Intelligent Monitoring Method and System for Overflow and Lost Circulation in Mud Logging Operations

Abstract

The present invention provides an intelligent monitoring method and system for overflow and lost circulation in mud logging operations. The intelligent monitoring method includes identifying the movement state of the drill string and obtaining overflow and lost circulation monitoring parameters. When tripping in, compare whether the observed time when the drill string is stationary is greater than the time upper limit and whether the outlet flow rate is not zero. If so, generate an alarm message. Every X stands of drill pipe, judge whether the difference between the tripping / jacking judgment index and the normal loss amount of the drilling fluid is greater than 0, and whether the sum of the tripping / jacking judgment index and the normal loss amount of the drilling fluid is less than 0. If so, generate an alarm message. At the same time, every time Y stands of drill pipe are lowered / raised, judge whether the change rate of the drilling fluid volume is greater than the change rate upper limit value. If so, generate an alarm message. The present invention has the characteristics of remote monitoring, timeliness, accuracy, and intelligence, and realizes remote monitoring, timely and accurate monitoring, and unattended intelligent monitoring of overflow and lost circulation during tripping in and out in mud logging.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling monitoring. Specifically, it relates to an intelligent monitoring method for overflow and well leakage in mud logging operations and an intelligent monitoring system for overflow and well leakage in mud logging operations. Background Art

[0002] During the tripping process at the mud logging operation site, by monitoring the overflow and loss of drilling fluid and judging the outlet flow rate, anomalies can be detected in a timely manner to avoid situations such as well leakage, overflow, and well kick caused by out-of-control formation pore pressure. This is a commonly used and timely and effective primary well control safety monitoring method.

[0003] Currently, there are two well control safety monitoring methods, namely manual monitoring and intelligent monitoring. Among them, manual monitoring means that workers sit on guard on the circulation tank, observe the changes in the pool volume scale and the flow rate in the buffer tank, and make records. Although the method of manually sitting on guard to monitor the overflow volume can accurately judge, it is relatively lagging. Therefore, some intelligent monitoring methods have emerged, such as the analysis method for warning trends of overflow and loss during drilling tripping operations, etc. It automatically reads the volume of the drilling fluid pool, sets a threshold warning of 1.0 m 3 and performs trend calculation according to the change in the number of drill pipe strings. However, this method has high requirements for the physical processing method of the instrument accuracy.

[0004] In the prior art, the main problems existing in the monitoring methods for overflow and well leakage at the mud logging operation site include:

[0005] (1) Conventionally, the method of relying on manual tracking to monitor abnormal states such as the overflow and loss of drilling fluid, and assisted by threshold alarm, is very likely to cause manual fatigue and easily generate manual measurement errors. For example, due to the agitation of the drilling fluid pump, the liquid level in the drilling fluid pool fluctuates greatly, which not only makes it inconvenient to measure the liquid volume in the drilling fluid tank, but also there will be a large difference in measurements by different people, and it is impossible to obtain a more accurate measurement result;

[0006] (2) The dependence on manual calibration during the tripping process is particularly obvious, and there is a lack of intelligent auxiliary judgment means;

[0007] (3) Using a simple single-parameter automatic anomaly warning method not only easily generates false alarms, but also the warning method is mainly single-well warning, and the established warning model cannot be generally applied to other single wells;

[0008] (4) The monitoring of the outlet flow rate usually uses a target-type outlet flowmeter or an ultrasonic sensor. The target-type outlet flowmeter obtains the percentage based on the inclination formed by the impact of the outlet drilling fluid on the target body. In actual use, its reliability will decrease due to the different maintenance frequencies of the staff and the status of the flowmeter itself; while the ultrasonic sensor will also experience frequent large fluctuations due to the adjustment of the subsea valve, resulting in a decrease in the reliability of the measured value.

[0009] A large number of scholars have done a lot of research work on the above problems and obtained some phased results. However, more or less, they obtained monitoring parameters for the selected monitoring objects and monitoring equipment, formed very complex algorithms to help identify the well leakage volume and overflow volume, and did not form new supplementary identification means.

[0010] For example, the patent document with the title of an intelligent monitoring method for drilling overflow and well leakage and the publication number of CN 101725327 A, which was published on June 29, 2010, records an intelligent monitoring method for drilling overflow and well leakage. Based on the existing hardware equipment, this method comprehensively utilizes the information of multiple sensors on site, imitates the experience of experts to propose reasonable rules for accident judgment and alarm control such as overflow and well leakage, and realizes automatic monitoring and alarm control through a computer. The patent document with the title of a method for analyzing the overflow and leakage warning trend during the drilling tripping operation and during the drilling running operation and the publication number of CN 109707368 A, which was published on May 3, 2019, records a new method for analyzing the overflow and leakage trend based on the change amount of the mud. That is, on the one hand, by comprehensively examining the relevant influencing factors in the drilling construction process, and on the other hand, applying advanced computer technology and intelligent algorithms, and using the original fuzzy mathematics processing method and trend analysis algorithm, it can quickly identify the mud overflow and leakage trend during the drilling tripping operation after newly obtaining the grouting volume or drainage volume of each stand of drill pipe, breaking the original cognitive limitations and solving the problems of complex calculation, slow speed and untimely of the current overflow monitoring and warning. Summary of the Invention

[0011] The purpose of the present invention is to solve at least one of the above deficiencies existing in the prior art. For example, one of the purposes of the present invention is to provide a method and system capable of intelligently monitoring the overflow and well leakage of drilling fluid during the tripping operation.

[0012] To achieve the above purpose, on the one hand, the present invention provides an intelligent monitoring method for overflow and well leakage in mud logging operations. The intelligent monitoring method includes the following steps:

[0013] Identify the movement state of the drill string and obtain the monitoring parameters for overflow and lost circulation. The monitoring parameters for overflow and lost circulation include the volume change of the drill string entering the well, the volume change of the drill string exiting the well, the actual volume change of the drilling fluid, the volume change rate of the drilling fluid, the normal loss of the drilling fluid during drilling, and the outlet flow rate.

[0014] During the process of running in the hole, when the movement state of the drill string is stationary, compare the observed time T of the drill string being stationary o with the time upper limit T c in terms of magnitude. If T o >T c , and the outlet flow rate is not 0, then generate an alarm message for overflow during running in the hole.

[0015] When the movement state of the drill string is running in the hole, if there is no grouting operation, then at every interval of X stands of drill string distance, compare the difference between the running-in-hole judgment index and the normal loss of the drilling fluid, and the sum of the running-in-hole judgment index and the normal loss of the drilling fluid with 0 respectively. If the difference between the running-in-hole judgment index and the normal loss of the drilling fluid is greater than 0, then generate an alarm message for overflow during running in the hole. If the sum of the running-in-hole judgment index and the normal loss of the drilling fluid is less than 0, then generate an alarm message for lost circulation during running in the hole.

[0016] When the movement state of the drill string is pulling out of the hole, if there is a continuous grouting operation, then at every interval of X stands of drill string distance, compare the difference between the pulling-out-of-hole judgment index and the normal loss of the drilling fluid, and the sum of the pulling-out-of-hole judgment index and the normal loss of the drilling fluid with 0 respectively. If the difference between the pulling-out-of-hole judgment index and the normal loss of the drilling fluid is greater than 0, then generate an alarm message for overflow during pulling out of the hole. If the sum of the pulling-out-of-hole judgment index and the normal loss of the drilling fluid is less than 0, then generate an alarm message for lost circulation during pulling out of the hole.

[0017] Meanwhile, during the process of running in and pulling out of the hole, at every interval of Y stands of drill string distance, judge whether the volume change rate of the drilling fluid is greater than the upper limit value of the change rate. If so, then generate an alarm message for overflow during running in / pulling out of the hole.

[0018] The running-in-hole judgment index is obtained by calculation according to formula (1), and the pulling-out-of-hole judgment index is obtained by calculation according to formula (2). Formula (1) and formula (2) are as follows:

[0019] RIHI = ΔV p - ΔV d1 (1)

[0020] ROHI = ΔV p + ΔV d2 (2)

[0021] In the formula, RIHI is the running-in-hole judgment index, m 3 ; ROHI is the pulling-out-of-hole judgment index, m 3 ; ΔV pis the actual volume change of the drilling fluid during the process of pulling out or running in the drill string, m 3 ; ΔV d1 is the volume change of the drill string entering the well, m 3 ; ΔV d2 is the volume change of the drill string exiting the well, m 3 .

