# Coincidental Pressures Led to Normal Human Heuristic and Error NPT Test Gauges TOO SIMILIAR to Riser Margin For Crew To Ignore.

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Coincidental Pressures Led to Normal Human Heuristic and Error NPT Test Gauges TOO SIMILIAR to Riser Margin For Crew To Ignore

Pressure of Reservoir Pushing “UP” is ~1,400 psi Pressure of Riser Mud Pushing “DOWN” is ~1,400 psi

Water Depth4,992' Water Density8.6 ppg RKB75' Gauge Height Off Mud Line25' Riser Mud Weight14.0 ppg Riser Margin1,439 psi Blowout Reservoir Pressure Density Equivalent13.1 ppg Blowout Reservoir Pressure (BRP)12,073 psi BRP Depth (can argue reservoir yet not 1,400 psi gauge result)17,791' Drillstring Depth8,367' Pressure of hydrostatic down to bottom of drillstring3,759 psi Pressure of hydrostatic from drillstring to reservoir Depth6,861 psi Pressure of reservoir at choke line pressure gauge1,453 psi "BLIPS" in NPT shows bottom plug acting as Back Pressure Valve of 50 psi50 psi Calculated Pressure1,403 psi NPT Pressure that the Macondo Crew Saw on Pressure Gauge1,400 psi Difference-3 psi

Coincidental Pressure Led to Normal Human Heuristic and Error Bizarre Coincidence? OR Mitigatable Confusion?

Coincidental Pressure Led to Normal Human Heuristic and Error A simulation of the stress path and yield envelope of the designed NPT would have highlighted the coincidence of confusion at the Safety Critical Moment (SCM). The First Rule of Engineering Process was violated – Weigh steps (stress path) on stress/yield envelope

Coincidental Pressure Led to Normal Human Heuristic and Error Heuristic /hjʉˈrɪstɨk/; Greek: "Εὑρίσκω", "find" or "discover") refers to where the exhaustive search is impractical, heuristic methods are used to speed up the process of finding a satisfactory solution via mental shortcuts to ease the cognitive load of making a decision./hjʉˈrɪstɨk/; Greek: "Εὑρίσκω", "find" or "discover") refers to where the exhaustive search is impractical, heuristic methods are used to speed up the process of finding a satisfactory solution via mental shortcuts to ease the cognitive load of making a decision.

Coincidental Pressure Led to Normal Human Heuristic and Error James Reason and other experts say the way to establish “Fault” is to use the “Substitution Test”. Basically ask if any other worker in the same situation ‘might’ have come to the same conclusion. The answer is an emphatic, Yes! Everyone on the rig came to exactly the same conclusion. The heuristic. The pressure was very close to the expected riser margin and thus the bladder effect WAS the heuristic.

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