standard oilfield formula for mechanical components

[Chel80]

Hi All,

I have been finding difficulty in standardising formulas.Basically for stress and strain, burst, collapse etc relating to mechanical components used in oilfield. Is there a book as such that gives a standard formula for calculating these values. I am simultaneously looking at imeche, to find out if they have a standard formula book for calculating stresses on mechanical component to check the integrity. If you need more info on my query please let me know.

Chellappan
Jnr design engineer

 

[JStephen]

I don't think you'll find a single source for what you are after. Some issues such as vessel or piping design are governed by codes that mandate allowable stresses and to some extent methods of analysis. Other items are covered by standards that state functional requirements and testing for the finished product, but don't specify stresses used (valves, for example). And some items just aren't covered by anything but the manufacturer's design methods.

If you're analyzing stresses, Roark's Formulas For Stress and Strain can be handy. In general, it won't tell you what the stress ought to be, just how to calculate what it is. And if it's an odd-shaped part, it won't be much help there.

 

[rorschach]

Also when working on things like lifting apparatus/appliances, there are multiple codes that could apply (same is true with piping/vessels). Generally speaking, the DNV codes for lifting apparatus/appliances are the most stringent, if you meet those, you're generally ok with the others.

 

[Cockroach]

You need to pull the API Bulletin 5C3 for the formulae on Casing, Tubing, Drill Pipe and Line Pipe properties. This will cover the various modes of yield, burst and collapse.

Threading properties can be found in API 5B, but formulae are better covered in alternate books like the Machinist Handbook for example. Acme screws are found in ASME/ANSI B1.5, Stub Acme in ASME/ANSI B1.8, UN in ANSI B1.1, Metric in ANSI B1.12M, B1.13M and Pipe Threads in ANSI B1.20.3.

There are miscellaneous sources for these properties also. I find that the Baker Field Handbook is an invaluable resource, the Halliburton one is good for cementing. Smith International has an excellent list for a large variety of oilfield threads, probably some you never even heard of! These are traditionally used for machining purposes, but you will need the threading geometry in order to carry forth an accurate stress computation. The key is getting the information!

You may want to cruise the various websites, the Grant Prideco one is perhaps the best for oilfield threading and burst/collapse equations.

Yeah, tough being a greenie. Just remember that all the good old boys with the white hair where green once. Try to get out in the field and see liner, cementing, fracturing, acidizing, completion, coil tubing and wire line operations. You'll learn more there than most textbooks.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada