Patent Application
20240209730
The invention relates generally to well operations and more particularly to systems and methods for determining well conditions below a suspension tool to prevent an unsafe condition following removal, release or cycling of the tool.
Is commonly necessary in oil and gas production to suspend production from a well. In many situations, this can be accomplished by running a plug in the well or by closing a valve (e.g., a downhole sleeve) that is already installed in the well.
It is often the case that when a well is plugged or otherwise sealed to suspend production, there is no information available as to the conditions in the well below the plug. While some completions hardware may provide the ability to obtain some information on these conditions, this equipment is very expensive and is normally incorporated into the well at the design stage and installed at the original deployment stage. Some well operators have hundreds of wells on a piece of land that may need to be suspended and worked over, so it is not economically feasible to deploy equipment with these types of control or monitoring mechanisms. Consequently, this equipment is typically not installed and not available to provide information on the well conditions below the plug.
The lack of information about the well conditions below the plug presents various risks. For example, in many cases, there is a need to resume production from a plugged well, so it is necessary to remove the plug or open the valve that is sealing the well. There may, however, be high pressure fluids or a gas bubble below the plug, and if this is not known, the unexpected surge in pressure can damage uphole equipment (e.g., a lubricator or any other uphole control devices) which is not configured to handle the pressure. Alternatively, if the pressure below the plug is lower than expected, the hydrostatic fluid above the plug can be lost, which results in the loss of the control mechanism for the well.
Prior to the innovations disclosed herein, resuming operation of a suspended well was typically a matter of pulling the plug and hoping that the well conditions did not cause any problems. It would therefore be desirable to provide a way to avoid the problems discussed above.
This disclosure is directed to systems and methods for determining well conditions (e.g., pressure or temperature) below a suspension tool installed in a well so that it can be determined whether the suspension tool can safely be removed or unsealed. The suspension tool has a simple sensor which is normally unpowered, but receives power when engaged by a shifting tool to enable the sensor to measure well conditions below the suspension tool. The shifting tool may be connected to a digital slickline which has electrical conductors that allow power to be transmitted from a power source at the surface of the well to the shifting tool. Sets of electrical contacts on the shifting tool and the suspension tool allow power to be provided through the shifting tool to the sensor in the suspension tool. Similarly, well condition measurements made by the sensor when it receives power through the shifting tool are communicated back through the shifting tool and the digital slickline to equipment at the surface of the well. The well condition information provided by the sensor enables the operators of the well to determine whether it is safe to proceed with a procedure to remove or unseal the suspension tool.
One embodiment comprises a system for determining well conditions below a suspension tool prior to moving the tool. The system includes a suspension tool which is installed in a well and configured to prevent fluid communication between a lower portion of the well below the tool and an upper portion of the well above the tool. The suspension tool has one or more sensors configured to measure one or more well conditions in the lower portion of the well. The system also includes a shifting tool which is configured to be lowered into the well to engage the suspension tool and to selectively move the suspension tool to allow fluid communication between the upper and lower portions of the well. The shifting tool is coupled to a power source so that when the shifting tool engages the suspension tool, the sensors are coupled through the shifting tool to the power source. When the sensors are coupled to the power source, the sensors make measurements of the well conditions in the lower portion of the well and communicates the measurements through the shifting tool to an operator of the well.
In some embodiments, the shifting tool includes a first set of electrical contacts and the suspension tool includes a second set of contacts, such that when the shifting tool engages the suspension tool, the first set of contacts comes into contact with the second set of contacts and thereby couples the sensors to the power source. The sensors may be configured to make the measurements of the well conditions in response to being coupled to the power source. In response to being coupled to the power source, the sensors may be further configured to provide the measurements of the well conditions to the shifting tool via the first and second sets of electrical contacts. In some embodiments, the sensors are unpowered except for the coupling of the sensors to the power source.
