Embodiments of the present disclosure relate generally to the field of drilling and processing of wells. More particularly, present embodiments relate to a system and method for detecting and/or tracking a cement plug during casing operations.
Cement plugs are typically utilized during casing operations to substantially remove cement from an interior surface of wellbore tubulars. In conventional oil and gas operations, an annulus is formed around the wellbore tubulars within a formation. During completion operations, casing (e.g., wellbore tubulars) may be secured to the formation via cementing. The cement is pumped through the casing to fill the annulus and secure the casing to the formation. After cement pumping is complete, the cement plug is introduced into the casing to clear the cement from the interior surface of the casing. As a result, cementing operations may continue with little to no mixing of cement with the drilling and/or displacement fluids pumped through the casing.
In accordance with one aspect of the disclosure a system includes a system that includes a cement plug and a sensor system. The sensor system includes a first sensor disposed within a tubular and configured to monitor a pressure within the tubular, a second sensor disposed within the tubular downstream of the first sensor with respect to a flow of fluid through the tubular, where the second sensor is configured to monitor the pressure within the tubular, and a controller configured to detect a launch of the cement plug when the first sensor detects a first pressure drop and when the second sensor detects a second pressure drop, where the second pressure drop occurs after the first pressure drop within a predetermined elapsed time range.
In accordance with another aspect of the disclosure, a drilling rig includes a casing string configured to receive and direct drilling fluids from a rig floor to a wellbore, a cement swivel configured to supply cement into the casing string to secure the casing string in the wellbore, a cement plug configured to remove cement from within the casing string, and a sensor system. The sensor system includes a first sensor disposed within the casing string and configured to monitor a pressure within the casing string, a second sensor disposed within the casing string downstream of the first sensor with respect to a flow of drilling fluid through the casing string, where the second sensor is configured to monitor the pressure within the casing string, and a controller configured to detect a launch of the cement plug when the first sensor detects a first pressure drop and when the second sensor detects a second pressure drop, where the second pressure drop occurs after the first pressure drop within a predetermined elapsed time range.
In accordance with another aspect of the disclosure, a method includes receiving feedback from a first sensor disposed in a casing string and a second sensor disposed in the casing string, where the second sensor is positioned downstream of the first sensor with respect to a flow of fluid within the casing string, detecting a first pressure drop from the first sensor, detecting a second pressure drop from the second sensor, and determining a launch of a cement plug in the casing string when the first pressure drop and the second pressure drop occur within a predetermined elapsed time range.
These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Present embodiments provide a system and method for detecting a launch of a cement plug within a casing or other tubular. For example, during casing cementing operations, a plug (e.g., rubber plug) is used to separate cement from displacement fluid as the plug is launched to substantially remove cement from an interior surface of wellbore tubulars (e.g., casing). In certain embodiments, the plug includes a port to allow cement to pass through the plug and into the casing or tubular. After a desired amount of cement is pumped into the casing or tubular, a solid ball is launched to occlude the port of the plug. Thereafter, displacement fluid (e.g., water or a water mixture) is pumped behind the ball and plug, thereby creating pressure and causing the plug to be launched down the casing or tubular. Unfortunately, the plug is not visible within the casing or tubular, thereby creating difficulty in ascertaining whether the plug is properly positioned within the tubular or casing and/or whether the plug has properly been launched down the casing. Existing plug detection systems utilize magnets, which may affect operation of components (e.g., sensors) of a drilling rig and/or a wellbore. Thus, present embodiments are directed to an improved system and method for detecting the launch of the plug within the casing or tubular.
As discussed in detail below, a plug detection system includes a first sensor (e.g., a first pressure sensor) and a second sensor (e.g., a second pressure sensor) positioned on or within the casing or tubular to detect a pressure drop that occurs as the plug travels over and/or past the first sensor and the second sensor. For example, first and second sensors may be disposed in openings in the casing or tubular and secured in the openings using threads, an adhesive, a sealant, a fastener (e.g., belts, straps, clamps, or other bands), and/or another suitable securement device. Once the first and second sensors are disposed in the openings, the openings may be sealed, such that fluid (e.g., cement, water, or a water mixture) may be blocked from exiting the casing or tubular through the openings.
