US3604256A
Expired / Lapsed
US
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Method for measuring the average vertical permeability of a subterranean earth formation
Assignee: Shell USA Inc
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Filing: 1969-01-31
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Granted: 1971-09-14
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Expires: 1989-01-31
Abstract
Abstract A method for measuring the average vertical permeability of a subterranean earth formation by extending a well borehole into the earth formation and sealing off the well borehole at least adjacent to the portion of the formation desired to be measured. The sealed-off portion of the well borehole is perforated at least at two vertically spaced points in the well borehole and the well borehole is sealed off between the perforations. Fluid is then flowed at a substantially constant rate through one of the perforations at one of the points while the pressure response in the well borehole is measured at the perforations of the other of the points without flowing fluid through the latter perforation.
Inventors
- 👤 Michael Prats
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:17
CPC Classifications
E; E21; E21B; E21B49/00; E21B49/008
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
227 words
A method for quantitatively determining the average vertical permeability of a single subterranean earth formation comprising the steps of: extending a well borehole into said single earth formation adjacent the portion of said formation desired to be measured; sealing said well borehole to a point at least adjacent a portion of said single earth formation desired to be measured; perforating said sealed-off portion of said well borehole by forming perforations at least at two vertically spaced points within said well borehole and opposite said single earth formation; packing off said well borehole between said two points in said well borehole by placing a packer in said well borehole whereby communication is eliminated between said two points; flowing fluid through at least one of the perforations at one of said points in said well borehole at a substantially constant mass rate of flow; determining the position of said two points with respect to the top and bottom of said single earth formation; measuring the pressure response in said well borehole at the perforations of the other of said points while flowing said fluid through said first-mentioned perforation without flowing fluid through said last-mentioned perforation; and quantitatively determining the average vertical permeability of said single earth formation from the measured pressure response and the position of said two points with respect to the top and bottom of the formation.
Claim 2
Independent Claim
227 words
A method for quantitatively determining the average vertical permeability of a single subterranean earth formation comprising the steps of: extending a well borehole into said single earth formation adjacent the portion of said formation desired to be measured; sealing said well borehole to a point at least adjacent a portion of said single earth formation desired to be measured; perforating said sealed-off portion of said well borehole by forming perforations at least at two vertically spaced points within said well borehole and opposite said single earth formation; packing off said well borehole between said two points in said well borehole by placing a packer in said well borehole whereby communication is eliminated between said two points; flowing fluid through at least one of the perforations at one of said points in said well borehole at a substantially constant mass rate of flow; determining the position of said two points with respect to the top and bottom of said single earth formation; measuring the pressure response in said well borehole at the perforations of the other of said points while flowing said fluid through said first-mentioned perforation without flowing fluid through said last-mentioned perforation; and quantitatively determining the average vertical permeability of said single earth formation from the measured pressure response and the position of said two points with respect to the top and bottom of the formation.
Claim 3
Dependent Claim
48 words
The method of claim 1 wherein the step of sealing said well borehole includes the step of placing a well casing in said well borehole; and subsequently perforating said well casing at substantially the top and bottom of said single earth formation on which permeability measurements are made.
Claim 4
Dependent Claim
46 words
The method of claim 1 wherein the step of perforating said sealed-off portion of said well borehole includes the step of perforating said well borehole at least at two points in said well borehole separated by a distance no less than about 25 well borehole radii.
Claim 5
Dependent Claim
132 words
The method of claim 1 wherein the step of perforating said sealed-off portion of said well borehole includes the steps of forming a first series of perforations in said well borehole adjacent substantially to the top of said single earth formation; and forming a second series of perforations in said well borehole adjacent substantially to the top of said single earth formation; and forming a second series of perforations in said well borehole adjacent substantially to the bottom of said single earth formation, the step of packing off said perforations including the step of placing packer means in said well borehole between said first and second series of perforations, the length of each series of said perforations being no greater than about 10 percent of the distance between the series of perforations.
Claim 6
Dependent Claim
28 words
The method of claim 1 wherein the step of flowing fluid through at least one oF the perforations includes the step of producing formation fluid through said perforation.
Claim 7
Dependent Claim
27 words
The method of claim 1 wherein the step of flowing fluid through at least one of the perforations includes the step of injecting fluid through said perforation.
Claim 8
Dependent Claim
120 words
The method of claim 1 including the step of determining the average vertical permeability (kv) of said single earth formation from the following equation: where phi porosity of the formation; Mu fluid viscosity in the formation; c fluid compressibility of the formation; h formation thickness; Delta p pressure measured at the perforation being measured minus the initial formation pressure; Delta p(1) Delta p at 1 hour; F(z/h,z'' /h) geometrical function which depends on the position of the flowing and measuring points from the vertical boundaries of the formation; z distance measured from the bottom of the formation of perforation at which pressure is measured; and z distance of perforation where fluid is flowed, measured from the bottom of the formation.
References Cited (Backward Citations)
US3332483A
Cited
US3285064A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |