The present disclosure relates to a gas lift system having gas lift valves that become operational by fracturing a frangible member.
Production of hydrocarbons that are retained within a subterranean formation typically involves drilling a well that intersects the formation. The well is generally completed by cementing casing inside the well, and deploying production tubing within the casing. A wellhead assembly is mounted at the upper ends of the casing and tubing, and the hydrocarbons are directed to the wellhead assembly through the production tubing. Formation pressures in some wells, even when initially formed, are inadequate to force produced liquids to surface; and over time, many hydrocarbon producing formations experience declines in pressure below that required to produce liquids. Artificial lift is generally employed to produce liquids from wells having inadequate formation pressure. Types of artificial lift include electrical submersible pumps, sucker rod pumping, gas lift, progressive cavity pumps, and plunger lift.
Gas lift systems inject a lift gas from surface into an annulus between the production tubing and casing, or into the production tubing itself. The lift gas lowers the density of liquid inside the well so that existing formation pressure is sufficient to drive the produced fluid to surface. The lift gas is injected into the production tubing from the annulus (or vice versa) through lift gas valves coupled with the production tubing. Most lift gas valves are spring loaded that automatically open and close in response to pressure downhole. Injection pressure operated (“IPO”) gas lift valves open and close in response to pressure in the annulus, and production pressure operated (“PPO”) gas lift valves open and close in response to pressure in the production tubing. Fluids that are usually in the production tubing are hydrocarbon liquids and gases produced from the surrounding formation. Sometimes these fluids are a result of forming the well or a workover, and have been directed into the production tubing from the annulus. One drawback of automatic spring loaded valves is that the well pressures at which they were designed to operate often change over time, which requires a costly and time consuming replacement of production tubing to return the well to its optimal production.
Disclosed herein is an example of a method of operating a wellbore which includes lifting liquid from within the wellbore, monitoring an output signal from a distributed fiber optic sensor that is deployed in the wellbore, identifying an anomaly with the step of lifting liquid based on the step of monitoring, and correcting the anomaly. In this example the anomaly is corrected by activating a shearable lift gas valve that is coupled to a production string deployed in the wellbore, and urging lift gas through the shearable lift gas valve into the liquid being lifted from within the wellbore. A conventional lift gas valve is optionally used to inject lift gas into liquid being lifted from within the wellbore prior to the step of identifying the anomaly; in this alternative the anomaly includes a malfunction of the convention lift gas valve or a change in a condition in the wellbore that reduces a rate of liquid being lifted from the wellbore. In an alternative the shearable lift gas valve is included in a string of shearable lift gas valves that is deployed in the wellbore, the method further includes estimating characteristics of an injection of lift gas in the wellbore for correcting the anomaly, the characteristics of the injection of lift gas include parameters such as a lift gas injection depth, a lift gas injection flowrate, and a lift gas injection pressure; and optionally includes identifying a particular one or more of the shearable lift gas valves in the string of shearable lift gas valves to be activated based on the estimated characteristics. The method of this alternative optionally further includes activating and injecting lift gas through the particular one or more of the shearable lift gas valves. In alternatives, the shearable lift gas valves are at different depths, have different set pressures, and different flow rate capacities. The step of identifying can be based on monitoring the output signal from the distributed fiber optic sensor. Prior to being installed in the wellbore, depths, set pressures, and flow rate capacities of the shearable lift gas valves are optionally designated based on a forecast of future conditions in the wellbore. In an example in which the anomaly is a reduction of pressure in the wellbore, prior to identifying the anomaly, the liquid is being lifted from within the wellbore by pressure in the wellbore. In embodiments, the liquid being lifted from the wellbore is production fluid that has flowed into the wellbore from a formation surrounding the wellbore, or optionally the liquid being lifted from the wellbore is completion fluid that is being unloaded from the wellbore.
