NOTICE: Our Mathcad database got attacked and infected with a virus. Unfortunately, we've had to shut it down until further notice.
You can safely browse the pages, as the Mathcad server was separate to this main website, and was only accessible here. (We used something called an iFrame, which is like a window into a different website).
UPDATE 28th of January 2020: the virus happened just over a week ago. We've temporarily cut and pasted the text parts of the Mathcad pages rather than having blank pages there.
UPDATE 3rd of February 2020: We've been unable to recover the Mathcad worksheets and offer them in a format that provided total security to users. They were published a decade ago, and our IT people say that they would need a complete re-creation with the latest code and security fixes.
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Stuck pipe, release 1, issued 11 April 2010. AUDIT version.
This worksheet exists in two versions. They are identical apart from the way they are formatted. The Work version hides intermediate calculations and allows the user to see the results just below the inputs. This is useful for quick “what-if” games, changing various inputs to see what works best. The Audit version displays all intermediate calculations.
This worksheet will calculate the depth of stuck point from stretch data.
Pipe OD and ID. L_Dpipe & L_dpipe
Pipe stretch. L_Δdp
Additional load. Fα
Enter a -ve value if axial compressive force
Click when modified to update the result.
Additional stress due to extra axial force;
Strain = stress / YM. Strain due to axial stress;
Strain = stretch / original length so original length = stretch / strain
Length of pipe above stuck point
Note – this is an estimate. Hole drag and pipe sticking over a length (eg packed off) rather than being stuck at a single point will affect the result. Use a free point indicator logging tool to find out the actual stuck pipe depth.
SUGGESTED METHOD OF GATHERING STRETCH DATA
If working the pipe in tension
If working the pipe in compression