In some embodiments, the suspension tool comprises a suspension plug and the shifting tool comprises a pulling tool which is adapted to engage the suspension plug and pull the suspension plug out of the well. In some embodiments, the suspension tool comprises a sliding sleeve tool and the shifting tool comprises a shifting tool adapted to engage the sliding sleeve tool and shift a sleeve of the sliding sleeve tool between an open position and a closed position.
In some embodiments, the well conditions include a pressure in the lower portion of the well and the sensors include a pressure sensor. In some embodiments, the well conditions include a temperature in the lower portion of the well and the sensors include a temperature sensor.
In some embodiments, the shifting tool is connected to a digital slickline that extends to the surface of the well. The digital slickline includes one or more electrical lines configured to convey power and data between the shifting tool and equipment positioned at the surface of the well.
An alternative embodiment comprises a method for determining well conditions below a suspension tool prior to moving the tool. This method includes providing a shifting tool which is coupled to a power source and lowering the shifting tool into a well. The shifting tool engages a suspension tool which is installed in the well, where the suspension tool provides a seal between an upper portion of the well above the suspension tool from a lower portion of the well below the suspension tool. The suspension tool includes one or more sensors which are configured to measure one or more corresponding well conditions in the lower portion of the well. When the shifting tool engages the suspension tool, a first set of electrical contacts on the shifting tool engage a second set of contacts on the suspension tool and thereby couple the sensors to receive power from the power source. In response to the sensors receiving power from the power source, the sensors make one or more measurements of the well conditions in the lower portion of the well and provide the measurements to the shifting tool via the first and second sets of electrical contacts. The method further includes determining whether the measurements are within corresponding ranges of acceptable values and, if the measurements are within the corresponding ranges of acceptable values, the shifting tool moves the suspension tool to enable fluid communication between the upper portion of the well and the lower portion of the well.
In some embodiments, the method further comprises, if the sensor measurements are not within the corresponding ranges of acceptable values, performing one or more actions to remediate the well and to thereby bring measured values of the one or more well conditions within the one or more corresponding ranges of acceptable values. Thereafter, the shifting tool moves the suspension tool to enable fluid communication between the upper portion of the well with the lower portion of the well.
In some embodiments, the method further comprises connecting the shifting tool to a digital slickline which extends to the surface of the well, where the digital slickline has one or more electrical lines which are configured to convey power and data between the shifting tool and equipment positioned at the surface of the well. For instance, the power source may be positioned at the surface of the well and coupled to the digital slickline to provide power to the shifting tool. The measurements from the sensors are then communicated from the sensors through the first and second sets of electrical contacts, the shifting tool and the digital slickline to the surface of the well. A well operator then determines whether the measurements are within the corresponding ranges of acceptable values.
Numerous other embodiments may also be possible.
The various embodiments of the invention may provide a number of advantages over existing systems. For example, embodiments disclosed herein reduce safety risks associated with operations to resume production in a suspended well. These risks may include, for example, unexpected surges in pressure that can damage uphole equipment such as lubricators or any other uphole control devices which are not configured to handle the surge or, if the pressure below the plug is lower than expected, the hydrostatic fluid above the plug can be lost, which can result in the loss of the control mechanism for the well. The present embodiments may also enable well operators to determine whether the conditions in a well are safe for the release of pressure below a suspension tool without having to incorporate expensive sensors into the well at the design stage or install this equipment at the original deployment stage. Other advantages may also be apparent to those of skill in the art.
Other objects and advantages of the invention may become apparent upon reading the following detailed description and upon reference to the accompanying drawings.
While the invention is subject to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and the accompanying detailed description. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to the particular embodiment which is described. This disclosure is instead intended to cover all modifications, equivalents and alternatives falling within the scope of the present invention as defined by the appended claims.
One or more embodiments of the invention are described below. It should be noted that these and any other embodiments described below are exemplary and are intended to be illustrative of the invention rather than limiting.
