Overflow and lost circulation monitoring method and system capable of preventing false alarms

Abstract

The present invention relates to an overflow and lost circulation monitoring method and system capable of preventing false alarms. An overflow and lost circulation monitoring method capable of preventing false alarms monitors in real time the volume of mud in the circulation tank into which the drilling mud flows back from the wellbore to the return tank, the volume of mud in the circulation tank from which the mud flows out of the mud inlet pipeline connecting the drilling pump, and the volume of mud in other circulation tanks participating in the mud circulation, and calculates the overall increase or decrease in volume ΔV of the circulation tank; monitors in real time the change rates S1 and S2 of the volume of mud in the mud inflow tank and the mud outflow tank and calculates the difference between S2 and S1, and determines whether there is an overflow or lost circulation based on the magnitude of this difference and in combination with ΔV. By utilizing the characteristic that the inflow order of the mud in each circulation tank is different during the mud circulation, monitors in real time the change rate of the mud volume in the circulation tank, and determines whether the drilling pump is at the start or stop moment by calculating and comparing the difference in the change rates, thereby avoiding misjudgment caused by liquid level fluctuations caused by starting and stopping the drilling pump and improving the accuracy of overflow or lost circulation alarms.

Description

Technical Field

[0001] The present invention relates to a method for analyzing and judging overflow or well leakage in oil drilling engineering, and in particular to an overflow and well leakage monitoring method that can effectively prevent false alarms. Background Art

[0002] During oil exploration, development and drilling, it is necessary to monitor the liquid level of the mud in the circulation tank at all times and in a timely manner. The change information of the liquid level of the mud in the circulation tank is the premise for analyzing and judging whether there is overflow or well leakage. At present, the commonly used overflow monitoring methods at home and abroad mainly install a float type liquid level gauge or an ultrasonic liquid level gauge on the mud circulation tank surface, and analyze and judge whether there is overflow by monitoring the change of the mud volume in the circulation tank. The disadvantage of these monitoring methods is frequent false alarms. The reason is that when the drilling pump starts, the liquid level of the mud in the circulation tank decreases, resulting in the monitoring system of the mud liquid level misjudging as well leakage; and when the drilling pump stops, the liquid level of the mud in the circulation tank increases, which in turn causes the monitoring system of the mud liquid level to misjudge as overflow. Such frequent false alarms are likely to produce an effect like "the boy who cried wolf", causing the drilling operators to become complacent and being unfavorable to ensuring the safe production operation of drilling. Summary of the Invention

[0003] In view of the deficiencies of the prior art, the present invention provides an overflow and well leakage monitoring method and system that can effectively prevent false alarms, which can monitor the increase and decrease of the total volume of the mud in the circulation tank in real time, and combine the difference between the change rate of the mud volume flowing into the circulation tank and the change rate of the mud volume flowing out of the circulation tank to judge the occurrence of overflow and well leakage, and can effectively avoid misjudgment caused by the liquid level fluctuation caused by starting and stopping the drilling pump, and improve the accuracy of overflow or well leakage alarm.

[0004] The technical solution adopted by the present invention is as follows:

[0005] An overflow and well leakage monitoring method that can prevent false alarms, the steps are as follows:

[0006] 1) Monitor in real time the volume of the mud in the circulation tank that returns from the wellbore to the return trough and flows into the tank;

[0007] Monitor in real time the volume of the mud in the circulation tank that flows out of the connection of the inlet pipeline of the drilling pump and the volume of the mud in the circulation tank of other circulation tanks participating in the mud circulation;

[0008] 2) Monitor in real time the change rates S1 and S2 of the volume of the mud in the mud inflow tank and the mud outflow tank;

[0009] Monitor in real time the increase and decrease amounts ΔV1 and ΔV2 of the volume of the mud in the mud inflow tank and the mud outflow tank, and calculate in real time the increase and decrease amount ΔV other of the volume of the mud in other circulation tanks participating in the mud circulation,

[0010] 3) Calculate the total volume increase or decrease ΔV of the circulation tank based on the obtained ΔV1, ΔV2, and ΔV others:

[0011] ΔV = ΔV1 + ΔV2 + ΔV others

[0012] 4) Calculate the difference between S2 and S1 in real time, and determine whether there is overflow or well leakage based on the magnitude of this difference and in combination with ΔV:

[0013] (1) If ΔV ≥ N and S2 - S1 ≥ n, it is determined that the drilling pump is at the start / stop moment, and no overflow or well leakage alarm is issued;

[0014] (2) If ΔV ≥ N and S2 - S1 < n, it is determined that the drilling pump is in the running or stationary state, and an overflow or well leakage alarm is issued;

[0015] 5) Calculate the difference between ΔV2 and ΔV1 in real time, and determine whether there is overflow or well leakage based on the magnitude of this difference and in combination with ΔV:

[0016] (1) If ΔV ≥ N and ΔV2 - ΔV1 ≥ m, it is determined that the drilling pump is at the start / stop moment, and no overflow or well leakage alarm is issued;

[0017] (2) If ΔV ≥ N and ΔV2 - ΔV1 < m, it is determined that the drilling pump is in the running or stationary state, and an overflow or well leakage alarm is issued; In the above formulas, N, m, and n are set judgment reference values.

[0018] In the overflow and well leakage monitoring method capable of preventing false alarms, in steps 1) and 2), let the volume of the mud in the circulation tank where the drilling mud flows from the wellbore to the return tank and then returns be V1; the volume of the mud in the circulation tank where the mud flows out of the mud outlet connecting the inlet pipeline of the drilling pump be V2; the volume of the mud in the other circulation tanks participating in the mud circulation be V others;

[0019] In step 2), the calculation processes of the change rates S1 and S2 of the mud volumes in the mud inflow tank and the mud outflow tank, the increase and decrease amounts ΔV1 and ΔV2 of the mud volumes in the mud inflow tank and the mud outflow tank, and the increase and decrease amount ΔV others of the mud volumes in the other circulation tanks participating in the mud circulation are as follows:

[0020] (2.1) Calculate the change rate S1 and the increase and decrease amount ΔV1 of V1 in real time based on the obtained V1:

[0021] S1 = V1t / V1t - 1

[0022] ΔV1 = V1t - V1t - 1

[0023] In the formula, V1t represents the volume of the mud flowing into the circulation tank at a certain moment t; V1t - 1 represents the volume of the mud flowing into the circulation tank at the previous moment t - 1 of a certain moment t; the unit of t is min or s;

[0024] (2.2) Calculate the change rate S2 and the increment and decrement ΔV2 of V2 in real time based on the obtained V2:

[0025] S2 = V2t / V2t-1

[0026] ΔV2 = V2t - V2t-1

[0027] In the formula, V2t represents the mud volume flowing out of the circulation tank at a certain moment t; V2t-1 represents the mud volume flowing out of the circulation tank at the previous moment t-1 of a certain moment t; the unit of t is min or s;

[0028] (2.3) Calculate the increment and decrement ΔVother in real time based on the obtained Vother

[0029] ΔVother = Vothert - Vothert-1

[0030] In the formula, Vothert represents the mud volume of other circulation tanks at a certain moment t; Vothert-1 represents the mud volume of other circulation tanks at the previous moment t-1 of a certain moment t; the unit of t is min.

[0031] An overflow and well leakage monitoring system that can prevent false alarms, including a liquid level sensor and a controller installed on the surface of each drilling mud circulation tank. The liquid level sensor outputs a signal to connect to the controller. The controller monitors the change rates S1 and S2 of the mud volume in the mud inflow tank and the mud outflow tank in real time, monitors the increments and decrements ΔV1 and ΔV2 of the mud volume in the mud inflow tank and the mud outflow tank in real time, calculates the increment and decrement ΔVother of the mud volume in other circulation tanks in real time, and determines whether there is an overflow or a well leakage by executing the following computer program:

[0032] 1) Calculate the total volume increment and decrement ΔV of the circulation tank according to the obtained ΔV1, ΔV2, and ΔVother

[0033] ΔV = ΔV1 + ΔV2 + ΔVother

[0034] 2) Calculate the difference between S2 - S1 in real time, and determine whether there is an overflow or a well leakage based on the magnitude of this difference and ΔV:

[0035] (1) If ΔV ≥ N and S2 - S1 ≥ n, it is determined that the drilling pump is at the start and stop moment, and no overflow or well leakage alarm is issued;

[0036] (2) If ΔV ≥ N and S2 - S1 < n, it is determined that the drilling pump is in the running or stationary state, and an overflow or well leakage alarm is issued;

[0037] 3) Calculate the difference between ΔV2 - ΔV1 in real time, and determine whether there is an overflow or a well leakage based on the magnitude of this difference and ΔV:

[0038] (1) If ΔV ≥ N and ΔV2 - ΔV1 ≥ m, it is determined that the drilling pump is at the start / stop moment, and no overflow or well leakage alarm is issued;

[0039] (2) If ΔV ≥ N and ΔV2 - ΔV1 ≥ <m, it is determined that the drilling pump is in the running or stationary state, and an overflow or well leakage alarm is issued; In the above formulas, N, m, and n are set judgment reference values.

[0040] Let the volume of the mud in the circulation tank where the drilling mud flows from the wellbore to the return tank be V1; the volume of the mud in the circulation tank where the mud flows out of the water inlet pipeline of the drilling pump be V2; the volume of the mud in the other circulation tanks participating in the mud circulation be Vother; the calculation processes of the change rates S1 and S2 of the mud volume in the mud inflow tank and the mud outflow tank and the increase and decrease amounts ΔV1 and ΔV2 of the mud volume in the mud inflow tank and the mud outflow tank and the increase and decrease amount ΔVother of the mud volume in the other circulation tanks participating in the mud circulation are as follows:

[0041] (1.1) Calculate the change rate S1 and the increase and decrease amount ΔV1 of V1 in real time according to the obtained V1:

[0042] S1 = V1t / V1t-1

[0043] ΔV1 = V1t - V1t-1

[0044] In the formula, V1t represents the volume of the mud flowing into the circulation tank at a certain moment t; V1t-1 represents the volume of the mud flowing into the circulation tank at the previous moment t-1 of a certain moment t; the unit of t is min or s;

[0045] (2.2) Calculate the change rate S2 and the increase and decrease amount ΔV2 of V2 in real time according to the obtained V2:

[0046] S2 = V2t / V2t-1

[0047] ΔV2 = V2t - V2t-1

[0048] In the formula, V2t represents the volume of the mud flowing out of the circulation tank at a certain moment t; V2t-1 represents the volume of the mud flowing out of the circulation tank at the previous moment t-1 of a certain moment t; the unit of t is min or s;

[0049] (2.3) Calculate the increase and decrease amount ΔVother in real time according to the obtained Vother

[0050] ΔVother = Vothert - Vothert-1

[0051] Wherein, V_other_t represents the mud volume in other circulation tanks at a certain moment t; V_other_(t - 1) represents the mud volume in other circulation tanks at the previous moment t - 1 of a certain moment t; the unit of t is min or s.

[0052] Advantages of the invention:

[0053] 1. The overflow and well leakage monitoring method and system capable of preventing false alarms of the present invention utilize the characteristics that the inflow order of mud in each circulation tank is different during mud circulation, and adopts a liquid level sensor to detect and calculate the change rate of the mud volume in the circulation tank in real time. By calculating and comparing the difference of the change rates, it can be judged whether the drilling pump is at the start or stop moment, thereby avoiding misjudgment caused by the liquid level fluctuation caused by starting and stopping the drilling pump.

[0054] 2. The overflow and well leakage monitoring method and system capable of preventing false alarms of the present invention monitor the increase and decrease of the total mud volume in the circulation tank in real time through a liquid level sensor, and combine the difference between the change rate of the mud volume flowing into the circulation tank and the change rate of the mud volume flowing out of the circulation tank to judge the occurrence of overflow and well leakage, which can effectively avoid misjudgment caused by the liquid level fluctuation caused by starting and stopping the drilling pump and improve the accuracy of overflow or well leakage alarms.

[0055] 3. The overflow and well leakage monitoring method and system capable of preventing false alarms of the present invention are scientifically and reasonably designed, easy to implement, convenient to promote. Without adding sensors, it can judge whether the drilling pump is at the start or stop moment, without changing the hardware of the existing tank surface monitoring system, without increasing the equipment cost, and has good social and economic benefits. Description of the drawings

[0056] Figure 1 The following shows the flow chart of the overflow and well leakage monitoring method capable of preventing false alarms of the present invention;

[0057] Figure 2 The following shows the application schematic diagram of the overflow and well leakage monitoring system capable of preventing false alarms of the present invention, 1 reflux tank, 2 sensor, 3 outflow pipeline. Detailed implementation manners

[0058] In order to make the technical concept and advantages of the invention for realizing its invention purpose clearer, the technical solutions of the present invention will be further described in detail below with reference to the drawings. It should be understood that the following embodiments are only used to explain and illustrate the preferred embodiments of the present invention, and should not constitute a limitation to the scope of patent protection required by the present invention. Embodiment

[0059] See Figure 1 、 Figure 2 The overflow and well leakage monitoring method capable of preventing false alarms of the present invention has the following steps:

[0060] 1) Real-time monitor the volume of mud in the circulation tank where the drilling mud flows from the wellbore to the return chute and then back into the tank.

[0061] Real-time monitor the volume of mud in the circulation tank where the mud flows out of the tank connected to the inlet pipeline of the mud pump and the volume of mud in other circulation tanks involved in the mud circulation. Figure 2 In the figure, No. 3 is the outflow pipeline.

[0062] 2) Real-time monitor the change rates S1 and S2 of the volume of mud in the mud inflow tank and the mud outflow tank.

[0063] Real-time monitor the increase and decrease amounts ΔV1 and ΔV2 of the volume of mud in the mud inflow tank and the mud outflow tank, and calculate in real time the increase and decrease amount ΔV other of the volume of mud in other circulation tanks involved in the mud circulation.

[0064] 3) Calculate the total increase and decrease amount ΔV of the volume of the circulation tank according to the obtained ΔV1, ΔV2, and ΔV other:

[0065] ΔV = ΔV1 + ΔV2 + ΔV other

[0066] 4) Calculate in real time the difference between S2 - S1, and judge whether there is overflow or well leakage based on the magnitude of this difference and in combination with ΔV:

[0067] (1) If ΔV ≥ N and S2 - S1 ≥ n, it is judged that the mud pump is at the start-stop moment, and no overflow or well leakage alarm is issued.

[0068] (2) If ΔV ≥ N and S2 - S1 < n, it is judged that the mud pump is in the running or static state, and an overflow or well leakage alarm is issued.

[0069] 5) Calculate in real time the difference between ΔV2 - ΔV1, and judge whether there is overflow or well leakage based on the magnitude of this difference and in combination with ΔV:

[0070] (1) If ΔV ≥ N and ΔV2 - ΔV1 ≥ m, it is judged that the mud pump is at the start-stop moment, and no overflow or well leakage alarm is issued.

[0071] (2) If ΔV ≥ N and ΔV2 - ΔV1 < m, it is judged that the mud pump is in the running or static state, and an overflow or well leakage alarm is issued. In the above formulas, N, m, and n are set judgment reference values. Embodiment

[0072] See Figure 1 、 Figure 2, The overflow and lost circulation monitoring method of the present invention can prevent false alarms. A liquid level sensor 2 is installed on the surface of each drilling mud circulation tank. Let the volume of the mud in the circulation tank where the drilling mud flows from the wellbore to the return trough 1 and returns be V1; let the volume of the mud in the circulation tank where the mud flows out and is connected to the inlet pipeline of the drilling pump be V2; let the volume of the mud in other circulation tanks participating in the mud circulation be V_other. Sensors and controllers are used to detect and calculate the change rates S1 and S2 of the mud volume flowing into and out of the tank in real time, and the increase and decrease amounts ΔV1 and ΔV2 of the mud volume in the tank where the mud flows into and out of the tank are detected and calculated in real time. The increase and decrease amount ΔV_other of the mud volume in other circulation tanks is calculated in real time. The controller determines whether there is an overflow or lost circulation by executing the following computer program:

[0073] 1) Calculate the change rate S1 and the increase and decrease amount ΔV1 of V1 in real time according to the obtained V1:

[0074] S1 = V1t / V1t - 1

[0075] ΔV1 = V1t - V1t - 1

[0076] Where V1t represents the volume of the mud flowing into the circulation tank at a certain moment t; V1t - 1 represents the volume of the mud flowing into the circulation tank at the previous moment t - 1 of a certain moment t; the unit of t is min;

[0077] 2) Calculate the change rate S2 and the increase and decrease amount ΔV2 of V2 in real time according to the obtained V2:

[0078] S2 = V2t / V2t - 1

[0079] ΔV2 = V2t - V2t - 1

[0080] Where V2t represents the volume of the mud flowing out of the circulation tank at a certain moment t; V2t - 1 represents the volume of the mud flowing out of the circulation tank at the previous moment t - 1 of a certain moment t; the unit of t is min;

[0081] 3) Calculate the increase and decrease amount ΔV_other according to the obtained V_other in real time

[0082] ΔV_other = V_othert - V_othert - 1

[0083] Where V_othert represents the volume of the mud in other circulation tanks at a certain moment t; V_othert - 1 represents the volume of the mud in other circulation tanks at the previous moment t - 1 of a certain moment t; the unit of t is min;

[0084] 4) Calculate the total increase and decrease amount ΔV of the circulation tank according to the obtained ΔV1, ΔV2, and ΔV_other

[0085] ΔV = ΔV1 + ΔV2 + ΔV_other

[0086] 5) Calculate the difference between S2 and S1 in real time, and determine whether there is overflow or lost circulation based on the magnitude of this difference and in combination with ΔV:

[0087] (1) If ΔV≥N and S2 - S1≥n, it is determined that the drilling pump is at the start / stop moment, and no overflow or lost circulation alarm is issued;

[0088] (2) If ΔV≥N and S2 - S1 < n, it is determined that the drilling pump is in the running or stationary state, and an overflow or lost circulation alarm is issued;

[0089] 6) Calculate the difference between ΔV2 and ΔV1 in real time, and determine whether there is overflow or lost circulation based on the magnitude of this difference and in combination with ΔV:

[0090] (1) If ΔV≥N and ΔV2 - ΔV1≥m, it is determined that the drilling pump is at the start / stop moment, and no overflow or lost circulation alarm is issued;

[0091] (2) If ΔV≥N and ΔV2 - ΔV1 < m, it is determined that the drilling pump is in the running or stationary state, and an overflow or lost circulation alarm is issued. Where N, m, and n are judgment values. Embodiment

[0092] See Figure 2 , this embodiment is an overflow and lost circulation monitoring system that can prevent false alarms, including a liquid level sensor installed on the surface of each drilling mud circulation tank and a controller. The output signal of the liquid level sensor is connected to the controller. The controller monitors in real time the change rates S1 and S2 of the mud volume in the mud inflow tank and the mud outflow tank, monitors in real time the increase and decrease amounts ΔV1 and ΔV2 of the mud volume in the mud inflow tank and the mud outflow tank, calculates in real time the increase and decrease amount ΔV other of the mud volume in other circulation tanks, and determines whether there is overflow or lost circulation by executing the following computer program:

[0093] 1) Calculate the total increase and decrease amount ΔV of the circulation tank according to the obtained ΔV1, ΔV2, and ΔV other

[0094] ΔV = ΔV1 + ΔV2 + ΔV other

[0095] 2) Calculate the difference between S2 and S1 in real time, and determine whether there is overflow or lost circulation based on the magnitude of this difference and in combination with ΔV:

[0096] (1) If ΔV≥N and S2 - S1≥n, it is determined that the drilling pump is at the start / stop moment, and no overflow or lost circulation alarm is issued;

[0097] (2) If ΔV≥N and S2 - S1 < n, it is determined that the drilling pump is in the running or stationary state, and an overflow or lost circulation alarm is issued;

[0098] 3) Calculate the difference between ΔV2 and ΔV1 in real time, and determine whether there is overflow or well leakage based on the magnitude of this difference and in combination with ΔV:

[0099] (1) If ΔV ≥ N and ΔV2 - ΔV1 ≥ m, it is determined that the drilling pump is at the start / stop moment, and no overflow or well leakage alarm is issued;

[0100] (2) If ΔV ≥ N and ΔV2 - ΔV1 < m, it is determined that the drilling pump is in the running or stationary state, and an overflow or well leakage alarm is issued; in the above formulas, N, m, and n are set judgment reference values.

[0101] Let the volume of mud in the circulation tank where the drilling mud flows from the wellbore to the return tank be V1; the volume of mud in the circulation tank where the mud flows out of the water inlet pipeline of the drilling pump is V2; the volume of mud in other circulation tanks participating in the mud circulation is Vother; the calculation processes of the change rates S1 and S2 of the mud volume in the mud inflow tank and the mud outflow tank, the increase and decrease amounts ΔV1 and ΔV2 of the mud volume in the mud inflow tank and the mud outflow tank, and the increase and decrease amount ΔVother of the mud volume in other circulation tanks participating in the mud circulation are as follows:

[0102] (1.1) Calculate the change rate S1 and the increase and decrease amount ΔV1 of V1 in real time based on the obtained V1:

[0103] S1 = V1t / V1t - 1

[0104] ΔV1 = V1t - V1t - 1

[0105] In the formula, V1t represents the volume of mud flowing into the circulation tank at a certain moment t; V1t - 1 represents the volume of mud flowing into the circulation tank at the previous moment t - 1 of a certain moment t; the unit of t is min or s;

[0106] (2.2) Calculate the change rate S2 and the increase and decrease amount ΔV2 of V2 in real time based on the obtained V2:

[0107] S2 = V2t / V2t - 1

[0108] ΔV2 = V2t - V2t - 1

[0109] In the formula, V2t represents the volume of mud flowing out of the circulation tank at a certain moment t; V2t - 1 represents the volume of mud flowing out of the circulation tank at the previous moment t - 1 of a certain moment t; the unit of t is min or s;

[0110] (2.3) Calculate the increase and decrease amount ΔVother in real time based on the obtained Vother

[0111] ΔVother = Vothert - Vothert - 1

[0112] Wherein V_other_t represents the mud volume of other circulation tanks at a certain moment t; V_other_t-1 represents the mud volume of other circulation tanks at the previous moment t-1 of a certain moment t; the unit of t is min or s.

[0113] Compared with the prior art, the overflow and well leakage monitoring method of the present invention can prevent false alarms. By utilizing the characteristic that the inflow order of mud in each circulation tank is different during mud circulation, a liquid level sensor is used to detect and calculate the change rate of the mud volume in the circulation tank in real time. By calculating and comparing the difference of the change rates, it can be judged whether the drilling pump is at the start or stop moment, thereby avoiding misjudgment caused by liquid level fluctuations caused by starting and stopping the drilling pump, and improving the accuracy of overflow or well leakage alarms.

[0114] The above description is only the preferred embodiment of the present invention and does not constitute a limitation to the present invention. Under the guidance of the prior art, those skilled in the art can make other modifications to the implementation of the present invention without creative labor. Any modification made within the spirit and principle of the present invention or any simple substitution or equivalent replacement using conventional technical means in the art shall be included in the protection scope of the present invention.

Claims

1. An overflow and well leakage monitoring method capable of preventing false alarms, characterized in that: It includes the following steps: 1) Real-time monitor the volume of mud in the circulation tank where the drilling mud flows back from the wellbore to the return chute and into the tank; Real-time monitor the volume of mud in the circulation tank where the mud flows out of the pipeline connecting to the inlet of the drilling pump and the volume of mud in other circulation tanks participating in the mud circulation; 2) Real-time monitor the change rates S1 and S2 of the volume of mud in the mud inflow tank and the mud outflow tank; Real-time monitor the increase and decrease amounts ΔV1 and ΔV2 of the volume of mud in the mud inflow tank and the mud outflow tank, and calculate in real time the increase and decrease amount ΔVother of the volume of mud in other circulation tanks participating in the mud circulation; 3) Calculate the total increase and decrease amount ΔV of the circulation tank according to the obtained ΔV1, ΔV2, and ΔVother: ΔV = ΔV1 + ΔV2 + ΔVother 4) Calculate in real time the difference between S2 - S1, and judge whether there is overflow or well leakage based on the magnitude of this difference and in combination with ΔV: (1) If ΔV ≥ N and S2 - S1 ≥ n, it is judged that the drilling pump is at the start / stop moment, and no overflow or well leakage alarm is issued; (2) If ΔV ≥ N and S2 - S1 < n, it is judged that the drilling pump is in the running or stationary state, and an overflow or well leakage alarm is issued; 5) Calculate in real time the difference between ΔV2 - ΔV1, and judge whether there is overflow or well leakage based on the magnitude of this difference and in combination with ΔV: (1) If ΔV ≥ N and ΔV2 - ΔV1 ≥ m, it is judged that the drilling pump is at the start / stop moment, and no overflow or well leakage alarm is issued; (2) If ΔV ≥ N and ΔV2 - ΔV1 < m, it is judged that the drilling pump is in the running or stationary state, and an overflow or well leakage alarm is issued; In the above formulas, N, m, and n are set judgment reference values.

2. The overflow and well leakage monitoring method capable of preventing false alarms according to claim 1, characterized in that: In steps 1) and 2), let the volume of mud in the circulation tank where the drilling mud flows back from the wellbore to the return chute and into the tank be V1; the volume of mud in the circulation tank where the mud flows out of the pipeline connecting to the inlet of the drilling pump be V2; the volume of mud in other circulation tanks participating in the mud circulation be Vother; In step 2), the calculation processes of the change rates S1 and S2 of the volume of mud in the mud inflow tank and the mud outflow tank, and the increase and decrease amounts ΔV1 and ΔV2 of the volume of mud in the mud inflow tank and the mud outflow tank, and the increase and decrease amount ΔVother of the volume of mud in other circulation tanks participating in the mud circulation are as follows: (2.1) Calculate in real time the change rate S1 and the increase and decrease amount ΔV1 of V1 according to the obtained V1: S1 = V1t / V1t - 1 ΔV1 = V1t - V1t - 1 In the formula, V1t represents the volume of mud flowing into the circulation tank at a certain moment t; V1t - 1 represents the volume of mud flowing into the circulation tank at the previous moment t - 1 of a certain moment t; (2.2) Calculate in real time the change rate S2 and the increase and decrease amount ΔV2 of V2 according to the obtained V2: S2 = V2t / V2t - 1 ΔV2 = V2t - V2t - 1 In the formula, V2t represents the volume of mud flowing out of the circulation tank at a certain moment t; V2t - 1 represents the volume of mud flowing out of the circulation tank at the previous moment t - 1 of a certain moment t; (2.3) Calculate in real time the increase and decrease amount ΔVother according to the obtained Vother ΔV other = V other t - V other t-1 Wherein, V other t represents the mud volume of other circulation tanks at a certain moment t; V other t-1 represents the mud volume of other circulation tanks at the previous moment t-1 of a certain moment t.

