Stage Completions Frequently Asked Questions
History
What is the number of valves installed to date?
Over 10,500 valves have been installed to date.
What is the opening success rate?
After an early period of development, the success rate since mid-2019 has been 99.5%.
What is the largest number of valves installed in a single well?
221 valves have been installed and opened in a single well.
Design
What is the maximum working pressure of the valves?
Housing burst pressure will match or exceed the casing value. Differential pressure across the ball/collet is determined by the ball material type and collet selection.
What is the ID of the valve prior to running collets?
| Casing | Weight | Casing Drift ID | Valve ID | Under Casing Drift |
|---|---|---|---|---|
| 4½” | 11.6lb | 3.875” | 3.812” | 0.063” (1.6%) |
| 13.5lb | 3.795” | 3.735” | 0.060” (1.6%) | |
| 5.1lb | 3.701” | 3.638” | 0.063” (1.7%) | |
| 5½” | 17.0lb | 4.767” | 4.625” | 0.142” (3.0%) |
| 20.0lb | 4.653” | 4.563” | 0.090” (1.9%) | |
| 23.0lb | 4.545” | 4.438” | 0.107” (2.4%) | |
| 26-26.8lb | 4.423” | 4.312” | 0.111” (2.5%) |
What is the valve ID after running the collet?
| Casing | Weight | Casing Drift ID | Collet ID | Under Casing Drift |
|---|---|---|---|---|
| 4½” | 11.6lb | 3.875” | 3.341” | 0.534” (13.8%) |
| 13.5lb | 3.795” | 3.264” | 0.531” (14.0%) | |
| 5.1lb | 3.701” | 3.167” | 0.534” (14.4%) | |
| 5½” | 17.0lb | 4.767” | 4.112” | 0.655” (13.7%) |
| 20.0lb | 4.653” | 4.092” | 0.561” (12.1%) | |
| 23.0lb | 4.545” | 3.967” | 0.578” (12.7%) | |
| 26-26.8lb | 4.423” | 3.842” | 0.581” (13.1%) |
Do you supply swell packers and toe valves?
Swell packers and toe valves are not part of Stage Completions’ product lines, but they can be supplied by Stage Completions to ensure the package is compatible with the valves.
Who are Stage Completions’ main clients and within which basins do they operate?
Stage Completions installs equipment in numerous basins around the world and are continually increasing their client base. References and non-confidential job data can be provided upon request. Several case studies and job highlights are available on our website
What is the difference between Bowhead and Orca?
The Bowhead system is designed for single point entry completions.
The Orca system is designed to deliver multiple entry points and offers a limited entry completion.
The Orca and Bowhead systems use the same collet and ball for activation. Each collet in the Bowhead system will open one valve, whereas each collet in the Orca system will open several valves (known as “clusters”).
What is your lead time?
Normal lead times are generally between 6 and 8 weeks pending material type, availability, and thread type. Premium threads must sometimes be sourced by a single supplier and may result in a longer lead time. Material availability can also impact lead times.
Can the collets be retrieved?
Yes, they can be retrieved using coiled tubing or stick pipe along with the Stage Completions collet retrieval tool. The process involves removing collets individually from valves from heel to toe, stacking them above the shallowest valve, and pulling to surface in designated intervals to unload. The number of collets retrieved in each interval is dependent on equipment and well design.
Do permanent ID restrictions due to collets in place result in limited wellbore access with cleanout tools?
Minimum IDs with the collet in place are approximately 0.5” (12.7 mm) under casing drift. If access is needed with a larger diameter tool, retrieving the collets would increase restriction ID to 97+% of casing drift.
Can a valve be opened a long time after it has been installed in a well?
Bowhead valves have been successfully opened 8 months after installation. Provided a well is left filled with inhibited fluid, the valves should remain functional indefinitely.
Where does Stage Completions manufacture their products?
Stage Completions maintains business relationships with multiple machine shops and process facilities throughout North America and Asia to ensure availability and quality of parts and materials. The valves are assembled and pressure-tested in Stage Completions’ Calgary facility.
What threads are available?
All standard market-available threads can be provided on Stage Completions’ valves. Lead times may be affected by some single source subcontractors of premium threads. A charge is applied for premium threads that have a higher cost relative to standard LT&C or BTC.
What are the risks of running a Stage Completions system?
The main risks when running any interventionless system:
- Inability to re-initiate the frac after sand-off.
- Cause: Sand-offs occur when the formation unable to accept volume of proppant being pumped, plugging off wellbore.
- Mitigation: With Stage Completions’ systems, isolation balls easily flow off-seat. After a sand-off, bleeding pressure on surface allows differential pressure from stages below to push the ball off-seat, allowing a surge to aid in flowback and reducing risk of inability to re-initiate or establish a feed rate.
- Contingency: If flowback is ineffective, wait until dissolvable ball has a reduced ID small enough to pump through collet and feed into zone below to clean up. If equipment is available, acid can be spotted over dissolvable ball to increase dissolution rate, and/or a cleanout can be performed with coiled tubing or stick pipe.
- Valve-opening failure.
- Cause: A valve could potentially fail to open if Stage Completions procedures and recommended landing flow rates are not followed.
- Mitigation: Stage Completions field technicians discuss the operations crew on critical landing rates and process, ensuring that requirements are communicated.
- Contingency: If procedures and recommended processes are not followed and a valve fails to open, a duplicate collet may be launched with correct procedures to open the correct valve.
- Out of sequence valve-opening.
- Cause: Launching an incorrect collet would cause a valve to open out of sequence.
- Mitigation: Stage Completions field technicians verify valve sequences before loading collet launcher and again with client field representative before each launch.
- Contingency: If required, valves opened out of sequence can be re-closed (and collet retrieved) using coiled tubing or stick pipe along with the Stage Completions retrieval tool.
- Compromised casing integrity due to leaking valve.
- Cause: A mechanical seal failure in any downhole tool could potentially lead to a casing string leak.
- Mitigation: All Stage Completions valves are pressure tested and certified prior to leaving the assembly facility for installation.
- Contingency: If a leak is detected in an uncemented string, it can be pulled out of hole and the valve can be replaced. If the string cannot be pulled, a casing patch can be run over the leak and plug and perf can be used to stimulate the wellbore below the patch.
- Inability to get casing to bottom.
- Cause: If casing cannot be run in to bottom, it is likely due to a count error or friction due to increased OD of additional equipment.
- Mitigation: Effective, precise tallies are always kept and maintained during installation of string containing Stage Completions systems. Field technicians ensure hole size and condition are sufficient.
- Contingency: If casing cannot reach bottom, the open hole portion in the toe would be abandoned. If valves are landed at depths which are unsuitable to frac, plug and perf may be considered for stimulation.
- Premature sleeve-opening.
- Cause: If large amounts of debris cause a blockage, it is possible that a large enough differential pressure could build across a valve to shear the pins, allowing the piston to shift to the open position.
- Mitigation: Stage Completions field technicians stress to operators the importance of keeping the wellbore clean and free of debris.
- Contingency: Once a Stage Completions valve has been opened, it can be reclosed using coiled tubing or stick pipe with a Stage Completions shifting tool after debris has been cleared.
Other risks exist when running interventionless systems, although they are less likely to occur:
- Inability to get casing to bottom.
- Cause: If casing cannot be run in to bottom, it is likely due to a count error or friction due to increased OD of additional equipment.
- Mitigation: Effective, precise tallies are always kept and maintained during installation of string containing Stage Completions systems. Field technicians ensure hole size and condition are sufficient.
- Contingency: If casing cannot reach bottom, the open hole portion in the toe would be abandoned. If valves are landed at depths which are unsuitable to frac, plug and perf may be considered for stimulation.
- Premature sleeve-opening.
- Cause: If large amounts of debris cause a blockage, it is possible that a large enough differential pressure could build across a valve to shear the pins, allowing the piston to shift to the open position.
- Mitigation: Stage Completions field technicians stress to operators the importance of keeping the wellbore clean and free of debris.
