This disclosure relates to wellbore management, and particularly to performing flow check within a wellbore.
Wellbores are formed in subterranean zones (a formation, a portion of a formation or multiple formations) to produce hydrocarbons entrapped in the subterranean zones to the surface. When forming wellbores or when operating wellbores, the stability of well conditions is periodically checked. Flow check is one such stability test in which a fluid level within a wellbore is monitored. Often, a flow check is a manual operation performed by an operator who visually inspects fluid levels within the wellbore.
This disclosure describes an ultrasonic flow check systems for wellbores.
Certain aspects of the subject matter described here can be implemented as a well tool system. The system includes a bell nipple attached to a well head of a wellbore at a surface. A rotary table is installed above the bell nipple such that the bell nipple is between the rotary table and the well head. A flow line is attached to a side surface of the bell nipple such that the flow line is between the rotary table and the well head. The flow line can permit flow of wellbore fluid into the bell nipple. An ultrasonic transceiver is attached to an inner surface of the bell nipple. The ultrasonic transceiver can transmit ultrasonic signals and receive ultrasonic response signals generated responsive to a reflection of the ultrasonic signals. An alarm is installed on the rotary table. The alarm is operatively coupled to the ultrasonic transceiver. A control system is operatively coupled to the ultrasonic transceiver and the alarm. The control system includes one or more computers, and a computer-readable medium (e.g., a non-transitory computer-readable medium) storing instructions executable by the one or more computers to perform operations. The operations include sending an instruction to the ultrasonic transceiver to transmit an ultrasonic signal into the bell nipple. The operations include receiving a signal from the ultrasonic transceiver. The received signal is representative of an ultrasonic response signal received by the ultrasonic transceiver responsive to a reflection of the transmitted ultrasonic signal by a wellbore fluid within the bell nipple. The ultrasonic response signal represents a fluid level of the wellbore fluid within the bell nipple. The operations include determining, based on the transmitted ultrasonic signal and the received ultrasonic response signal, whether the fluid level within the bell nipple is static or mobile.
An aspect combinable with any other aspect can include the following features. The control system is installed on the rotary table.
An aspect combinable with any other aspect can include the following features. The alarm includes a visual alarm.
An aspect combinable with any other aspect can include the following features. The alarm includes an audible alarm.
An aspect combinable with any other aspect can include the following features. The transmitted ultrasonic signal is an ultrasonic status signal. Before sending the instructions to the ultrasonic transceiver to transmit the ultrasonic status signal, the operations include sending an instruction to the ultrasonic transceiver to transmit an ultrasonic test signal into the bell nipple. The operations include receiving a signal from the ultrasonic transceiver. The received signal is representative of an ultrasonic response-to-status signal received by the ultrasonic transceiver responsive to a reflection of the ultrasonic test signal by the wellbore fluid within the bell nipple. The operations include determining, based on the ultrasonic test signal and the ultrasonic response-to-status signal, that the fluid level is ready to be determined by transmitting the ultrasonic status signal.
An aspect combinable with any other aspect can include the following features. To determine, based on the ultrasonic test signal and the ultrasonic response-to-status signal, that the fluid level is ready to be determined by transmitting the ultrasonic status signal, the operations include determining that the level of the wellbore fluid within the bell nipple represented by the ultrasonic response-to-status signal matches a threshold fluid level.
An aspect combinable with any other aspect can include the following features. The operations include, in response to determining that the level of the wellbore fluid within the bell nipple represented by the ultrasonic response-to-status signal matches the threshold fluid level, triggering the visual alarm.
An aspect combinable with any other aspect can include the following features. The operations include, after receiving the signal from the ultrasonic transceiver, which is representative of the ultrasonic response signal received by the ultrasonic transceiver responsive to the reflection of the transmitted ultrasonic signal by the wellbore fluid within the bell nipple, determining that the fluid level within the bell nipple is mobile. In response to determining that the fluid level within the bell nipple is mobile, the operations include triggering the audible alarm.
An aspect combinable with any other aspect can include the following features. To determine, based on the transmitted ultrasonic signal and the received ultrasonic response signal, whether the fluid level within the bell nipple is static or mobile, the operations include determining whether a magnitude of the ultrasonic response signal remains constant over time or varies over time.
An aspect combinable with any other aspect can include the following features. The operations include determining that the magnitude of the ultrasonic response signal remains constant over time. In response to determining that the magnitude of the ultrasonic response signal remains constant over time, the operations include not triggering the alarm.
