with drilling monitoring, distorting logging data and delaying well control measures. In severe cases, gas intrusion can rapidly escalate into a blowout. Therefore, early detection, early treatment, and early prevention are crucial for gas intrusion.

[0003] A degasser is a specialized device used to treat gas-infiltrated drilling fluid. It has high degassing efficiency, can remove a large amount of gas from the drilling fluid, restore the specific gravity of the drilling fluid, stabilize its viscosity, and effectively prevent well blowouts and well kicks, thereby reducing drilling costs and improving drilling safety.

[0004] Currently, the decision to activate the degasser during drilling largely relies on manual judgment. The degasser and degasser supply pump are manually activated. While this method eliminates the need for technical logic, it is time-consuming, labor-intensive, requires dedicated personnel for monitoring, and involves high labor intensity. Furthermore, the effectiveness depends on the skill level of the personnel; insufficient experience may lead to low degassing efficiency or energy waste. More importantly, relying solely on manual judgment cannot respond to changes in operating conditions in real time, resulting in delayed processing. In emergencies, the degasser cannot be activated immediately for degassing, which can severely delay the handling of well control accidents and create safety hazards. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems by providing an intelligent degassing system and method for drilling fluid. This system automatically controls the start and stop of the degasser by monitoring and analyzing the state data of the drilling mud or the gas it passes through online. This allows for early detection of gas intrusion and timely activation of the degasser, reducing manual reaction time, improving the degasser's efficiency, enabling unmanned operation of the degasser, and preventing over-activation of the degasser, thus reducing energy waste.

[0006] The technical solution adopted in this invention is as follows: an intelligent degassing system for drilling fluid, applied to mud degassing, including an electrical control system and a degasser, wherein the electrical control system collects status data obtained by sensors arranged on the path of mud flow and / or on the equipment through which the mud flows, and / or collects status data in the drilling control system, and controls the opening and closing of the degasser according to the status data.

[0007] Furthermore, it also includes an aerated mud chamber with a mud inlet for communication with the wellhead, the mud outlet of the aerated mud chamber being connected to the inlet of a deaerator, the outlet of the deaerator being connected to the inlet of a jet pipeline, the outlet of the jet pipeline being connected to a discharge pipeline, the inlet of the discharge pipeline being connected to the outlet of the deaerated mud chamber via a centrifugal pump, and the outlet of the discharge pipeline being connected to the inlet of the deaerated mud chamber; wherein: the connection position between the jet pipeline and the discharge pipeline exhibits a Venturi effect.

[0008] Furthermore, it also has a mud pump suction chamber, the inlet of which is connected to the outlet of the degassed mud chamber, and the outlet of the mud pump suction chamber is used to connect to the mud pump.

[0009] Furthermore, the electrical control system includes multiple sensors and a control assembly. The multiple sensors are connected to the signal input terminals of the control assembly, and the output terminals of the control assembly are connected to the degasser and the centrifugal pump. The multiple sensors include at least a first density sensor, a second density sensor, a third density sensor, and a fourth density sensor; wherein: The first density sensor is installed at the mud inlet of the gas-bearing mud chamber or at the wellhead to detect the density of the mud flowing out of the wellhead. The second density sensor is installed inside the aerated mud chamber to detect the density of the mud inside the chamber. The third density sensor is installed in the deaerated mud chamber to detect the density of the mud in the deaerated mud chamber. The fourth density sensor is installed inside the mud pump suction chamber to detect the density of the mud entering the wellhead.

[0010] Furthermore, the electrical control system includes a gas detector and a control assembly. The gas detector is installed inside the distribution box to obtain the gas concentration inside the distribution box. The gas detector is connected to the signal input terminal of the control assembly, and the output terminal of the control assembly is connected to the degasser and the centrifugal pump.

[0011] Furthermore, the electrical control system includes a drilling data system and a control assembly. The drilling data system is connected to the signal input terminal of the control assembly, and the output terminal of the control assembly is connected to the degasser and the centrifugal pump.

[0012] Furthermore, the electrical control system includes a first pressure sensor, which is installed on the liquid-gas separator to obtain the gas pressure inside the liquid-gas separator; the first pressure sensor is connected to the signal input terminal of the control assembly, and the output terminal of the control assembly is connected to the degasser and the centrifugal pump.

[0013] Furthermore, it also has a second pressure sensor, which is installed at the outlet of the centrifugal pump to obtain the output pressure of the centrifugal pump.

[0014] A smart degassing method for drilling fluid involves installing sensors along the path of the mud flow and / or on the equipment through which it flows, acquiring state data detected by the sensors and / or acquiring state data from the drilling control system, and controlling the opening and closing of the degasser based on the state data.

[0015] Furthermore, the intelligent degassing system for the drilling fluid includes any one or more of the following steps S1, S2, S3, and S4, wherein: S1: Includes steps S11-S15; S11: The control assembly acquires data ρ1 from the first density sensor, data ρ2 from the second density sensor, data ρ3 from the third density sensor, and data ρ4 from the fourth density sensor; and the control assembly, using ρ1 and ρ4 as inputs, outputs the theoretical density value ρ0 through the data model built into the control assembly. S12: The control assembly determines the relationship between ρ1 and ρ4; if ρ1 < ρ4, the drilling operation is abnormal, an alarm is triggered, and a process check is performed; if ρ1 ≥ ρ4, the drilling operation is normal, and the control assembly does not issue any action commands. S13: The control assembly determines the magnitude relationship between ρ0 and ρ2; If ρ0≤ρ2, the control assembly acquires the status of the degasser and centrifugal pump; if they are in the working state, the control assembly controls the degasser and centrifugal pump to shut down, switching to the non-working state; if they are in the non-working state, the control assembly does not issue any action commands. If ρ0 > ρ2, the control assembly issues a command to start the degasser and centrifugal pump, and the degasser and centrifugal pump start and enter the working state. S14: When the degasser and centrifugal pump are started and put into working state in step S13, the control assembly acquires the data P2 of the second pressure sensor and determines whether the data of P2 is normal. If the P2 data is normal, the control assembly will not issue action commands to the degasser or centrifugal pump, and the degasser and centrifugal pump will remain in working condition. If the P2 data is abnormal, the control assembly will shut down the degasser and centrifugal pump, and issue a centrifugal pump fault alarm. S15: In step S14, after the degasser and centrifugal pump have been in operation for a set time, the control assembly determines whether ρ2 and ρ3 have decreased. If so, the control assembly will not issue action commands to the degasser or centrifugal pump, and the degasser and centrifugal pump will remain in operation. If not, the control assembly shuts down the degasser and centrifugal pump and issues an alarm. S2: Includes steps S21-S22; S21: The control assembly acquires data c from the gas detector and determines whether data c has increased; If no increase occurs, the control assembly obtains the status of the degasser and centrifugal pump; if they are in the working state, the control assembly controls the degasser and centrifugal pump to shut down, switching to the non-working state; if they are in the non-working state, the control assembly does not issue any action commands. If an increase occurs, the control assembly issues a command to start the degasser and centrifugal pump, and the degasser and centrifugal pump start and enter the working state. S22: When the degasser and centrifugal pump are started and put into working state in step S21, the control assembly acquires the data P2 from the second pressure sensor and determines whether the data of P2 is normal. If the P2 data is normal, the control assembly will not issue action commands to the degasser or centrifugal pump, and the degasser and centrifugal pump will remain in working condition. If the P2 data is abnormal, the control assembly will shut down the degasser and centrifugal pump, and issue a centrifugal pump fault alarm. S3: Includes steps S31-S32; S31: The control assembly acquires logging data from the drilling data system and determines whether a permeable layer exists; If there is no permeable layer, the control assembly obtains the status of the degasser and centrifugal pump; if they are in the working state, the control assembly controls the degasser and centrifugal pump to shut down, changing to the non-working state; if they are in the non-working state, the control assembly does not issue any action commands. If a permeable layer exists, the control assembly issues a command to start the degasser and centrifugal pump, and the degasser and centrifugal pump start and enter the working state. S32: When the degasser and centrifugal pump are started and put into working state in step S31, the control assembly acquires the data P2 of the second pressure sensor and determines whether the data of P2 is normal. If the P2 data is normal, the control assembly will not issue action commands to the degasser or centrifugal pump, and the degasser and centrifugal pump will remain in working condition. If the P2 data is abnormal, the control assembly will shut down the degasser and centrifugal pump, and issue a centrifugal pump fault alarm. S4: Includes steps S41-S42; S41: The control assembly acquires data P1 from the first pressure sensor and determines whether data P1 has increased; If no increase occurs, the control assembly obtains the status of the degasser and centrifugal pump; if they are in the working state, the control assembly controls the degasser and centrifugal pump to shut down, switching to the non-working state; if they are in the non-working state, the control assembly does not issue any action commands. If an increase occurs, the control assembly issues a command to start the degasser and centrifugal pump, and the degasser and centrifugal pump start and enter the working state. S42: When the degasser and centrifugal pump are started and put into working state in step S41, the control assembly acquires the data P2 of the second pressure sensor and determines whether the data of P2 is normal. If the P2 data is normal, the control assembly will not issue action commands to the degasser or centrifugal pump, and the degasser and centrifugal pump will remain in working condition. If the P2 data is abnormal, the control assembly will shut down the degasser and centrifugal pump, and issue a centrifugal pump fault alarm.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: This invention automatically controls the start and stop of the degasser by monitoring and analyzing the state data of mud (actually drilling fluid) or gas in the equipment through which mud (actually drilling fluid) passes, so as to detect gas intrusion as early as possible and start the degasser in time, reduce manual reaction time, improve the working efficiency of the degasser, realize unmanned operation of the degasser, and avoid over-opening of the degasser, thus reducing energy waste. Attached Figure Description