- Contingency: Once a Stage Completions valve has been opened, it can be reclosed using coiled tubing or stick pipe with a Stage Completions shifting tool after debris has been cleared.
What warranty is offered on Stage Completions’ equipment?
All Stage Completions products have passed stringent QC inspections prior to being installed. As additional and optional measure, Stage Completions welcomes customers to inspect the product and QC results prior to delivery. If a Stage Completions product does not function as designed, the events and procedures will be fully evaluated before resolution. Stage Completions cannot take responsibility for failures caused by other parties.
How are frac ports designed?
Frac ports are designed differently depending on product line.
Bowhead ports are designed to achieve a balance between accommodating maximum flow rate for the casing string, providing sufficient tensile strength, and preventing formation debris entering the ports.
Orca ports are designed to provide desired limited entry pressures and are completely customizable dependent on individual values.
What is the opening pressure of a Stage Completions valve?
All Stage Completions valves can be pinned and adjusted depending on static and flowing bottom hole pressures.
Bowhead valves and Orca landing valves can be configured to an opening pressure anywhere from 2,000 to 3,200 psi (13.7 MPa 22.1 MPa) differential.
Orca cluster valves can be configured to an opening pressure from 500 to 1000 psi (3.4MPa – 6.9 MPa) differential.
How is it ensured that the ball remains seated on the collet as it goes through the buffalo head?
With all Stage Completions collets, the ball cannot bypass the collet, and the collet will not travel unless the ball is seated. There is no need to secure the ball on the collet.
What are the material specifications for the valves?
Recommended hole size to run Stage Completion valves is dependent on cement design and valve OD. In most cases, existing hole size design for casing without valves is sufficient clearance for casing with valves. It is advised to consult with the cement provider to calculate pressure increase and cement flow characteristics.
4½” (114.3 mm) Casing
Casing Collar OD: 5” (127 mm)
Valve OD: 5.24” (133 mm)
Recommended hole size: 6.125” or larger (157 mm or larger)
5½” (139.7 mm) Casing
Casing collar OD: 6.05” (153.7 mm)
Valve OD: 6.5” (165.1 mm)
Recommended hole size: 7.875” or larger (200 mm or larger)
Are Stage Completion valves compatible with ancillary equipment?
Stage Completions valves are compatible with most casing equipment. Stage Completions prefers to inspect any ancillary equipment that could be cause for concern and run tests if necessary.
In the case of cement wiper plugs, the IDs of Stage Completions valves are very close to the drift ID of the casing. A normal, stiff-rib wiper plug is preferred to help ensure the casing is free of cement debris after cementing. Specialty wiper plugs should be tested by the Stage Completions to ensure they pass through a valve with no issues.
Can Stage Completions systems be rotated?
Stage Completions systems can be rotated upon installation. In most cases torque limitations will be dictated by the casing thread. The internal threads on the valves are shouldered and capable of high torque values and can be found in the Technical Specification Sheet for the product.
Installation
What are the minimum spacing requirements between Stage Completions valves?
The minimum distance required between Stage Completions valves is 10 ft (3 m). As collets travel through non-matching valves, the slight suction effect of the seals cause a minor temporary increase in velocity. Minimum spacing between valves ensures that the collets do not slingshot from one valve to another causing high travel speeds and posing the risk of bypassing the matching valve.
How many Stage Completions valves can be run in a single well?
Over 400 Stage Completions profile combinations currently exist. The highest number of Stage Completions valves installed in a single well is currently 221.
Can valves be torqued through when being installed?
Internal threaded connections on Stage Completions valves are shouldered and in most cases can tolerate a higher torque than the casing connections.
Can valves be built “box by box”?
Stage Completions valves’ bottom subs can be built “box by pin” or “box by box” to eliminate the use of collars. This often generates cost savings to the operator, especially when premium threading is being employed.
What length of bails are required to run a “box by box” valve?
Each Stage Completions valve is approximately 48” (1.2 m) in length. Longer-than-standard bails are generally not required.