[0022] In an exemplary embodiment of the intelligent monitoring method for overflow and lost circulation in mud logging operations of the present invention, X can be 1 to 100, and Y can be 1 to 100.

[0023] In an exemplary embodiment of the intelligent monitoring method for overflow and lost circulation in mud logging operations of the present invention, the time upper limit T c can be 100 s to 180 s.

[0024] In an exemplary embodiment of the intelligent monitoring method for overflow and lost circulation in mud logging operations of the present invention, the step of identifying the motion state of the drill string may include:

[0025] Obtain the real-time bit position and time of the drill string;

[0026] According to the real-time bit position and time, obtain the motion speed of the bit;

[0027] Compare the motion speed of the bit with 0. If the motion speed of the bit is greater than 0, then determine that the drilling motion state is running in the drill string. If the motion speed of the bit is equal to 0, then determine that the drilling motion state is stationary. If the motion speed of the bit is less than 0, then determine that the drilling motion state is pulling out the drill string.

[0028] In an exemplary embodiment of the intelligent monitoring method for overflow and lost circulation in mud logging operations of the present invention, the step of obtaining the volume change of the drill string entering the well or the volume change of the drill string exiting the well may include:

[0029] Obtain the cross-sectional area and time of the drill string entering / exiting the well;

[0030] According to the motion speed of the bit, the cross-sectional area of the drill string entering / exiting the well and the time, obtain the volume change of the drill string entering the well or the volume change of the drill string exiting the well.

[0031] In an exemplary embodiment of the intelligent monitoring method for overflow and lost circulation in mud logging operations of the present invention, during the whole process of running in the drill string, the cross-sectional area of the drill string entering the well can be calculated by formula (3); during the whole process of pulling out the drill string, the cross-sectional area of the drill string exiting the well can be calculated by formula (4);

[0032] The formula (3) and formula (4) are:

[0033]

[0034]

[0035] Wherein, S1(t) is the cross-sectional area of the drill string entering the well at time t, m 2 ; S2(t) is the cross-sectional area of the drill string exiting the well at time t, m 2 ; d0(t) is the outer diameter of the drill pipe at time t, m; d i (t) is the inner diameter of the drill pipe at time t, m.

[0036] In an exemplary embodiment of the intelligent monitoring method for overflow and lost circulation in mud logging operations of the present invention, the step of obtaining the actual volume change of the drilling fluid may include:

[0037] Obtain the volume of the circulating total pit at different times;

[0038] Obtain the actual volume change of the drilling fluid according to the volumes of the circulating total pit corresponding to two different times.

[0039] In an exemplary embodiment of the intelligent monitoring method for overflow and lost circulation in mud logging operations of the present invention, the step of determining the upper limit value of the change speed may include:

[0040] Track the value of the change speed of the drilling fluid volume to obtain the probability distribution density curve;

[0041] Determine the maximum value of the change speed of the drilling fluid volume corresponding to the probability distribution density value equal to α on the probability distribution density curve as the upper limit value v max of the change speed, where 0 < α < 0.5.

[0042] In an exemplary embodiment of the intelligent monitoring method for overflow and lost circulation in mud logging operations of the present invention, the step of determining the normal loss amount of the drilling fluid may include:

[0043] Obtain at least three groups of reference data, and the parameter data includes the number of change columns of the drill string entering / leaving the well and the normal loss amount of the drilling fluid;

[0044] Construct a normal loss function of the drilling fluid according to the at least three groups of parameter data;

[0045] Obtain the normal loss amount of the drilling fluid corresponding to the number of drill strings to be calculated according to the normal loss function of the drilling fluid.

[0046] In an exemplary embodiment of the intelligent monitoring method for overflow and lost circulation in mud logging operations of the present invention, the intelligent monitoring method may further include:

[0047] During the process of lowering the drill string, when there is a grouting operation, the overflow and lost circulation monitoring parameters between before grouting and the previous monitoring point are obtained, and the judgment calculation of the drill string distance from overflow and lost circulation without grouting is carried out to judge whether there is overflow and / or lost circulation;

[0048] The overflow and lost circulation monitoring parameters during the grouting process are obtained again, and it is judged whether there is overflow and / or lost circulation;

[0049] Taking the bit position after grouting as a new monitoring point, continue to carry out the judgment calculation of the drill string distance from overflow and lost circulation without grouting every X drill string distances to judge whether there is overflow and / or lost circulation.

[0050] In an exemplary embodiment of the intelligent monitoring method for overflow and lost circulation in mud logging operations of the present invention, the intelligent monitoring method may further include:

[0051] When there is an intermittent grouting operation during the process of pulling out the drill string, every X drill string distances, it is judged whether the difference between the pulling-out judgment index and the normal loss amount of the drilling fluid is greater than 0. If so, a pulling-out overflow alarm message is generated; if not, a pulling-out lost circulation alarm message is generated;

[0052] Meanwhile, it is monitored whether the outlet flow rate before grouting during the process of pulling out the drill string is not 0. If so, a pulling-out overflow alarm message is generated.

[0053] In an exemplary embodiment of the intelligent monitoring method for overflow and lost circulation in mud logging operations of the present invention, the intelligent monitoring method may further include:

[0054] When the drill string depth does not reach the X-column depth, the position of the current bit can be manually used to replace the position of the bit at the X-column, and the judgment calculation of the drill string distance from overflow and lost circulation without grouting is carried out to judge whether there is overflow and / or lost circulation.

[0055] On the other hand, the present invention provides an intelligent monitoring system for overflow and lost circulation in mud logging operations. The intelligent monitoring system may include a drill string movement state recognition module, an overflow and lost circulation monitoring parameter acquisition module, a drill string static monitoring module, an X-column distance overflow monitoring module, an X-column distance lost circulation monitoring module, a total pit volume change trend determination module, and an alarm module. Among them,

[0056] The drill string movement state recognition module is configured to be able to obtain the movement speed of the bit in real time and output the drill string movement state at the current moment;

[0057] The overflow and lost circulation monitoring parameter acquisition module is connected to the drill string movement state recognition module and is configured to be able to acquire overflow and lost circulation monitoring parameters in real time. The overflow and lost circulation monitoring parameters include the volume change of the drill string entering the well, the volume change of the drill string exiting the well, the actual volume change of the drilling fluid, the volume change rate of the drilling fluid, the normal loss of the drilling fluid during drilling, and the outlet flow rate;

[0058] The drill string static monitoring module is connected to the drill string movement state module and the overflow and lost circulation monitoring parameter acquisition module and is configured to be able to monitor the static state of the drill string and the outlet flow rate during the process of running in the hole. If the observed time T of the drill string being static o is greater than the time upper limit T c , and the outlet flow rate is not 0, then an overflow and lost circulation alarm signal is output;

[0059] The X-column distance overflow monitoring module is connected to the drill string movement state module and the overflow and lost circulation monitoring parameter acquisition module and is configured to be able to monitor and judge whether the difference between the downhole judgment index and the normal loss of the drilling fluid is greater than 0 every X-column drill string distance when the drill string movement state is running in the hole and there is no grouting action. If so, a downhole overflow alarm signal is output,

[0060] The X-column distance overflow monitoring module is also configured to be able to monitor and judge whether the difference between the uphole judgment index and the normal loss of the drilling fluid is greater than 0 every X-column drill string distance when the drill string movement state is pulling out of the hole and there is continuous grouting action. If so, an uphole overflow alarm signal is output;

[0061] The X-column distance lost circulation monitoring module is connected to the drill string movement state module and the overflow and lost circulation monitoring parameter acquisition module and is configured to be able to monitor and judge whether the sum of the downhole judgment index and the normal loss of the drilling fluid is less than 0 every X-column drill string distance when the drill string movement state is running in the hole and there is no grouting action. If so, a downhole lost circulation alarm signal is output,

[0062] The X-column distance lost circulation monitoring module is also configured to be able to monitor and judge whether the sum of the uphole judgment index and the normal loss of the drilling fluid is less than 0 every X-column drill string distance when the drill string movement state is pulling out of the hole and there is continuous grouting action. If so, an uphole lost circulation alarm signal is output;

[0063] The total pit volume change trend determination module is connected to the overflow and lost circulation monitoring parameter acquisition module and is configured to be able to monitor and judge whether the volume change rate of the drilling fluid is greater than the change rate upper limit value every Y-column drill string distance during the process of running in and pulling out of the hole. If so, a downhole / uphole overflow alarm signal is output;

[0064] The alarm module is respectively connected to the drill tool static monitoring module, the X-column distance overflow monitoring module, the X-column distance well leakage monitoring module, and the total pool volume change trend determination module, and is configured to be able to generate corresponding overflow and / or well leakage alarm information after obtaining an overflow and / or well leakage alarm signal.

