Performs buckling calculations
of a pipe inside a wellbore or pressure control stack.
This software is intended for engineers, and uses Excel
as the user interface. A user must have an engineering
background and a working knowledge of Excel to use the
software.
The
example on the right demonstrates the capability of the
software. 2-3/8" tubing with a 4-3/4" packer is being
snubbed into a well through a stripper. The stripper appears
as a purple horizontal line. The pressure below the stripper
is 5,000 psi, and there is 4,400 lbs of stripper friction.
At the top and bottom of the packer there is a thread relief,
causing higher stresses in these areas. As the BHA moves
downward it buckles until the packer contacts the 7 1/16" ID
lubricator. There is a significant wall contact force (WCF)
at the point the packer touches the lubricator. The first
2 plots show the string (red) inside the well control stack
(black), looking at it from the Y and Z directions. Note
that the vertical direction is X. Also note that the scale
length of 50' in the X direction and ±4" in the Y and Z
directions causes the string to be distorted. The third
plot shows the maximum radial displacement (RD) along the
length of the string. This RD may be at any rotational
orientation. The fourth plot shows the wall contact forces.
There is a spike in the wall contact force where the packer
touches the lubricator. The fifth plot shows the maximum
Von Mises stress and the yield stress. In this case there
is a point at about 14' in which the Von Mises stress exceeds
the yield stress, and thus the string would likely bend.
The model can also output values versus time, as shown
in the following figures.
The maximum Von Mises stress along the entire length of
the BHA is shown versus time. The buckling continued for
the first 5 seconds but then stopped as the packer approached
the stripper. The sharp increase in compressive force and
Von Mises stress near the end of the simulation occurred
as the bottom of the packer was pushed into the stripper.
The following figure shows the corresponding displacement
and compressive force.
For immediate assistance
please contact Ken Newman at 936-521-2203 or by email. A
demo of the software can be downloaded by visiting
our demo page. For
additional information, download the brochure.
