US 12,607,766 B2 · Detecting anomalies in annular materials of single and dual casing string environments

Abstract

An x-ray based cement evaluation tool for measurement of the density of material volumes within single, dual and multiple-casing wellbore environments is provided, the tool including at least an internal length comprising a sonde section, wherein said sonde section further comprises an x-ray source; a radiation shield for radiation measuring detectors; sonde-dependent electronics; and a plurality of tool logic electronics and PSUs, wherein the tool uses x-rays to illuminate the formation surrounding a borehole and a plurality of detectors are used to directly measure the density of the cement annuli and any variations in density within. Detectors used to measure casing standoff such that other detector responses are compensated for tool stand-off and centralization; a plurality of reference detectors is used to monitor the output of the x-ray source, and a shortest-axial offset detector is configured to distribute incoming photons into energy classifications such that photoelectric measurements may be made.

Claims20

Dependent claims

An x-ray based borehole evaluation tool comprising:

an x-ray source;
a first detector group of azimuthally distributed detectors that is offset from the x-ray source in an axial direction by a first distance, the first detector group to measure density within a first radial depth of the tool using radiant energy generated by the x-ray source;
and
a second detector group of azimuthally distributed detectors that is offset from the x-ray source in the axial direction by a second distance greater than the first distance, the second detector group to measure density within an annular region located between the first radial depth and a second radial depth greater than the first radial depth using the radiant energy, the second detector group comprising azimuthally-adjacent detectors to measure azimuthal density variations within the annular region,
wherein the tool is to deconvolve data from each detector using data from a corresponding azimuthally-coherent detector with a lower axial offset relative to the x-ray source.

2 more elements

A method of using an x-ray based borehole evaluation tool, the method comprising:

generating, by a first detector group of the tool, first output data that characterizes density within a first radial depth of the tool using radiant energy emitted by an x-ray source of the tool positioned within a borehole, the first detector group formed by azimuthally distributed detectors that are offset from the x-ray source in an axial direction by a first distance;
generating, by a second detector group of the tool using the radiant energy, second output data that characterizes density within an annular region located between the first radial depth and a second radial depth of the tool greater than the first radial depth, the second detector group formed by azimuthally distributed detectors that are offset from the x-ray source in the axial direction by a second distance greater than the first distance;
deconvoluting the second output data using lower order output data to reduce multiple Compton scatter event mechanisms within the second output data, the lower order output data characterizing density within a lower radial depth of the tool that is less than the second radial depth;
detecting a radial position of a density variation within the annular region using the first output data and the second output data;
and
detecting an azimuthal position of the density variation using the second output data generated by azimuthally-adjacent detectors of the second detector group.

3 more elements

Dependencies are inferred from the claim text.

Detecting anomalies in annular materials of single and dual casing string environments

Life of this patent

Detecting anomalies in annular materials of single and dual casing string environments

Life of this patent

Abstract

Claims20