Embodiments disclosed herein are directed to systems and methods for determining the pressure below a suspension tool (i.e., a tool that suspends production from the well, such as a suspension plug, a sliding sleeve, etc.) which is installed in a suspended well so that it can be determined whether the suspension tool can safely be removed or unsealed. The suspension tool has a simple sensor which is normally unpowered, but receives power when engaged by a shifting tool to enable the sensor to measure well conditions below the suspension tool and to communicate this information back to the shifting tool, which is coupled to equipment at the surface of the well by a digital slickline or similar means. The information provided by the sensor enables the operators of the well to determine whether it is safe to proceed with a procedure to remove or unseal the suspension tool. (“Shifting tool” is used herein to refer to any type of tool that is adapted to pull, shift, release or otherwise move a suspension tool, including, for example, a pulling tool that is used to pull a suspension plug, a shifting tool adapted to shift the position of a sliding sleeve, etc.)
In some embodiments, the shifting tool may also incorporate a load cell which is positioned between the shifting tool and the line from which the tool is suspended. The load cell enables the well operator to determine how much force is applied to the shifting tool. Based on this real time information, the well operator can determine whether a shifting procedure being performed by the shifting tool is proceeding as expected (i.e., the load sensed by the load cell is within acceptable limits), or if the system must be reconfigured to account for unexpected loading.
Referring to
The present embodiments, however, provide a low cost sensor in the suspension tool which is configured to measure the pressure, p2, in the region below the suspension tool. The sensor is normally inactive (i.e., powered off), but is activated by engagement with a shifting tool 120. The unpowered sensor does not require a permanent connection to a power source or a permanent communication channel. Instead, power is provided to the sensor via an electrical line of a digital slickline 140 that is used to run the shifting tool into the well. When the shifting tool engages the suspension tool, electrical contacts on the shifting tool engage electrical contacts on the suspension tool, electrically coupling the sensor of the suspension tool to the electrical line of the digital slickline. Power from surface equipment 150 is then provided to the sensor through the digital slickline and the shifting tool. The shifting tool could alternatively carry its own power source (e.g., a battery) that is configured to supply power to the sensor(s) in the suspension tool when engaged by the shifting tool.
It should be noted that “digital slickline” is used herein to refer to a slickline that includes one or more conductors (electrical lines) that can be used to transmit power and/or data between the shifting tool and the surface of the well. This may also be referred to “e-slickline.” Conventional slickline does not normally include the electrical lines that are incorporated into digital slickline. While wireline could be used for this purpose as well, digital slickline is typically less expensive than wireline.
It should be noted that it may be desirable to sense parameters other than pressure below the suspension tool, so the tool may incorporate types of sensors other than pressure sensors. For example, it may be desirable to sense temperature below the suspension tool, so the tool may incorporate a temperature sensor that is configured to be coupled to a power source and a communication channel in the same manner as the pressure sensor described above. The suspension tool may also use multiple, different types of sensors, each of which is configured to be powered on when the shifting tool is engaged with the suspension tool, and to communicate data through the shifting tool to the surface of the well.
Similarly, a set of contacts on the shifting tool which are coupled to a data line of the digital slickline engage corresponding contacts on the suspension tool, electrically coupling data outputs of the sensor in the suspension tool to the data line of the digital slickline. Data output by the powered sensor is then provided through the shifting tool and the digital slickline to an operator at the surface of the well. The well operator uses this data to determine the pressure, p2, in the region of the well below the suspension tool, and can then determine whether it is safe to shift the suspension tool and release the pressure below the tool (i.e., to enable fluid communication between the regions above and below the tool).
