US 5,787,998 AGranted

Down hole pressure intensifier and drilling assembly and method

AssigneeFlowdril Corporation

InventorsThomas A. O'Hanlon, Douglas P. Kelley, Scott D. Veenhuizen

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Abstract

A jet assisted drill system which uses a high pressure intensifier, positioned in a down hole drill assembly. Drill fluid from a drill stem is directed into the drill assembly, and in one mode this drill fluid is passed through the pressure intensifier to cause a piston assembly of the intensifier to reciprocate, with high pressure pistons of the piston assembly delivering high pressure drill fluid to a discharge jet in the drill bit assembly. The lower pressure fluid which drives the low pressure pistons is discharged into a downstream annular passageway and to the drill bit assembly. In a by-pass mode, a selector valve directs drill fluid from an upstream main passageway portion directly to a downstream main passageway portion to pass out the drill bit assembly. This flushes out debris which is carried upwardly out of the drill hole. There is a control valve to operate the piston assembly and a trigger valve operated by the piston assembly to direct fluids selectively to the control valve.

Claims40

Dependent claims

A pump and drilling assembly for drilling into an earth formation, said assembly comprising:

a. an elongate housing structure having a longitudinal axis, an upstream end adapted to be connected to a drill string and to receive drill fluid therefrom, and a downstream end, said housing comprising a tubular outer housing and an inner housing positioned within said outer housing;
b. a drill bit assembly connected to the downstream end of the housing structure, said drill bit assembly having a high pressure fluid jet discharge means;
c. a pressure intensifier means positioned in the inner housing and comprising:
i. low pressure piston means mounted for reciprocating motion in low pressure chamber means within said inner housing;
ii. high pressure piston means connected to said low pressure piston means and mounted for reciprocating motion in high pressure chamber means within said inner housing;
d. a longitudinally extending main fluid passageway means having an inlet end to receive fluid flow of the drill fluid from said drill stem, and an outlet end at a downstream location, at least a portion of said main fluid passageway means being adjacent to said pressure intensifier means and positioned between said inner housing and said outer housing, said main fluid passageway means having an upstream passageway portion and a downstream passageway portion;
e. a valve section means positioned in said housing structure between said upstream and said downstream end, said valve section means comprising a control valve means to receive fluid flow from the upstream passageway portion and selectively direct said fluid flow to said low pressure chamber means to cause said low pressure piston means to reciprocate and cause said high pressure piston means to reciprocate, and to direct fluid from said low pressure chamber means to said downstream passageway portion;
f. pressure intensifier valve and passageway means arranged to direct low pressure drill fluid into said high pressure chamber means and to direct higher pressure drill fluid from said high pressure chamber means to said high pressure fluid jet discharge means.

5 more elements

A method of high pressure jet assisted drilling into an earth formation, said method comprising:

a. providing an elongate housing structure having a longitudinal axis, an upstream end and a downstream end, said housing comprising a tubular outer housing and an inner housing positioned within said outer housing;
b. connecting the upstream end of the housing structure to receive drill fluid therefrom,
c. connecting a drill bit assembly to the downstream end of the housing structure, said drill bit assembly having a high pressure fluid jet discharge means;
d. positioning a pressure intensifier means positioned in the inner housing, with said pressure intensifier means comprising:
i. low pressure piston means mounted for reciprocating motion in low pressure chamber means within said inner housing;
ii. high pressure piston means connected to said low pressure piston means and mounted for reciprocating motion in high pressure chamber means within said inner housing;
e. directing drill fluid from said drill stem into a longitudinally extending main fluid passageway means having an inlet end to receive fluid flow of the drill fluid from said drill stem, and an outlet end at a downstream location, at least a portion of said main fluid passageway means being adjacent to said pressure intensifier means and positioned between said inner housing and said outer housing, said main fluid passageway means having an upstream passageway portion and a downstream passageway portion;
f. positioning a valve section means in said housing structure between said upstream and said downstream end, said valve section means comprising a control valve means;
g. directing fluid flow from the upstream passageway portion to said control means and selectively directing said fluid flow to said low pressure chamber means to cause said low pressure piston means to reciprocate and cause said high pressure piston means to reciprocate, and directing fluid from said low pressure chamber means to said downstream passageway portion;
h. directing low pressure drill fluid into said high pressure chamber means and directing higher pressure drill fluid from said high pressure chamber means to said high pressure fluid jet discharge means.

7 more elements

Dependencies are inferred from the claim text.