A device and method for monitoring overflow and leakage in deep wells in fractured formations

Abstract

The application discloses a kind of fractured formation deep well overflow monitoring devices, including inlet flow sensor, pump pressure sensor, outlet flow sensor;The inlet flow sensor is arranged on drill pipe;The pump pressure sensor is arranged on drill pipe;The outlet flow sensor is arranged on slurry pipe.The application further discloses a kind of fractured formation deep well overflow monitoring method.The application obtains pump pressure, drilling fluid inlet flow and drilling fluid outlet flow by sensor in real time and passes to computer, compares after being calculated by computer with the threshold value set, to reach the purpose of downhole overflow and well leakage early warning;Through real-time data transmission, the timeliness of early warning monitoring is guaranteed, compared with the traditional alarm mode by experience subjective judgment, effectively improve the early warning precision, can timely discover and accurately forecast well leakage overflow in the process of drilling, avoid the occurrence of major accidents.

Description

Technical Field

[0001] This invention belongs to the field of drilling engineering technology, specifically relating to a device and method for monitoring leakage in deep wells with fractured formations. Background Technology

[0002] With advancements in oil and gas field exploration and development, the drilling of deep wells, ultra-deep wells, horizontal wells, directional wells, and sidetracked wells has increased, placing higher demands on the monitoring of spillage and well leakage data in the field, and increasing the difficulty of well control management. Among these, monitoring well leakage during drilling is crucial to ensuring the safety of the drilling process; therefore, leakage monitoring technology is an important technology in the drilling field.

[0003] Currently, drilling site spill and leakage monitoring technology mainly relies on real-time monitoring of drilling engineering parameters, mud circulation parameters, and gas logging parameters to identify spills and well leaks. The judgment process primarily depends on the on-site personnel's personal experience.

[0004] By observing the parameters directly measured by the integrated logging tool and observing the changes in multiple parameters, early signs of accidents can be detected in a timely manner. The changes in the mud level in the mud pit can be observed. Under normal drilling conditions, the mud level in the mud pit fluctuates around a certain value. When an overflow accident occurs, the mud level in the mud pit rises, and when a well leakage accident occurs, the mud level in the mud pit drops.

[0005] The existing leakage monitoring technology has many problems in use:

[0006] (1) The method of monitoring by integrated logging technology is limited by the quality of equipment and the quality of personnel. At the same time, since the identification of accidents is based on the personal experience of logging technicians, there is still a serious lack of intelligence.

[0007] (2) The method of observing the liquid level in the mud pit can monitor overflow and well leakage, but this method has serious time lag and insufficient real-time warning; due to the large bottom area of ​​the mud pit, the liquid level rise is not sensitive enough to small overflows.

[0008] Based on the above problems, this application proposes a deep well leakage monitoring device and method in fractured formations. The device uses sensors to obtain pump pressure, drilling fluid inlet flow rate, and drilling fluid outlet flow rate in real time and transmits this data to a computer. The computer performs calculations and compares these data with set thresholds, thereby achieving the purpose of downhole leakage and well leakage early warning. Real-time data transmission ensures the timeliness of early warning monitoring. Compared with traditional methods that rely on subjective judgment based on experience, this method effectively improves early warning accuracy, enabling timely detection and accurate prediction of well leakage and overflow during drilling, thus preventing major accidents. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a device and method for monitoring leakage in deep wells with fractured formations.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A deep well leakage monitoring device for fractured formations, wherein a drill pipe is installed inside the wellbore and a slurry outlet pipe connected to the wellbore is installed at the top of the wellbore;

[0012] The deep well overflow monitoring device includes an inlet flow sensor, a pump pressure sensor, and an outlet flow sensor;

[0013] The inlet flow sensor is mounted on the drill pipe;

[0014] The pump pressure sensor is mounted on the drill pipe;

[0015] The outlet flow sensor is installed on the slurry outlet pipe.

[0016] Preferably, the deep well overflow monitoring device further includes a computer;

[0017] The inlet flow sensor, pump pressure sensor, and outlet flow sensor are all connected to the computer.

[0018] Preferably, the computer is connected to the alarm.

[0019] Preferably, the outlet flow sensor is a pipeline electromagnetic flow meter.

[0020] Preferably, the inlet flow sensor is an external clamp-on ultrasonic sensor.

[0021] Preferably, there are two external clamp-on ultrasonic sensors.

[0022] Preferably, the distance between the two clamp-on ultrasonic flow meters is 20-30 cm.

[0023] The present invention also provides a method for monitoring leakage in deep wells in fractured formations.

[0024] A method for monitoring leakage in deep wells in fractured formations, implemented using a deep well leakage monitoring device in fractured formations, includes the following steps:

[0025] Step 1: The inlet flow sensor, pump pressure sensor, and outlet flow sensor are turned on simultaneously, and data is transmitted to the computer at intervals of Δt. The inlet flow sensor transmits the drilling fluid inlet flow rate, the pump pressure sensor transmits the pump pressure, and the outlet flow sensor transmits the drilling fluid outlet flow rate.

