Patent EP0092476A2 successfully refreshed from Google Patents.
EP0092476A2
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Pressure activated well perforating technique
Assignee: Schlumberger Technology Corp
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Filing: 1983-04-14
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Granted: —
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Expires: 2003-04-14
Abstract
Abstract A well perforating technique utilizes a predetermined pressure difference developed at different points in the borehole to actuate the firing mechanism of a tubing conveyed perforating gun. A first embodiment incorporated as part of a well test string includes a packer for isolating a wellbore interval and a perforating gun connected in the string below the packer which is fired in response to development of a greater pressure in the annulus above the packer than in the isolated interval, thereby causing perforation at «underbalanced» conditions. A modified «full-bore» embodiment has an annular configuration firing mechanism as part of a tubing string and fires the perforating gun in response to development of a predetermined difference between the pressures at a point in the annulus and a point in the central bore of the tubing string.
Inventors
- 👤 James M. Upchurch
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 11:56
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/11; E21B43/116; E21B43/1185; E21B43/11852
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
97 words
A method of perforating earth formations surrounding a wellbore with a perforating device comprising explosive charges and an actuating mechanism for setting off the explosive charges, said method comprising the steps of: inserting the perforating device into said wellbore; and characterized by manipulating the pressure of fluid in a channel in the wellbore that communicates with the surface until a predetermined pressure difference exists between a first point in the wellbore annulus and a second point in the wellbore; and triggering said actuating mechanism into setting off the explosive charges when the predetermined pressure difference is reached.
Claim 2
Independent Claim
97 words
A method of perforating earth formations surrounding a wellbore with a perforating device comprising explosive charges and an actuating mechanism for setting off the explosive charges, said method comprising the steps of: inserting the perforating device into said wellbore; and characterized by manipulating the pressure of fluid in a channel in the wellbore that communicates with the surface until a predetermined pressure difference exists between a first point in the wellbore annulus and a second point in the wellbore; and triggering said actuating mechanism into setting off the explosive charges when the predetermined pressure difference is reached.
Claim 3
Dependent Claim
19 words
The method of claim 1, characterized in that the second point in the wellbore is within an isolated interval.
Claim 4
Dependent Claim
19 words
The method of claim 2, characterized in that the manipulation step comprises bleeding down pressure in the isolated interval.
Claim 5
Dependent Claim
65 words
The method of claim 2, wherein the perforating device is lowered into the wellbore on the end of a pipe string, said pipe string including a valve acting between the pressure in the pipe string and the pressure in the isolated interval, and characterized in that the manipulating step comprises opening said valve to equalize the pressure between the pipe string and the isolated interval.
Claim 6
Dependent Claim
33 words
The method of claim 1, wherein the perforating device is mounted at the end of a pipe string and characterized in that the second point in the wellbore is within said pipe string.
Claim 7
Dependent Claim
23 words
The method of claim 4, characterized in that the predetermined pressure differential is reached by bleeding down the pressure in the pipe string.
Claim 8
Independent Claim
31 words
The method of any one of claims 1 to 6 further characterized by the steps of isolating an interval within said wellbore and perforating the earth formations surrounding said isolated interval.
Claim 9
Independent Claim
35 words
The method of any one of claims 1 to 6 further comprising the steps of applying pressure at the surface to the well annulus to develop at least a portion of the predetermined pressure differential.
Claim 10
Dependent Claim
85 words
Apparatus for perforating earth formations surrounding a wellbore comprising explosive charges and an actuating mechanism for setting off the explosive charges, said actuating mechanism characterized by: means for manipulating the pressure of fluid in a channel in the wellbore that communicates with the surface until a predetermined pressure difference exists between a first point in the wellbore annulus and a second point in the wellbore; and means for triggering said actuating mechanism into setting off the explosive charges when the predetermined pressure difference is reached.
Claim 11
Dependent Claim
85 words
Apparatus for perforating earth formations surrounding a wellbore comprising explosive charges and an actuating mechanism for setting off the explosive charges, said actuating mechanism characterized by: means for manipulating the pressure of fluid in a channel in the wellbore that communicates with the surface until a predetermined pressure difference exists between a first point in the wellbore annulus and a second point in the wellbore; and means for triggering said actuating mechanism into setting off the explosive charges when the predetermined pressure difference is reached.
Claim 12
Dependent Claim
34 words
The apparatus of claim 9, wherein said second point in the wellbore is within an isolated interval and characterized in that the manipulating means comprises means for bleeding down pressure in the isolated interval.
Claim 13
Dependent Claim
77 words
The apparatus of claim 9, wherein said second point in the wellbore is within an isolated interval and wherein the perforating device is lowered into the wellbore on the end of a pipe string with a valve acting between the pressure in the pipe string and the pressure in the isolated interval, and characterized in that the manipulating means comprises means for opening said valve to equalize the pressure between the pipe string and the isolated interval.
Claim 14
Dependent Claim
33 words
The apparatus of claim 9, wherein the perforating device is mounted at the end of a pipe string and characterized in that the second point in the wellbore is within said pipe string.
Claim 15
Dependent Claim
23 words
The apparatus of claim 12, characterized in that the predetermined pressure differential is reached by bleeding down the pressure in the pipe string.
Claim 16
Independent Claim
31 words
The apparatus of any one of claims 9 to 13 further characterized by means for isolating an interval within said wellbore whereby the earth formations surrounding said isolated interval are perforated.
References Cited (Backward Citations)
No citation records indexed.
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