[0017] The present invention will be described by way of example and with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram showing all implementation methods of an intelligent degassing system; Figure 2 This is a schematic diagram of the first implementation of an intelligent degassing system; Figure 3 This is a schematic diagram of a second implementation of the intelligent degassing system; Figure 4 This is a schematic diagram of the third implementation of the intelligent degassing system; Figure 5 This is a schematic diagram of the fourth implementation method of the intelligent degassing system; Figure 6 The flowchart for step S1 of the intelligent degassing method; Figure 7 The flowchart for step S2 of the intelligent degassing method; Figure 8 The flowchart for step S3 of the intelligent degassing method; Figure 9 The flowchart for step S4 of the intelligent degassing method; The diagram is labeled as follows: 1-Degasser; 11-Jet line; 3-Gas-bearing mud chamber; 4-Degassed mud chamber; 5-Mud pump suction chamber; 6-Centrifugal pump; 61-Electric butterfly valve; 62-Discharge line; 7-Control assembly; 71-Data acquisition unit; 72-Data processor; 73-Controller; 8-Liquid-gas separator; 9-Wellhead; 101-First density sensor; 102-Second density sensor; 103-Third density sensor; 104-Fourth density sensor; 105-Second pressure sensor; 106-Gas detector; 107-Drilling data system; 108-First pressure sensor. Detailed Implementation

[0018] In the description of this specification, it should also be noted that, unless otherwise expressly specified and limited, the terms “set up,” “install,” “connect,” and “link” should be interpreted broadly. For example, a link can be a fixed link, a detachable link, or an integral link; it can be a mechanical link or an electrical link; it can be a direct link or an indirect link through an intermediate medium; it can be a connection within two components.

[0019] Example 1 like Figures 1-5 As shown, an intelligent degassing system for drilling fluid is applied to mud degassing, where mud is drilling fluid. The system includes an electrical control system and a degasser 1. The electrical control system collects status data from sensors arranged along the mud flow path and / or on the equipment through which the mud flows, and / or collects status data from the drilling control system, and controls the opening and closing of the degasser 1 based on the status data.

[0020] In this embodiment, the status data can be one or more of the following: mud density at various locations, gas concentration in the diversion box, and gas pressure in the liquid-gas separator 8. It can also be logging data from the drilling control system. By monitoring and analyzing the status data online in real time, the start and stop of the degasser 1 can be automatically controlled. This achieves the goal of detecting gas intrusion as early as possible and starting the degasser 1 in a timely manner, reducing manual reaction time, improving the working efficiency of the degasser 1, realizing unmanned operation of the degasser 1, and avoiding over-opening of the degasser 1 to reduce energy waste.

[0021] Example 2 Based on Example 1, further feasible implementation methods are proposed.

[0022] One feasible implementation further includes an aerated mud chamber 3 with a mud inlet connected to the wellhead 9. The mud outlet of the aerated mud chamber 3 is connected to the inlet of the deaerator 1. The outlet of the deaerator 1 is connected to the inlet of the jet line 11. The outlet of the jet line 11 is connected to the discharge line 62. The inlet of the discharge line 62 is connected to the outlet of the deaerated mud chamber 4 via a centrifugal pump 6. The outlet of the discharge line 62 is connected to the inlet of the deaerated mud chamber 4. The connection between the jet line 11 and the discharge line 62 has a Venturi effect, that is, a narrowing section is provided on the discharge line 62. The flow cross-sectional area of ​​the narrowing section is smaller than the flow cross-sectional area at other locations on the discharge line 62. The jet line 11 is connected to the narrowing section.

[0023] In this embodiment, the mud in the wellhead 9 flows into the aerated mud chamber 3 for buffering; the centrifugal pump 6 serves as the power equipment for conveying the mud. When degassing of the mud is required, the centrifugal pump 6 and the degasser 1 are turned on. The centrifugal pump 6 draws degassed mud from the degassed mud chamber 4 and circulates it to the inlet of the degassed mud chamber 4. During this circulation process, the discharge pipeline 62 has a narrowing section, which can increase the flow rate of the mud, thereby creating low pressure. The aerated mud is further drawn from the aerated mud chamber 3 through the degasser 1. The aerated mud enters the degasser 1 for degassing, enters the discharge pipeline 62 through the jet pipe and merges with the degassed mud, and together they enter the degassed mud chamber 4.

[0024] This setting enables thorough mixing of the previously deaerated mud with the currently deaerated mud, preventing density gradations in the mud in the deaerated mud chamber 4 and improving the accuracy of subsequent density acquisition of the mud in the chamber.

[0025] Furthermore, an electric butterfly valve 61 is installed at the inlet and outlet of the centrifugal pump 6. The electric butterfly valve 61 is connected to the electrical control system, so that the opening and closing of the electric butterfly valve 61 can be controlled by the electrical control system to ensure the stability of mud flow or obstruction.

[0026] Furthermore, the equipment for transporting the degassed mud to the wellhead 9 is a mud pump. The mud pump can directly draw mud from the degassed mud chamber 4, but this can easily interfere with the normal circulation of the mud. Moreover, under normal circumstances, the degassed mud needs to be replenished with chemicals before it can be transported to the wellhead 9. However, it is difficult to directly replenish chemicals in the degassed mud chamber 4, and the amount of chemicals replenished is not easy to control (because mud is continuously added during degassed processes). Therefore, a mud pump suction chamber 5 is also provided. The inlet of the mud pump suction chamber 5 is connected to the outlet of the degassed mud chamber 4 through a series of pipes or intermediate equipment, and the outlet of the mud pump suction chamber 5 is used to connect to the mud pump. This allows the storage of mud sent into the wellhead 9 and the storage of degassed mud to be independent of each other.

[0027] Example 3 Based on any of the implementation methods in Example 2, a further implementation method for the "electrical control system" is proposed.

[0028] The first implementation method, such as Figure 2 As shown, the electrical control system includes multiple sensors and a control assembly 7. The multiple sensors are connected to the signal input terminals of the control assembly 7, and the output terminals of the control assembly 7 are connected to the degasser 1, the centrifugal pump 6, and the electric butterfly valve 61. The multiple sensors include at least a first density sensor 101, a second density sensor 102, a third density sensor 103, and a fourth density sensor 104. The first density sensor 101 is installed at the mud inlet of the gas-bearing mud chamber 3 or at the wellhead 9 to detect the density of the mud flowing out of the wellhead 9. The second density sensor 102 is installed inside the aerated mud chamber 3 to detect the density of the mud inside the aerated mud chamber 3. The third density sensor 103 is installed in the deaerated mud chamber 4 to detect the density of the mud in the deaerated mud chamber 4. The fourth density sensor 104 is installed inside the mud pump suction chamber 5 to detect the density of the mud entering the wellhead 9.