Before the cementing process is completed, the plug (e.g., annular plug) is positioned or “stabbed” into the casing or tubular. The ball to block the port of the plug is launched to block the port of the plug, and displacement fluid is then pumped into the casing above the plug. Once the plug is launched down the casing by the displacement fluid, the first and second sensors each detect a pressure drop as the plug travels through the casing past the sensors. The pressure drop measured by the first and second sensors may be detected by a controller, which may provide an indication to a user or operator confirming a positive launch of the plug. In some embodiments, a distance between the first and second pressure sensors may be greater than a length of the plug, such that the pressure drop detected by the first sensor occurs prior to the pressure drop detected by the second sensor. Accordingly, the user or operator may confirm that the plug has launched when the first sensor measures a first pressure drop and the second sensor detects a second pressure drop that occurs within a predetermined elapsed time range after the first pressure drop.
Turning now to the drawings,
A tubular drive system 40, hoisted by the traveling block 22, positions the tubular 38 above the wellbore 30. In the illustrated embodiment, the tubular drive system 40 includes a top drive 42 and a gripping device 44. The gripping device 44 of the tubular drive system 40 is engaged with a distal end 48 (e.g., box end) of the tubular 38. The tubular drive system 40, once coupled with the tubular 38, may then lower the coupled tubular 38 toward the stump 36 and rotate the tubular 38 such that it connects with the stump 36 and becomes part of the casing string 28. The casing string 28 (and the tubular 38 now coupled to the casing string 28) may then be lowered (and rotated) further into the wellbore 30.
The drilling rig 10 further includes a control system 50, which is configured to control the various systems and components of the drilling rig 10 that grip, lift, release, and support the tubular 38 and the casing string 28 during a casing running or tripping operation. For example, the control system 50 may control operation of the gripping device 44 and the power slips 34 based on measured feedback to ensure that the tubular 38 and the casing string 28 are adequately gripped and supported by the gripping device 44 and/or the power slips 34 during a casing running operation. In this manner, the control system 50 may reduce and/or eliminate incidents where lengths of tubular 38 and/or the casing string 28 are unsupported. Moreover, the control system 50 may control auxiliary equipment such as mud pumps, robotic pipe handlers, and the like.
In the illustrated embodiment, the control system 50 includes a controller 52 having one or more microprocessors 54 and a memory 56. For example, the controller 52 may be an automation controller, which may include a programmable logic controller (PLC). The memory 56 is a non-transitory (not merely a signal), tangible, computer-readable media, which may include executable instructions that may be executed by the microprocessor 54. The controller 52 receives feedback from other components and/or sensors that detect measured feedback associated with operation of the drilling rig 10. For example, the controller 52 may receive feedback from a plug detection system described below and/or other sensors via wired or wireless transmission. Based on the measured feedback, the controller 52 may regulate operation of the tubular drive system 40 (e.g., increasing rotation speed).
In the illustrated embodiment, the drilling rig 10 also includes a casing drive system 70. The casing drive system 70 is configured to reciprocate and/or rotate the tubular 38 (e.g., casing) during casing and/or cementing operations. In the illustrated embodiment, the casing drive system 70 is placed above the rig floor 12. However, in other embodiments the casing drive system 70 may be placed beneath the rig floor 12, at the rig floor 12, within the wellbore 30, or any other suitable location on the drilling rig 10 to enable rotation of the tubular 38 during casing and/or cementing operations. As mentioned above, in certain embodiments, the control system 50 may control the operation of the casing drive system 70. For example, the control system 50 may increase or decrease the speed of rotation of the tubulars 38 based on wellbore conditions.
The casing drive system 70 may be used during cementing operations to direct cement into the casing string 28. In the illustrated embodiment, the casing drive system 70 is coupled to a cement swivel 72 configured to supply cement for cementing operations. For example, the cement swivel 72 may receive cement from a pumping unit 74 via a supply line 76. Additionally, the casing drive system 70 may include an inner bore configured to direct the cement through the casing drive system 70 and into the casing string 28.
Furthermore, a plug 80 coupled to a casing drive system adapter 82 may be positioned within (e.g., “stabbed” into) the casing string 28. As mentioned above, the plug 80 may include a port or central passage that enables cement to flow from the casing drive system 70, through the plug 80, and into the casing 28. After the casing cementing process is completed, the plug 80 is used to substantially remove cement from an interior surface of the casing string 28. To this end, a ball launcher 78 positioned in the supply line 76 between the cement swivel 72 and the pumping unit 74 is configured to launch a ball through the casing drive system 70 to the plug 80. The ball occludes the port or central passage of the plug 80 to block fluid from passing across the plug 80. Once the ball is launched from the ball launcher 78 to block the port of the plug 80, a displacement fluid (e.g., water, a water mixture, and/or a chemical substance) is pumped behind the ball and plug 80, which causes the plug 80 to be launched down the casing string 28. As the plug 80 travels down the casing string 28, the plug 80 cleans and/or removes cement from the inner surface of the casing string 28.