[0065] In an exemplary embodiment of the intelligent monitoring system for overflow and well leakage in mud logging operations of the present invention, the intelligent monitoring system may further include a grouting trigger monitoring module. The grouting trigger monitoring module is respectively connected to the X-column distance overflow monitoring module and the X-column distance well leakage monitoring module, and is configured to be able to control the X-column distance overflow monitoring module and the X-column distance well leakage monitoring module to respectively obtain overflow and well leakage monitoring parameters and perform drill tool distance overflow and well leakage judgment calculations before and after grouting during the process of lowering the drill string, so as to judge whether there is overflow and well leakage.

[0066] The grouting trigger monitoring module is further configured to be able to control the X-column distance overflow monitoring module and the X-column distance well leakage monitoring module to judge whether the difference between the lifting judgment index and the normal loss amount of the drilling fluid is greater than 0 every X-column drill tool distance during the process of pulling out the drill string when there is an intermittent grouting action. If so, a lifting overflow alarm signal is generated; if not, a lifting well leakage alarm signal is generated.

[0067] In an exemplary embodiment of the intelligent monitoring system for overflow and well leakage in mud logging operations of the present invention, the intelligent monitoring system may further include a manual monitoring module. The manual monitoring module is connected to the X-column distance overflow monitoring module and the X-column distance well leakage monitoring module, and is configured to be able to control the X-column distance overflow monitoring module and the X-column distance well leakage monitoring module to obtain and calculate the overflow and well leakage monitoring parameters between the current drill tool depth and the previous monitoring point, so as to judge whether there is overflow and well leakage.

[0068] In an exemplary embodiment of the intelligent monitoring system for overflow and well leakage in mud logging operations of the present invention, the intelligent monitoring system may further include an outlet flow monitoring module. The outlet flow monitoring module is respectively connected to the drill tool movement state recognition module and the overflow and well leakage monitoring parameter acquisition module, and is configured to be able to monitor and judge whether the outlet flow when there is no grouting is not 0 when the drill tool movement state is pulling out the drill string and there is an intermittent grouting action. If so, a lifting overflow alarm signal is output.

[0069] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0070] (1) The present invention supplements and identifies critical operating conditions by calculating the motion state of the drill string, determines the tripping-in and tripping-out judgment index by establishing the formula derivation of the normal loss amount and the time balance relationship between volumes, and comprehensively applies the change in the change rate of the drilling fluid volume and its distribution density, and the relationship between the actual loss amount of the drilling fluid and the tripping-in and tripping-out judgment index to identify and predict the occurrence of overflow and lost circulation, improving the accuracy of the entire overflow and lost circulation prediction scheme;

[0071] (2) The present invention has the characteristics of remote monitoring, timeliness, accuracy, and intelligence, realizing remote monitoring, timely and accurate monitoring, and unattended intelligent monitoring of overflow and lost circulation during the tripping-in and tripping-out process of mud logging;

[0072] (3) The present invention has strong auxiliary judgment ability even in high-risk areas, not only with low cost, but also can save manpower, improve the working environment and enhance work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Through the following description with reference to the accompanying drawings, the above and other objects and / or features of the present invention will become clearer, wherein:

[0074] Figure 1 The flow chart of the monitoring method of overflow and lost circulation during the tripping-in process of an exemplary embodiment of the intelligent monitoring method of overflow and lost circulation for mud logging operations of the present invention is shown.

[0075] Figure 2 The flow chart of the monitoring method of overflow and lost circulation during the tripping-out process of an exemplary embodiment of the intelligent monitoring method of overflow and lost circulation for mud logging operations of the present invention is shown.

[0076] Figure 3 The function curve graph of the normal loss of the drilling fluid of an exemplary embodiment of the intelligent monitoring method of overflow and lost circulation for mud logging operations of the present invention is shown.

[0077] Figure 4 The probability distribution density graph of the change rate of the drilling fluid volume of an exemplary embodiment of the intelligent monitoring method of overflow and lost circulation for mud logging operations of the present invention is shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0078] Hereinafter, the intelligent monitoring method and system for overflow and lost circulation in mud logging operations of the present invention will be described in detail with reference to exemplary embodiments.

[0079] In order to change the current situation of completely relying on manual labor for monitoring overflow and lost circulation during tripping-in and tripping-out in the mud logging operation site, the present invention provides an intelligent monitoring method for overflow and lost circulation in mud logging operations on the one hand.

[0080] In an exemplary embodiment of the present invention, an intelligent monitoring method for overflow and well leakage in mud logging operations includes: a monitoring method for overflow and well leakage during the process of running in the drill string, and / or a monitoring method for overflow and well leakage during the process of pulling out the drill string.

[0081] Specifically, as Figure 1 shown, the monitoring method for overflow and well leakage during the process of running in the drill string may include the following steps:

[0082] S11. During the whole process of running in the drill string, identify the movement state of the drill string and obtain the monitoring parameters for overflow and well leakage. Among them, the monitoring parameters for overflow and well leakage to be obtained during running in the drill string may include the volume change amount ΔV of the drill string entering the well d1 , the actual volume change amount ΔV of the drilling fluid p , the volume change rate of the drilling fluid , the normal loss amount E of the drilling fluid and the outlet flow rate Q.

[0083] S12. During the process of running in the drill string, when the movement state of the drill string is stationary, adopt the drill string stationary monitoring method to monitor the duration of the drill string being stationary and the outlet flow rate, and compare the observed time T o of the drill string being stationary with the time upper limit T c . If the result of the drill string stationary monitoring shows that: T o > T c , and the outlet flow rate is not 0, then generate an overflow alarm message during running in the drill string.

[0084] It should be noted that during the whole process of running in the drill string, if the drill bit does not move, theoretically the outlet flow rate should be 0. Therefore, if it is observed that the drill bit does not move and the observed time T o exceeds the time upper limit T c , but there is an outlet flow rate, then an alarm should be issued, and the alarm content can be "suspected overflow, when sitting and clamping, the outlet does not stop flowing". For example, the time upper limit T c can be 100 s to 180 s.

[0085] S13. When the movement state of the drill string is running in the drill string, if there is no grouting action, the X-column distance monitoring method can be adopted to monitor the possible overflow and well leakage abnormalities during the process of the drill string descending. The specific monitoring content of the X-column distance monitoring method is: every interval of the X-column drill string distance, compare the difference between the run-in-hole judgment index RIHI (Run in hole Index) and the normal loss amount E of the drilling fluid, and the sum of the run-in-hole judgment index RIHI and the normal loss amount E of the drilling fluid with 0 respectively. If the difference between the run-in-hole judgment index RIHI and the normal loss amount E of the drilling fluid is greater than 0, then generate an overflow alarm message during running in the drill string; if the sum of the run-in-hole judgment index RIHI and the normal loss amount E of the drilling fluid is less than 0, then generate a well leakage alarm message during running in the drill string.

[0086] Wherein, X is a positive integer, and X ∈ [1, 2, ……, len], where len is the maximum number of stands in the drill string table. For example, X can be 1 to 100.

[0087] It should be noted that the tripping-in judgment index RIHI is obtained by calculating with formula (1), and formula (1) is:

[0088] RIHI = ΔV p -ΔV d1 (1)

[0089] In the formula, RIHI is the tripping-in judgment index, m 3 ; ΔV p is the actual volume change of the drilling fluid during tripping-in, m 3 ; ΔV d1 is the volume change of the drill string entering the well, m 3 .

[0090] The tripping-in overflow alarm message can be "Suspected tripping-in overflow, the drill string from stand xxx to stand xxx, the bit position changes from xxx meters to xxx meters, should return xxx strokes, actually returned xxx strokes, returned xxx more strokes"; the tripping-in lost circulation alarm message can be "Suspected tripping-in lost circulation, the drill string from stand xxx to stand xxx, the bit position changes from xxx meters to xxx meters, should return xxx strokes, actually returned xxx strokes, returned xxx fewer strokes".

[0091] It should be noted that the theoretical balance relationship between the volume change of the drill string entering the well and the actual volume change of the drilling fluid is as follows.

[0092] Let the volume of the drilling fluid in the wellbore be V w (t), the volume of the drilling fluid in the auxiliary pipeline is V l (t), and the volume of the drilling fluid in the total circulation pit is V p (t). Assuming that the drilling fluid is an incompressible fluid, during the circulation process, the total amount of the drilling fluid remains unchanged.

