Well Integrity Technical Section

A query for the WITS community that I hope you can help with.

Can someone provide me with the background of the HSC (High Sealed & Coupled) connection and whether or not it is considered a premium/gas-tight connection?

Although it is marketed as one, I have heard some debate over its effectiveness.

Appreciate any feedback on your experience in the selection/use of this connection and/or how it is currently viewed in the industry.

Many thanks

Justin Parker

-------------------------------------------

Justin,

I am surprised the experts didn't chime in yet. Maybe repost on the Completions and Drilling threads.  I am not a connection expert but have viewed many test reports, and worked with qualifying connections for my use, over my career. 

To answer your question;  Check the API RP 5C qualification report for the size of connection you are using.  I would look at the sizes above and below too; 4 1/2, 5 1/2, and 6 1/2 inch connection qualifications for a 5 1/2 in purchase.  AND check all the connection weight and grades tested in your size.  They advertise Special Clearance connections...check those too. If you don't have a copy of 5C get one and look at the requirements. 

What you are looking for first, is thoroughness .... have they tested these connections over a wide range of sizes, weights, and grades.  If not the connection is probably immature and hasn't been fully vetted. 

Second, you are looking for results .... has the connection passed all these tests?  Are there specific weights or grades that have an issue.  If you can't find certain materials; P110 or Q125 is there an issue with high strength steels?  If you can't find light weight pipe is there an issue with thin wall pipe? And same for extra heavy weights.  

Third, and in results are there any anomalies .... one connection passed liquid tests but had issue with gas tests.  There was an issue with makeup and some signs of galling or damage. Issues with reuse of the connection.

The biggest issue is omission....you don't see the tests that failed or haven't been done.  This is why One and Two are so important to look for a complete set of thorough tests across a wide range of pipe weights and steel grades.  These API tests cost a lot of money. So companies often won't do them until a customer asks.  So if they are missing the connection just might be immature and not widely used in the industry.  Or the tests are missing because of issues with the connection.  Unfortunately, you also have to verify if the tests are real and have actually been done for your size and weight.  This all becomes a judgement call.

If there is a significant business value to pursuing the connection then it is worth the effort to do the required testing and get expert help.  

I hoped this helped.  Feel free to contact me with any questions. 

------------------------------
Dan Gibson
aka The Well Doctor
Completion & Well Integrity Advisor
Houston, Texas
------------------------------

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Original Message:
Sent: 11/10/2025 8:43:00 AM
From: Dan Gibson
Subject: RE: HSC (High Sealed & Coupled) connection

Justin,

I am surprised the experts didn't chime in yet. Maybe repost on the Completions and Drilling threads.  I am not a connection expert but have viewed many test reports, and worked with qualifying connections for my use, over my career. 

To answer your question;  Check the API RP 5C qualification report for the size of connection you are using.  I would look at the sizes above and below too; 4 1/2, 5 1/2, and 6 1/2 inch connection qualifications for a 5 1/2 in purchase.  AND check all the connection weight and grades tested in your size.  They advertise Special Clearance connections...check those too. If you don't have a copy of 5C get one and look at the requirements. 

What you are looking for first, is thoroughness .... have they tested these connections over a wide range of sizes, weights, and grades.  If not the connection is probably immature and hasn't been fully vetted. 

Second, you are looking for results .... has the connection passed all these tests?  Are there specific weights or grades that have an issue.  If you can't find certain materials; P110 or Q125 is there an issue with high strength steels?  If you can't find light weight pipe is there an issue with thin wall pipe? And same for extra heavy weights.  

Third, and in results are there any anomalies .... one connection passed liquid tests but had issue with gas tests.  There was an issue with makeup and some signs of galling or damage. Issues with reuse of the connection.

The biggest issue is omission....you don't see the tests that failed or haven't been done.  This is why One and Two are so important to look for a complete set of thorough tests across a wide range of pipe weights and steel grades.  These API tests cost a lot of money. So companies often won't do them until a customer asks.  So if they are missing the connection just might be immature and not widely used in the industry.  Or the tests are missing because of issues with the connection.  Unfortunately, you also have to verify if the tests are real and have actually been done for your size and weight.  This all becomes a judgement call.

If there is a significant business value to pursuing the connection then it is worth the effort to do the required testing and get expert help.  

I hoped this helped.  Feel free to contact me with any questions. 

------------------------------
Dan Gibson
aka The Well Doctor
Completion & Well Integrity Advisor
Houston, Texas
------------------------------

I am not familiar with the connection.  Reviewing their website, you can see that this connection has some of the features that can make it a gas tight connection.  However, I did not find any reference to a certification of the connection being gas tight.

I would reach out to your supplier/HSC and ask for the certification or how they verified it as gas tight.

------------------------------
Hans-Jacob LundConocoPhillips Co
Principal Well Integrity Engineer
------------------------------

As a former member of the ISO 13679 committee, I can state here that
the standard included specific testing requirements for a
qualification of the 'connection family' of weights and grades.

That said, an individual test for a specific single connection size,
weight and grade (which includes a full connection including the pins
and coupling/female ends) can qualify just that specific connection.
A 'family' qualification is only required if the buyer wishes to
contract for the connection over a wide range of choices.

So musing over added sizes, wts, and grades should instead be replaced
with the specifics from the ISO13679/API5C standard if you want to
reduce your risk.

Regards

Olli Coker

Manager
Diamond C Enterprises
832.330.5066


Original Message:
Sent: 11/11/2025 8:22:00 AM
From: Hans-Jacob Lund
Subject: RE: HSC (High Sealed & Coupled) connection

I am not familiar with the connection.  Reviewing their website, you can see that this connection has some of the features that can make it a gas tight connection.  However, I did not find any reference to a certification of the connection being gas tight.

I would reach out to your supplier/HSC and ask for the certification or how they verified it as gas tight.

------------------------------
Hans-Jacob LundConocoPhillips Co
Principal Well Integrity Engineer
------------------------------

Justin

There are different requirements and testing severity for premium connections.  The most common protocol for testing is the API Recommended Practice 5C5.  There are four "Connection Assessment Levels" or CAL's.  CAL I being the least rigorous and CAL IV being the most rigorous.  The selection of which CAL level depends on the severity of the intended application, but most users want to see at least CAL III or preferably CAL IV testing. 

Typically, the connection manufacturer performs a significant amount of physical testing on various OD's, weights, and grades to validate a product line.  One test on one size, weight, and grade tested to full CAL IV requirements can take several months.

Even with a significant amount of full-scale product line testing and validation, depending on the application and materials involved, a test may be requested or performed on a specific size weight and grade. 

When evaluating a premium connection, a review of the amount of product line testing performed, as well as testing on products similar to the specific need is the first step.  When reviewing specific tests, it is important to note the CAL level tested, results, and any deviations or exceptions taken to the test protocol.

As others have noted, it would be good to do some homework in evaluating a premium connection and having a copy of API Recommended Practice 5C5 Procedure for Testing Casing and Tubing Connections would be very useful.

Bruce Bradley

Houston Texas

 

-------------------------------------------

Greetings Justin,

I looked at this when you first posted and then went down a rabbit hole.  Apologies.

Dan and others have hit the key points.  I'll add a few more:

• 100% agree that if the connection lacks an API RP 5C5 or ISO 13679 validation, you're in the wild west.  It may be an awesome connection, but it could equally be a dog.  IMO, it's more likely to be a dog because much of the market won't touch a connection that lacks validation, at least above the production packer (I won't).
• I looked online and saw no reference to validation on the HSC supplier's website, but I may have missed it.  
• Validation proves more than just the seal.  The standards require repeated make and break across a wide range of thread tolerances, proving both the seal and the galling tendency at the machining limits (not just nominals).  I have a mate who recently saw this difference in the real world: same rig, same crew, running the same 13Cr pipe, but different thread.  The pipe with the latest CAL IV ran beautifully.  The "cheaper" pipe with a dubious 2002 CAL IV was slow with far more rejects.  No savings there.
• You want to look at both grade (80 KSI vs 110 KSI) and material (carbon steel vs 13Cr, etc), as this will really impact galling, etc.
• Many thread suppliers will claim to have an ISO or API validation.  Be skeptical.  I know of one major supplier who call their pipe CAL IV but were recently disqualified from a tender when they were unable to provide the full scope of required tests.  They had some, but not all.  Why?  Did it fail?  All we got was silence.  I honestly believe that they're counting on the client to not take the time to really dig into the details (it's painful), and I'll wager this strategy works 99% of the time.
• I've seen "modified CAL IV" tests.  There is no provision for this in any standard.  If you want to consider this, lay out the testing that was done against the standard's test matrix to understand what you're giving up.  They usually do little to no make and break testing (so no data on galling tendency), little to no validation of seal performance at the machining tolerance limits (and if you run hundreds or thousands of connections, at least one or two will have a pin and box combo that can challenge the seal), and very limited failure testing.  There may be a place in your well for this thread; in my wells it's below the production packer (only).
• There are different editions of these standards, and older editions' CAL IV are less stringent than the latest (2017 for API and 2019 for ISO).  However, 99% of the time you'll just see "ISO 13679 CAL IV".  If you see that, assume it's the least stringent 2002 unless you can verify which edition they're claiming validation to.  If you have a really challenging application, high rig costs, or high consequence of failure, you'll want a connection that's been validated to the latest standard.  This is what sets the legacy VAM ACE and VAM TOP apart from the latest VAM 21, for example.  ACE and TOP are great connections, but 21 has been validated to a much tougher standard.  I've not run it, but I've heard good things about JFE Lion too.  

Hope that helps,

R

------------------------------
Ron Nelson
Subsea Completion Consultant
ron@deep-blue.ca
------------------------------

Justin,

Good comments and several contacts to follow up with if you have detailed questions.,

Dan

------------------------------
Dan Gibson
aka The Well Doctor
Completion & Well Integrity Advisor
Houston, Texas
------------------------------

Many thanks for the feedback.

I guess I had (naively) assumed the question would have resulted in a fairly black or white response – 'yes, it is' or 'no its not', based on industry experience of its use. 

However, the responses paint a greyer picture in that it could be, but don't necessarily trust the provided documentation and, if necessary, request/perform your own (independent) suite of tests to validate.

Other feedback received indicates that this HSC connection is a copy of the NEW VAM-type connection, which had some issues with its design and is no longer listed in the data sheets available on the VAM website.

So, it seems that a bit more work needs to be done to confirm whether or not this connection is fit-for-purpose for the life-of-well application required.

Once again, my thanks to the group for your time in providing the feedback.

Justin

Original Message:
Sent: 11-14-2025 03:46 PM
From: Dan Gibson
Subject: HSC (High Sealed & Coupled) connection

Justin,

Good comments and several contacts to follow up with if you have detailed questions.,

Dan

------------------------------
Dan Gibson
aka The Well Doctor
Completion & Well Integrity Advisor
Houston, Texas
------------------------------

Greetings Justin,

Interesting that this may be a NEW VAM variant. 

I'm not a VAM historian but I think the original VAM connection came out in the 1960s and was one of (or possibly the first) gas-tight connections on the market.  NEW VAM was an improvement that replaced the original VAM connection, sometime in the 70's I think.  Then (I think) came VAM TOP in the early '80s, VAM ACE sometime later, and VAM 21 in the 2000s.  NEW VAM has been obsolete for years; Vallourec stopped marketing it before I started in the industry 35 years ago and finally stopped supporting it 15-20 years ago.  I think VAM ACE is gone now too, though Shell Oil ran their VARST2 variant into the 2000s.  

I saw an online article, explaining how the Saudis worked with Vallourec and a Chinese supplier to provide tubing with a NEW VAM connection in 2024.  I have to believe this is 100% cost-driven, and the article said they were using this as an upgrade in wells that had previously been using API threads.  If true, this is setting a pretty low bar.

If this HSC thread is in fact a rebranded NEW VAM, then it predates all the API and ISO thread validation standards by decades.  Given that Vallourec was marketing the much better TOP connection when the standards first came out, I doubt NEW VAM was ever validated. 