3. An overflow and well leakage monitoring system capable of preventing false alarms, comprising a liquid level sensor installed on the surface of each drilling mud circulation tank and a controller, wherein the liquid level sensor outputs a signal to be connected to the controller, and is characterized in that: The controller monitors in real time the change rates S1 and S2 of the mud volume in the mud inflow tank and the mud outflow tank, monitors in real time the increase and decrease amounts ΔV1 and ΔV2 of the mud volume in the mud inflow tank and the mud outflow tank, calculates in real time the increase and decrease amount ΔV other of the mud volume in other circulation tanks, and determines whether there is overflow or well leakage by executing the following computer program: (1) Calculate the total increase and decrease amount ΔV of the circulation tank according to the obtained ΔV1, ΔV2, and ΔV other ΔV = ΔV1 + ΔV2 + ΔV other (2) Calculate in real time the difference between S2 and S1, and determine whether there is overflow or well leakage based on the magnitude of this difference and in combination with ΔV: (1) If ΔV ≥ N and S2 - S1 ≥ n, it is determined that the drilling pump is at the start / stop moment, and no overflow or well leakage alarm is issued; (2) If ΔV ≥ N and S2 - S1 < n, it is determined that the drilling pump is in the running or stationary state, and an overflow or well leakage alarm is issued; (3) Calculate in real time the difference between ΔV2 and ΔV1, and determine whether there is overflow or well leakage based on the magnitude of this difference and in combination with ΔV: (1) If ΔV ≥ N and ΔV2 - ΔV1 ≥ m, it is determined that the drilling pump is at the start / stop moment, and no overflow or well leakage alarm is issued; (2) If ΔV ≥ N and ΔV2 - ΔV1 < m, it is determined that the drilling pump is in the running or stationary state, and an overflow or well leakage alarm is issued; In the foregoing formulas, N, m, and n are set judgment reference values.

4. The overflow and well leakage monitoring system capable of preventing false alarms according to claim 3, wherein: Let the mud volume in the circulation tank where the drilling mud flows back from the wellbore to the return trough be V1; the mud volume in the circulation tank where the mud flows out of the water inlet pipeline of the drilling pump is V2; the mud volume in other circulation tanks participating in mud circulation is V other; The calculation processes of the change rates S1 and S2 of the mud volume in the mud inflow tank and the mud outflow tank, and the increase and decrease amounts ΔV1 and ΔV2 of the mud volume in the mud inflow tank and the mud outflow tank, and the increase and decrease amount ΔV other of the mud volume in other circulation tanks participating in mud circulation are as follows: (1.1) Calculate in real time the change rate S1 and the increase and decrease amount ΔV1 of V1 according to the obtained V1: S1 = V1t / V1t-1 ΔV1 = V1t - V1t-1 Wherein, V1t represents the mud volume flowing into the circulation tank at a certain moment t; V1t-1 represents the mud volume flowing into the circulation tank at the previous moment t-1 of a certain moment t; the unit of t is min or s; (2.2) Calculate in real time the change rate S2 and the increase and decrease amount ΔV2 of V2 according to the obtained V2: S2 = V2t / V2t-1 ΔV2 = V2t - V2t-1 Wherein, V2t represents the mud volume flowing out of the circulation tank at a certain moment t; V2t-1 represents the mud volume flowing out of the circulation tank at the previous moment t-1 of a certain moment t; the unit of t is min or s; (2.3) Calculate in real time the increase and decrease amount ΔV other according to the obtained V other ΔV other = V other t - V other t-1 Where V_other_t represents the mud volume in other circulation tanks at a certain moment t; V_other_t-1 represents the mud volume in other circulation tanks at the previous moment t-1 of a certain moment t; the unit of t is min or s.

Images