[0026] Step 2: The computer calculates the rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate. iand the rate of change of pump pressure difference K′ i ;

[0027]

[0028] In formula (1)

[0029] Δv i+1 =v i+1 -v′ i+1 (2)

[0030] Δv i =v i -v′ i (3)

[0031]

[0032] In formula (4)

[0033] Δp i+1 =p i+2 -p i+1 (5)

[0034] Δp i =p i+1 -p i (6)

[0035] in:

[0036] Δv i+1 This is the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate at the (i+1)th time node;

[0037] Δv i This represents the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate at the i-th time point.

[0038] v i+1 This represents the drilling fluid outlet flow rate at the (i+1)th time node;

[0039] v′ i+1 This represents the drilling fluid inlet flow rate at the (i+1)th time node;

[0040] v i Let i be the drilling fluid outlet flow rate at the i-th time node;

[0041] v′ i Let be the drilling fluid inlet flow rate at the i-th time node;

[0042] Δp i+1 It is the difference between the pump pressure at the (i+2)th time node and the pump pressure at the (i+1)th time node;

[0043] Δp i It is the difference between the pump pressure at the (i+1)th time node and the pump pressure at the ith time node;

[0044] p i+2 The pump pressure at the (i+2)th time node;

[0045] p i+1 The pump pressure at the (i+1)th time node;

[0046] p i Let be the pump pressure at the i-th time node;

[0047] i represents the time node;

[0048] Δt represents the duration between adjacent time points;

[0049] Step 3: Based on the calculated rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate. i and the rate of change of pump pressure difference K i Determine if a well leak or overflow has occurred.

[0050] Preferably, in step 3, the rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate is calculated. i and the rate of change of pump pressure difference K′ i The methods for determining whether a well leak or overflow has occurred are as follows:

[0051] When K′ i K′ i+1 K′ i+2 ... K′ i+N All less than K m And K i K i+1 K i+2 ... K i+N All less than K q At that time, it was determined to be a well leak;

[0052] When K′ i K′ i+1 K′ i+2 ... K′ i+N All are greater than K m And K i K i+1 K i+2 ... K i+N All are greater than K q At that time, it was determined to be an overflow;

[0053] Where: K m K q Determined based on the actual situation on site.

[0054] Preferably, in step 3, N≥2.

[0055] Preferably, in step 3, 2 ≤ N ≤ 4.

[0056] Preferably, in step 3, the alarm sounds when it is determined that a well leak or overflow has occurred.

[0057] The beneficial effects of this invention are:

[0058] This invention uses sensors to obtain pump pressure, drilling fluid inlet flow rate, and drilling fluid outlet flow rate in real time and transmits them to a computer. The computer then calculates the data and compares it with a set threshold to achieve early warning of downhole overflow and well leakage. By transmitting data in real time, the timeliness of early warning monitoring is ensured. Compared with the traditional method of alarming based on subjective judgment, this invention effectively improves the accuracy of early warning and can promptly detect and accurately predict well leakage and overflow during the drilling process, thus avoiding major accidents. Attached Figure Description

[0059] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0060] Figure 1 This is a schematic diagram of the structure of the deep well leakage monitoring device for fractured formations of the present invention;

[0061] Figure 2 This is a graph showing the change in pump pressure of well SY-1 over time in Example 10;

[0062] Figure 3 This is a graph showing the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate of well SY-1 in Example 10 as a function of time.

[0063] Figure 4 This is a graph showing the change in pump pressure of well MX-22 over time in Example 11;

[0064] Figure 5 This is a graph showing the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate of well MX-22 in Example 11 as a function of time.

[0065] Figure 6 This is a graph showing the change in pump pressure of well GS-008 over time in Example 12;

[0066] Figure 7 This is a graph showing the change of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate in well GS-008 in Example 12 over time.

[0067] Figure 8 This is a graph showing the change in pump pressure of well TF-2 over time in Example 13;

[0068] Figure 9 This is a graph showing the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate of well TF-2 in Example 13 over time.

[0069] in:

[0070] 01-Drill pipe;

[0071] 02-shaft;

[0072] 03-Slurry outlet pipe;

[0073] 1-Inlet flow sensor;

[0074] 2-Pump pressure sensor;

[0075] 3-Outlet flow sensor;

[0076] 4-Computer;

[0077] 5-Alarm. Detailed Implementation

[0078] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0079] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0080] In this invention, terms such as "upper," "lower," "bottom," and "top" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are merely relational terms determined for the convenience of describing the structural relationship of the various components or elements of this invention, and do not specifically refer to any component or element in this invention, and should not be construed as limiting this invention.

[0081] In this invention, terms such as "connected" and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can determine the specific meaning of these terms in this invention based on the specific circumstances, and they should not be construed as limitations on the invention.