An aspect combinable with any other aspect can include the following features. The operations include determining that the magnitude of the ultrasonic response signal varies over time. In response to determining that the magnitude of the ultrasonic response signal varies over time, the operations include triggering the alarm.
Certain aspects of the subject matter described here can be implemented as a method. An ultrasonic transceiver is installed within an inner surface of a bell nipple attached to a well head of a wellbore at a surface. The bell nipple receives wellbore fluid from a flow line attached to a side surface of the bell nipple. An alarm is installed on a rotary table installed above the bell nipple such that the bell nipple is between the rotary table and the well head. A ultrasonic signal is caused to be transmitted, by the ultrasonic transceiver, into the bell nipple. The ultrasonic signal is reflected by the wellbore fluid within the bell nipple resulting in an ultrasonic response signal. The ultrasonic response signal is caused to be received by the ultrasonic transceiver. Based on the ultrasonic response signal, it is determined whether the fluid level within the bell nipple is static or mobile.
An aspect combinable with any other aspect can include the following features. The transmitted ultrasonic signal is an ultrasonic status signal. Before transmitting the ultrasonic status signal, the ultrasonic transceiver is caused to transmit an ultrasonic test signal into the bell nipple. The ultrasonic transceiver is caused to receive an ultrasonic response-to-status signal responsive to a reflection of the ultrasonic test signal by the wellbore fluid within the bell nipple. Based on the ultrasonic test signal and the ultrasonic response-to-status signal, it is determined that the fluid level is ready to be determined by transmitting the ultrasonic status signal.
An aspect combinable with any other aspect can include the following features. To determine, based on the ultrasonic test signal and the ultrasonic response-to-status signal, that the fluid level is ready to be determined by transmitting the ultrasonic status signal, it is determined that the level of the wellbore fluid within the bell nipple represented by the ultrasonic response-to-status signal matches a threshold fluid level.
An aspect combinable with any other aspect can include the following features. In response to determining that the level of the wellbore fluid within the bell nipple represented by the ultrasonic response-to-status signal matches the threshold fluid level, the visual alarm is triggered.
An aspect combinable with any other aspect can include the following features. After determining that the fluid level is ready to be determined by transmitting the ultrasonic status signal, it is determined that the fluid level within the bell nipple is mobile. In response to determining that the fluid level within the bell nipple is mobile, the audible alarm is triggered.
An aspect combinable with any other aspect can include the following features. To determine, based on the ultrasonic response signal, whether the fluid level within the bell nipple is static or mobile, it is determined whether a magnitude of the ultrasonic response signal remains constant over time or varies over time.
An aspect combinable with any other aspect can include the following features. It is determined that the magnitude of the ultrasonic response signal remains constant over time. In response to determining that the magnitude of the ultrasonic response signal remains constant over time, the alarm is not triggered.
An aspect combinable with any other aspect can include the following features. It is determined that the magnitude of the ultrasonic response signal varies over time. In response to determining that the magnitude of the ultrasonic response signal varies over time, the alarm is triggered.
The details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims.
Like reference numbers and designations in the various drawings indicate like elements.
A flow check operation is performed by stopping wellbore operations (e.g., drilling, tripping, circulating or similar wellbore operations) and by monitoring to see if the wellbore is static or mobile (i.e., not static). The flow check operation is performed to ensure that the wellbore is stable. A manual flow check operation is performed by an operator who visually observes (sometimes with a flashlight) the wellbore fluid from a rig floor. In particular, the operator observes the wellbore fluid level within a bell nipple, which is a section of a large diameter tubular fitted to the top of the blowout preventers. If the wellbore fluid level is static in the bell nipple, then the operator concludes that the wellbore itself is static.
This disclosure describes an ultrasonic flow check system deployed to use ultrasonic signals to perform the flow check operation. Implementing the techniques described in this disclosure can yield accurate flow check results, which are sometimes better than the results of a manual flow check by a human operator. The techniques can prevent wellbore incidents such as blow out. Also, the techniques can warn an operator by sound and light in case the operator fails to detect blow out.
A bell nipple 108 is attached to the well head 104, particularly to the top of the blow out preventer 106. The bell nipple 108 is an elongated hollow tubular defining an interior volume. A flow line 110 is attached to the bell nipple 108. Specifically, an inlet to the flow line 110 is attached to a side, circumferential surface 112 of the bell nipple 108. An outlet of the flow line 110 leads to wellbore equipment installed at the surface 102, such as shale shakers and mud tanks (not shown). In operation, wellbore fluid (e.g., drilling fluid, production fluid or similar wellbore fluid) flows through the wellbore 100, through the well head 104, through the blow out preventer 106, through the bell nipple 108 and into the flow line 10.
A rotary table 114 is installed above the bell nipple 108 such that the bell nipple 108 is between the rotary table 114 and the well head 104. In some implementations, the ultrasonic flow check system is installed partly within the bell nipple 108 and partly on the rotary table 114. The ultrasonic flow check system includes an ultrasonic transceiver 116 attached to an inner surface 118 of the bell nipple 108. The ultrasonic transceiver 116 is configured to transmit ultrasonic signals and receive ultrasonic response signals generated responsive to a reflection of the ultrasonic signals. In some implementations, the ultrasonic transceiver 116 is attached near an upper end of the bell nipple 108 and is arranged such that the transceiver 116 transmits ultrasonic signals downward into the bell nipple and receives ultrasonic response signals flowing upward. By this arrangement, the ultrasonic transceiver 116 can transmit ultrasonic signals onto a surface of a wellbore fluid within the bell nipple 108 and receive ultrasonic response signals reflected at the surface of the wellbore fluid within the bell nipple 108.
The ultrasonic flow check system also includes an alarm 120 operatively coupled to the ultrasonic transceiver 116. In some implementations, the alarm 120 is installed on the rotary table 114. Alternatively, the alarm 120 can be installed on other wellbore equipment or at a location away from the wellbore 100 or wellbore equipment. In some implementations, the ultrasonic transceiver 116 and the alarm 120 are operatively coupled by wired connections. Alternatively, the connections can be wireless allowing the alarm 120 to be located at locations remote from the wellbore 100. In some implementations, the alarm 120 includes a visual alarm, e.g., a light, that turns on or off responsive to instructions. In some implementations, the alarm 120 includes an audible alarm, e.g., a speaker or other audio-producing device, that produces an audible sound responsive to instructions. In some implementations, the alarm 120 can include the visual alarm and the audible alarm.
In some implementations, the ultrasonic flow check system includes a control system 122 (or controller) that is operatively coupled (e.g., via wired or wireless connections) to the ultrasonic transceiver 116 and the alarm 120. For example, the control system 122 can be implemented as one or more computer systems and a computer-readable medium (e.g., non-transitory computer-readable medium) storing instructions executable by the one or more computers to perform operations, such as a flow check operation. Alternatively or in addition, the control system 122 can be implemented as processing circuitry, firmware, software, hardware or a combination of any of them. In some implementations, the control system 122 is a component of the ultrasonic transceiver 116 and resides in the same housing as the ultrasonic transceiver 116. Alternatively, the control system 122 can be a separate unit residing elsewhere, e.g., on the rotary table 122.
In operation, the operator decides to perform a flow check operation and ceases all flow through the wellbore 100. For example, if the operator is drilling the wellbore 100, then the operator can stop operation of the drilling equipment. In another example, if the operator is producing through the wellbore 100, then the operator can stop operation of any pumps or close flow control valves. Once flow through the wellbore 100 has ceased, the wellbore fluid rises to a location within the bell nipple 108. Once flow through the wellbore 100 has stopped, if the wellbore 100 is static, then the wellbore fluid levels within the wellbore 100 should be unchanged, i.e., the wellbore fluid levels should remain static. If the wellbore fluid levels are not static (i.e., the wellbore fluid level is mobile), then the wellbore 100 is unstable and remedial operations need to be initiated.
In some implementations, the operator can operate the control system 122 to perform the flow check operation. For example, in response to an instruction (e.g., a digital signal) from the operator (e.g., in response to being turned on), the control system 122 can send an instruction to the ultrasonic transceiver 116 to transmit an ultrasonic signal into the bell nipple 108. In response to receiving the instruction, the ultrasonic transceiver 116 generates and transmits an ultrasonic signal which travels downward into the bell nipple 108. The ultrasonic signal reflects on the surface of the wellbore fluid within the bell nipple 108 and produces an ultrasonic response signal, which travels upward toward the ultrasonic transceiver 116. Because the ultrasonic response signal is generated responsive to a reflection at a surface of the wellbore fluid within the bell nipple 108, the ultrasonic response signal represents a fluid level of the wellbore fluid within the bell nipple 108. The ultrasonic transceiver 116 receives the ultrasonic response signal and generates a signal (e.g., a digital signal) that is representative of the ultrasonic response signal. For example, a magnitude of the signal generated by the ultrasonic transceiver 116 can be directly proportional to a magnitude of the ultrasonic response signal. The control system 122 receives the signal and, using the signal, determines if the fluid level within the bell nipple 108 is static or mobile. In this manner, the ultrasonic flow check system determines whether the fluid level within the bell nipple 108 is static or mobile based on the ultrasonic signal transmitted into the bell nipple 108 and the ultrasonic response signal received responsive to a reflection of the transmitted ultrasonic signal on the surface of the wellbore fluid within the bell nipple 108.