[0093] Then there is: V w (t) + V p (t) + V l (t) = C m (constant).

[0094] In addition, assuming that during the tripping process, the capacity of the wellbore remains unchanged.

[0095] Then there is: V w (t) + V d1 (t) = C w (constant).

[0096] Where V d (t) is the volume of the drill string entering the well.

[0097] In summary, and assuming that the drilling fluid in the auxiliary pipeline remains unchanged at different times, the following set of equations can be obtained at time t1 and time t2.

[0098]

[0099] After simplification, we have: V d1 (t2)-V d1 (t1) = V p (t2)-V p (t1)=-(V w (t2)-V w (t1)).

[0100] remember Then ΔV d =ΔV p =-ΔV w , if they are not equal, it is necessary to determine whether an exception occurs.

[0101] But in fact, there will be a certain amount of loss of drilling fluid in the wellbore circulation. If the loss causes ΔV d ≠ΔV p If the situation is not abnormal, it does not belong to overflow and well leakage.

[0102] That is, when ΔV d1 ≠ΔV p When drilling, it is necessary to judge whether overflow and well leakage occur according to the relationship between the drilling judgment index RIHI and the loss of drilling fluid. p -ΔV d1 -E(X)>0 (i.e., RIHI>E(X)), which means that after the drill string descends X columns, the actual volume of drilling fluid returned from the circulating pool is greater than the theoretical volume of drilling fluid returned, and it can be considered that drilling overflow occurs; if ΔV p -ΔV d1 +E(X)<0 (i.e., RIHI<-E(X)), which means that after the drill string descends X columns, the actual volume of drilling fluid returned from the circulating total pool is less than the theoretical volume of drilling fluid returned, which can be considered as leakage in the drilling well.

[0103] S14. At the same time, the volume change rate of the drilling fluid can also be monitored during the drilling process. When the volume change rate of the drilling fluid exceeds the upper limit of the change rate, it can be determined that an overflow abnormality has occurred.

[0104] For example, every time the Y-column drill goes down, it can be determined whether the drilling fluid volume change rate is greater than the change rate upper limit value v max, if so, generate a kick warning message during tripping out. For another example, Y can be from 1 to 100.

[0105] As Figure 2 shown, the method for monitoring kick and lost circulation during tripping out may include the following steps:

[0106] S21. During the whole process of tripping out, identify the movement state of the drill string and obtain the monitoring parameters for kick and lost circulation. Among them, the monitoring parameters for kick and lost circulation to be obtained during tripping out may include the volume change ΔV of the drill string out of the well d2 , the actual volume change ΔV of the drilling fluid p , the volume change rate of the drilling fluid the normal loss E of the drilling fluid and the outlet flow rate Q.

[0107] S22. When the movement state of the drill string is tripping out, if there is a continuous grouting operation, adopt the X-column distance monitoring method to monitor the possible kick and lost circulation abnormalities during the upward movement of the drill string. The specific monitoring content of the X-column distance monitoring method is: every X-column drill string distance, compare the difference between the tripping out judgment index ROHI (Run out of hole Index) and the normal loss E of the drilling fluid, and the sum of the tripping out judgment index ROHI and the normal loss E of the drilling fluid with 0 respectively. If the difference between the tripping out judgment index ROHI and the normal loss E of the drilling fluid is greater than 0, generate a kick warning message during tripping out; if the sum of the tripping out judgment index ROHI and the normal loss E of the drilling fluid is less than 0, generate a lost circulation warning message during tripping out. Among them, X is a positive integer, and X ∈ [1, 2, ……, len], where len is the maximum number of columns in the drill string table. For example, X can be from 1 to 100.

[0108] For example, the kick warning message during tripping out can be "Suspected kick during tripping out, the drill string from xxx column to xxx column, the bit position changes from xxx meters to xxx meters, the volume of the grouting tank changes from xxx cubic meters to xxx cubic meters, rising (or falling) xxx cubic meters, and the volume of the drill string out of the well is xxx cubic meters"; the lost circulation warning message during tripping out can be "Suspected lost circulation during tripping out, the drill string from xxx column to xxx column, the bit depth changes from xxx meters to xxx meters, the volume of the grouting tank changes from xxx cubic meters to xxx cubic meters, and the volume of the drill string out of the well is xxx cubic meters".

[0109] It should be noted that since there is an operation of replenishing the drilling fluid from the circulation tank to the grouting tank, this is a disturbing factor for calculating the volume of the grouting tank. Therefore, when doing the following calculations, all data during the replenishment of the drilling fluid are excluded. When adopting the continuous grouting method, the tripping out judgment index ROHI is obtained by calculating with formula (2), and formula (2) is:

[0110] ROHI = ΔV p +ΔV d2 (2)

[0111] In the formula, ROHI is the tripping-out judgment index, m 3 ; ΔV p is the actual volume change of the drilling fluid during the tripping-in process, m 3 ; ΔV d2 is the volume change of the drill string out of the well, m 3 .

[0112] It should be noted that theoretically, the balance relationship between the volume change of the drill string out of the well and the actual volume change of the drilling fluid can also be: ΔV d = ΔV p = -ΔV w . If they are not equal, it is necessary to judge whether there is an abnormality.

[0113] However, in practice, there will inevitably be a certain loss of the drilling fluid during the circulation in the wellbore. If this loss leads to the situation of ΔV d ≠ΔV p , it does not belong to the abnormal situations of overflow and lost circulation.

[0114] That is to say, when ΔV d2 ≠ΔV p , it is necessary to judge whether there are abnormal situations of overflow and lost circulation according to the magnitude relationship between the tripping-out judgment index ROHI and the loss of the drilling fluid. For example, when X stands of drill string are lifted, if the situation of ΔV p +ΔV d2 -E(X)>0 (i.e., ROHI>E(X)) occurs, it means that after X stands of drill string are lifted, the actual changed volume of the drilling fluid in the grouting tank is greater than the theoretically changed volume of the drilling fluid, and it can be considered that there is a situation of tripping-out overflow; if the situation of ΔV p +ΔV d2 +E(X)<0 (i.e., ROHI<-E(X)) occurs, it means that after X stands of drill string are lowered, the actual changed volume of the drilling fluid in the grouting tank is less than the theoretically changed volume of the drilling fluid, and it can be considered that there is a situation of tripping-in lost circulation.

[0115] S23. At the same time, during the tripping-out process, the change speed of the drilling fluid volume can also be monitored. When the change speed of the drilling fluid volume exceeds the upper limit value of the change speed, it can be judged that there is an overflow abnormality.

[0116] For example, it can be judged whether the change speed of the drilling fluid volume is greater than the upper limit value of the change speed v max every time Y stands of drill string are lifted. If so, overflow and lost circulation alarm information is generated. For another example, Y can be 1 to 100.

[0117] In this embodiment, the method for monitoring overflow and lost circulation during tripping operations may include: tracking the movement characteristics of the drill string and supplementing the automatic identification of key control actions.

[0118] Among them, the identification rules for key tripping actions are as follows:

[0119] Grouting into the drill string during tripping (only applicable when there is a backpressure valve): There is continuous pump stroke.

[0120] Identify pump start and stop, summarize the previous tripping section. Record the reference volume and number of stands. After identifying pump stop, the delay time T c , record the reference volume. Compare the actual injected volume with the theoretical volume and output information. Re - establish monitoring, record the number of stands and volume. Identify the pump start method and the duration T c There is pump stroke. In addition, use the standpipe pressure to identify whether it is real grouting. If the standpipe pressure does not rise significantly, it is regarded as not grouting into the drill string. There is no standpipe pressure during grouting. When there is standpipe pressure, it means it is almost full. At this time, if continuous grouting is carried out, there will be outlet flow.

[0121] The identification rules for key pulling - out actions are as follows:

[0122] Supplementary drilling fluid: There is continuous pump stroke for more than T1 seconds, and the volume in the grouting tank rises.

[0123] Grouting into the wellbore (only applicable to intermittent grouting): The grouting tank continuously drops during intermittent grouting, and the grouting tank will not continuously drop.

[0124] Supplementary drilling fluid (regardless of intermittent or continuous grouting, it is necessary to identify pump start to supplement drilling fluid): Identify pump start (there is pump stroke for T2 seconds), summarize the previous pulling - out section, record the grouting volume before T3, identify the delay T4 seconds after pump stop, record and submit it as a reference, and re - establish monitoring. The values of T1, T2, T3, and T4 can be set according to the time situation.