[0082] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0083] Example 1:

[0084] A deep well leakage monitoring device for fractured formations, wherein a drill pipe 01 is installed inside the wellbore 02 of the deep well, and a slurry outlet pipe 03 connected to the wellbore 02 is installed at the upper part of the wellbore 02;

[0085] The deep well leakage monitoring device includes an inlet flow sensor 1, a pump pressure sensor 2, and an outlet flow sensor 3;

[0086] The inlet flow sensor 1 is mounted on drill pipe 01;

[0087] The pump pressure sensor 2 is mounted on drill pipe 01;

[0088] The outlet flow sensor 3 is installed on the slurry outlet pipe 03.

[0089] Example 2:

[0090] like Figure 1 As shown, a deep well leakage monitoring device for fractured formations is provided, wherein a drill pipe 01 is installed inside the wellbore 02 of the deep well, and a slurry outlet pipe 03 connected to the wellbore 02 is installed at the upper part of the wellbore 02.

[0091] The deep well overflow monitoring device includes an inlet flow sensor 1, a pump pressure sensor 2, an outlet flow sensor 3, and a computer 4.

[0092] The inlet flow sensor 1 is mounted on drill pipe 01;

[0093] The pump pressure sensor 2 is mounted on drill pipe 04;

[0094] The outlet flow sensor 3 is installed on the slurry outlet pipe 03;

[0095] The inlet flow sensor 1, pump pressure sensor 2, and outlet flow sensor 3 are all connected to the computer 4.

[0096] Example 3:

[0097] A deep well leakage monitoring device for fractured formations, wherein a drill pipe 01 is installed inside the wellbore 02 of the deep well, and a slurry outlet pipe 03 connected to the wellbore 02 is installed at the upper part of the wellbore 02;

[0098] The deep well overflow monitoring device includes an inlet flow sensor 1, a pump pressure sensor 2, an outlet flow sensor 3, and a computer 4.

[0099] The inlet flow sensor 1 is mounted on drill pipe 01;

[0100] The pump pressure sensor 2 is mounted on drill pipe 04;

[0101] The outlet flow sensor 3 is installed on the slurry outlet pipe 03;

[0102] The inlet flow sensor 1, pump pressure sensor 2, and outlet flow sensor 3 are all connected to the computer 4.

[0103] Preferably, the computer 4 is connected to the alarm 5.

[0104] Example 4:

[0105] A deep well leakage monitoring device for fractured formations, wherein a drill pipe 01 is installed inside the wellbore 02 of the deep well, and a slurry outlet pipe 03 connected to the wellbore 02 is installed at the upper part of the wellbore 02;

[0106] The deep well overflow monitoring device includes an inlet flow sensor 1, a pump pressure sensor 2, an outlet flow sensor 3, and a computer 4.

[0107] The inlet flow sensor 1 is mounted on drill pipe 01;

[0108] The pump pressure sensor 2 is mounted on drill pipe 04;

[0109] The outlet flow sensor 3 is installed on the slurry outlet pipe 03;

[0110] The inlet flow sensor 1, pump pressure sensor 2, and outlet flow sensor 3 are all connected to the computer 4.

[0111] Preferably, the computer 4 is connected to the alarm 5.

[0112] Preferably, the outlet flow sensor 3 is a pipeline electromagnetic flow meter.

[0113] Example 5:

[0114] A deep well leakage monitoring device for fractured formations, wherein a drill pipe 01 is installed inside the wellbore 02 of the deep well, and a slurry outlet pipe 03 connected to the wellbore 02 is installed at the upper part of the wellbore 02;

[0115] The deep well overflow monitoring device includes an inlet flow sensor 1, a pump pressure sensor 2, an outlet flow sensor 3, and a computer 4.

[0116] The inlet flow sensor 1 is mounted on drill pipe 01;

[0117] The pump pressure sensor 2 is mounted on drill pipe 04;

[0118] The outlet flow sensor 3 is installed on the slurry outlet pipe 03;

[0119] The inlet flow sensor 1, pump pressure sensor 2, and outlet flow sensor 3 are all connected to the computer 4.

[0120] Preferably, the computer 4 is connected to the alarm 5.

[0121] Preferably, the outlet flow sensor 3 is a pipeline electromagnetic flow meter.

[0122] Preferably, the inlet flow sensor 1 is an ultrasonic sensor.

[0123] Example 6:

[0124] A deep well leakage monitoring device for fractured formations, wherein a drill pipe 01 is installed inside the wellbore 02 of the deep well, and a slurry outlet pipe 03 connected to the wellbore 02 is installed at the upper part of the wellbore 02;

[0125] The deep well overflow monitoring device includes an inlet flow sensor 1, a pump pressure sensor 2, an outlet flow sensor 3, and a computer 4.

[0126] The inlet flow sensor 1 is mounted on drill pipe 01;

[0127] The pump pressure sensor 2 is mounted on drill pipe 04;

[0128] The outlet flow sensor 3 is installed on the slurry outlet pipe 03;

[0129] The inlet flow sensor 1, pump pressure sensor 2, and outlet flow sensor 3 are all connected to the computer 4.

