US 12,655,688 B2Granted

Pack system for a downhole assembly

AssigneePark City Drilling Technologies LLC

InventorJoe Ficken

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Abstract

A pack system for a downhole assembly is provided. One end of the pack system is connected to a drill bit for drilling a wellbore, the other end of the pack system interfaces with a motor to receive torque. The pack system described herein has a simple design that reduces the number of parts, eliminates some seals and shims, and relies on a portion of drilling mud for lubrication. As a result, wear on parts of the system is greatly reduced and the longevity of the system is greatly increased. The hardness of various components of the system in key areas is increased, for example, with carbide, to further reduce wear and increase longevity. In addition, the simpler, more balanced arrangement of components allows for reduced vibration and high rotational speeds, which improves the performance of the overall downhole assembly.

Claims18

Dependent claims

A pack system for use in a downhole assembly, the pack system comprising:

a mandrel extending between an upper end and a lower end, the mandrel having an outer surface and having an inner surface that defines a central cavity that extends from the upper end to the lower end;
a bearing adapter connected to the upper end of the mandrel, the bearing adapter having at least one slot extending from an outer surface of the bearing adapter to an enclosed volume in the bearing adapter, wherein the enclosed volume is in fluid communication with the central cavity of the mandrel, the bearing adapter also having a shaft cavity at an upper end of the bearing adapter;
a shaft operably engaged with the shaft cavity of the bearing adapter such that a torque applied to the shaft is transmitted to the bearing adapter and to the mandrel, wherein a lower end of the shaft is positioned in the shaft cavity against a concave surface of a seat, the shaft having a plurality of protrusions extending outwardly from the shaft and positioned in corresponding plurality of channels of the shaft cavity of the bearing adapter;
a bearing housing disposed about the mandrel to define an annular space between an inner surface of the bearing housing and the outer surface of the mandrel;
at least one bearing positioned in the annular space to support at least one load on the mandrel, wherein the at least one bearing is not attached to a seal and is not positioned adjacent to a seal, wherein a first portion of a drilling fluid is configured to flow through the at least one slot of the bearing adapter, the enclosed volume of the bearing adapter, and the central cavity of the mandrel to cool a drill bit, and a second portion of the drilling fluid is configured to flow through the annular space between the bearing housing and the mandrel to lubricate the at least one bearing, wherein the at least one bearing comprises:
a lower radial bearing that supports a radial load on the mandrel;
and
a thrust bearing that supports an axial load on the mandrel;
and
a thrust ring positioned between the thrust bearing and a shoulder of the bearing housing, wherein the thrust ring distributes load forces about a circumference of the mandrel, and wherein at least one notch extends into an outer surface of the thrust ring and at least one notch extends into an inner surface of the thrust ring to channel the second portion of the drilling mud into the thrust bearing.

7 more elements

A pack system for use in a downhole assembly, the pack system comprising:

a mandrel extending between an upper end and a lower end, the mandrel having an outer surface and having an inner surface that defines a central cavity that extends from the upper end to the lower end, wherein the mandrel extends along a longitudinal axis and the mandrel rotates around the longitudinal axis;
a bearing adapter connected to the upper end of the mandrel, the bearing adapter having at least one slot extending from an outer surface of the bearing adapter to an enclosed volume in the bearing adapter, wherein the enclosed volume is in fluid communication with the central cavity of the mandrel, the bearing adapter also having a shaft cavity at an upper end of the bearing adapter;
a shaft operably engaged with the shaft cavity of the bearing adapter such that a torque applied to the shaft is transmitted to the bearing adapter and to the mandrel, wherein a lower end of the shaft is positioned in the shaft cavity against a concave surface of a seat, the shaft having a plurality of protrusions extending outwardly from the shaft and positioned in corresponding plurality of channels of the shaft cavity of the bearing adapter, wherein the shaft extends along a shaft axis and the shaft rotates around the shaft axis, and wherein the longitudinal axis and the shaft axis are positioned at an angle greater than zero as measured from a point where the mandrel longitudinal axis and the shaft axis intersect one another;
a bearing housing disposed about the mandrel to define an annular space between an inner surface of the bearing housing and the outer surface of the mandrel;
and
at least one bearing positioned in the annular space to support at least one load on the mandrel, wherein the annular space does not contain seals, wherein a first portion of a drilling fluid is configured to flow through the at least one slot of the bearing adapter, the enclosed volume of the bearing adapter, and the central cavity of the mandrel to cool a drill bit, and a second portion of the drilling fluid is configured to flow through the annular space between the bearing housing and the mandrel to lubricate the at least one bearing.

3 more elements

A pack system for use in a downhole assembly, the pack system comprising:

a mandrel extending between an upper end and a lower end, the mandrel having an outer surface and having an inner surface that defines a central cavity that extends from the upper end to the lower end;
a bearing adapter connected to the upper end of the mandrel, the bearing adapter having at least one slot extending from an outer surface of the bearing adapter to an enclosed volume in the bearing adapter, wherein the enclosed volume is in fluid communication with the central cavity of the mandrel, the bearing adapter also having a shaft cavity at an upper end of the bearing adapter;
a shaft operably engaged with the shaft cavity of the bearing adapter such that a torque applied to the shaft is transmitted to the bearing adapter and to the mandrel, wherein a lower end of the shaft is positioned in the shaft cavity against a concave surface of a seat, the shaft having a plurality of protrusions extending outwardly from the shaft and positioned in corresponding plurality of channels of the shaft cavity of the bearing adapter;
a bearing housing disposed about the mandrel to define an annular space between an inner surface of the bearing housing and the outer surface of the mandrel;
and
at least one bearing positioned in the annular space to support at least one load on the mandrel, wherein the at least one bearing is not attached to a seal and is not positioned adjacent to a seal, wherein a first portion of a drilling fluid is configured to flow through the at least one slot of the bearing adapter, the enclosed volume of the bearing adapter, and the central cavity of the mandrel to cool a drill bit, and a second portion of the drilling fluid is configured to flow through the annular space between the bearing housing and the mandrel to lubricate the at least one bearing,
wherein the mandrel, the bearing adapter, and the shaft rotate at a first speed, and the bearing housing rotates at a slower, second speed.

4 more elements

Dependencies are inferred from the claim text.