[0029] In this embodiment, the determination of whether to activate the degasser 1 and centrifugal pump 6, and the assessment of the internal working conditions of the wellhead 9 are made by acquiring the density of the mud at different locations. The specific control method is described in step S1 of the intelligent degassing method described later, and will not be detailed here. It should be noted that in this embodiment, to acquire the density of the mud flowing out of the wellhead 9, the first density sensor 101 can be installed inside the overflow chamber connected to the overflow pipe of the wellhead 9, or it can be directly installed on the overflow pipe of the wellhead 9. The mud density data is monitored in real time by setting up a first density sensor 101, a second density sensor 102, a third density sensor 103, and a fourth density sensor 104. The control assembly 7 has a built-in data model, which is established based on parameters such as well depth, rock formation conditions, and screen mesh size. Taking the density data obtained by the first density sensor 101 and the fourth density sensor 104 as input, the theoretical density of the mud is output. This theoretical density is used as a comparison value and compared with the density values ​​obtained by the second density sensor 102 and the third density sensor 103 in real time. Based on the comparison, corresponding control commands are sent to control the opening and closing of the degasser 1, the centrifugal pump 6, and the electric butterfly valve 61, thereby realizing unmanned operation.

[0030] It should be noted that the theoretical density obtained by using the density data acquired by the first density sensor 101 and the fourth density sensor 104 as input is closer to the density of the mud at the bottom of the wellbore, and the prediction accuracy is more accurate.

[0031] In this embodiment, based on emergency situations, the mud flowing out of the wellhead 9 flows into the gas-bearing mud chamber 3 mentioned above after passing through the blowout preventer, choke and kill manifold, liquid-gas separator 8, diversion box and vibrating screen. Thus, the following redundant control methods can be proposed.

[0032] The second implementation method, such as Figure 3 As shown, the electrical control system includes a gas detector 106 and a control assembly 7. The gas detector 106 is installed inside the distribution box to obtain the gas concentration inside the distribution box. The gas detector 106 is connected to the signal input terminal of the control assembly 7, and the output terminal of the control assembly 7 is connected to the degasser 1, the centrifugal pump 6, and the electric butterfly valve 61. The specific control method is described in step S2 of the intelligent degassing method described later, and will not be explained in detail here.

[0033] The third implementation method, such as Figure 4 As shown, the electrical control system includes a drilling data system 107 and a control assembly 7. The drilling data system 107 is connected to the signal input terminal of the control assembly 7, and the output terminal of the control assembly 7 is connected to the degasser 1 and the centrifugal pump 6. The specific control method is described in step S3 of the intelligent degassing method described later, and will not be explained in detail here.

[0034] The fourth implementation method, such as Figure 5 As shown, the electrical control system includes a first pressure sensor 108, which is installed on the liquid-gas separator 8 to obtain the gas pressure inside the liquid-gas separator 8. The first pressure sensor 108 is connected to the signal input terminal of the control assembly 7, and the output terminal of the control assembly 7 is connected to the degasser 1 and the centrifugal pump 6. The specific control method is described in step S4 of the intelligent degassing method described later, and will not be explained in detail here.

[0035] It should be noted that the above four implementation methods can be combined arbitrarily to jointly control the degasser 1 and the centrifugal pump 6, or they can be implemented individually; preferably, such as Figure 1 As shown, the first embodiment is used for mud degassing control under normal drilling operation conditions, while the second and third embodiments are used as redundant mud degassing control, and the fourth embodiment is used for mud degassing control under emergency drilling operation conditions. When implementing the combined embodiments, the control assembly 7 can be merged into a single control assembly 7.

[0036] Furthermore, the control assembly 7 includes at least a data acquisition unit 71, a data processor 72, and the control assembly 7; the input terminal of the data acquisition unit 71 is connected to various sensors and / or detectors and / or drilling data system 107 for acquiring logging data from various sensors and / or detectors and / or drilling data system 107; the input terminal of the data processor 72 is connected to the output terminal of the data acquisition unit 71 for acquiring the data acquired by the data acquisition unit 71, and the data model is built into the data processor 72 to process the acquired data; the controller 73 is connected to the output terminal of the data processor 72 and issues specific control commands based on the processed data.