[0130] Preferably, the computer 4 is connected to the alarm 5.

[0131] Preferably, the outlet flow sensor 3 is a pipeline electromagnetic flow meter.

[0132] Preferably, the inlet flow sensor 1 is an external clamp-on ultrasonic sensor.

[0133] Example 7:

[0134] A deep well leakage monitoring device for fractured formations, wherein a drill pipe 01 is installed inside the wellbore 02 of the deep well, and a slurry outlet pipe 03 connected to the wellbore 02 is installed at the upper part of the wellbore 02;

[0135] The deep well overflow monitoring device includes an inlet flow sensor 1, a pump pressure sensor 2, an outlet flow sensor 3, and a computer 4.

[0136] The inlet flow sensor 1 is mounted on drill pipe 01;

[0137] The pump pressure sensor 2 is mounted on drill pipe 04;

[0138] The outlet flow sensor 3 is installed on the slurry outlet pipe 03;

[0139] The inlet flow sensor 1, pump pressure sensor 2, and outlet flow sensor 3 are all connected to the computer 4.

[0140] Preferably, the computer 4 is connected to the alarm 5.

[0141] Preferably, the outlet flow sensor 3 is a pipeline electromagnetic flow meter.

[0142] Preferably, the inlet flow sensor 1 is an external clamp-on ultrasonic sensor.

[0143] Preferably, there are two clamp-on ultrasonic sensors. Both clamp-on ultrasonic flow meters are mounted on the outer wall of the drill rod 01.

[0144] Example 8:

[0145] A deep well leakage monitoring device for fractured formations, wherein a drill pipe 01 is installed inside the wellbore 02 of the deep well, and a slurry outlet pipe 03 connected to the wellbore 02 is installed at the upper part of the wellbore 02;

[0146] The deep well leakage monitoring device includes an inlet flow sensor 1, a pump pressure sensor 2, and an outlet flow sensor 3;

[0147] The inlet flow sensor 1 is mounted on drill pipe 01;

[0148] The pump pressure sensor 2 is mounted on drill pipe 01;

[0149] The outlet flow sensor 3 is installed on the slurry outlet pipe 03.

[0150] Preferably, the deep well overflow monitoring device further includes a computer 4;

[0151] The inlet flow sensor 1, pump pressure sensor 2, and outlet flow sensor 3 are all connected to the computer 4.

[0152] Preferably, the computer 4 is connected to the alarm 5.

[0153] Preferably, the outlet flow sensor 3 is a pipeline electromagnetic flow meter.

[0154] Preferably, the inlet flow sensor 1 is an external clamp-on ultrasonic sensor.

[0155] Preferably, there are two clamp-on ultrasonic sensors. Both clamp-on ultrasonic flow meters are mounted on the outer wall of the drill rod 01.

[0156] Preferably, the distance between the two clamp-on ultrasonic flow meters is 20-30 cm.

[0157] Example 9:

[0158] A method for monitoring leakage in deep wells in fractured formations, implemented using the leakage monitoring device for deep wells in fractured formations as described in Example 2, Example 3, Example 4, Example 5, Example 6, Example 7, or Example 8, includes the following steps:

[0159] Step 1: The inlet flow sensor 1, pump pressure sensor 2, and outlet flow sensor 3 are turned on simultaneously, and data is transmitted to the computer 4 at intervals of Δt. The inlet flow sensor 1 transmits the drilling fluid inlet flow, the pump pressure sensor 2 transmits the pump pressure, and the outlet flow sensor 3 transmits the drilling fluid outlet flow.

[0160] Step 2: Computer 4 calculates the rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate. i and the rate of change of pump pressure difference K′ i ;

[0161]

[0162] In formula (1)

[0163] Δv i+1 =v i+1 -v′ i+1 (2)

[0164] Δv i =v i -v′ i (3)

[0165]

[0166] In formula (4)

[0167] Δp i+1 =p i+2 -p i+1 (5)

[0168] Δp i =p i+1 -p i (6)

[0169] in:

[0170] Δv i+1 This is the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate at the (i+1)th time node;

[0171] Δv i This represents the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate at the i-th time point.

[0172] v i+1 This represents the drilling fluid outlet flow rate at the (i+1)th time node;

[0173] v′i+1 This represents the drilling fluid inlet flow rate at the (i+1)th time node;

[0174] v i Let i be the drilling fluid outlet flow rate at the i-th time node;

[0175] v′ i Let be the drilling fluid inlet flow rate at the i-th time node;

[0176] Δp i+1 It is the difference between the pump pressure at the (i+2)th time node and the pump pressure at the (i+1)th time node;

[0177] Δp i It is the difference between the pump pressure at the (i+1)th time node and the pump pressure at the ith time node;

[0178] p i+2 The pump pressure at the (i+2)th time node;

[0179] p i+1 The pump pressure at the (i+1)th time node;

[0180] p i Let be the pump pressure at the i-th time node;

[0181] i represents the time node;

[0182] Δt represents the duration between adjacent time points;

[0183] Step 3: Based on the calculated rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate. i and the rate of change of pump pressure difference K′ i Determine if a well leak or overflow has occurred.

