US 2025/0084749 A1 · ENHANCED SPINE-AND-RIB PROCESS FOR EVALUATION OF FORMATION DENSITY

Abstract

Methods for determining formation density of downhole formations include obtaining first density data (ρSS) using a short-spaced detector configured to detect reflections of a signal transmitted into the downhole formation, obtaining second density data (ρLS) using a long-spaced detector configured to detect reflections of the transmitted signal from the downhole formation, wherein the long-spaced detector is located a greater distance from a source than the short-spaced detector, and determining if a measured data point based on ρSS and ρLS falls within a unity area of a spine-and-rib plot. When the measured data point falls within the unity area, the formation density using a first mathematical relationship is determined and when the measured data point falls outside the unity area, the formation density using a second mathematical relationship different from the first mathematical relationship is determined.

Claims20

Dependent claims

A method for determining a formation density of a downhole formation, the method comprising:

obtaining first density data (ρSS) using a short-spaced detector configured to detect a first scattered radiation of a radiation transmitted into the downhole formation by a radiation source;
obtaining second density data (ρLS) using a long-spaced detector configured to detect a second scattered radiation of the radiation transmitted into the downhole formation, wherein the long-spaced detector is located a greater distance from the radiation source than the short-spaced detector;
determining if a measured data point based on the obtained first density data (ρSS) and the obtained second density data (ρLS) falls within a unity area of a spine-and-rib plot;
when the measured data point falls within the unity area, determining the formation density using the first density data (ρSS) and the second density data (ρLS) and a first mathematical relationship;
and
performing a wellbore operation using the determined formation density.

3 more elements

A method for determining a formation density of a downhole formation, the method comprising:

generating tool model data of a downhole tool to be used for measuring density of the downhole formation;
generating requirement data comprising information associated with standoff values, fluid densities, and range of potential formation densities;
using the tool model data and the requirement data, generating a set of responses of a short-spaced detector and a long-spaced detector;
generating a set of basic ribs of a spine-and-rib plot based on the set of responses;
obtaining a first mathematical relationship based on the basic ribs;
defining a unity area of the spine-and-rib plot based on the basic ribs;
generating a lookup table based on coefficients of the first mathematical relationship;
determining the formation density using the lookup table;
and,
performing a wellbore operation using the determined formation density.

7 more elements

Dependencies are inferred from the claim text.

Enhanced spine-and-rib process for evaluation of formation density

Life of this patent

Enhanced spine-and-rib process for evaluation of formation density

Life of this patent

Abstract

Claims20