Another example method of operating a wellbore is disclosed, which includes monitoring an output signal from a distributed fiber optic sensor that is deployed in the wellbore, identifying a designated lift gas injection into the wellbore based on the step of monitoring, activating a shearable lift gas valve that is coupled to a production string deployed in the wellbore, and injecting lift gas through the shearable lift gas valve into liquid being lifted from the wellbore. In this example the designated lift gas injection maximizes a rate at which the liquid is being lifted from the wellbore. Optionally, prior to activating the shearable lift gas valve, the liquid was lifted from the wellbore by pressure in the wellbore. In an example, prior to activating the shearable lift gas valve, the liquid was lifted from the wellbore by an injection of lift gas through a conventional lift gas valve. In one embodiment in which the shearable lift gas valve is a first shearable lift gas valve and where a second shearable lift gas valve is coupled to the production string, the method further includes comparing a first flow rate of liquid being lifted from the wellbore by injecting lift gas through the first shearable lift gas valve to a second flow rate of liquid being lifted from the wellbore by injecting lift gas through the second shearable lift gas valve; and that optionally further includes activating the first shearable lift gas valve if the first flow rate exceeds the second flow rate and activating the second shearable lift gas valve if the second flow rate exceeds the first flow rate, and injecting lift gas through the first shearable lift gas valve after activating the first shearable lift gas valve, and injecting lift gas through the second shearable lift gas valve after activating the second shearable lift gas valve. In an alternative in which the shearable lift gas valve is one of a plurality of shearable lift gas valves that are coupled to the production string, the method further includes maximizing a rate of the liquid being lifted from the wellbore by activating a designated one of the plurality of shearable lift gas valves and injecting lift gas through the designated one of the plurality of shearable lift gas valves.
Yet another example method of operating a wellbore is disclosed that includes monitoring an output signal from a distributed fiber optic sensor that is deployed in the wellbore, and based on the step of monitoring, estimating a designated lift gas injection from a string of shearable lift gas valves for lifting liquid from the wellbore, activating less than all of the shearable lift gas valves, and injecting lift gas through the activated shearable lift gas valves and into the liquid.
Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:
While subject matter is described in connection with embodiments disclosed herein, it will be understood that the scope of the present disclosure is not limited to any particular embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents thereof.
The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout. In an embodiment, usage of the term “about” includes +/−5% of a cited magnitude. In an embodiment, the term “substantially” includes +/−5% of a cited magnitude, comparison, or description. In an embodiment, usage of the term “generally” includes +/−10% of a cited magnitude.
It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation.
Shown in a side sectional view in
Included with the well system 10 is a gas lift system 32 that includes a lift gas source 34, which provides lift gas 36 to the wellbore 12. A lift gas injection line 38 has one end connected to the lift gas source 34 and at opposite disposed within the wellbore 12 below the wellhead assembly 28. A lift gas control valve 40 is in the lift gas line 38, which is shown in a closed configuration that blocks lift gas 36 from flowing through the line 38 into wellbore 12. Examples of the lift gas source 34 include a pressurized vessel, a transmission line, an adjoining well, or combinations. Coupled at different elevations along the production tubing 26 are lift gas valves 421-n. For the purposes of discussion herein, the lift gas valves 421-n are referred to as conventional lift gas valves, which in examples include IPO type valves, PPO valves, and combinations of these types of valves. As explained in more detail below, the IPO and PPO valves are spring-loaded valves and that operate in response to pressure surrounding valves. Shearable lift gas valves 441-n are included with the gas lift system 32, which in the example of
Still referring to
Referring now to
A packer 56 is shown circumscribing a lower end of production tubing 26 and that defines a barrier to fluid communication between the annulus 54 and the lower end of the production tubing 26. The lift gas valves 421-n when initially installed are in the open configuration and when pressure in the wellbore 12 is between the first and second pressures, which allows free flow of the completion fluid 52 between the annulus 54 and inside of the production tubing 26 through the lift gas valves 421-n, so that a liquid level 58 of completion fluid 52 in the annulus 54 is the same as in the production tubing 26.