[0184] Preferably, in step 3, the rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate is calculated. i and the rate of change of pump pressure difference K′ i The methods for determining whether a well leak or overflow has occurred are as follows:

[0185] When K′ i K′ i+1 K′ i+2 ... K′ i+N All less than K m And K i K i+1 K i+2 ... K i+N All less than K q At that time, it was determined to be a well leak;

[0186] When K′ i K′ i+1 K′i+2 ... K i ' +N All are greater than K m And K i K i+1 K i+2 ... K i+N All are greater than K q At that time, it was determined to be an overflow;

[0187] Where: K m K q Determined based on the actual situation on site.

[0188] Preferably, in step 3, N≥2.

[0189] Preferably, in step 3, 2 ≤ N ≤ 4.

[0190] Preferably, in step 3, when it is determined that a well leak or overflow has occurred, the alarm 5 issues an alarm.

[0191] This invention uses sensors to obtain pump pressure, drilling fluid inlet flow rate, and drilling fluid outlet flow rate in real time and transmits them to a computer. The computer then calculates the data and compares it with a set threshold to achieve early warning of downhole overflow and well leakage. By transmitting data in real time, the timeliness of early warning monitoring is ensured. Compared with the traditional method of alarming based on subjective judgment, this invention effectively improves the accuracy of early warning and can promptly detect and accurately predict well leakage and overflow during the drilling process, thus avoiding major accidents.

[0192] Example 10:

[0193] The leakage monitoring method for deep wells in fractured formations described in Example 9 was used to determine whether well leakage or overflow occurred in well SY-1 in the study area.

[0194] First, regarding the K corresponding to well SY-1... m K q To confirm, follow these steps:

[0195] The logging parameters of well SY-1 were collected, and the curve of pump pressure variation of well SY-1 over time is shown in the figure below. Figure 2 As shown in the figure, the curves showing the variation of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate of well SY-1 over time are as follows: Figure 3 As shown;

[0196] According to the drilling log, well SY-1 experienced a blowout after time point 33.

[0197] like Figure 2 As shown, the drilling was in normal condition before the 33rd time point, and after the 33rd time point, the pump pressure showed a downward trend and overflow occurred.

[0198] according to Figure 3 It can be seen that before the 33rd time point, the difference between the well fluid outlet flow rate and the drilling fluid inlet flow rate fluctuated between 0.05 and 0.2, and its trend was relatively stable. After the 33rd time point, the difference between the well fluid outlet flow rate and the drilling fluid inlet flow rate increased instantaneously, and overflow occurred.

[0199] Calculate K at the 33rd time node corresponding to well SY-1. 33 and K′ 33 Value, where K 33 0.0421, K′ 33 It is -0.0043;

[0200] Therefore, K corresponds to well SY-1 m -0.0043, K q It is 0.0421.

[0201] Then, the leakage or overflow monitoring method for deep wells in fractured formations described in Example 9 was used to determine the leakage or overflow during the continued drilling process of well SY-1 in the study area. The steps are as follows:

[0202] Step 11: The inlet flow sensor 1, pump pressure sensor 2, and outlet flow sensor 3 are turned on simultaneously, and data is transmitted to the computer 4 at intervals of Δt. The inlet flow sensor 1 transmits the drilling fluid inlet flow of well SY-1, the pump pressure sensor 2 transmits the pump pressure of well SY-1, and the outlet flow sensor 3 transmits the drilling fluid outlet flow of well SY-1.

[0203] Step 12: Computer 4 calculates the rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate in well SY-1. i and the rate of change of pump pressure differential K′ in well SY-1 i ;

[0204] Step 13: Based on the calculated rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate of well SY-1. i and the rate of change of pump pressure differential K′ in well SY-1 i Determine if a well leak or overflow has occurred;

[0205] When K′ i K′ i+1 K′ i+2 ... K′ i+N All are less than -0.0043, and K i K i+1 K i+2 ... K i+N If all values ​​are less than 0.0421, it is considered a well leak.

[0206] When K′ i K′ i+1 K′ i+2 ... K′ i+N All are greater than -0.0043, and K i K i+1 K i+2 ... K i+N When all values ​​are greater than 0.0421, it is judged as an overflow.

[0207] Preferably, in step 3, N≥2.

[0208] Preferably, in step 3, 2 ≤ N ≤ 4.

[0209] Preferably, in step 3, when it is determined that a well leak or overflow has occurred, the alarm 5 issues an alarm.