How are valves transported to location?
Valve transportation from Stage Completions’ closest facility to the well site is at the customer’s cost. A designated hot shot service or piggybacking onto another well site load is normal. This transportation can be coordinated by Stage Completions if requested.
How does Stage Completions ensure that the valves are installed in the correct order?
Stage Completions’ assembly and installation standard operating procedures contain multiple levels of checks to ensure the valves are run in the correct sequence. A customized running order is designed and approved for each well prior to ordering components for manufacturing. Each valve has a serial number, and the profile identifier is displayed through a frac port. Valves are arranged in the correct running order during assembly. The sequence is then checked during pressure testing, again during packaging, and multiple times at the well site prior to and during installation.
Can the valves be installed in cemented and/or open-hole completions?
Stage Completions valves can be installed in a cemented casing string or between open hole packers.
Does Stage Completions supply open hole packers?
Stage Completions can supply third-party open hole packers. Stage Completions is open to work with any customer-preferred packer supplier given Stage Completions collets can pass through them without issue. An inspection of the packer prior to commitment may be necessary.
What QC checks are performed before each installation?
The following QC checks are performed prior to the installation of Stage Completions valves:
- The valve inventory on location is checked against the Bill of Lading and well diagram.
- Valve serial numbers are checked against the well diagram and arranged in order.
- Each piston profile is checked against the valve serial number.
- Each valve is drifted, and the threads are checked for damage.
Hydraulic Fracturing
To what maximum differential pressure is the collet rated?
Small dimensional differences in individual profiles can impact maximum allowable differential pressure. These variations are taken into consideration. When choosing the combinations that best suit the customer’s treatment design, full consideration is given to ensure that the tool differential pressure limitations exceed the treatment design maximums.
To what maximum differential pressure is the ball rated?
Stage Completions qualifies dissolvable balls in three differential pressure categories.
Category 1: 8,000 psi (55 MPa)
Category 2: 10,000 psi (69 Mpa)
Category 3: 12,000 psi (83 Mpa)
Stage Completions’ certified dissolvable balls all come off the seat at 500 psi (3.5 MPa) differential or less.
When should the ball/collet be launched?
For typical jobs, Stage Completions recommends pumping a flush volume of lateral length volume (to the current valve) plus surface line volume at full rate before launching the ball/collet. This will ensure proppant is flushed to the ports before the collet reaches the heel and will prevent settling if the pump rate is slowed to observe collet travel through the lateral.
At what rate can the ball/collet be launched?
The ball/collet can be launched at the wellhead at full frac rates.
At what rate must the ball/collet be landed when it reaches its corresponding valve downhole?
To ensure the collet profile engages successfully into its corresponding valve, Stage Completions recommends reducing travel speed to 17 – 21 ft/s (5.0 – 6.3 m/s) before ball/collet lands. These speeds are approximately equivalent to 15 – 18 bpm (2.4 – 3.0 m³/min) in 4 ½” (114.3 mm) casing and 18 – 24 bpm (3.0 – 3.8 m³/min) in 5 ½” (139.7 mm) casing.
Although it is not operationally necessary, Stage Completions also recommends to slow pump rates before the ball/collet reaches the heel (uppermost) stage. This will ensure that pressure signatures can be observed through high-resolution pressure recordings for each un-matched valve the collet travels through.
How many ball/collets can be loaded into the launcher?
The Gyro launcher used for launching Stage Completions collets can be loaded with 23 ball/collets in sequence. Single ball/collet launchers can also be used which consist of a wellhead funnel to direct the loaded ball/collet into the flow.
How long does it take to load the launcher?
Provided with the correct lift equipment, Stage Completions field technicians can load/reload the launcher in approximately 10 – 15 minutes.
Is it possible to unintentionally open a valve out of sequence?
Stage Completions has very detailed QC procedures that ensure the collet sequence is identical to the sequence of installed valves. In the unlikely event that a valve is opened out of sequence, the collet can be removed, and the valve closed using a Stage Completions retrieval and shifting tool. These tools are ready on location to ensure downtime is minimized.
Can the system tolerate proppant settling out in the well bore?
Allowing proppant to settle in the wellbore should be generally avoided during any completion. When stimulating with a Stage Completions system, proppant settled throughout the wellbore may influence travel, especially if rate is shut down before the collet reaches its valve. If pump rates can be increased enough to suspend proppant and re-initiate movement, the ball/collet should continue to travel.
What indications are given when the ball/collet is moving?
Stage Completions uses high-resolution pressure transducers to monitor the travel of the ball/collet through the wellbore, along with acoustic data for indication of launch, seat and shift.
What assurance exists that the collet opened the correct valve?
The unique profile configuration of Stage Completions systems ensures that each collet will only open matching valves. The collet external profile must be identical to the internal valve profile to engage and shift. Using high-resolution pressure transducers and acoustic data, the collet is tracked throughout the wellbore and the number of unmatched valves that have been travelled through can be demonstrated, and the seat and shift of the correct valve is observed through unique signature.
Can a valve be closed after being opened?
Stage Completions valves can be closed after opening. Conveyed by coiled tubing or stick pipe, a Stage Completions shifting tool is used to shift pistons closed, and the collet can either be retrieved or left behind. Using the shifting tool, the collets can also be reopened after closing.
Can collets be retrieved?
Yes, they can be retrieved using coiled tubing or stick pipe along with the Stage Completions collet retrieval tool. The process involves removing collets individually from valves from heel to toe, stacking them above the shallowest valve, and pulling to surface in designated intervals to unload. The number of collets retrieved in each interval is dependent on equipment and well design.
Can the collets be milled?
Stage Completions’ collets do not have an anti-rotational mechanism. The preferred method of removal is to retrieve the entire collet with a retrieval tool.
How long does it take for the dissolvable balls to dissolve?
Stage Completions’ dissolvable ball materials are designed with a wide variance of dissolution rates based on temperature and salinity. Based on testing, frac design and downhole environment, a suitable material can be chosen to ensure appropriate dissolution times. Selection would be based on time to pass-through diameter (time required for dissolution resulting in a ball diameter small enough to flow through the ID of the collets) and time for full dissolution.
How does a dissolvable ball react to acid?
In general, acid greatly accelerates dissolution rate. Different composition of balls will dissolve at different rates and dissolution tests can be performed prior to the frac treatment.
Stage Completions recommends a minimum 12-bbl (2-m³) spacer between a standard ball and spearhead acid.
Stage Completions also supplies acid balls which are designed with resistance to premature dissolution in contact with acid.
Have balls ever not fully dissolved?
Dissolvable material technology is constantly evolving and has been since its introduction to the oil and gas industry. There have undoubtedly been many instances of undissolved materials in every application of the technology. These instances can always occur due to unpredicted events, lack of contact with salinity, poor material selection, etc. Stage Completions’ Engineering team performs constant tests and research to ensure the recommended material is suitable for the precise wellbore environment during and after the frac. Job-specific testing can be performed, and selection is made based on a balance of ball integrity and rate of dissolution.
What size crane is required to install the collet launcher?
The weight of a Gyro launcher loaded with collets is approximately 1,200 lb (545 kg). The hook height of a picker will need to reach wellhead height plus 12 ft (4 m). Typically, the minimum crane size is 18 ton. Larger cranes that can perform multiple component picks may help facilitate faster rig ins.
Does acoustic monitoring tie into the data van’s recording system?
The acoustic and high-resolution pressure monitoring used by Stage Completions is a stand-alone service with proprietary, portable equipment. The computer equipment that reads and displays real-time and recorded data can be operated in the data van or manually connected to a spare monitor if available.
How is it ensured that the collets are launched in the correct order?
Stage Completions fracturing standard operating procedures are very detailed to ensure collets are launched in the correct order. Collets are clearly labeled and can be identified easily while being loaded and while in the launcher, and sequence is examined several times to ensure it is identical to the valves installed. For confirmation, Stage Completions recommends a customer representative witnesses the loading of the collets.