[0037] In this embodiment, all the described implementations also include a second pressure sensor 105, which is installed at the outlet of the centrifugal pump 6. It can be installed at the outlet of the electric butterfly valve 61 located at the outlet of the centrifugal pump 6 to obtain the output pressure of the centrifugal pump 6, so as to detect the working status of the centrifugal pump 6 and ensure the normal operation of the degassing work.

[0038] It should be noted that when centrifugal pump 6 malfunctions, other centrifugal pumps connected in parallel with centrifugal pump 6 (such as other centrifugal pumps used as sand pumps) can be used to replace centrifugal pump 6 in transporting mud. Specifically, when it is determined that centrifugal pump 6 is malfunctioning (e.g., after centrifugal pump 6 is turned on, the pressure measured by the second pressure sensor 105 does not change significantly), the status of other centrifugal pumps is detected. The detection method can be manual, or preferably, the other centrifugal pumps can be connected to the output terminal of the control assembly 7, and the status of other centrifugal pumps can be detected by the control assembly 7. If the other centrifugal pumps are in working condition, manual interaction is performed twice to confirm whether the other centrifugal pumps can stop their current operation and switch to replace centrifugal pump 6 in transporting mud. If the other centrifugal pumps cannot stop their current operation, the control assembly 7 does not issue any action command. If they can stop their current operation, the control assembly 7 issues a switching command to switch the other centrifugal pumps to replace centrifugal pump 6 in transporting mud. If the other centrifugal pumps are not in working condition, the control assembly 7 issues a switching command to switch the other centrifugal pumps to replace centrifugal pump 6 in transporting mud.

[0039] Example 4 like Figures 6-9 As shown, an intelligent degassing method for drilling fluid involves installing sensors along the path of the mud flow and / or on the equipment through which it flows, acquiring state data detected by the sensors and / or acquiring state data from the drilling control system, and controlling the opening and closing of the degasser 1 based on the state data.

[0040] In this embodiment, the status data can be one or more of the following: mud density at various locations, gas concentration in the diversion box, and gas pressure in the liquid-gas separator 8. It can also be logging data from the drilling control system. By monitoring and analyzing the status data online in real time, the start and stop of the degasser 1 can be automatically controlled. This achieves the goal of detecting gas intrusion as early as possible and starting the degasser 1 in a timely manner, reducing manual reaction time, improving the working efficiency of the degasser 1, realizing unmanned operation of the degasser 1, and avoiding over-opening of the degasser 1 to reduce energy waste.

[0041] Example 5 Based on the intelligent degassing method disclosed in Example 4, and applying the intelligent degassing system disclosed in any one of the embodiments in Examples 2-3, a further specific implementation of the intelligent degassing method is proposed.

[0042] The intelligent degassing method includes any one or more of the following steps S1, S2, S3, and S4, as detailed below.

[0043] S1: Includes steps S11-S15; such as Figure 6 As shown; S11: The control assembly 7 acquires data ρ1 from the first density sensor 101, data ρ2 from the second density sensor 102, data ρ3 from the third density sensor 103, and data ρ4 from the fourth density sensor 104; and the control assembly 7 takes ρ1 and ρ4 as inputs and outputs the theoretical density value ρ0 through the data model built into the control assembly 7. S12: Control assembly 7 determines the relationship between ρ1 and ρ4; if ρ1 < ρ4, the drilling operation is abnormal and an alarm is triggered for process inspection; if ρ1 ≥ ρ4, the drilling operation is normal and control assembly 7 does not issue any action commands. S13: Control assembly 7 determines the size relationship between ρ0 and ρ2; If ρ0≤ρ2, the control assembly 7 obtains the status of the degasser 1 and the centrifugal pump 6; if they are in the working state, the control assembly 7 controls the degasser 1 and the centrifugal pump 6 to shut down and switch to the non-working state; if they are in the non-working state, the control assembly 7 does not issue any action commands. If ρ0 > ρ2, the control assembly 7 issues a command to start the degasser 1 and centrifugal pump 6, and the degasser 1 and centrifugal pump 6 start and enter the working state. S14: When the degasser 1 and centrifugal pump 6 are started and put into working state in step S13, the control assembly 7 acquires the data P2 of the second pressure sensor 105 and determines whether the data of P2 is normal. If the P2 data is normal, the control assembly 7 will not issue action commands to the degasser 1 and centrifugal pump 6, and the degasser 1 and centrifugal pump 6 will remain in working condition. If the P2 data is abnormal, the control assembly 7 will shut down the degasser 1 and centrifugal pump 6, and at the same time issue an alarm for centrifugal pump 6 failure. S15: In step S14, after the degasser 1 and centrifugal pump 6 have maintained their working state for a set time, the control assembly 7 determines whether ρ2 and ρ3 have decreased. If so, the control assembly 7 will not issue action commands to the degasser 1 and centrifugal pump 6, and the degasser 1 and centrifugal pump 6 will remain in working condition. If not, the control assembly 7 will shut down the degasser 1 and centrifugal pump 6, and simultaneously issue an alarm. S2: Includes steps S21-S22; such as Figure 7 As shown; S21: The control assembly 7 acquires data c from the gas detector 106 and determines whether data c has increased; If no increase occurs, the control assembly 7 obtains the status of the degasser 1 and the centrifugal pump 6; if they are in the working state, the control assembly 7 controls the degasser 1 and the centrifugal pump 6 to close and switch to the non-working state; if they are in the non-working state, the control assembly 7 does not issue any action commands. If an increase occurs, the control assembly 7 issues a command to start the degasser 1 and centrifugal pump 6, and the degasser 1 and centrifugal pump 6 start and enter the working state. S22: When the degasser 1 and centrifugal pump 6 are started and put into working state in step S21, the control assembly 7 acquires the data P2 of the second pressure sensor 105 and determines whether the data of P2 is normal. If the P2 data is normal, the control assembly 7 will not issue action commands to the degasser 1 and centrifugal pump 6, and the degasser 1 and centrifugal pump 6 will remain in working condition. If the P2 data is abnormal, the control assembly 7 will shut down the degasser 1 and centrifugal pump 6, and at the same time issue an alarm for centrifugal pump 6 failure. S3: Includes steps S31-S32; such as Figure 8 As shown; S31: The control assembly 7 obtains logging data from the drilling data system 107 and determines whether a permeable layer exists; If there is no permeable layer, the control assembly 7 obtains the status of the degasser 1 and the centrifugal pump 6; if they are in the working state, the control assembly 7 controls the degasser 1 and the centrifugal pump 6 to close and switch to the non-working state; if they are in the non-working state, the control assembly 7 does not issue any action commands. If a permeable layer exists, the control assembly 7 issues a command to start the degasser 1 and centrifugal pump 6, and the degasser 1 and centrifugal pump 6 start and enter the working state. S32: When the degasser 1 and centrifugal pump 6 are started and put into working state in step S31, the control assembly 7 acquires the data P2 of the second pressure sensor 105 and determines whether the data of P2 is normal. If the P2 data is normal, the control assembly 7 will not issue action commands to the degasser 1 and centrifugal pump 6, and the degasser 1 and centrifugal pump 6 will remain in working condition. If the P2 data is abnormal, the control assembly 7 will shut down the degasser 1 and centrifugal pump 6, and at the same time issue an alarm for centrifugal pump 6 failure. S4: Includes steps S41-S42; such as Figure 9 As shown; S41: The control assembly 7 acquires the data P1 from the first pressure sensor 108 and determines whether the data P1 has increased; If no increase occurs, the control assembly 7 obtains the status of the degasser 1 and the centrifugal pump 6; if they are in the working state, the control assembly 7 controls the degasser 1 and the centrifugal pump 6 to close and switch to the non-working state; if they are in the non-working state, the control assembly 7 does not issue any action commands. If an increase occurs, the control assembly 7 issues a command to start the degasser 1 and centrifugal pump 6, and the degasser 1 and centrifugal pump 6 start and enter the working state. S42: When the degasser 1 and centrifugal pump 6 are started and put into working state in step S41, the control assembly 7 acquires the data P2 of the second pressure sensor 105 and determines whether the data of P2 is normal. If the P2 data is normal, the control assembly 7 will not issue action commands to the degasser 1 and centrifugal pump 6, and the degasser 1 and centrifugal pump 6 will remain in working condition. If the P2 data is abnormal, the control assembly 7 will shut down the degasser 1 and centrifugal pump 6, and at the same time issue a fault alarm for centrifugal pump 6.