[0210] In Example 10, the pump pressure, drilling fluid inlet flow rate, and drilling fluid outlet flow rate of well SY-1 are obtained in real time by sensors and transmitted to a computer. After calculation by the computer, the data is compared with the set threshold to achieve the purpose of downhole overflow and well leakage early warning. By transmitting data in real time, the timeliness of early warning monitoring is ensured. Compared with the traditional method of alarm based on subjective judgment based on experience, the early warning accuracy is effectively improved. It can detect and accurately predict well leakage and overflow in a timely manner during the drilling process of well SY-1, and avoid the occurrence of major accidents in well SY-1.

[0211] Example 11:

[0212] The leakage monitoring method for deep wells in fractured formations described in Example 9 was used to determine whether well leakage or overflow occurred in well MX-22 in the study area.

[0213] First, the K corresponding to well MX-22... m K q To confirm, follow these steps:

[0214] The logging parameters of well MX-22 were collected, and the pump pressure of well MX-22 as a function of time nodes is shown in the figure below. Figure 4 As shown in the figure, the curve of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate of well MX-22 as a function of time is as follows. Figure 5 As shown;

[0215] According to the drilling log, well MX-22 experienced a well leakage condition after time point 25.

[0216] according to Figure 4 It can be seen that the pump pressure fluctuation is small from time 0 to 25, which is a normal operating condition. At time 25, the pump pressure drops, indicating well leakage.

[0217] according to Figure 5 It can be seen that before the 25th time point, the difference between the well fluid outlet flow rate and the drilling fluid inlet flow rate is relatively stable. After the 25th time point, the difference between the well fluid outlet flow rate and the drilling fluid inlet flow rate drops rapidly, resulting in well leakage.

[0218] Calculate K at the 25th time node corresponding to well MX-22. 25 and K' 25 Value, where K 25 -1.179, K' 25 It is -0.02146;

[0219] Therefore, the K corresponding to well MX-22 m -0.02146, K q It is -1.179.

[0220] Then, the leakage or overflow monitoring method for deep wells in fractured formations described in Example 9 was used to determine the leakage or overflow during the continued drilling process of well MX-22 in the study area. The steps are as follows:

[0221] Step 11: The inlet flow sensor 1, pump pressure sensor 2, and outlet flow sensor 3 are turned on simultaneously, and data is transmitted to the computer 4 at intervals of Δt. The inlet flow sensor 1 transmits the drilling fluid inlet flow of the MX-22 well, the pump pressure sensor 2 transmits the pump pressure of the MX-22 well, and the outlet flow sensor 3 transmits the drilling fluid outlet flow of the MX-22 well.

[0222] Step 12: Computer 4 calculates the rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate in well MX-22. i and the rate of change of pump pressure differential K′ in MX-22 well i ;

[0223] Step 13: Based on the calculated rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate of well MX-22. i and the rate of change of pump pressure differential K′ in MX-22 well i Determine if a well leak or overflow has occurred;

[0224] When K′ i K′ i+1 K′ i+2 ... K′ i+N All are less than -0.02146, and K i K i+1 K i+2 ... K i+N When all values ​​are less than -1.179, it is judged as well leakage;

[0225] When K′ i K′i+1 K′ i+2 ... K′ i+N All are greater than -0.02146, and K i K i+1 K i+2 ... K i+N When all values ​​are greater than -1.179, it is judged as an overflow.

[0226] Preferably, in step 3, N≥2.

[0227] Preferably, in step 3, 2 ≤ N ≤ 4.

[0228] Preferably, in step 3, when it is determined that a well leak or overflow has occurred, the alarm 5 issues an alarm.

[0229] In Example 11, the pump pressure, drilling fluid inlet flow rate, and drilling fluid outlet flow rate of the MX-22 well are obtained in real time by sensors and transmitted to a computer. After calculation by the computer, the data is compared with the set threshold to achieve the purpose of downhole overflow and well leakage early warning. By transmitting data in real time, the timeliness of early warning monitoring is guaranteed. Compared with the traditional method of alarm based on subjective judgment based on experience, the early warning accuracy is effectively improved. It can detect and accurately predict well leakage and overflow in a timely manner during the drilling process of the MX-22 well, and avoid the occurrence of major accidents in the MX-22 well.

[0230] Example 12:

[0231] The leakage monitoring method for deep wells in fractured formations described in Example 9 was used to determine whether well leakage or overflow occurred in well GS-008 in the study area.

[0232] First, regarding the K corresponding to well GS-008... m K q To confirm, follow these steps:

[0233] Logging parameters for well GS-008 were collected, including the pump pressure variation curve of well GS-008 over time. Figure 6 As shown in the figure, the curves showing the variation of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate of well GS-008 over time are as follows: Figure 7 As shown;

[0234] According to the drilling log, well GS-008 experienced a well leakage condition after the 60th time point;

[0235] according to Figure 6 It can be seen that the pump pressure fluctuation is small from time 0 to 60, which is a normal operating condition. At time 60, the pump pressure drops, indicating well leakage.

