US 4,287,957 A · Cooling a drilling tool component with a separate flow stream of reduced-temperature gaseous drilling fluid

Abstract

A flow stream of drilling gas in a gaseous drilling fluid circulation drilling system is separated from that drilling gas supplied to the drill string, and the flow stream is reduced in temperature prior to supplying the flow stream to a drilling tool component to be cooled. A heat exchanger is employed to remove heat from the flow stream, and a second separate flow stream of drilling gas is directed over the heat exchanger to remove the heat. The temperature of the second cooling stream is reduced by thermodynamic effects. Various drilling tool components may be cooled, including bearing means operative between two relatively movable parts, a seal assembly operative to seal lubricant between two relatively moving parts, and cutter elements of a drag-type drill bit. The seal assembly includes a flange-like projection member and a fluid conducting conduit in thermal transferring relationship with the projection member. Flexible flank members form a movable sealing relationship with the projection member and the reduced-temperature flow stream is forced through the conduit. The drag-type drill bit includes a plurality of cooling jet means which direct jets of reduced-temperature drilling gas from the flow stream into thermal transferring relationship with each of the cutter elements.

Claims23

Dependent claims

An improved method of cooling a drilling tool component of a gaseous drilling fluid circulation drilling system, comprising the following steps:

conducting a supply of pressurized drilling gas into a borehole through a drilling fluid passageway for the primary purpose of carrying particle cuttings out of the borehole,
separating in the borehole a part of the supplied drilling gas into a flow stream separate from the remaining drilling gas in the drilling fluid passageway,
conducting the whole of the flow stream to the drilling tool component to be cooled,
passing the flow stream through a heat exchanger which is thermally separate from the drilling component to be cooled prior to conducting the flow stream to the drilling tool component to be cooled, and
cooling the flow stream in the heat exchanger to a temperature less than the temperature of the remaining drilling gas in the drilling fluid passageway by thermally immersing the heat exchanger in a cooling stream of drilling gas separate from that of the flow stream and that in the drilling fluid passageway, the cooling stream having been reduced in temperature due to thermodynamic effects of the cooling stream drilling gas within the borehole.

2 more elements

Apparatus for cooling a drilling tool component in a gaseous drilling fluid circulation drilling system, in which said drilling system comprises a drill string defining a drilling fluid passageway therein for conducting pressurized drilling gas into the borehole formed by the drilling system, a drilling tool component operatively connected to said drill string, and means supplying pressurized drilling gas to the drilling fluid passageway, said cooling apparatus comprising:

conduit means extending from the drilling fluid passageway to the drilling tool component for conducting the whole of a flow stream of drilling gas from the drilling fluid passageway to the component,
heat exchanger means thermally connected to said conduit means between the drilling fluid passageway and the drilling tool component, said heat exchanger means being substantially thermally isolated from the drilling tool component, said heat exchanger means thermally inducing the transfer of heat from the whole of the flow stream of drilling gas passing through said conduit means prior to the drilling gas being conducted to the component;
means positioning said heat exchanger means on the drill string and within the borehole to direct heat transferred from said heat exchanger means into the environment exterior of the drill string in the borehole.

Apparatus operative in a gaseous drilling fluid drilling system wherein a drilling fluid passageway extends in a drill string and conducts pressurized drilling gas into the borehole for the primary purpose of carrying particle cuttings out of the borehole, said apparatus comprising in combination:

a lubricant seal assembly operative between two relatively movable parts of a drilling tool of said drilling system, said seal assembly comprising:
a flank member operatively connected to one of said relatively movable parts, said flank member including a contact sealing surface formed thereon;
a projection member operatively connected to the other of said relatively movable parts, said projection member including a sealing surface formed thereon in movable sealing relation with the contact sealing surface of said flank member;
and
a fluid conductive conduit extending in thermally conductive relationship with said projection member, said conduit including an inlet and an outlet;
and
means operative from the pressurized drilling gas for reducing the temperature of a flow stream of drilling gas to a temperature less than the temperature of the drilling gas in the drilling fluid passageway and for supplying the reduced-temperature flow stream to the inlet of said conduit whereby to remove heat from said projection member.

4 more elements

a drag-type drill bit attached to the drill string, said drill bit comprising a plurality of diamond material cutter elements attached to said drill bit, and cooling jet means for expelling fluid into thermal transferring relation with each diamond material cutter element, and means for conducting fluid to each said cooling jet means;
and
means operative from the pressurized drilling gas for reducing the temperature of a flow stream of drilling gas to a temperature less than the temperature of the drilling gas in the drilling fluid passageway and for supplying the reduced-temperature flow stream to said means for conducting fluid to each said cooling jet means whereby to remove heat from each diamond material cutter element.

Dependencies are inferred from the claim text.

Cooling a drilling tool component with a separate flow stream of reduced-temperature gaseous drilling fluid

Life of this patent

Cooling a drilling tool component with a separate flow stream of reduced-temperature gaseous drilling fluid

Life of this patent

Abstract

Claims23