[0125] In this embodiment, the steps for identifying the movement state of the drill string may include:

[0126] (a) Obtain the real - time bit position and time of the drill string;

[0127] (b) Based on the real - time bit position and time, obtain the movement speed of the bit at the current moment;

[0128] (c) Compare the movement speed of the bit with 0. If the movement speed of the bit is greater than 0, then judge the drilling movement state as tripping; if the movement speed of the bit is equal to 0, then judge the drilling movement state as stationary; if the movement speed of the bit is less than 0, then judge the drilling movement state as pulling - out.

[0129] That is to say, the calculation method of the drill string movement state can be: assuming the drill bit position is u (unit: meter), and u is a function of time t, that is, u = u(t), then the derivative of u with respect to time is the movement speed of the drill bit. According to the value-taking situation, the following characteristics of the drill string movement state can be obtained:

[0130]

[0131] In this embodiment, the steps of obtaining the volume change of the drill string entering the well may include:

[0132] (a) Obtain the cross-sectional area and time of the drill string entering the well;

[0133] (b) Obtain the volume change of the drill string entering the well according to the movement speed of the drill bit, the cross-sectional area of the drill string entering the well, and the time.

[0134] The steps of obtaining the volume change of the drill string exiting the well may include:

[0135] (a) Obtain the cross-sectional area and time of the drill string exiting the well;

[0136] (b) Obtain the volume change of the drill string exiting the well according to the movement speed of the drill bit, the cross-sectional area of the drill string exiting the well, and the time.

[0137] For example, during the whole process of running in the hole, assuming the cross-sectional area of the drill string at the wellhead is S1(t), the value of S1(t) needs to be calculated depending on two factors according to the configuration of the drill string table at that time. One is the outer diameter d0(t) and inner diameter d i (t) of the current drill pipe; the other is whether there is a back pressure valve in the current drilling assembly. Therefore, the cross-sectional area of the drill string entering the well can be calculated by formula (3), and the expression of formula (3) is as follows:

[0138]

[0139] In the formula, S1(t) is the cross-sectional area of the drill string entering the well at time t, m 2 ; d0(t) is the outer diameter of the drill pipe at time t, m; d i (t) is the inner diameter of the drill pipe at time t, m.

[0140] During the whole process of pulling out of the hole, assuming the cross-sectional area of the drill string at the wellhead is S2(t), the value of S2(t) can be obtained according to the configuration of the drill string table at that time. The outer diameter d0(t) and inner diameter d i (t) of the current drill pipe can be obtained, and the cross-sectional area of the drill string exiting the well can be calculated by formula (4), and the expression of formula (4) is as follows:

[0141]

[0142] Wherein, S2(t) is the cross-sectional area of the drill string exiting the wellbore at time t, in m 2 ; d0(t) is the outer diameter of the drill pipe at time t, in m; d i (t) is the inner diameter of the drill pipe at time t, in m.

[0143] Based on the cross-sectional area S1(t) of the drill string entering the wellbore at the wellhead, the volume change ΔV of the drill string entering the wellbore from time t1 to time t2 can be obtained d1 as follows:

[0144]

[0145] wherein, ΔV d1 is the volume change of the drill string entering the wellbore, in m 3 ; V d1 (t1) is the volume of the drill string entering the wellbore at time t1, in m 3 ; V d1 (t2) is the volume of the drill string entering the wellbore at time t2, in m 3 ; S1(t) is the cross-sectional area of the drill string entering the wellbore at time t, in m 2 ; is the moving speed of the drill bit, in m / s.

[0146] Similarly, based on the cross-sectional area S2(t) of the drill string exiting the wellbore at the wellhead, the volume change ΔV of the drill string exiting the wellbore from time t1 to time t2 can be obtained d2 as follows:

[0147]

[0148] wherein, ΔV d2 is the volume change of the drill string exiting the wellbore, in m 3 ; V d2 (t1) is the volume of the drill string leaving the wellbore at time t1, in m 3 ; V d2 (t2) is the volume of the drill string leaving the wellbore at time t2, in m 3 ; S2(t) is the cross-sectional area of the drill string exiting the wellbore at time t, in m 2 ; is the moving speed of the drill bit, in m / s.

[0149] In this embodiment, the steps of obtaining the actual volume change of the drilling fluid may include:

[0150] (a) Obtaining the volume of the total circulation pit at different times;

[0151] (b) Obtaining the actual volume change of the drilling fluid based on the volumes of the total circulation pit corresponding to two different times.

[0152] For example, according to the pit volume data collected by the observation logging instrument, the change in the drilling fluid volume ΔV from time t1 to time t2 can be obtained. p It is:

[0153] ΔV p =V p (t2)-V p (t1)

[0154] In the formula, ΔV p is the actual change in the drilling fluid volume during the process of running in the drill string, m 3 ; V p (t1) is the volume of the total circulation pit at time t1, m 3 ; V p (t2) is the volume of the total circulation pit at time t2, m 3 .

[0155] It should be noted that in the case of continuous grouting, t1 is the start time of string X, and t2 is the end time of string X.

[0156] In the case of intermittent grouting, t1 is the start time of grouting, and t2 is the end time of grouting.

[0157] In this embodiment, the steps for determining the normal loss amount E of the drilling fluid may include:

[0158] (a) Obtain at least three groups of reference data, and the parameter data includes the number of changing columns of the drilling fluid entering / leaving the well and the normal loss amount of the drilling fluid;

[0159] (b) Construct a normal loss function of the drilling fluid according to the at least three groups of parameter data;

[0160] (c) Obtain the normal loss amount of the drilling fluid corresponding to the drill string number to be calculated according to the normal loss function of the drilling fluid.

[0161] Since there will be some normal losses of the drilling fluid during the drilling fluid circulation process, it is necessary to calculate the normal loss amount E of the drilling fluid. It can be set according to specific situations. Select at least three data points (n, E(n)), and use the interpolation method to construct a quadratic function as the normal loss function of the drilling fluid, denoted as the normal loss function of the drilling fluid is E(n), where n represents the number of changing columns of the drill string entering the well. In practical applications, multiple n values can be set according to the situation. Here, n s , n l respectively represent a smaller number of columns and a larger number of columns. For example, three reference data points can be selected: data point 1 (0, 0), that is, when running in 0 columns of the drill string, the drilling fluid loss is 0 cubic meters; data point 2 (n s , α s ), that is, when running in n s columns of the drill string, the drilling fluid loss is α sSide; data point 3(n l , α l ), that is, drilling n l columns, and the mud loss α l cubic meters. According to the above three reference data points, a relationship curve between the normal mud loss and the number of columns entering the well can be drawn, and the finally obtained function curve of the normal mud loss is as shown in Figure 3 . After interpolation calculation, the normal mud loss function is shown as follows.

[0162]

[0163] In the formula, E(n) is the normal mud loss, m 3 ; n is the number of columns of drill pipes entering the well that changes.

[0164] In this embodiment, the steps for determining the upper limit value v max of the change speed may include:

[0165] (a) Tracking the value of the mud volume change speed to obtain a probability distribution density curve;

[0166] (b) Determining the maximum value of the mud volume change speed corresponding to when the probability distribution density value on the probability distribution density curve is equal to α as the upper limit value v max of the change speed, where 0 < α < 0.5.

[0167] It should be noted that the actual change speed of the mud volume is the derivative with respect to time, that is, The trend of the total pit volume change can be judged according to the value. For example, by tracking and counting the value, the probability distribution density of can be approximately obtained. Let v max be the upper bound acceptable for , and the probability 0 < α < 0.05. When , it can be judged that an overflow anomaly has occurred. For example, as shown in Figure 4 , when the probability distribution density value on the vertical coordinate is equal to α, the corresponding mud volume change speed on the horizontal coordinate can be regarded as the upper limit value v max .

[0168] In this embodiment, the intelligent monitoring method for overflow and lost circulation during the tripping operation may further include: during the tripping operation, when there is a grouting action, the monitoring process is divided into two stages, namely the processing before the grouting action and the processing after the grouting action.

[0169] (a) Processing before the grouting action

[0170] Capture the start time of grouting. Use the total pit volume at this time as the total pit end value, and judge whether overflow occurs according to the non-grouting method for the change of the total pit volume in the previous stage.

[0171] (b) Treatment after grouting operation

[0172] After the grouting process is completed, calculate the changes in relevant parameters caused by the changes in the total pit volume and the bit depth before and after grouting, and output the information "The total pit volume before and after grouting changes from xxx cubic meters to xxx cubic meters, a decrease of xxx cubic meters". Then use the bit position at the time of pump shutdown as the bit depth of the new tracking point; use the circulating total pit volume at the pump shutdown time as the circulating total pit volume of the new tracking point.