[0236] according to Figure 7It can be seen that before the 60th time point, the difference between the well fluid outlet flow rate and the drilling fluid inlet flow rate fluctuated and increased. After the 60th time point, the difference between the well fluid outlet flow rate and the drilling fluid inlet flow rate decreased significantly, resulting in well leakage.

[0237] Calculate K at the 60th time node corresponding to well GS-008. 60 and K' 60 Value, where K 60 -0.15, K' 60 It is -0.027;

[0238] Therefore, the K corresponding to well GS-008 m -0.027, K q It is -0.15.

[0239] Then, the leakage or overflow monitoring method for deep wells in fractured formations in Example 9 was used to determine the leakage or overflow during the continued drilling process of well GS-008 in the study area. The steps are as follows:

[0240] Step 11: The inlet flow sensor 1, pump pressure sensor 2, and outlet flow sensor 3 are turned on simultaneously, and data is transmitted to the computer 4 at intervals of Δt. The inlet flow sensor 1 transmits the drilling fluid inlet flow of the GS-008 well, the pump pressure sensor 2 transmits the pump pressure of the GS-008 well, and the outlet flow sensor 3 transmits the drilling fluid outlet flow of the GS-008 well.

[0241] Step 12: Computer 4 calculates the rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate in well GS-008. i and the rate of change K of the pump pressure difference in well GS-008 i ';

[0242] Step 13: Based on the calculated rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate of well GS-008. i and the rate of change of pump pressure differential K′ in well GS-008 i Determine if a well leak or overflow has occurred;

[0243] When K′ i K′ i+1 K′ i+2 ... K′ i+N All are less than -0.027, and K i K i+1 K i+2 ... K i+N If all values ​​are less than -0.15, it is considered a well leak.

[0244] When K′ i K′ i+1 K′i+2 ... K′ i+N All are greater than -0.027, and K i K i+1 K i+2 ... K i+N If all values ​​are greater than -0.15, it is considered an overflow.

[0245] Preferably, in step 3, N≥2.

[0246] Preferably, in step 3, 2 ≤ N ≤ 4.

[0247] Preferably, in step 3, when it is determined that a well leak or overflow has occurred, the alarm 5 issues an alarm.

[0248] In Example 12, the pump pressure, drilling fluid inlet flow rate, and drilling fluid outlet flow rate of the GS-008 well are obtained in real time by sensors and transmitted to a computer. After calculation by the computer, the data is compared with the set threshold to achieve the purpose of downhole overflow and well leakage early warning. By transmitting data in real time, the timeliness of early warning monitoring is ensured. Compared with the traditional method of alarm based on subjective judgment based on experience, the early warning accuracy is effectively improved. It can detect and accurately predict well leakage and overflow in a timely manner during the drilling process of the GS-008 well, thus avoiding the occurrence of major accidents in the GS-008 well.

[0249] Example 13:

[0250] The leakage monitoring method for deep wells in fractured formations described in Example 9 was used to determine whether well leakage or overflow occurred in the TF-2 well in the study area.

[0251] First, the K corresponding to well TF-2... m K q To confirm, follow these steps:

[0252] The logging parameters of well TF-2 were collected, and the curve of pump pressure variation of well TF-2 over time is shown in the figure below. Figure 8 As shown in the figure, the curves showing the variation of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate of well TF-2 over time are as follows: Figure 9 As shown;

[0253] According to the drilling log, well TF-2 experienced a blowout after time point 15.

[0254] according to Figure 8 It can be seen that the pump pressure fluctuation is small from time 0 to 15, which is a normal operating condition. At time 15, the pump pressure drops and overflow occurs.

[0255] according to Figure 9It can be seen that before the 15th time point, the difference between the well fluid outlet flow rate and the drilling fluid inlet flow rate fluctuated but did not show a significant increase. After the 15th time point, the difference between the well fluid outlet flow rate and the drilling fluid inlet flow rate fluctuated and increased, resulting in an overflow condition.

[0256] Calculate K at the 15th time node corresponding to well TF-2. 15 and K′ 15 Value, where K 15 1.584, K′ 15 It is -0.00486;

[0257] Therefore, K corresponds to well TF-2 m -0.00486, K q It is 1.584.

[0258] Then, the leakage or overflow monitoring method for deep wells in fractured formations described in Example 9 was used to determine the leakage or overflow during the continued drilling process of well TF-2 in the study area. The steps are as follows:

[0259] Step 11: The inlet flow sensor 1, pump pressure sensor 2, and outlet flow sensor 3 are turned on simultaneously, and data is transmitted to the computer 4 at intervals of Δt. The inlet flow sensor 1 transmits the inlet flow rate of the drilling fluid in the TF-2 well, the pump pressure sensor 2 transmits the pump pressure of the TF-2 well, and the outlet flow sensor 3 transmits the outlet flow rate of the drilling fluid in the TF-2 well.

