Rapid data-based data adequacy procedure for pipeline integrity assessment
First Claim
1. A method of evaluating a sufficiency of a number of measurements of an integrity of a pipeline, comprising:
- receiving sampled measurement data of pipeline wall thickness loss for the pipeline, wherein the sampled measurement data was obtained at a plurality of sample locations along an external surface of the pipeline;
identifying a maximum wall thickness loss measurement from the sampled measurement data;
identifying in-line inspection measurement data of pipeline wall thickness loss for a plurality of reference pipeline datasets stored in a data library;
selecting a subset of the in-line inspection measurement data having maximum wall thickness loss measurements that are greater than a first predetermined value when the maximum wall thickness loss measurement from the sampled measurement data is less than the first predetermined value;
calculating differences between a distribution of the sampled measurement data of pipeline wall thickness loss and distributions of the subset of the in-line inspection measurement data of pipeline wall thickness loss;
selecting at least a portion of the in-line inspection measurement data from the subset of the in-line inspection measurement data having distributions similar to the distribution of the sampled measurement data of pipeline wall thickness loss, wherein the similarity is determined by comparing the calculated differences;
retrieving, from the data library, at least a first statistic for the portion of the in-line inspection measurement data, the first statistic indicating a sample coverage required to accept a first premise regarding an extreme value of wall thickness loss for the pipeline to a specified confidence level;
determining, by a computer, from at least the first statistic and the sampled measurement data, a sufficiency of the sampled measurement data to allow a determination of the integrity of the pipeline;
acquiring a new set of sample measurements of pipeline wall thickness loss for the pipeline responsive to the determining indicating that the sampled measurement data is insufficient to allow the determination of the integrity of the pipeline, wherein sample coverage for the new set of sample measurements is greater than sample coverage for the sampled measurement data;
replacing at least a portion of the pipeline responsive to the determining indicating that the sampled measurement data is sufficient to allow the determination of the integrity of the pipeline.
1 Assignment
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Accused Products
Abstract
A method and system for evaluating the sample coverage of ultrasonic or radiography (UT/RT) measurements of pipeline wall thickness for statistical validity. A data library contains distributions of in-line inspection (ILI) measurements for other pipelines, calibrated to correspond to UT/RT measurements as needed. The data library for these ILI-measured pipelines also includes statistics generated from Monte Carlo simulation, by way of which various sample coverage levels sample the ILI measurements, for determining whether a measurement exceeds a given threshold or meets another premise related to determining the extreme wall loss measurement for the pipeline. A pipeline with sampled UT/RT measurements is used to identify one or more ILI-measured pipeline datasets that are most similar, and the statistics from those most similar pipeline datasets determine whether the sample coverage of the UT/RT measurements is sufficient to draw conclusions about the extreme value of wall loss in the sampled pipeline.
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Citations
26 Claims
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1. A method of evaluating a sufficiency of a number of measurements of an integrity of a pipeline, comprising:
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receiving sampled measurement data of pipeline wall thickness loss for the pipeline, wherein the sampled measurement data was obtained at a plurality of sample locations along an external surface of the pipeline; identifying a maximum wall thickness loss measurement from the sampled measurement data; identifying in-line inspection measurement data of pipeline wall thickness loss for a plurality of reference pipeline datasets stored in a data library; selecting a subset of the in-line inspection measurement data having maximum wall thickness loss measurements that are greater than a first predetermined value when the maximum wall thickness loss measurement from the sampled measurement data is less than the first predetermined value; calculating differences between a distribution of the sampled measurement data of pipeline wall thickness loss and distributions of the subset of the in-line inspection measurement data of pipeline wall thickness loss; selecting at least a portion of the in-line inspection measurement data from the subset of the in-line inspection measurement data having distributions similar to the distribution of the sampled measurement data of pipeline wall thickness loss, wherein the similarity is determined by comparing the calculated differences; retrieving, from the data library, at least a first statistic for the portion of the in-line inspection measurement data, the first statistic indicating a sample coverage required to accept a first premise regarding an extreme value of wall thickness loss for the pipeline to a specified confidence level; determining, by a computer, from at least the first statistic and the sampled measurement data, a sufficiency of the sampled measurement data to allow a determination of the integrity of the pipeline; acquiring a new set of sample measurements of pipeline wall thickness loss for the pipeline responsive to the determining indicating that the sampled measurement data is insufficient to allow the determination of the integrity of the pipeline, wherein sample coverage for the new set of sample measurements is greater than sample coverage for the sampled measurement data; replacing at least a portion of the pipeline responsive to the determining indicating that the sampled measurement data is sufficient to allow the determination of the integrity of the pipeline. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An evaluation system for evaluating measurements of pipeline wall thicknesses, comprising:
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a memory resource for storing a data library; one or more central processing units for executing program instructions; and program memory, coupled to the central processing unit, for storing a computer program including program instructions that, when executed by the one or more central processing units, is capable of causing the evaluation system to perform a sequence of operations for evaluating a sufficiency of a number of measurements of an integrity of a pipeline, the sequence of operations comprising; receiving sampled measurement data of pipeline wall thickness loss for the pipeline, wherein the sampled measurement data was obtained at a plurality of sample locations along an external surface of the pipeline; identifying a maximum wall thickness loss measurement from the sampled measurement data; identifying in-line inspection measurement data of pipeline wall thickness loss for a plurality of reference pipeline datasets stored in a data library; selecting a subset of the in-line inspection measurement data having maximum wall thickness loss measurements that are greater than a first predetermined value when the maximum wall thickness loss measurement from the sampled measurement data is less than the first predetermined value; calculating differences between a distribution of the sampled measurement data of pipeline wall thickness loss and distributions of the subset of the in-line inspection measurement data of pipeline wall thickness loss; selecting at least a portion of the in-line inspection measurement data from the subset of the in-line inspection measurement data having distributions similar to the distribution of the sampled measurement data of pipeline wall thickness loss, wherein the similarity is determined by comparing the calculated differences; retrieving, from the data library, at least a first statistic for the portion of the in-line inspection measurement data, the first statistic indicating a sample coverage required to accept a first premise regarding an extreme value of wall thickness loss for the pipeline to a specified confidence level; comparing a sample coverage of the sampled measurement data for the pipeline to the required sample coverage indicated by the first statistic to determine a sufficiency of the sampled measurement data to allow a determination of the integrity of the pipeline; requiring acquisition of a new set of sample measurements of pipeline wall thickness loss for the pipeline responsive to the comparing indicating that the sampled measurement data is insufficient to allow the determination of the integrity of the pipeline, wherein sample coverage for the new set of sample measurements is greater than sample coverage for the sampled measurement data; replacing at least a portion of the pipeline responsive to the comparing indicating that the sampled measurement data is sufficient to allow the determination of the integrity of the pipeline. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. A non-transitory computer-readable medium storing a computer program that, when executed on a computer system, causes the computer system to perform a sequence of operations for evaluating a sufficiency of a number of measurements of an integrity of a pipeline, the sequence of operations comprising:
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receiving sampled measurement data of pipeline wall thickness loss for the pipeline, wherein the sampled measurement data was obtained at a plurality of sample locations along an external surface of the pipeline; identifying a maximum wall thickness loss measurement from the sampled measurement identifying in-line inspection measurement data of pipeline wall thickness loss for a plurality of reference pipeline datasets stored in a data library; selecting a subset of the in-line inspection measurement data having maximum wall thickness loss measurements that are greater than a first predetermined value when the maximum wall thickness loss measurement from the sampled measurement data is less than the first predetermined value; calculating differences between a distribution of the sampled measurement data of pipeline wall thickness loss and distributions of the subset of the in-line inspection measurement data of pipeline wall thickness loss; selecting at least a portion of the in-line inspection measurement data from the subset of the in-line inspection measurement data having distributions similar to the distribution of the sampled measurement data of pipeline wall thickness loss, wherein the similarity is determined by comparing the calculated differences; retrieving, from the data library, at least a first statistic for the portion of the in-line inspection measurement data, the first statistic indicating a sample coverage required to accept a first premise regarding an extreme value of wall thickness loss for the pipeline to a specified confidence level; determining, from at least the first statistic and the sampled measurement data, a sufficiency of the sampled measurement data to allow a determination of the integrity of the pipeline; requiring acquisition of a new set of sample measurements of pipeline wall thickness loss for the pipeline responsive to the determining indicating that the sampled measurement data is insufficient to allow the determination of the integrity of the pipeline, wherein sample coverage for the new set of sample measurements is greater than sample coverage for the sampled measurement data; replacing at least a portion of the pipeline responsive to the comparing indicating that the sampled measurement data is sufficient to allow the determination of the integrity of the pipeline. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26)
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Specification