[0173] For example, a grouting trigger monitoring method can be used to monitor the grouting operation during the lowering process with a distance of grouting operation. The grouting trigger monitoring method can include:

[0174] When there is a grouting operation during the lowering process, obtain the overflow and lost circulation monitoring parameters between before grouting and the previous monitoring point, and perform the judgment calculation of overflow and lost circulation of the drill string distance without grouting to judge whether there is overflow and / or lost circulation;

[0175] Re-obtain the overflow and lost circulation monitoring parameters during the grouting process, and judge whether there is overflow and / or lost circulation;

[0176] Take the bit position after grouting as the new monitoring point, and continue to perform the judgment calculation of overflow and lost circulation of the drill string distance without grouting every X drill string distances to judge whether there is overflow and / or lost circulation.

[0177] It should be noted that the grouting trigger monitoring method is only applicable in the case of having a back pressure valve.

[0178] In addition, in this embodiment, the intelligent monitoring method for overflow and lost circulation during the pulling out process can also include: using the grouting trigger monitoring method to monitor the intermittent grouting operation during the pulling out process with a distance of grouting operation.

[0179] Among them, the grouting trigger monitoring method under the intermittent grouting operation can include:

[0180] When there is an intermittent grouting operation during the pulling out process, every X drill string distances, judge whether the difference between the pulling out judgment index and the normal loss of the drilling fluid is greater than 0. If so, generate a pulling out overflow alarm message. If not, generate a pulling out lost circulation alarm message;

[0181] At the same time, monitor whether the outlet flow before grouting during the pulling out process is not 0. If so, generate a pulling out overflow alarm message.

[0182] It should be noted that during the process of pulling out the drill string, the drill string moves upward, causing the drilling fluid to drop. However, due to mud grouting, the drilling fluid in the wellbore can be restored. The mud grouting is completed by a dedicated grouting tank, and the volume of this tank can be obtained for use. There are two mud grouting methods, namely continuous grouting and intermittent grouting. Due to the differences between these two grouting methods, the judgment methods are also different. When there is continuous grouting during the process of pulling out the drill string, according to the change in the pool volume of the grouting tank, the X-column distance monitoring method can be used to monitor the abnormal conditions of overflow and lost circulation. However, when intermittent grouting occurs during the process of pulling out the drill string, since during the period without grouting, the drill string is pulled up, and in the case of no overflow, there is no liquid returning to the grouting tank from the well, and the pool volume of the grouting tank should remain unchanged. Therefore, it is impossible to use the pool volume of the grouting tank to judge whether there is overflow or lost circulation. Only the amount of mud grouted each time can be used to judge the reduction of the drilling fluid in the well.

[0183] In addition, during the process of pulling out the drill string, if intermittent grouting occurs, then when there is no grouting, there should be no outlet flow. If there is, it is predicted as overflow during pulling out the drill string.

[0184] In this embodiment, the intelligent monitoring method for overflow and lost circulation during the process of running in and pulling out the drill string may further include: adopting a manual monitoring method to monitor the overflow and lost circulation. The specific content of the manual monitoring method is: when the depth of the drill string does not reach the X-column depth, the position of the current bit can be manually used to replace the position of the bit at the X-column, and the judgment calculation of the drill string distance overflow and lost circulation without mud grouting can be carried out to judge whether there is overflow and / or lost circulation.

[0185] On the other hand, the present invention provides an intelligent monitoring system for overflow and lost circulation in mud logging operations.

[0186] In another exemplary embodiment of the present invention, an intelligent monitoring system for overflow and lost circulation in mud logging operations may include a drill string motion state recognition module, an overflow and lost circulation monitoring parameter acquisition module, a drill string stationary monitoring module, an X-column distance overflow monitoring module, an X-column distance lost circulation monitoring module, a total pool volume change trend determination module, and an alarm module.

[0187] Among them, the drill string motion state recognition module is configured to be able to obtain the motion speed of the bit in real time and output the motion state of the drill string at the current moment.

[0188] The overflow and lost circulation monitoring parameter acquisition module is connected to the drill string motion state recognition module and is configured to be able to obtain the overflow and lost circulation monitoring parameters in real time. The overflow and lost circulation monitoring parameters include the volume change amount of the drill string entering the well, the volume change amount of the drill string leaving the well, the actual volume change amount of the drilling fluid, the volume change speed of the drilling fluid, the normal loss amount of the drilling fluid, and the outlet flow.

[0189] The drill string static monitoring module is connected to the drill string motion state module and the overflow and lost circulation monitoring parameter acquisition module, and is configured to monitor the static state of the drill string and the outlet flow rate during the lowering process. If the observed time T of the drill string being static o is greater than the time upper limit T c , and the outlet flow rate is not 0, then an alarm signal for lowering overflow is output.

[0190] The X-string distance overflow monitoring module is connected to the drill string motion state module and the overflow and lost circulation monitoring parameter acquisition module, and is configured to monitor and judge whether the difference between the lowering judgment index and the normal loss amount of the drilling fluid is greater than 0 every X-string drill string distance when the drill string motion state is lowering and there is no grouting action. If so, an alarm signal for lowering overflow is output. The X-string distance overflow monitoring module is also configured to monitor and judge whether the difference between the tripping judgment index and the normal loss amount of the drilling fluid is greater than 0 every X-string drill string distance when the drill string motion state is tripping and there is a continuous grouting action. If so, an alarm signal for tripping overflow is output.

[0191] The X-string distance lost circulation monitoring module is connected to the drill string motion state module and the overflow and lost circulation monitoring parameter acquisition module, and is configured to monitor and judge whether the sum of the lowering judgment index and the normal loss amount of the drilling fluid is less than 0 every X-string drill string distance when the drill string motion state is lowering and there is no grouting action. If so, an alarm signal for lost circulation during lowering is output. The X-string distance lost circulation monitoring module is also configured to monitor and judge whether the sum of the tripping judgment index and the normal loss amount of the drilling fluid is less than 0 every X-string drill string distance when the drill string motion state is tripping and there is a continuous grouting action. If so, an alarm signal for lost circulation during tripping is output.

[0192] The total pit volume change trend determination module is connected to the overflow and lost circulation monitoring parameter acquisition module, and is configured to monitor and judge whether the change speed of the drilling fluid volume is greater than the change speed upper limit value every Y-string drill string distance during tripping. If so, an alarm signal for lowering / tripping overflow is output.

[0193] The alarm module is respectively connected to the drill string static monitoring module, the X-string distance overflow monitoring module, the X-string distance lost circulation monitoring module, and the total pit volume change trend determination module, and is configured to generate corresponding overflow and / or lost circulation alarm information after obtaining the overflow and / or lost circulation alarm signal.

[0194] In this embodiment, the intelligent monitoring system may further include a grouting trigger monitoring module. The grouting trigger monitoring module is respectively connected to the X-column distance overflow monitoring module and the X-column distance lost circulation monitoring module, and is configured to control the X-column distance overflow monitoring module and the X-column distance lost circulation monitoring module to obtain the overflow and lost circulation monitoring parameters before and after grouting respectively and calculate the overflow and lost circulation judgment of the drill string distance during the process of lowering the drill string when a grouting action occurs, so as to judge whether there is overflow and lost circulation.

[0195] The grouting trigger monitoring module is further configured to be able to control the X-column distance overflow monitoring module and the X-column distance lost circulation monitoring module to judge whether the difference between the tripping judgment index and the normal loss of the drilling fluid is greater than 0 every X-column drill string distance when an intermittent grouting action occurs during the process of pulling out the drill string. If so, a tripping overflow alarm signal is generated; if not, a tripping lost circulation alarm signal is generated.

[0196] In this embodiment of the present invention, the intelligent monitoring system may further include a manual monitoring module. The manual monitoring module is connected to the X-column distance overflow monitoring module and the X-column distance lost circulation monitoring module, and is configured to control the X-column distance overflow monitoring module and the X-column distance lost circulation monitoring module to obtain and calculate the overflow and lost circulation monitoring parameters between the current drill string depth and the previous monitoring point to judge whether there is overflow and lost circulation.

[0197] In this embodiment, the intelligent monitoring system may further include an outlet flow monitoring module. The outlet flow monitoring module is respectively connected to the drill string movement state recognition module and the overflow and lost circulation monitoring parameter acquisition module, and is configured to be able to monitor and judge whether the outlet flow when there is no grouting is not 0 when the drill string movement state is pulling out the drill string and there is an intermittent grouting action. If so, a tripping overflow alarm signal is output.

