US 11,875,096 B2 · Mitigation of backward whirl in drill bits

Abstract

Design parameters for PDC drill bit are correlated to instances of backward whirl, where backward whirl is detected along a lateral axis in the frequency domain during downhole drilling. Two regimes of backward whirl are described and detected—cutting-induced backward whirl and friction-induced backward whirl—where each regime has different characteristic frequencies, detection methods, and mitigation guidelines. Design parameters are quantified by gauge fullness, drilling efficiency (DE), and whirl index (WI). Design guidelines to mitigate backward whirl are generated by correlating design parameter quantifiers and instances of backward whirl, including both cutting-induced backward whirl and friction-induced backward whirl. Potential drill bit designs are then validated against the generated guidelines in order to mitigate backward whirl in future drilling runs.

Claims20

Dependent claims

A method comprising:

determining values for a first drill bit design parameter for a plurality of drill bit designs;
detecting instances of backward whirl based on vibrational data;
determining a correlation between the instances of backward whirl and the values of the first drill bit design parameter, wherein determining the correlation includes determining a set of values for the first drill bit design parameter based on an aggregate of the values for the first drill bit design parameter identified for the instances of backward whirl;
based on the correlation, determining a set of one or more limits for the first drill bit design parameter that mitigates backward whirl;
and
generating drill bit design rules based on the determined set of one or more limits for the first drill bit design parameter.

3 more elements

A non-transitory, computer-readable medium having instructions stored thereon that are executable by a computing device, the instructions to:

determine values for a first drill bit design parameter for a plurality of drill bit designs;
detect instances of backward whirl based on vibrational data;
determine a correlation between the instances of backward whirl and the values of the first drill bit design parameter, wherein the instructions to determine the correlation include instructions to determine a set of values for the first drill bit design parameter based on an aggregate of the values for the first drill bit design parameter identified for the instances of backward whirl;
based on the correlation, determine a set of one or more limits for the first drill bit design parameter that mitigates backward whirl;
and
generate drill bit design rules based on the determined set of one or more limits for the first drill bit design parameter.

3 more elements

An apparatus comprising:

a processor;
and
a computer-readable medium having instructions stored thereon that are executable by the processor to cause the apparatus to,
determine values for a first drill bit design parameter for a plurality of drill bit designs;
detect instances of backward whirl based on vibrational data;
determine a correlation between the instances of backward whirl and the values of the first drill bit design parameter, wherein the instructions to cause the apparatus to determine the correlation include instructions to cause the apparatus to determine a set of values for the first drill bit design parameter based on an aggregate of the values for the first drill bit design parameter identified for the instances of backward whirl;
based on the correlation, determine a set of one or more limits for the first drill bit design parameter that mitigates backward whirl;
and
generate drill bit design rules based on the determined set of one or more limits for the first drill bit design parameter.

6 more elements

Dependencies are inferred from the claim text.

Mitigation of backward whirl in drill bits

Life of this patent

Mitigation of backward whirl in drill bits

Life of this patent

Abstract

Claims20