From: Garry Denke on
BP Exploration of Alaska Doesn't Know
Cause of Accident That Injured Worker

http://www.wellintegrity.net/Documents/AOGCC%20A-22%20Report%2011-17-03.pdf

Nov. 25--BP Exploration (Alaska) Inc. officials told the Alaska Oil
and Gas Conservation Commission Nov. 14 they're still working to
determine the cause of an Aug. 14 well casing failure on a North Slope
production well that caused an explosion and severely injured BP
worker Don Shugak.

Preliminary results of the company's internal inquiry found no
evidence that corrosion or drilling operations damaged the casing,
according to Tom Gray, Prudhoe Operations Integrity Manager for BP.

"Instead, we believe the pressure in the outer annulus (of the well
casing) exceeded the surface casing pressure rating of 5,380 pounds
per square inch, due to thermal expansion related to well startup,"
Gray told the commission.

Gray explained that as well A-22 in the Prudhoe Bay field was
restarted after a shutdown in production, rising temperatures in the
well caused fluids in the outer annulus -- a space between steel
casing, or pipe, inside the well and the outer casing -- to expand.
This increased pressure beyond the tolerance ...

http://www.highbeam.com/doc/1G1-94875708.html

Casing Burst Pressure Study
From: Denoco Inc. on
On Jul 15, 11:41 am, Garry Denke <garryde...(a)gmail.com> wrote:
> BP Exploration of Alaska Doesn't Know
> Cause of Accident That Injured Worker
>
> http://www.wellintegrity.net/Documents/AOGCC%20A-22%20Report%2011-17-...
>
> Nov. 25--BP Exploration (Alaska) Inc. officials told the Alaska Oil
> and Gas Conservation Commission Nov. 14 they're still working to
> determine the cause of an Aug. 14 well casing failure on a North Slope
> production well that caused an explosion and severely injured BP
> worker Don Shugak.
>
> Preliminary results of the company's internal inquiry found no
> evidence that corrosion or drilling operations damaged the casing,
> according to Tom Gray, Prudhoe Operations Integrity Manager for BP.
>
> "Instead, we believe the pressure in the outer annulus (of the well
> casing) exceeded the surface casing pressure rating of 5,380 pounds
> per square inch, due to thermal expansion related to well startup,"
> Gray told the commission.
>
> Gray explained that as well A-22 in the Prudhoe Bay field was
> restarted after a shutdown in production, rising temperatures in the
> well caused fluids in the outer annulus -- a space between steel
> casing, or pipe, inside the well and the outer casing -- to expand.
> This increased pressure beyond the tolerance ...
>
> http://www.highbeam.com/doc/1G1-94875708.html
>
> Casing Burst Pressure Study

Surface Casing Macondo

http://www.energy.gov/open/documents/3.1_Item_2_Macondo_Well_07_Jun_1900.pdf

BOP Casing: 36" Burst Pressure: 5,444 Psi
Surface Casing: 28" Burst Pressure: 2,437 Psi
Well Head Casing: 22" Burst Pressure: 7,954 Psi

http://www.drillscience.com/bp/macondo-well-layout-neat.xls

Top 5' Weakest Cement

Garry Denke