[0198] By using the intelligent monitoring system of the present invention to read data, identify actions such as pulling out the drill string and grouting, and comprehensively judge using calculation indicators, it is suspected that overflow is found at 18:21 and an alarm is issued. This alarm time is 6 minutes earlier than that of manual work, which wins time for effectively controlling the bottom hole pressure and successfully avoids possible well control risks.

[0199] In addition, compared with the current mud logging tripping monitoring that completely relies on manual work, the present invention can realize remote intelligent monitoring, and has strong auxiliary judgment ability even in high-risk areas, with low cost, saving manpower, improving the working environment and enhancing work efficiency.

[0200] Taking a risk well in the Sichuan-Chongqing region as an example, assuming a well with a designed depth of 6000 meters and 30 trippings in the whole well, and the average time for each tripping is 1.5 days. By using this method as an auxiliary discrimination means, it can effectively reduce manual fatigue, improve work efficiency, save the working hours of manual rotation, and a well can save 45 days of manual working hours.

[0201] In summary, the beneficial effects of the present invention include at least one of the following:

[0202] (1) By adopting the calculation of the drill string motion state, the present invention supplements and identifies the key working conditions operationally. By establishing the formula derivation of the normal loss amount and the time balance relationship between volumes, etc., the tripping judgment index is determined. By comprehensively applying the change in the change rate of the drilling fluid volume and its distribution density, and the relationship between the actual loss amount of the drilling fluid and the tripping judgment index, the occurrence of overflow and lost circulation is identified and predicted, improving the accuracy of the entire overflow and lost circulation prediction scheme;

[0203] (2) The present invention features remote monitoring, timeliness, accuracy, and intelligence, realizing remote monitoring, timely and accurate monitoring, and unattended intelligent monitoring of overflow and lost circulation during the tripping process of mud logging;

[0204] (3) The present invention has strong auxiliary judgment ability even in high-risk areas, not only with low cost, but also capable of saving manpower, improving the working environment, and enhancing work efficiency.

[0205] Although the present invention has been described above in conjunction with the exemplary embodiments and the drawings, those of ordinary skill in the art should clearly understand that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. An intelligent monitoring method for overflow and lost circulation in mud logging operations, characterized in that, The intelligent monitoring method includes the following steps: Identify the movement state of the drill string and obtain the monitoring parameters for overflow and lost circulation. The monitoring parameters for overflow and lost circulation include the volume change of the drill string entering the well, the volume change of the drill string exiting the well, the actual volume change of the drilling fluid, the volume change rate of the drilling fluid, the normal loss of the drilling fluid during drilling, and the outlet flow rate; During the process of running in the hole, when the moving state of the drill string is stationary, compare the observed time T of the stationary drill string o with the time limit T c . If T o > T c , and the outlet flow rate is not zero, then generate an alarm message for overflow during running in the hole; When the movement state of the drill string is running in, if there is no grouting action, then at every interval of X drill string lengths, compare the difference between the running-in judgment index and the normal loss of the drilling fluid, and the sum of the running-in judgment index and the normal loss of the drilling fluid with 0 respectively. If the difference between the running-in judgment index and the normal loss of the drilling fluid is greater than 0, generate a running-in overflow alarm message. If the sum of the running-in judgment index and the normal loss of the drilling fluid is less than 0, generate a running-in lost circulation alarm message; When the movement state of the drill string is pulling out, if there is a continuous grouting action, then at every interval of X drill string lengths, compare the difference between the pulling-out judgment index and the normal loss of the drilling fluid, and the sum of the pulling-out judgment index and the normal loss of the drilling fluid with 0 respectively. If the difference between the pulling-out judgment index and the normal loss of the drilling fluid is greater than 0, generate a pulling-out overflow alarm message. If the sum of the pulling-out judgment index and the normal loss of the drilling fluid is less than 0, generate a pulling-out lost circulation alarm message; Meanwhile, during running in and pulling out, at every interval of Y drill string lengths, judge whether the volume change rate of the drilling fluid is greater than the upper limit of the change rate. If so, generate a running-in / pulling-out overflow alarm message; The running-in judgment index is obtained by calculation according to formula (1), and the pulling-out judgment index is obtained by calculation according to formula (2). Formula (1) and formula (2) are as follows: RIHI = ΔV p -ΔV d1 (1) ROHI = ΔV p +ΔV d2 (2) wherein, RIHI is the tripping-in judgment index, m 3 ; ROHI is the tripping-out judgment index, m 3 ; ΔV p is the actual volume change of the drilling fluid during tripping-in or tripping-out, m 3 ; ΔV d1 is the volume change of the drill string entering the well, m 3 ; ΔV d2 is the volume change of the drill string leaving the well, m 3 ; The steps for determining the normal loss of the drilling fluid include: Obtain at least three sets of reference data, where the parameter data includes the number of columns of drilling fluid entering / leaving the well and the normal loss amount of drilling fluid; construct a normal loss function of drilling fluid according to the at least three sets of parameter data; obtain the normal loss amount of drilling fluid corresponding to the number of drill pipes to be calculated according to the normal loss function of drilling fluid; where the construction of the normal loss function of drilling fluid is denoted as E(n); there are multiple n values set according to the situation, and here n s , n l respectively represent a smaller number of columns and a larger number of columns; select three reference data points: data point 1(0, 0), when lowering the drill string by 0 columns, the loss of drilling fluid is 0 cubic meters; data point 2(n s , e s ), when lowering the drill string by n s columns, the loss of drilling fluid is e s cubic meters; data point 3(n l , e l ), when lowering the drill string by n l columns, the loss of drilling fluid is e l cubic meters; according to the three reference data points, a relationship curve between the normal loss amount of drilling fluid and the number of columns entering the well can be drawn to obtain a function curve graph of the normal loss of drilling fluid; The normal loss function of the drilling fluid is: Where, E(n) is the normal loss of drilling fluid, m 3 ; n is the number of changed columns of drill pipes entering the well.

2. The intelligent monitoring method for overflow and lost circulation in mud logging operations according to claim 1, wherein, X is 1 to 100, and Y is 1 to 100.

3. The intelligent monitoring method for overflow and lost circulation in mud logging operations according to claim 1, wherein The upper time limit T c is 100 s to 180 s.

4. The intelligent monitoring method for overflow and lost circulation in mud logging operations according to claim 1, wherein The steps for identifying the movement state of the drill string include: Obtain the real-time bit position and time of the drill string; Based on the real-time bit position and time, obtain the movement speed of the bit; Compare the movement speed of the bit with 0. If the movement speed of the bit is greater than 0, judge that the drilling movement state is running in. If the movement speed of the bit is equal to 0, judge that the drilling movement state is stationary. If the movement speed of the bit is less than 0, judge that the drilling movement state is pulling out.

5. The intelligent monitoring method for overflow and lost circulation in mud logging operations according to claim 4, characterized in that, The steps for obtaining the volume change of the drill string entering the well or the volume change of the drill string exiting the well include: Obtain the cross-sectional area and time of the drill string entering / exiting the well; Based on the movement speed of the bit, the cross-sectional area of the drill string entering / exiting the well, and the time, obtain the volume change of the drill string entering the well or the volume change of the drill string exiting the well.

6. The intelligent monitoring method for overflow and lost circulation in mud logging operations according to claim 5, characterized in that, During the whole process of running in, the cross-sectional area of the drill string entering the well is obtained by calculation according to formula (3); during the whole process of pulling out, the cross-sectional area of the drill string exiting the well is obtained by calculation according to formula (4); Formula (3) and formula (4) are as follows: where S1(t) is the cross-sectional area of the drill string entering the well at time t, m 2 ; $S_2(t)$ is the cross-sectional area of the drill string out of the well at time $t$, $m$ 2 ; $d_0(t)$ is the outer diameter of the drill pipe at time $t$, in m; $d$ i (t) is the inner diameter of the drill pipe at time $t$, in m.

7. The intelligent monitoring method for overflow and lost circulation in mud logging operations according to claim 5, characterized in that, The steps for obtaining the actual volume change of the drilling fluid include: Obtain the volume of the circulation sum pit at different times; Based on the volumes of the circulation sum pit corresponding to two different times, obtain the actual volume change of the drilling fluid.

