METHOD OF DESIGNING A PIPE JOINT FOR USE IN A SUBSEA PIPELINE
First Claim
1. A method of determining a wall thickness of a pipe joint for use in a subsea pipeline, the method comprising:
- determining an internal diameter of the pipe joint;
determining a minimum allowable hydrostatic pressure at a depth at which the pipe joint is to be used;
determining a target wall thickness for the pipe joint, the target wall thickness corresponding to the internal diameter and the minimum allowable hydrostatic pressure;
manufacturing a plurality of preliminary pipe joints having the internal diameter and the target wall thickness;
carrying out external pressure collapse tests resulting in data representative of the hydrostatic collapse pressures at which the plurality of preliminary pipe joints collapse;
determining a probability distribution corresponding to the data based on a statistical tail model derived from Extreme Value Theory;
determining from the probability distribution a hydrostatic collapse pressure occurring with a probability of 10−
5 or lower; and
,determining a wall thickness of the pipe joint corresponding to the internal diameter and the hydrostatic collapse pressure.
1 Assignment
0 Petitions
Accused Products
Abstract
A method of determining a minimum wall thickness for a pipe joint for use in a subsea pipeline comprises the steps of: i) determining an internal diameter of the pipe joint; ii) determining a minimum allowable hydrostatic pressure at the depth at which the pipe joint is to be used; iii) determining a target wall thickness for the pipe joint, the target wall thickness corresponding to the internal diameter and the minimum allowable hydrostatic pressure; iv) manufacturing a plurality of preliminary pipe joints having the internal diameter and the target wall thickness; v) carrying out external pressure collapse tests resulting in data representative of the hydrostatic collapse pressures at which the plurality of preliminary pipe joints collapse; vi) determining a probability distribution corresponding to the data based on a statistical tail model derived from Extreme Value Theory; vii) determining from the probability distribution a hydrostatic collapse pressure occurring with a probability of 10−5 or lower; and, viii) determining a wall thickness of the pipe joint corresponding to the internal diameter and the hydrostatic collapse pressure.
4 Citations
24 Claims
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1. A method of determining a wall thickness of a pipe joint for use in a subsea pipeline, the method comprising:
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determining an internal diameter of the pipe joint; determining a minimum allowable hydrostatic pressure at a depth at which the pipe joint is to be used; determining a target wall thickness for the pipe joint, the target wall thickness corresponding to the internal diameter and the minimum allowable hydrostatic pressure; manufacturing a plurality of preliminary pipe joints having the internal diameter and the target wall thickness; carrying out external pressure collapse tests resulting in data representative of the hydrostatic collapse pressures at which the plurality of preliminary pipe joints collapse; determining a probability distribution corresponding to the data based on a statistical tail model derived from Extreme Value Theory; determining from the probability distribution a hydrostatic collapse pressure occurring with a probability of 10−
5 or lower; and
,determining a wall thickness of the pipe joint corresponding to the internal diameter and the hydrostatic collapse pressure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A method of determining a hydrostatic collapse pressure of a pipe joint for use in a subsea pipeline, the method comprising:
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determining an internal diameter of the pipe joint; determining a minimum allowable hydrostatic pressure at a depth at which the pipe joint is to be used; determining a target wall thickness for the pipe joint, the target wall thickness corresponding to the internal diameter and the minimum allowable hydrostatic pressure; manufacturing a plurality of preliminary pipe joints having the internal diameter and the target wall thickness; carrying out external pressure collapse tests resulting in data representative of the hydrostatic collapse pressures at which the plurality of preliminary pipe joints collapse; determining a probability distribution corresponding to the data based on a statistical tail model derived from Extreme Value Theory; and
,determining from the probability distribution a hydrostatic collapse pressure occurring with a probability of 10−
5 or lower. - View Dependent Claims (24)
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Specification