The present disclosure generally relates to wireline automation systems and methods.
The wireline shifting tool string normally include one or more anchor modules, a linear actuator module, and a shifter with its key matching the target profile, as illustrated in
Initial conveyance of the downhole shifting tool string to the target depth (i.e., getting the shifter close to the shifting target) is critical for successful shifting. In conventional shifting operation, it is possible to miss the collar joint, waste considerable time finding the location, or even perform the operation at the wrong location. Completion mapping depth correlation based on the operator-provided completion table creates a channel similar to a casing collar locator (CCL) recording and enables side-by-side correlation directly on the depth log. The completion-based depth control process renders details of the well completion mapping and the shifting tool string on the same graph, thus visualizes the relative locations of the tool string, the shifting target, and the collar joints in real time and making the depth control intuitive and straightforward.
Once the tool is close to the shifting target, latching to the shifting profile is an operation outside wireline standard workflows and requires extreme finesse and control. With the newly introduced advanced software, the user can initiate automated seeking function to locate and latch the shifter key onto the target profile reliably and efficiently. The system enabled the unprecedented position of the tool with an accuracy of few mm in any well including Extended-Reach Drilling (ERD) and wells intervened on a floating installation.
Then, with the shifting control panel, user can open/close the valve in power mode or high accuracy mode with mm shifter displacement accuracy providing detailed valve status.
Throughout the workflow, the critical data and the result for each user operation are logged and displayed in a two-dimensional plot and customized table. The user can generate a detailed operation report that includes all the relevant information.
One of the biggest challenges in shifting operation is to convey the tool string to the vicinity of the target to be shifted, which is usually at a location so that the shifter is about 20 feet above or below the target in the well. In conventional shifting operation, this can be an extremely difficult task for the field engineer, especially in the situation that a CCL reference log for the well is not available. Without correlation run, the engineer cannot trust the depth reading from winch and will have to perform manual correlation based on the completion mapping information provided for the well. To do that, the engineer must dig through the completion mapping file line by line and crunch the numbers of the pipe joint intervals on a piece of paper, then comparing to the moving CCL log on the computer screen. The whole process is very tedious and error prone as there is a lot of manual computation dealing with a lot of numbers, and the engineer has to go back and forth between paper and computer screen. A slight misstep could lead to missing joint for the correlation and put the shifter dozens of feet off from the target depth.
Despite effort made on surface system integration test (SIT), the major contributor to miss run and non-productive time (NPT) was the depth control. This aspect cannot be replicated at surface yet create a real difficulty. Several SITs are made using cable flagging providing information on shifting key placement within centimeter of the valve to be shifted. This precious information helping client and service company to make an efficient SIT are not available in operational context @ 20,000 to 30,000 ft to the decision maker (Engineer, Company man). The challenge of latching and its uncertainty is explained in Reference [1]. Latch characterizations take time and high-resolution investigation is around 1 ft. It is then critical to start this step only once due diligence on depth control is made and tool is on the proper joint.
To understand the challenge of depth control, the elasticity of the cable, its friction against well bore as well as the large tension difference between RIH (Gravity driven) and POOH (Surface induced motion) need to be realized.
The several examples below demonstrate the criticality of depth determination.
This first example (
The 2nd example (see
In the 3rd example (see
In the fourth example (see
The examples presented here prove CCL and head tension are the most critical parameter for depth determination. Unlike winch depth measurement located 30,000 ft above, affected by drag, friction, and stretch, the CCL along with the head tension are the true connection with the completion hardware joint and cross-over. They are the only true indication of tool position. Depth understanding is best estimated as BHA travel from last know CCL signature.
The previously example were made using las/dlis file from the field jobs and Techlog postprocessing. The following innovation describes how the critical correlation can now be done by shifting software, which is accessible onsite at wireline unit or from remote operation and providing well site immediate diagnostic without compromising depth accuracy. This is a huge step ahead into de-risking shifting operation and reducing NPT.
To address this challenge, the completion mapping based correlation process is embedded into the software as part of the shifting operation workflow:
The excel file for completion mapping takes 5 fields - Depth, ID, OD, QT, and Description. Ideally, each entry for the table denotes a well shape change. ID is the inner diameter of the section. OD is the outer diameter of the section. QT is the number of repeated components for the section, or the number of repeated casing segments. Description marks the type of the component, and the Depth is the top depth for that component. This excel file is imported to the shifting software.
Besides, the CCL log is put in the middle of the well ID and OD drawing to help with the correlation as shown in
A few more custom UIs are in place to further assist depth control operation.
The engineer first specifies the profile depth and the target depth (initial conveyance depth for shifter, which is usually a few feet below the profile depth for seeking up operation, or a few feet above the profile depth for seeking down operation) in the well through the Tool Position UI shown in 10.
Next, the engineer can open the Depth Control Panel shown in 11.
The well rendering is based on the imported completion mapping information as described in the previous section. Every pipe joint is drawn out with the proper inner and outer diameter ratio and with depth mark. The tool string inside the well is displayed with the important features shown at proper location, such as anchor arm and shifter dog. In addition, the CCL log is plotted at the side with the depth coordinate background. The various depth related numbers and messages are laid out in the right pane to give user the accurate depth information for tool movement. During the operation, the engineer can see the real time movement of the tool string in the well.
Combining completion mapping based log channels (
Once the tool string is conveyed to the vicinity of the shifting target in the well, the next operation is to latch the shifter to the target profile. This operation has been performed manually by the experienced engineer with intense user intervention. The procedures involve manipulating each and all tool modules (anchor, linear actuator, and shifter) in specific sequence. Accidental deviation from the required sequence results re-run of the whole procedure. So, it often takes long time to successfully find and latch onto the target profile. It is not uncommon that the shifter key sometimes latches at wrong place due to user misjudgments and results failure of the shifting job.
To address this challenge, tool control automation is embedded to the surface software. This advanced software feature enables automatic seeking, latching, and even shifting of the target. The user only needs to provide several operational parameters to the “Parameters Input Field”, before hitting the “Start” button in the Automated-Seeking UI shown in
The software orchestrates the opening and closing of the anchor arm, the extension and retracting of the linear actuator, and the opening and closing of the shifter key, with user specified pressure and force. Under the software control, the downhole shifting tool string moves automatically in the inch-worming fashion, to look for the target nearby. If the shifter latching force limit is set high enough, the target can be automatically shifted after successful latching between the shifter key and the target profile.
While the software is controlling the downhole tool operation, the user can monitor the progress from the UI “Operation Log” message box shown in
Much more reliable and efficient job execution can be achieved with this software implemented automation, comparing to manual operation of the tool.
To better understand the downhole seeking and latching status, linear actuator force vs linear displacement 2D plot is available, allowing the user to monitor and identify latching signatures. For details, please refer to the Case Study section.
When seeking with inch-worming movement described in previous section, the force reading from the linear actuator in the different stage of seeking operation can help engineer (or software, in the case of automated seeking) to decide if the shifter is correctly latched. This is not applicable when the seeking operation is performed with winch pull, since the linear actuator is not used for moving the shifter through the profile.
In winch seeking operation, knowing the shifter open diameter can greatly help the engineer understand better the shifter’s position inside the profile, since the different parts of profile have the different inner diameter. But due to the lack of downhole sensor to measure the shifter open diameter, it seems impossible to know the shifter diameter during the operation. This makes seeking with winch rather tricky operation as the determination of correct latch is a guesswork for the engineer.