8. The intelligent monitoring method for overflow and lost circulation in mud logging operations according to claim 7, characterized in that, The steps for determining the upper limit of the change rate include: Track the value of the change rate of the drilling fluid volume to obtain a probability distribution density curve; Determine the maximum value of the drilling fluid volume change rate corresponding to the probability distribution density value equal to α on the probability distribution density curve as the upper limit value v of the change rate max , where 0 < α < 0.

5.

9. The intelligent monitoring method for overflow and well leakage in mud logging operations according to claim 1, characterized in that, The intelligent monitoring method further includes: When there is a grouting operation during the process of lowering the drill string, the overflow and lost circulation monitoring parameters between before grouting and the previous monitoring point are obtained, and the judgment calculation of the drill string distance from overflow and lost circulation without grouting is carried out to judge whether there is overflow and / or lost circulation; Re-obtain the overflow and lost circulation monitoring parameters during the grouting process, and judge whether there is overflow and / or lost circulation; Taking the position of the drill bit after grouting as the new monitoring point, continue to carry out the judgment calculation of the drill string distance from overflow and lost circulation without grouting every X drill string distances to judge whether there is overflow and / or lost circulation.

10. The intelligent monitoring method for overflow and lost circulation in mud logging operations according to claim 9, characterized in that, The intelligent monitoring method further includes: When there is an intermittent grouting operation during the process of pulling out the drill string, judge every X drill string distances whether the difference between the pulling-out judgment index and the normal loss amount of the drilling fluid is greater than 0. If so, generate a pulling-out overflow alarm message; if not, generate a pulling-out lost circulation alarm message; Meanwhile, monitor whether the outlet flow rate before grouting during the process of pulling out the drill string is not 0. If so, generate a pulling-out overflow alarm message.

11. The intelligent monitoring method for overflow and lost circulation in mud logging operations according to claim 1, characterized in that, The intelligent monitoring method further includes: When the depth of the drill string does not reach the depth of X drill strings, the position of the current drill bit can be manually used to replace the position of the drill bit of X drill strings, and the judgment calculation of the drill string distance from overflow and lost circulation without grouting is carried out to judge whether there is overflow and / or lost circulation.

12. An intelligent monitoring system for overflow and lost circulation in mud logging operations, characterized in that, The intelligent monitoring system includes a drill string motion state recognition module, an overflow and lost circulation monitoring parameter acquisition module, a drill string static monitoring module, an X-drill-string-distance overflow monitoring module, an X-drill-string-distance lost circulation monitoring module, a total pool volume change trend determination module, and an alarm module. Among them, The drill string motion state recognition module is configured to be able to obtain the motion speed of the drill bit in real time and output the motion state of the drill string at the current moment; The overflow and lost circulation monitoring parameter acquisition module is connected to the drill string motion state recognition module and is configured to be able to obtain the overflow and lost circulation monitoring parameters in real time. The overflow and lost circulation monitoring parameters include the volume change amount of the drill string entering the well, the volume change amount of the drill string leaving the well, the actual volume change amount of the drilling fluid, the volume change speed of the drilling fluid, the normal loss amount of the drilling fluid, and the outlet flow rate; The steps for determining the normal loss amount of the drilling fluid include: Obtain at least three sets of reference data, where the parameter data includes the number of changing columns of the drilling fluid entering / leaving the well and the normal loss amount of the drilling fluid; construct a normal loss function of the drilling fluid according to the at least three sets of parameter data; obtain the normal loss amount of the drilling fluid corresponding to the drill pipe number to be calculated according to the normal loss function of the drilling fluid; where the construction of the normal loss function of the drilling fluid is denoted as E(n); there are multiple n values set according to the situation, and here n s , n l respectively represent a smaller number of columns and a larger number of columns; select three reference data points: data point 1(0, 0), when lowering the drill pipe by 0 columns, the loss of the drilling fluid is 0 cubic meters; data point 2(n s , e s ), when lowering the drill pipe by n s columns, the loss of the drilling fluid is e s cubic meters; data point 3(n l , e l ), when lowering the drill pipe by n l columns, the loss of the drilling fluid is e l cubic meters; according to the three reference data points, a relationship curve between the normal loss amount of the drilling fluid and the number of columns entering the well can be drawn, and a function curve graph of the normal loss of the drilling fluid can be obtained; The normal loss function of the drilling fluid is: where E(n) is the normal loss of drilling fluid, m 3 ; n is the number of changed stands of drill pipes entering the well The drill tool static monitoring module is connected to the drill tool motion state module and the overflow and well leakage monitoring parameter acquisition module, and is configured to be able to monitor the static state of the drill tool and the outlet flow rate during the process of lowering the drill string. If the observed time T o of the drill tool being static is greater than the time upper limit T c , and the outlet flow rate is not zero, then an alarm signal for overflow during lowering the drill string is output; The X-drill-string-distance overflow monitoring module is connected to the drill string motion state module and the overflow and lost circulation monitoring parameter acquisition module, and is configured to be able to monitor and judge every X drill string distances whether the difference between the lowering judgment index and the normal loss amount of the drilling fluid is greater than 0 when the motion state of the drill string is lowering and there is no grouting operation. If so, output a lowering overflow alarm signal, The X-drill-string-distance overflow monitoring module is further configured to be able to monitor and judge every X drill string distances whether the difference between the pulling-out judgment index and the normal loss amount of the drilling fluid is greater than 0 when the motion state of the drill string is pulling out and there is a continuous grouting operation. If so, output a pulling-out overflow alarm signal; The X-column distance well leakage monitoring module is connected to the drill string movement state module and the overflow and well leakage monitoring parameter acquisition module, and is configured to be able to monitor and judge whether the sum of the downhole drilling judgment index and the normal loss of drilling fluid is less than 0 every X-column drill string distance when the drill string movement state is tripping in and there is no grouting action. If so, it outputs a downhole well leakage alarm signal. The X-column distance well leakage monitoring module is also configured to be able to monitor and judge whether the sum of the tripping out judgment index and the normal loss of drilling fluid is less than 0 every X-column drill string distance when the drill string movement state is tripping out and there is a continuous grouting action. If so, it outputs a tripping out well leakage alarm signal. The total pit volume change trend determination module is connected to the overflow and well leakage monitoring parameter acquisition module, and is configured to be able to monitor and judge whether the change speed of the drilling fluid volume is greater than the upper limit of the change speed every Y-column drill string distance during tripping in and out. If so, it outputs a tripping in / tripping out overflow alarm signal. The alarm module is respectively connected to the drill string stationary monitoring module, the X-column distance overflow monitoring module, the X-column distance well leakage monitoring module, and the total pit volume change trend determination module, and is configured to be able to generate corresponding overflow and / or well leakage alarm information after obtaining the overflow and / or well leakage alarm signal.

13. The intelligent monitoring system for overflow and lost circulation in mud logging operations according to claim 12, characterized in that, The intelligent monitoring system further includes a grouting trigger monitoring module, which is respectively connected to the X-column distance overflow monitoring module and the X-column distance well leakage monitoring module, and is configured to be able to control the X-column distance overflow monitoring module and the X-column distance well leakage monitoring module to obtain the overflow and well leakage monitoring parameters and perform the drill string distance overflow and well leakage judgment calculations before and after grouting when a grouting action occurs during tripping in, so as to judge whether there is overflow and well leakage. The grouting trigger monitoring module is also configured to be able to control the X-column distance overflow monitoring module and the X-column distance well leakage monitoring module to judge whether the difference between the tripping out judgment index and the normal loss of drilling fluid is greater than 0 every X-column drill string distance when an intermittent grouting action occurs during tripping out. If so, it generates a tripping out overflow alarm signal, and if not, it generates a tripping out well leakage alarm signal.

14. The intelligent monitoring system for overflow and lost circulation in mud logging operations according to claim 12, characterized in that, The intelligent monitoring system further includes a manual monitoring module, which is connected to the X-column distance overflow monitoring module and the X-column distance well leakage monitoring module, and is configured to be able to control the X-column distance overflow monitoring module and the X-column distance well leakage monitoring module to obtain and calculate the overflow and well leakage monitoring parameters between the current drill string depth and the previous monitoring point, so as to judge whether there is overflow and well leakage.

15. The intelligent monitoring system for overflow and lost circulation in mud logging operations according to claim 12, characterized in that, The intelligent monitoring system further includes an outlet flow monitoring module, which is respectively connected to the drill string movement state identification module and the overflow and well leakage monitoring parameter acquisition module, and is configured to be able to monitor and judge whether the outlet flow when there is no grouting is not 0 when the drill string movement state is tripping out and there is an intermittent grouting action. If so, it outputs a tripping out overflow alarm signal.

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