Referring to
Sensor 210 is a very low energy sensor, so that it can be Operated using power that is provided through electrical lines 250. Electrical lines in set 250 may include separate lines for power and data, or common lines may be used for power and communications (“comms-on” power). The electrical lines in set 250 may include intervening components such as repeaters between the shifting tool and the surface equipment. The electrical lines may be provided in the form of a digital slickline. While a conventional slickline is not designed to provide the capability to transmit electrical signals, electrical lines are incorporated into a digital slickline so that it can transmit
As noted above, the suspension tool may include multiple sensors, so sensor 210 as depicted in the figure should be construed to include either an individual sensor, or a group of sensors. If there are multiple sensors, the sensors may share contacts in the set of contacts 220, or specific contacts within the set may be dedicated to particular sensors. Similarly, there may be shared and or dedicated contacts within the set of contacts 230 in the shifting tool, and there may be corresponding shared and/or dedicated electrical lines in the set 250.
Referring to
A shifting tool is then lowered into the well (304). The shifting tool is connected to a digital slickline or similar means to suspend the tool and provide one or more electrical lines for transmitting power from a power source at the surface of the well to the shifting tool. The electrical lines also provide a channel for communicating data from the shifting tool to equipment at the surface of the well. This surface equipment may be a simple receiver for allowing the data to be provided to a well operator, or it may be control equipment that is used to operate the shifting tool (e.g., to shift or remove the suspension tool).
When the shifting tool reaches the suspension tool, a set of contacts on the shifting tool engages a corresponding set of contacts on the suspension tool (306). This electrically couples the electrical lines through the shifting tool to the sensors of the suspension tool And enables the shifting tool to provide power to the sensors of the suspension tool (308). When the sensors of the suspension tool are powered up following the engagement of the respective contacts, they make measurements of the corresponding conditions in the lower region of the well (310). For example, the sensors may make measurements of the pressure and temperature in the region below the suspension tool (312). Outputs from the sensors are provided through the shifting tool and are communicated to the surface of the well via the electrical lines coupled to the shifting tool (314). The received information can then be used at the surface of the well (either by an operator or by automated equipment) to determine whether it is safe to shift or remove the suspension tool and release the pressure in the region below the suspension tool. If the information received from the sensors is within an acceptable range (which may be dependent upon various other factors related to the conditions in the well), the suspension tool is shifted or removed to allow the fluid in the well to be communicated between the upper and lower regions, which were previously separated by the suspension tool.
Embodiments of the invention can be implemented with a variety of different types of suspension tools. For example, one embodiment is implemented in a suspension plug and a corresponding pulling tool. This embodiment is illustrated in
If it is desired to remove plug 400 from the well, a pulling tool 420 is lowered into the well. Pulling tool 420 is suspended at the end of a digital slickline 430. Pulling tool 420 includes an equalizing probe 422 which extends downward from the lower end of the pulling tool. At the lower end of equalizing probe 422 is a set of contacts 424. Contacts 424 are electrically coupled to one or more electrical lines of the digital slickline. A power source and a receiver are electrically coupled to the upper end of digital slickline 430 so that power and data can be communicated between contacts 424 and the power source and receiver.
In
Based on the data received from sensor 402, the well operator can make a decision as to whether or not the conditions measured by the sensor indicate that it is safe to remove suspension plug 400. If it is determined to be safe to remove the plug, pulling tool 420 engages suspension plug 400, and the digital slickline is pulled to lift the pulling tool and the suspension plug no of the well. If come on the other hand, it is determined from the measurements of sensor 402 that the conditions in lower region 412 are not acceptable for removal of suspension plug 400, the plug removal process can be interrupted so that measures can be taken to relieve or remediate the undesirable conditions. The plug removal process can then be re-attempted. Alternatively, if the sensor indicates that the conditions in lower region 412 are not acceptable, the plug removal process can simply be abandoned.
Referring to
As with the suspension plug, when the sliding sleeve 502 of tool 500 is in the closed position, the region below the tool is sealed off, and pressure can build up in this lower region so that it may present an unreasonable risk to simply move the sleeve to the open position and release this pressure into the upper region of the well. Sliding sleeve tool 500 therefore incorporates an unpowered sensor 504 which is positioned to sense conditions in the lower region of the well.
