Li I Zheng

US Patent:

20150041119, Feb 12, 2015

Filed:

Aug 8, 2013

Appl. No.:

13/962413

Inventors:

- Houston TX, US
Yanyan Wu - Houston TX, US
Chad Eric Yates - Houston TX, US
Xichang Zhang - Houston TX, US
Li Zheng - Niskayuna NY, US
Pinghai Yang - Niskayuna NY, US

Assignee:

Vetco Gray Inc. - Houston TX

International Classification:

E21B 47/12

US Classification:

16625001

Abstract:

A wellhead assembly having a tubular magnetized in at least one selected location, and a sensor proximate the magnetized location that monitors a magnetic field from the magnetized location. The magnetic field changes in response to changes in mechanical stress of the magnetized location, so that signals from the sensor represent loads applied to the tubular. Analyzing the signals over time provides fatigue loading data useful for estimating structural integrity of the tubular and its fatigue life. Example tubulars include a low pressure housing, a high pressure housing, conductor pipes respectively coupled with the housings, a string of tubing, a string of casing, housing and tubing connections, housing and tubing seals, tubing hangers, tubing risers, and other underwater structural components that require fatigue monitoring, or can be monitored for fatigue.