Method and apparatus for measuring defects in ferromagnetic tubing
First Claim
1. Apparatus for simultaneously determining the extent of defects in used tubular elements forming a tubular string after use in a subterranean oil or gas well comprising:
- first means for determining the extent of the reduction in average wall thickness of each tubular element;
second means for determining the extent of corrosion pitting in each tubular element;
third means for determining the extent of wear due to sucker rod interference on each tubular element, the first, second and third means being mutually compatible wherein the reduction in wall thickness, the extent of corrosion pitting and the wear due to sucker rod interference can be simultaneously determined at the same location on a tubular element; and
means for positioning the apparatus in a fixed position at the surface of a well whereby defects in the tubular elements can be detected by multiple, overlapping, compatible inspection means as the tubular elements travel relative to the apparatus into or out of the well.
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Accused Products
Abstract
A method and apparatus for determining the extent of defects in ferromagnetic tubular elements comprising a continuous string for use in an oil or gas well is disclosed. The tubing trip tool measures tubing average wall thickness, local defects, such as corrosion pitting, and axial defects, such as sucker rod wear during removal of the tubing from the well. Tubing velocity is also measured, and couplings between tubing sections are detected and counted, in order to specify the axial location of defects on each tube, and also provide a profile of the condition of the overall string. A saturating magnetic field and a fluctuating magnetic field are applied to the tubing and the magnitude of the induced fields and the changes are measured to quantify defects in the tubing.
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Citations
13 Claims
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1. Apparatus for simultaneously determining the extent of defects in used tubular elements forming a tubular string after use in a subterranean oil or gas well comprising:
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first means for determining the extent of the reduction in average wall thickness of each tubular element; second means for determining the extent of corrosion pitting in each tubular element; third means for determining the extent of wear due to sucker rod interference on each tubular element, the first, second and third means being mutually compatible wherein the reduction in wall thickness, the extent of corrosion pitting and the wear due to sucker rod interference can be simultaneously determined at the same location on a tubular element; and means for positioning the apparatus in a fixed position at the surface of a well whereby defects in the tubular elements can be detected by multiple, overlapping, compatible inspection means as the tubular elements travel relative to the apparatus into or out of the well. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of determining the extent of defects in used tubular elements forming a tubular string after use in a subterranean oil or gas well, comprising the steps of:
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determining the extent of the reduction in average wall thickness at successive positions on each tubular element at the well surface during movement of each tubular element into or out of the well; determining the extent of corrosion pitting at successive positions on each tubular element at the well surface during movement of each tubular element into or out of the well; determining the extent of wear due to sucker rod interference at successive positions on each tubular element at the well surface during movement, into or out of the well, wherein the determination of the reduction in wall thickness, corrosion pitting, and wear due to sucker rod interference are simultaneously determined at the same position on each tubular element.
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Specification