If you're like the Saudis and have been running an API connection in your wells and are looking for a cheap but marginal improvement, then a rebranded NEW VAM may be your thread.  However, this is the grand-daddy of gas-tight connections and all that followed were developed to correct shortcomings of the previous generation, like improved resistance to compressive loads, improved tolerance to bending loads, easier to run with fewer rejects, etc.  Unlike today's iPhones, Vallourec had a legitimate reason to spend the R&D money required to obsolete NEW VAM and replace it with the much-improved TOP, which is now in the process of being replaced with the even better 21.  I'd think that after the cost of the tubular and the labor costs associated with threading, that an upgrade to a newer, better thread (even if still legacy) could be justified.  And I keep talking about VAM only because this is a thread family I've been running since the 1990's.  I've run most of them, but never NEW VAM.  There are many good T&C thread families out there: the old Hydril threads, JFE, Benoit, etc.  

Another consideration is repair: whatever you get, make sure you have access to a competent / licensed machine shop with the thread gauges and other tools required to cut your thread, so you can make pup joints and repair the connections that will invariably be damaged in the field.

Thanks for the post and good luck!

R

------------------------------
Ron Nelson
Subsea Completion Consultant
ron@deep-blue.ca
------------------------------

Original Message:
Sent: 11-23-2025 02:54 AM
From: Justin Parker
Subject: HSC (High Sealed & Coupled) connection

Many thanks for the feedback.

I guess I had (naively) assumed the question would have resulted in a fairly black or white response – 'yes, it is' or 'no its not', based on industry experience of its use. 

However, the responses paint a greyer picture in that it could be, but don't necessarily trust the provided documentation and, if necessary, request/perform your own (independent) suite of tests to validate.

Other feedback received indicates that this HSC connection is a copy of the NEW VAM-type connection, which had some issues with its design and is no longer listed in the data sheets available on the VAM website.

So, it seems that a bit more work needs to be done to confirm whether or not this connection is fit-for-purpose for the life-of-well application required.

Once again, my thanks to the group for your time in providing the feedback.

Justin

Original Message:
Sent: 11-14-2025 03:46 PM
From: Dan Gibson
Subject: HSC (High Sealed & Coupled) connection

Justin,

Good comments and several contacts to follow up with if you have detailed questions.,

Dan

------------------------------
Dan Gibson
aka The Well Doctor
Completion & Well Integrity Advisor
Houston, Texas

Justin,

Ron's comments are spot on. I may disagree on the timing of Vam ACE but that is a minor issue. :-) 

I have some information I can share that is not confidential but I don't want to place commercial info for just one vendor on the SPE site. Reach out to me at my personal email I have provided. 

Thanks

------------------------------
Dan Gibson
aka The Well Doctor
Completion & Well Integrity Advisor
Houston, Texas
------------------------------

Original Message:
Sent: 11-23-2025 02:54 AM
From: Justin Parker
Subject: HSC (High Sealed & Coupled) connection

Many thanks for the feedback.

I guess I had (naively) assumed the question would have resulted in a fairly black or white response – 'yes, it is' or 'no its not', based on industry experience of its use. 

However, the responses paint a greyer picture in that it could be, but don't necessarily trust the provided documentation and, if necessary, request/perform your own (independent) suite of tests to validate.

Other feedback received indicates that this HSC connection is a copy of the NEW VAM-type connection, which had some issues with its design and is no longer listed in the data sheets available on the VAM website.

So, it seems that a bit more work needs to be done to confirm whether or not this connection is fit-for-purpose for the life-of-well application required.

Once again, my thanks to the group for your time in providing the feedback.

Justin

Original Message:
Sent: 11-14-2025 03:46 PM
From: Dan Gibson
Subject: HSC (High Sealed & Coupled) connection

Justin,

Good comments and several contacts to follow up with if you have detailed questions.,

Dan

------------------------------
Dan Gibson
aka The Well Doctor
Completion & Well Integrity Advisor
Houston, Texas