In some implementations, the visual alarm (e.g., a light bulb) included in the alarm 120 can be turned off when the ultrasonic transceiver 116 transmits and receives the ultrasonic signals, and the control system 122 processes the digital signals received from the ultrasonic transceiver 116. Upon determining that the magnitude of the signals does not change over time, the control system 122 can transmit a signal to turn on the visual alarm (i.e., turn on the light bulb). The visual alarm being turned on can communicate to the wellbore operator that the wellbore fluid levels are static.
In some implementations, the visual alarm (e.g., the light bulb) included in the alarm 120 can be turned on when the ultrasonic transceiver 116 transmits and receives the ultrasonic signals, and the control system 122 processes the digital signals received from the ultrasonic transceiver 116. Upon determining that the magnitude of the signals does not change over time, the control system 122 can transmit a signal to turn off the visual alarm (i.e., turn off the light bulb). The visual alarm being turned off can communicate to the wellbore operator that the wellbore fluid levels are static.
If the visual alarm was turned on when performing the flow check operation and a status operation was performed to determine if the flow check operation can be performed (as described above with reference to
At 300, an ultrasonic transceiver (e.g., ultrasonic transceiver 116) is installed within an inner surface of a bell nipple (e.g., bell nipple 108) attached to a well head of a wellbore at a surface. The bell nipple receives wellbore fluid from a flow line attached to a side surface of the bell nipple.
At 304, an alarm is installed on a rotary table (e.g., rotary table 114) installed above the bell nipple such that the bell nipple is between the rotary table and the well head. The alarm can include a visual alarm (e.g., a light bulb) and an audible alarm (e.g., a speaker or siren).
At 306, an ultrasonic signal is caused to be transmitted by the ultrasonic transceiver. To do so, for example, a control system (e.g., control system 122) can send an instruction to the ultrasonic transceiver in response to which the ultrasonic transceiver transmits the ultrasonic signal into the bell nipple. The ultrasonic signal is reflected by the wellbore fluid within the bell nipple resulting in an ultrasonic response signal. The ultrasonic transceiver receives the ultrasonic response signal.
At 308, a flow check operation is performed based on the transmitted ultrasonic signal and the received ultrasonic response signal. For example, the ultrasonic signal is transmitted into the bell nipple for a duration of time, either continuously or as periodic bursts. If the fluid level is static, then the distance traveled by the ultrasonic signal and the ultrasonic response signal remains the same over the duration of time. Consequently, a magnitude of the ultrasonic response signal remains constant for the duration of time (i.e., a difference between the magnitudes of the ultrasonic response signals received over the duration remains less than a threshold). Because the control system converts the ultrasonic response signal into a digital signal, a constant ultrasonic response signal results in a constant digital signal as well (i.e., i.e., a difference between the magnitudes of the digital signals received over the duration remains less than a threshold). A constant digital signal indicates that the wellbore fluid level is static and the flow check operation is negative. The alarm need not be triggered because the flow check operation is negative.
In contrast, if the fluid level is moving (e.g., rising) within the bell nipple 108, then the distance traveled by the ultrasonic signal and the ultrasonic response signal changes over the duration of time. Consequently, a magnitude of the ultrasonic response signal changes for the duration of time (i.e., a difference between the magnitudes of the ultrasonic response signals received over the duration exceeds a threshold). Because the control system converts the ultrasonic response signal into a digital signal, a changing ultrasonic response signal results in a changing digital signal as well (i.e., i.e., a difference between the magnitudes of the digital signals received over the duration exceeds a threshold). A changing digital signal indicates that the wellbore fluid level is not static (i.e., the fluid level is mobile), and the flow check operation is positive. The alarm can be triggered because the flow check operation is positive.
In some implementations, the alarm can be triggered in stages. For example, the visual alarm can be triggered when the flow check operation is performed and the audible alarm can be further triggered if the flow check operation is positive.
Thus, particular implementations of the subject matter have been described. Other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.