Difference between threads???? 3

[ih8wk]

After recently graduating I have started working offshore and I do not know the difference between threads.

Please give me some advice on how I can tell the difference. I need even the basics, such as how you measure the diamter (inner box/outerbox/back of pin????). IF, FH, VAM EIS is all new to me. Or if you could give me any sites which explain it that would also be good.

Thanks

 

[chicopee]

WOW!!!what type of an engineering program did you graduate from?

 

[ih8wk]

Thanks for your reply, very helpful. I graduated as an aeronautical engineer and started working in the oil industry, so I am pretty unqualified. I thought that I had already made it clear that I was unqualified, but if you need me to repeat myself again let me know

 

[GregLamberson]

When someone posts a question, they are looking for help.

ih8wk:

I would suggest a google search on pipe thread definitions, I came up with:

http://www.plumbingsupply.com/pipethreadsizing.html

http://mdmetric.com/tech/tict.htm

http://www.drews-plumbing.com/glossary.html

To name just a few. You may want to google the Tips site as well, it may have come up on here before.

Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website:

http://www.oil-gas-consulting.com

 

[chicopee]

I did not mean to criticize your background, however, it seems that I must be out of the loop with engineering curriculae. When I went to college,in any pre enginnering program during the freshmen year, you had to take mechanical drafting which dealt with threads, so I am amazed that as an aeronautical engineer that was not in your curiculum.
Latest versions of the Machinist Handbook has a good deal of helpful info. on threads ( english and metric). Such rather inexpensive book should be part of your library.

 

[littlechickend]

should you refer to ASME Code as attachment herewith

 

[elmanelmanelman]

Don't worry mate, it is not so easy to recognize connections and many even in the oilfield do not know about them. The attached file may help you on specifications of connections. TO identify there are several tools which you can find on the rigs. But I think the best way is asking somebody to show you on job. Here are the list of known connection products and they have manuals and specs for their products:

http://www.vetcogray.com/main/main.cfm

http://www.drilltec.com/

http://www.dril-quip.com/

http://www.grantprideco.com/premium/premium_products.asp

http://www.huntingoilfield.com/

http://www.hydril.com/

http://www.jfe-holdings.co.jp/en/

http://www.oilstates-uk.com/solutions/offshore/tubular_connectors/file.asp?id=241

http://www.vampts.com/

http://www.tenaris.com/en/default.asp

They have both tubulars and pipe connections.

 

[JLSeagull]

Engineering classes do not address many of the common mechanical aspects of the process industry. Too many decades ago with my degree in electronics I knew nothing about flange size and ratings, pipe size and schedules, even terms like nozzle for vessel piping connections. My first industrial job was in a refinery where we picked up on much of this. I learned a lot more when I began sizing and selecting control valves and orifice plates for a contractor. Also, the codes and standards change. Don't be surprised if you are still learning about different connections the week before you retire.

 

[TitoPri]

I´m only familiar with API, TENARIS & GrantPrideco threads.

Te main diference between API and premium conection is that the second one has a shoulder where the pipe make seal to the coupling. Therefore the make-up is made by torque and toque-shoulder

Api has no shoulder so the make-up is made only buy torque

To diferentiate the premium conections you have to see TPI, and seal area shape.

To diferentiate API conections the kind of thread, round or square (BUTTRESS).

Any further question please ask.

 

[jjwamp]

ih8wk

For drillpipe connections

IF
FH
Reg

Get with smith drilco. They should be able to give you a thread gauge that you can carry around with you. Also they have a real good drill collar/drill pipe inspection book. If you work for the drilling contractor ask you company man to get you one. If you are the company man then call smith drilco and tell them to send one to the heliport for you. I cant tell them apart either and yes it is a pain when looking at XOs.

For XT HT grant prideco specialty connections it just takes time but there are some difference. They have pictures on their website.

Casing connections are a bit more tricky. Usually they are stenciled on the side of the casing or on the thread protector. That said things could be mis-stenciled or labeled wrong. One thing to always check is the FLOAT EQUIPMENT. Take the shoe or collar out and actually screw it into the casing if you can to double check of course with anything bigger than 9-5/8" casing this is tough unless you are willing to take steroids. At a minimum take off the thread protector and screw it into the float equipment.

 

[DrillerNic]

Drill pipe connections (or rotary shouldered connections to give them their proper name) have the fluid seal is at the shoulder and the thread is to hold the joints together and transmit torque and stress along the drill string. There are a range of API drill string connections, NC50, NC38 and so on (but a lot of people continue to use the old names such as 4-1/2" IF) and a number of proprietry threads such as DSTJ, PAC90 and so on. All you really need to know about drill string connections at the rigsite is what a your connection's make up torque is, and which connections are interchangable. The Baker Tech Facts book will help with the commonly available connections, both API and speciality drill pipe connections from the likes of Prideco. The Engineer will select a particular thread type based on the torsional strength of the connection, but may also consider things like the OD of the connection (will it fit into the hole? Could it be fished?) the ID of the connection (what is the hydraulic performance? Could I run tools through the middle of it, or fish my MWD tools through it?).

Casing and tubing connections come in two main types: API connections (8 round and buttress) which rely on dope to make a seal, and premium connections from a whole host of casing manufacturers that don't and instead have a metal to metal seal, either via a step in the middle of the thread or at the pin. API connections are made up to a marker on the joint, premium connections are made up to a specific torque, and correct make up is checked with a torque- turn graph.

All you really need to know on the rigsite about casing & tubing connections is what the torque rating is (if you think you might have to rotate the casing string) and for premium connections what the required make up torque is and what the make up loss in length is. For Engineering, you need to know the tensile and rotational strength of the connections (it's almost always less than the strength of the pipe) and choose your connection according to the design stresses on the casing and whether you have any corrosive fluids present. The various manfacturers' websites have lots of infomation on their connections and connection selection. Often different brands of casing connections are more common in certain areas: VAM's connections are ubiquitous in the North Sea, whereas Hunting's connections are probably more common in the Gulf of Mexico.

Finally, there are the large diameter threads for top hole casing (36", 20" etc) that are solely designed to be made up quickly (Vetco's RLS4, and so on).