When it is desired to resume production from the well, a shifting tool 510 which is coupled to the end of a digital slickline 520 is lowered into the well. Shifting tool 510 is lowered until it is positioned within a cavity inside sliding sleeve tool 500. In this position, shifting tool 510 can engage the sliding sleeve mechanism of the sliding sleeve tool.
Shifting tool 510 includes a set of contacts 512 which are electrically coupled to corresponding electrical lines of digital slickline 520. When shifting tool 510 is positioned to engage sliding sleeve tool 500, contacts 512 engage corresponding contacts 506 of the sliding sleeve tool. Contacts 506 are electrically coupled to sensor 504 of the sliding sleeve tool so that when the shifting tool engages the sliding sleeve tool, the sensor is electrically coupled to digital slickline 520 through the contacts and the shifting tool. 504 therefore receives power from a power source at the upper end of digital slickline 520 and is powered on when the shifting tool engages the sliding sleeve tool.
when since her 504 is powered on, it makes measurements of the conditions within the lower region of the well (below the sliding sleeve tool). output signals corresponding to these measurements are provided by sensor 504 through contacts 506/512 and shifting tool 510 to digital slickline 520. the electrical lines of the digital slickline then communicate these signals to the surface of the well, where they can be used by the well operator or automated equipment to make a determination as to whether the conditions in the region below the sliding sleeve tool are within an acceptable range. if the signals received from sensor 504 indicate that the conditions are acceptable, the jars and stem 514 at the upper end of shifting tool 510 are used to jar the shifting tool and thereby move sliding sleeve 502 of the tool to the open position. If the conditions in the lower region of the well are not within an acceptable range, steps can be taken to prepare for the sensed conditions prior to moving the sliding sleeve to the open position, or the shifting tool can simply be disengaged from the sliding sleeve tool and the operation to move the sliding sleeve tool can be abandoned.
If it is determined that the suspension tool should be removed or shifted, there may be a number of dangers apart from the unexpected surge of pressure that may damage the lubricator or other equipment that may not be configured correctly to handle the “kick.” In addition to the pressure surge, operating downhole equipment with slickline may cause a number of problems. For example, when jarring a tool to activate a function (e.g., to shift a sliding sleeve), the load at the shifting profile can exceed allowable limits, which can cause deformation of the profile. This damage could prevent the sliding sleeve from being moved, so it could be stuck in either an open position or a closed position. Exceeding the allowable load at the shifting profile may also cause an accidental emergency release of the tool.
These risks can be mitigated by leveraging the digital slickline with simple sensors that can monitor loads on the digital slickline and the downhole tool. In one embodiment, illustrated in
The various embodiments of the invention may provide a number of advantages over existing systems and methods. For instance, they may reduce safety risks associated with operations to resume production in a suspended well, such as potentially unexpected and damaging surges in pressure or unexpected low pressure that can cause loss of hydrostatic fluid above the suspension tool and resulting loss of the control mechanism for the well. These embodiments also enable reduction of these risks without requiring that expensive sensors be incorporated into the design and initial installation/deployment of the well equipment at the original deployment stage. Still other advantages may be apparent to those skilled in the art.
The benefits and advantages which may be provided by the present invention have been described above with regard to specific embodiments. These benefits and advantages, and any elements or limitations that may cause them to occur or to become more pronounced are not to be construed as critical, required, or essential features of any or all of the described embodiments. As used herein, the terms “comprises,” “comprising,” or any other variations thereof, are intended to be interpreted as non-exclusively including the elements or limitations which follow those terms. Accordingly, a system, method, or other embodiment that comprises a set of elements is not limited to only those elements, and may include other elements not expressly listed or inherent to the described embodiment.
While the present invention has been described with reference to particular embodiments, it should be understood that the embodiments are illustrative and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions and improvements to the embodiments described above are possible. It is contemplated that these variations, modifications, additions and improvements fall within the scope of the invention as detailed by the claims of the application.