Referring now to
As shown in the example of
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A non-exhaustive list of anomalies includes mechanical failures, which as mentioned above, a valve might not open due to blockage or mechanical failure, even when the pressure conditions should allow it to. Pressure anomalies include sudden spikes or drops in annulus or tubing pressure could occur that are not associated with normal operations, and pressure readings that are consistently different from expected values based on the depth and fluid column. Temperature anomalies include unusual temperature readings from the distributed fiberoptic sensor line could indicate issues. For instance, an unexpected rise in temperature might suggest a leak or rupture, while an unexpected drop might indicate blockage or fluid ingress. Gas bubble size anomalies, which as noted, injecting lift gas at too great a pressure difference can create very large gas bubbles, reducing the efficiency of the lift. Conversely, too small bubbles might indicate insufficient gas injection or a valve not opening fully. Flow rate anomalies, in which a sudden decrease in the flow rate of produced fluids, or a flow rate that doesn't match the expected rate based on the gas injection rate and pressure readings. Composition anomalies, which include changes in the composition of the produced fluids, such as an unexpected increase in water content or a decrease in hydrocarbon content, could indicate issues with the reservoir or the gas lift system. Sensor failures can create inconsistent or erratic readings from sensors, or a complete lack of data from a particular depth, could indicate a sensor failure or a problem with the communication system. Operational anomalies could be due to shearable lift gas valves not transitioning from a nonactivated state to an activated state even when subjected to the expected activation pressure. External interference or damage, signs of which could be from drilling operations in nearby wells or geological events like earthquakes, could affect the operation of the gas lift system. Acoustic anomalies, which manifest as unusual noises or vibrations detected by sensors could indicate mechanical issues or flow irregularities. Actual conditions constituting an anomaly often depend on the specific design and operational parameters of the gas lift system, as well as the characteristics of the well and reservoir. Regular monitoring, maintenance, and system checks are implemented to detect and address these anomalies promptly.
Further in this example, one or more of the anomalies described above are recognized by monitoring signals from the distributed fiberoptic sensor line 46. Example signals include those representing values of pressure and/or temperature within the production tubing 26, and where the recognition is by an operator on surface or logics, such as within controller 48. Based on the signal monitoring, the operator or logics identify a corrective action to remedy the anomaly. An example of a corrective action is to reconfigure one of the shearable lift gas valves 441-n from a non-activated to an activated state; which in the example of
illustrated in
In the examples of
Designated characteristics of a lift gas valve vary when conditions in the wellbore 12 change, such as a reduction in pressure due to hydrocarbon depletion from the surrounding formation 14, so that in examples a lift gas valve or valves, when initially operating, results in optimal production, and after time the production is less than optimal. Optionally, a lift gas valve 42 is improperly designed so that its operational characteristics result in a production of fluid from the wellbore 12 that is initially less than optimal production. In alternatives, less than optimal production is due to a lift gas valve 42 experiencing a mechanical failure, and is in a closed or partially closed configuration so that lift gas injection is at a rate, pressure, and/or depth that is different from a designated rate, pressure, and/or depth.
Similar to the operation described above, monitoring of signals from the distributed fiberoptic line 46 recognizes the anomaly and provides information necessary to identify a corrective action. Further in the example of
Referring now to
For the purposes of discussion herein, a designated lift gas injection is defined by a particular amount flow of lift gas 36 being injected into the production tubing 26, at a particular pressure, at a particular flowrate, and through a particular one or more of the shearable lift gas valves 441-n, or through a particular one or more of the lift gas valves 421-n. An upper end of a column of produced fluid 20 is what is illustrated by liquid level 58.
In alternatives, controller 48 includes a computer, examples of which have a master node processor and memory coupled to a processor to store operating instructions, control information and database records therein. Optionally, controller 48 includes a multicore processor with nodes such as those from Intel Corporation or Advanced Micro Devices (AMD), or an HPC Linux cluster computer, a mainframe computer of any conventional type of suitable processing capacity such as those available from International Business Machines (IBM) of Armonk, N.Y. or other source, a computer of any conventional type of suitable processing capacity, such as a personal computer, laptop computer, or any other suitable processing apparatus. It should thus be understood that multiple commercially available data processing systems and types of computers may be used for this purpose. Controller 48 is optionally accessible to operators or users through a user interface with an option for displaying output data or records of processing results obtained according to the present disclosure with an output graphic user display, which includes components such as a printer and an output display screen capable of providing printed output information or visible displays in the form of graphs, data sheets, graphical images, data plots and the like as output records or images. The user interface optionally includes a suitable user input device or input/output control unit to provide a user access to control or access information and database records and operate the computer. A database of data stored in computer memory is optionally included, such as internal memory, or an external, networked, or non-networked memory in an associated database or in a server. Logics in the controller 48 include executable code stored in non-transitory memory of the computer. The executable code according to the present disclosure is in the form of computer operable instructions the implement some or all elements of the process and cause the data processor to determine subsurface three-phase saturations according to the present disclosure. Examples of executable code include microcode, programs, routines, and symbolic computer operable languages capable of providing a specific set of ordered operations controlling the functioning of the well system 10 and direct its operation. In embodiments, the instructions of executable code are stored in memory of the controller 48, or on computer diskette, magnetic tape, conventional hard disk drive, electronic read-only memory, optical storage device, or other appropriate data storage device having a non-transitory computer readable storage medium stored thereon. Executable code is alternatively contained on a data storage device such as server as a non-transitory computer readable storage medium. Alternatives of controller 48 include a single CPU or a computer cluster, including computer memory and other hardware to make it possible to manipulate data and obtain output data from input data. A cluster is a collection of computers, referred to as nodes, connected via a network. Cluster optionally includes one or two head nodes or master nodes used to synchronize the activities of the other nodes, referred to as processing nodes. The processing nodes each execute the same computer program and work independently on different segments.
In alternatives, sensor technology is expanded by combining the distributed fiber optic sensor with another sensor technology to enhance the accuracy of anomaly detection. Remote activation is considered herein, and in which the shearable lift gas valve is remotely activated using a wireless communication system. Predictive analysis is optionally included with the methods disclosed, and that utilizes machine learning algorithms to predict potential anomalies based on historical data from the distributed fiber optic sensor. In alternatives, safety protocol are initiated in the event of detecting certain predefined critical anomalies. The shearable lift gas valve is optionally made of a material selected for its corrosion resistance and durability under high-pressure conditions. The disclosed methods optionally include other systems, which integrate an output signal from the distributed fiber optic sensor with other wellbore monitoring systems for a comprehensive overview. A feedback loop is optionally included in which the results of the correction are fed back into the system to refine the anomaly detection process. Further considered in the present disclosure is the option of deploying multiple distributed fiber optic sensors at different depths in the wellbore to provide layered monitoring. In alternatives, customizable thresholds are set for anomaly detection based on specific wellbore conditions. Embodiments of the disclosed methods include automated reporting for generating automated reports based on the data from the distributed fiber optic sensor, detailing the anomalies detected, and the corrective actions taken. The energy required for the operation of the shearable lift gas valves is optionally sourced from renewable energy sources deployed near the wellbore. In examples, a maintenance schedule is established for the shearable lift gas valve based on the frequency and nature of anomalies detected. Alternative activation mechanisms are considered for activating the shearable lift gas valves, including but not limited to temperature changes, chemical reactions, or mechanical triggers. Output data from the distributed fiber optic sensor is optionally stored in a cloud-based storage system for long-term analysis and trend prediction. Collaborative operation is included in embodiments, and that includes collaborating with neighboring wellbore operations to share data and insights on anomalies and their corrections.
The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.