[0260] Step 12: Computer 4 calculates the rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate in well TF-2. i and the rate of change of pump pressure differential K′ in TF-2 well i ;

[0261] Step 13: Based on the calculated rate of change K of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate of well TF-2. i and the rate of change of pump pressure differential K′ in TF-2 well i Determine if a well leak or overflow has occurred;

[0262] When K′ i K′ i+1 K′ i+2 ... K′ i+N All are less than -0.00486, and K i K i+1 K i+2 ... K i+N If all values ​​are less than 1.584, it is considered a well leak.

[0263] When K′ i K′ i+1 K′i+2 ... K′ i+N All are greater than -0.00486, and K i K i+1 K i+2 ... K i+N When all values ​​are greater than 1.584, it is judged as an overflow.

[0264] Preferably, in step 3, N≥2.

[0265] Preferably, in step 3, 2 ≤ N ≤ 4.

[0266] Preferably, in step 3, when it is determined that a well leak or overflow has occurred, the alarm 5 issues an alarm.

[0267] In Example 13, the pump pressure, drilling fluid inlet flow rate, and drilling fluid outlet flow rate of the TF-2 well are obtained in real time by sensors and transmitted to a computer. After calculation by the computer, the data is compared with the set threshold to achieve the purpose of downhole overflow and well leakage early warning. By transmitting data in real time, the timeliness of early warning monitoring is guaranteed. Compared with the traditional method of alarm based on subjective judgment based on experience, the early warning accuracy is effectively improved. It can detect and accurately predict well leakage and overflow in a timely manner during the drilling process of the TF-2 well, and avoid the occurrence of major accidents in the TF-2 well.

[0268] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, they are not intended to limit the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for monitoring leakage in deep wells of fractured formations, characterized in that, The monitoring of leakage in deep wells in fractured formations is carried out using a deep well drilling pipe with a slurry outlet pipe connected to the wellbore at the top. The deep well overflow monitoring device includes an inlet flow sensor, a pump pressure sensor, and an outlet flow sensor; The inlet flow sensor is mounted on the drill pipe; The pump pressure sensor is mounted on the drill pipe; The outlet flow sensor is installed on the slurry outlet pipe; The deep well overflow monitoring device also includes a computer; The inlet flow sensor, pump pressure sensor, and outlet flow sensor are all connected to the computer. The monitoring method includes the following steps: Step 1: The inlet flow sensor, pump pressure sensor, and outlet flow sensor are activated simultaneously at intervals. The system transmits data to the computer in real time. The inlet flow sensor transmits the drilling fluid inlet flow rate, the pump pressure sensor transmits the pump pressure, and the outlet flow sensor transmits the drilling fluid outlet flow rate. Step 2: The computer calculates the rate of change of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate. and the rate of change of pump pressure difference ; （1） In formula (1) （2） （3） （4） In formula (4) （5） （6） in: For the first i +1 time point: the difference between drilling fluid outlet flow rate and drilling fluid inlet flow rate; For the first i The difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate at each time point; For the first i +1 drilling fluid outlet flow rate at a time point; For the first i +1 drilling fluid inlet flow rate at a time point; For the first i Drilling fluid outlet flow rate at each time point; For the first i Drilling fluid inlet flow rate at each time point; For the first i Pump pressure at +2 time points and the first i +1 time point pump pressure difference; For the first i Pump pressure at +1 time node and the first i The difference in pump pressure at each time point; For the first i Pump pressure at +2 time points; For the first i Pump pressure at +1 time point; For the first i Pump pressure at each time point; i For time nodes; The duration between adjacent time points; Step 3: Based on the calculated rate of change of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate. and the rate of change of pump pressure difference Determine if a well leak or overflow has occurred; In step 3, the rate of change of the difference between the drilling fluid outlet flow rate and the drilling fluid inlet flow rate is calculated. and the rate of change of pump pressure difference The methods for determining whether a well leak or overflow has occurred are as follows: when All less than ,and All less than At that time, it was determined to be a well leak; when All greater than ,and All greater than At that time, it was determined to be an overflow; in: Determined based on the actual situation on site; In step 3, 2 ≤ N ≤ 4.

2. The method for monitoring leakage in deep wells of fractured formations as described in claim 1, characterized in that, The computer is connected to the alarm.

3. The method for monitoring leakage in deep wells of fractured formations as described in claim 1, characterized in that, The outlet flow sensor is a pipeline electromagnetic flow meter.

4. The method for monitoring leakage in deep wells of fractured formations as described in claim 1, characterized in that, The inlet flow sensor is an external clamp-on ultrasonic sensor.

5. The method for monitoring leakage in deep wells of fractured formations as described in claim 4, characterized in that, There are two external clamp-on ultrasonic sensors.

6. The method for monitoring leakage in deep wells of fractured formations as described in claim 5, characterized in that, The distance between the two clamp-on ultrasonic flow meters is 20~30cm.

7. The method for monitoring leakage in deep wells of fractured formations as described in claim 1, characterized in that, In step 3, when it is determined that a well leak or overflow has occurred, the alarm will sound.

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