[0044] It should be noted that when the control assembly 7 issues an alarm for a malfunction of the centrifugal pump 6 in steps S1, S2, S3, and S4 above, the structure and method described in Example 3 can be used to ensure the degassing operation is carried out; that is, other centrifugal pumps are used instead of centrifugal pump 6 to transport mud. The control process has been described in detail above and will not be described in detail again.

[0045] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. An intelligent degassing system for drilling fluid, characterized in that: It is applied to mud degassing, including an electrical control system and a degasser (1), wherein the electrical control system collects status data from sensors arranged on the path of mud flow and / or on the equipment through which the mud flows, and / or collects status data from the drilling control system, and controls the opening and closing of the degasser (1) according to the status data. It also includes an aerated mud chamber (3) for connecting the mud inlet to the wellhead (9), the mud outlet of the aerated mud chamber (3) is connected to the inlet of the degasser (1), the outlet of the degasser (1) is connected to the inlet of the jet line (11), the outlet of the jet line (11) is connected to the discharge line (62), the inlet of the discharge line (62) is connected to the outlet of the degassed mud chamber (4) through a centrifugal pump (6), and the outlet of the discharge line (62) is connected to the inlet of the degassed mud chamber (4); wherein: the connection position between the jet line (11) and the discharge line (62) has a Venturi effect; It also has a mud pump suction chamber (5), the inlet of which is connected to the outlet of the degassed mud chamber (4), and the outlet of the mud pump suction chamber (5) is used to connect to the mud pump. The electrical control system includes multiple sensors and a control assembly (7). The multiple sensors are connected to the signal input terminals of the control assembly (7), and the output terminals of the control assembly (7) are connected to the degasser (1) and the centrifugal pump (6). The multiple sensors include at least a first density sensor (101), a second density sensor (102), a third density sensor (103), and a fourth density sensor (104). The first density sensor (101) is installed at the mud inlet of the gas-bearing mud chamber (3) or at the wellhead (9) to detect the density of the mud flowing out of the wellhead (9); The second density sensor (102) is installed inside the aerated mud chamber (3) to detect the density of the mud inside the aerated mud chamber (3); The third density sensor (103) is installed in the deaerated mud chamber (4) to detect the density of the mud in the deaerated mud chamber (4); The fourth density sensor (104) is installed in the mud pump suction chamber (5) to detect the density of the mud entering the wellhead (9).

2. The intelligent degassing system according to claim 1, characterized in that: The electrical control system includes a gas detector (106) and a control assembly (7). The gas detector (106) is installed in the distribution box to obtain the gas concentration in the distribution box. The gas detector (106) is connected to the signal input terminal of the control assembly (7), and the output terminal of the control assembly (7) is connected to the degasser (1) and the centrifugal pump (6).

3. The intelligent degassing system according to claim 1, characterized in that: The electrical control system includes a drilling data system (107) and a control assembly (7). The drilling data system (107) is connected to the signal input terminal of the control assembly (7), and the output terminal of the control assembly (7) is connected to the degasser (1) and the centrifugal pump (6).

4. The intelligent degassing system according to claim 1, characterized in that: The electrical control system includes a first pressure sensor (108), which is installed on the liquid-gas separator (8) to obtain the gas pressure inside the liquid-gas separator (8); the first pressure sensor (108) is connected to the signal input terminal of the control assembly (7), and the output terminal of the control assembly (7) is connected to the degasser (1) and the centrifugal pump (6).

5. The intelligent degassing system according to any one of claims 1-4, characterized in that: It also has a second pressure sensor (105), which is installed at the outlet of the centrifugal pump (6) to obtain the output pressure of the centrifugal pump (6).

6. A method for intelligent degassing of drilling fluid, using the intelligent degassing system for drilling fluid as described in any one of claims 1-5, characterized in that: Sensors are installed along the path of the mud flow and / or on the equipment through which the mud flows to acquire the status data detected by the sensors and / or the status data in the drilling control system, and the opening and closing of the degasser (1) is controlled according to the status data.

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