One feature provided by the shifting software is called the profilometer mode, which can estimate the shifter open diameter from the shifter force reading. In the profilometer mode seeking, the shifter hydraulic chamber is isolated. When the tool string moves through the different sections of the profile, the shifter force will change accordingly with the ID of the sections. So, the well ID can be estimated from the shifter pressure. During the operation, the user inputs Seek Limit pressure and Initial Open Diameter as shown in 13. The shifter is first opened to the target pressure. The open diameter is estimated from the shifter force based on the hydraulic system design information. Then, the computation method is calibrated by comparing the estimated diameter with the user input known diameter. When the tool string is pulled by the winch to seek the target, the shifter open diameter is computed from the force measurement. Comparing the computed shifter open diameter with the known profile inner diameters of different sections, the engineer can tell where the shifter is inside the profile and if it is in the correct latch location.
Note that the profilometer mode and the shifter open diameter measurement is a useful tool for inch-worming seeking or tractor-conveyed seeking.
Historically, for either on-the-job troubleshooting or after-job deliverable preparation, the engineers need to go through the whole context of operation, look at the various data channels on the log, try to interpret the events and make the necessary annotation on the log. The whole process is labor intensive, time consuming, and error prone. This is especially true for complex and long-lasting jobs.
To address this issue, an automated real-time reporting tool is built into the surface software as part of integral shifting workflow. A data interpretation module is designed and implemented to mimic what the engineer used to do: correlate the tool operational status with relevant data channels from the downhole tools, interpret and record key operational events together with essential real time measurements at the events. Shifting Deliverable Logging UI shown in
There are three types of events being logged onto Shifting Deliverable Logging Table. The first event type is the operation of the shifting modules, such as opening/closing anchor, extending/retracting linear actuator, and seeking/shifting with shifter. The second event type is the updates of the completion component information, such as manufacturer, part number, size of any completion component in the well. These updates are necessary when the operating engineer or client noticed error in the completion mapping input information. The third event type is the start/stop of the station log, which correlates the operation events with the relevant station log graphs.
The hydraulic system in the downhole shifting tool string malfunctions sometimes. The most common issue is clogged solenoids, which causes inability to control hydraulic pressure in the system and ends up with the tool modules not operating properly, such as not being able to open the anchor, or not being able to move the linear actuator. Often time the solenoids can be unclogged without opening the tools. Instead, toggling the solenoids on and off while the motor is running and trying to build up pressure in the tool, can flush the debris away from the solenoids and resume normal tool functionality. But the solenoids need to be manipulated in defined sequence to achieve the flushing purpose. This requires the user to control the motor and each solenoid one by one, step by step. The process is time consuming and error prone.
The software comes to the rescue once again, by automating the process. The automation is implemented in two stages: individual solenoid flushing or flushing all solenoids. The following sequence is programmed to flush individual solenoid:
By click “Flush All” button on Shifting Automated Flushing UI (see
It is worth noting that this UI interface is generated during software run-time, to represent the proper solenoid configuration for the specific tool string composition. When tool string changes, such as adding or removing an anchor, the UI updates accordingly to add or remove solenoid inside the anchor.
The following section presents test results from a system integration test performed at surface. The test setup consisted of a 333 ft long completion, including the following sections in order from one end to the other end:
The completion schematic with the different tubing IDs is presented in 7. The completion mapping information was uploaded into the software per
The wireline tool string used in this test consisted of a 4-section tractor, followed by the shifting tool modules.
The depth control panel was used to display the shifting tool string inside the completion, as shown in
The objectives of the test were to use the depth control panel to deliver the tool 7 ft above the sliding sleeve lower profile and then start the automated seeking/shifting sequence to latch and shift the sliding sleeve down to open. The system integration test was started with the tool string inserted at the uphole end of the tubing. The tractor was used to tractor down. Refer to
The tractor navigation sequence was continued by opening the first drive and closing the second drive and by tractoring down again. This allowed the tool to move down til the 3rd drive hit the restriction (refer to caption E in
At this point the shifting tool was opened in seek mode. In this mode the shifting tool is compliant. It incorporates a suspension system that allows it to compress to pass through restrictions or expand into openings. The 3rd tractor drive was opened, and the 4th most upper drive was closed. The tractor was started, and the tool moved down until the tractor stalled (refer to caption G). Higher tractoring force was selected. This caused the shifting tool to be compressed and pass the 4.5″ to 3.5″ restriction. In seek mode, a profilometer option can be used to isolate the hydraulic chamber in the shifting tool. Fluctuation of the pressure then gives an indication of the change in diameter. The indirect ID measured by the tool going from the 4.5″ to 3.5″ tubing is presented in
The shifting tool diameter change measurement can be used to measure change in diameter up to 1″. In this case the shifting is compressed from 3.9″ diameter to 2.99″. This measurement is another indicator that help locate the tool string in the completion. In
After the shifting tool indicates that it passed the restricition and entered the 3.5″ tubing, the next indication came from the CCL module passing through the 4.5″ to 3.5″ casing joints (refer to caption I in
In this test, the depth control panel along with the CCL signal, the tractor motor stall indicator and the shifting tool ID measurement were used to confidently deliver the shifting tool 5 feet above the sliding sleeve.
The shifting tool pressure was increased then to use it as an anchor and prevent tool string sliding inside the tubing. The tractor drives were closed. Afterwards, the rest of the operation was completed using the automated seeking/shifting sequence. The sequence consists of activating the tool by preselecting parameter so that it moves in an inch-worm motion toward the profile, latch and shift the sleeve. The UI was described earlier in the document. In this case, the downhole direction was selected, a Seek Pressure Limit of 400 psi was used, a Shift Pressure Limit (shifter used as an anchor phase) of 2500 psi, the Anchor Open Force Limit set to 8000 lbf and the Auto-Seeking Latch Force Limit was set to 4000 lbf. By setting the auto-seeking latch force limit to 4000lbf the shifting tool did not stop after latching on the profile and before shifting the sleeve. It latched and shifted the sleeve without stopping.
As the tool was inch-worming downward towards the sleeve profile, the 2D plot of linear actuator force and displacement vs accumulated displacement is used to track the progress as shown in
The advanced software features presented here are essential to address some long-standing challenges for wireline shifting services. These features mainly aim to automate the critical steps of shifting operational workflow. The automation helps to greatly improve the reliability, efficiency, and service quality of the wireline shifting jobs.
One-click operation is envisioned to be the ultimate future of shifting operation. This requires fully automated tool conveyance over the wireline. So, the automated winch operation needs to be incorporated into the workflow. More intelligent decision-making method will likely be needed, to identify different phases of the operation. For example, AI based pattern recognition can be used to confirm successful latching to the target, by analyzing real-time force vs displacement waveform using pre-trained algorithm. Further improvement on linear actuator displacement measurement is going to be beneficial too, to allow micro-level correlation with sub-millimeter grade accuracy. This can potentially be achieved by fusing multiple measurements, including the accelerometer measurement, the tractor speed, the pumping motor speed of the shifting tool, and the winch depth measurement.
Meanwhile, some of the new features presented in this paper can be utilized on other wireline services as well, such as perforation, plug setting, and mechanical slot cutter. All these services require precise depth control. The visually intuitive depth control UIis directly applicable to them. The real-time or after-job tabulated operational report is also very useful.
Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and/or within less than 0.01% of the stated amount. As another example, in certain embodiments, the terms “generally parallel” and “substantially parallel” or “generally perpendicular” and “substantially perpendicular” refer to a value, amount, or characteristic that departs from exactly parallel or perpendicular, respectively, by less than or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degree.
Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments described may be made and still fall within the scope of the disclosure. It should be understood that various features and aspects of the disclosed embodiments can be combined with, or substituted for, one another in order to form varying modes of the embodiments of the disclosure. Thus, it is intended that the scope of the disclosure herein should not be limited by the particular embodiments described above.
Number | Date | Country | |
---|---|---|---|
63289462 | Dec 2021 | US |