As mentioned above, embodiments of the present disclosure are directed to a plug detection system 100 configured to detect a position and/or movement of the plug 80. The plug detection system 100 includes a first sensor 102 (e.g., a first pressure sensor) and a second sensor 104 (e.g., a second pressure sensor) disposed on or within the casing string 28 at the rig floor 12. In other embodiments, the plug detection system 100 having the first sensor 102 and the second sensor 104 is disposed at another suitable location above the rig floor 12 or below the rig floor 12. For example, the first and second sensors 102 and 104 are be disposed in openings (e.g., threaded openings) of the casing string 28 and secured in the openings using threads, an adhesive, a sealant, a fastener (e.g., belts, straps, clamps, or other bands), and/or another suitable securement device. Once the first and second sensors 102 and 104 are disposed in the openings, the openings may be sealed, such that fluid (e.g., cement, water, or a water mixture) may be blocked from exiting the casing or tubular through the openings.
In some embodiments, a distance between the first and second sensors 102 and 104 is greater than a height of the plug 80, such that the pressure drop detected by the first sensor 102 occurs prior to the pressure drop detected by the second sensor 104. Accordingly, the user or operator may confirm that the plug 80 has launched when the first sensor 104 measures a first pressure drop and the second sensor 104 measures a second pressure drop that occurs within a predetermined elapsed time range after the first pressure drop. Further, the first and second sensors 102 and 104 are positioned below the plug 80, such that both the first and second sensors 102 and 104 measure a pressure drop as the plug 80 travels past the first and second sensors 102 and 104. As shown in the illustrated embodiment of
It should be noted that the illustration of
In some embodiments, the openings 120 are sealed once the first sensor 102 and the second sensor 104 are disposed in the openings 120. In some embodiments, the openings 120 are sealed using welding, a sealing component (e.g., an o-ring), a silicone sealant, an epoxy sealant, and/or another suitable sealant. Sealing the openings 120 blocks fluid within the casing string 28 from leaking and/or otherwise flowing out of a passageway 130 of the casing string 28.
The first sensor 102 and the second sensor 104 are configured to detect a pressure in the passageway 130 of the casing string 28. For example, the first sensor 102 and the second sensor 104 may be pressure transducers that measure pressure within the casing string 28. In some embodiments, the first sensor 102 and the second sensor 104 are battery powered. In other embodiments, the first sensor 102 and the second sensor 104 are configured to receive power from the controller 52. In any case, the first sensor 102 and the second sensor 104 are communicatively coupled to the controller 52 of the control system 50, such that the first sensor 102 and the second sensor 104 provide feedback to the controller 52 indicative of the pressure within the passageway 130 of the casing string 28. The feedback received from the first sensor 102 and the second sensor 104 may enable the controller 52 to determine a flow rate of fluid (e.g., cement, water, a water mixture, and/or another chemical) through the passageway 130. For example, when the first sensor 102 and the second sensor 104 provide feedback indicative of a pressure drop experienced within the passageway 130 at approximately the same time (e.g., within 10 milliseconds, within 50 milliseconds or within 100 milliseconds), the controller 52 may determine that the flow of fluid in the passageway 130 has decreased and/or stopped. Additionally, the first sensor 102 and the second sensor 104 may enable the controller 52 to determine pulsing of the flow of fluid resulting from a pump that drives the flow of fluid through the passageway 130. For example, the first sensor 102 and the second sensor 104 may each provide feedback that includes a fluctuating pressure profile. The fluctuating pressure profiles of both the first sensor 102 and the second sensor 104 may substantially mirror one another, such that pressure fluctuations occur at approximately the same time as one another (e.g., within 10 milliseconds, within 50 milliseconds, or within 100 milliseconds).
As discussed above, the first sensor 102 and the second sensor 104 may be utilized to determine whether the plug 80 launches into the casing string 28. As shown in the illustrated embodiment of
In some embodiments, the first sensor 102 and/or the second sensor 104 may be disposed in an extension portion 133 of the casing string 28. For example, the extension portion 133 may be a portion of the casing string 28 that includes an outer diameter 137 that is greater than an outer diameter 135 of the remainder of the casing string 28. Disposing the first sensor 102 and/or the second sensor 104 in the extension portion 133 of the casing string 28 may enable the plug detection system 100 to monitor a flow rate of the fluid flowing through the casing string 28. For example, the extension portion 133 may enable the first sensor 102 and/or the second sensor 104 to detect a pressure differential of the fluid flowing through the casing string 28, and thus determine a flow rate of the fluid. The fluid flowing through the casing string 28 may flow within the extension portion to enable the first sensor 102 and/or the second sensor 104 to detect a pressure differential of the fluid over a predetermined period of time. Thus, the controller 52 may calculate a flow rate of the fluid based on the pressure differential detected by the first sensor 102 and/or the second sensor 104. While the illustrated embodiment of
Further, the illustrated embodiment of
In any case, the first pressure profile 160 corresponding to the first sensor 102 includes a first pressure drop 164 that occurs at a first time 166. The first pressure drop 164 at the first time 166 is indicative of the plug 80 moving past the first sensor 102. Similarly, the second pressure profile 162 corresponding to the second sensor 104 includes a second pressure drop 168 that occurs at a second time 170, which is later than the first time 166. The second pressure drop 168 is indicative of the plug 80 moving past the second sensor 104, which is positioned downstream of the first sensor 102 with respect to the flow of fluid through the casing string 28. As such, the second pressure drop 168 occurs after the first pressure drop 166. The controller 52 may determine that the plug 80 has launched when the feedback from the first sensor 102 and the second sensor 104 includes the first pressure drop 164 and the second pressure drop 168 that occur sequentially (e.g., the first pressure drop 164 measured by the first sensor 102 occurs before the second pressure drop 166 measured by the second sensor 104), and when the difference between the first time 166 and the second time 170 falls within a predetermined elapsed time range. As discussed above, the predetermined elapsed time range may be between 250 milliseconds and 10 seconds, between 500 milliseconds and 5 seconds, or between 750 milliseconds and 2 seconds.
While the illustrated embodiment of
As such, the controller 52 may detect the pressure drops 164 and 168 when the pressures measured by the first sensor 102 and the second sensor 104, respectively, fluctuate by a predetermined amount. For example, the pressure drops 164 and 168 indicative of the plug 80 moving past the sensors 102 and 104, respectively, may be determined when the pressure fluctuates by more than 10%, more than 15%, more than 20%, or more than 25% over a predetermined time interval (e.g., 10 milliseconds, 50 milliseconds, or 100 milliseconds). Pressure fluctuations that do not exceed the predetermined amount may effectively be identified by the controller 52 as fluctuations caused by the pump and/or pressure fluctuations within the wellbore 30.
In some embodiments, when the controller 52 receives the feedback from the first sensor 102 and the second sensor 104 indicative of the launch of the plug 80, the controller 52 may send a signal to a user (e.g., via a user interface) to indicate that the plug 80 has launched into the casing string 28. For example, the user may initiate the launch of the plug (e.g., via the user interface) and subsequently receive an indication (e.g., illumination of a light emitting diode (LED), sounding of a horn, or another suitable audio or visual form of communication from the controller) from an indicator 198 (see, e.g.,
The controller 52 may also send a signal to the user (e.g., via a user interface) indicating that the plug 80 has launched. Alternatively, if the first pressure drop 164 and the second pressure drop 168 do not occur within the predetermined elapsed time range and/or the first pressure drop 164 and/or the second pressure drop 168 do not occur at all, the controller 52 may send a second signal to the user (e.g., via the user interface) indicating that the plug 80 did not launch.
While the present disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and tables and have been described in detail herein. However, it should be understood that the embodiments are not intended to be limited to the particular forms disclosed. Rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the following appended claims. Further, although individual embodiments are discussed herein, the disclosure is intended to cover all combinations of these embodiments.
Number | Name | Date | Kind |
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20160230533 | Steele | Aug 2016 | A1 |
20160362938 | Gan | Dec 2016 | A1 |
20170138177 | Hazel | May 2017 | A1 |
Number | Date | Country | |
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20190093472 A1 | Mar 2019 | US |