US3577643A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Borehole deformation gage
Assignee: Shell USA Inc
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Filing: 1967-05-18
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Granted: 1971-05-04
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Expires: 1987-05-18
Abstract
Abstract Internal stress of earth structure in situ may be determined by drilling a pilot hole and inserting a recording borehole deformation gage therein. Subsequently, the pilot hole including the recorder is recovered as a core by drilling out an annulus of the earth including the pilot hole. The borehole deformation gage is an optical interferometer instrument that is continuously monitored at short time intervals photographically.
Inventors
- 👤 Thomas R Schmidt
- 👤 Walter H Husing
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:50
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/08; E21B47/26; E21B49/00; E21B49/006; E21F; E21F17/00; E21F17/18; E21F17/185; G; G01; G01B; G01B11/00; G01B11/16
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
137 words
A method of measuring dimensional variations of a borehole comprising the following steps: spanning a dimension of said borehole with resiliently biased movable finger elements; mechanically linking the spread of said finger elements to a movable optical flat; directing light waves from a substantially monochromatic source through a stationary optical flat having a partially reflective surface and against a partially reflective surface of said moving flat; moving said partially reflective surface of said movable flat with respect to the partially reflective surface of said stationary flat a distance proportional to a dimension variation sensed by a change in the spread of said finger elements; and noting the number of spaces a particular fringe line seen above said stationary optical flat laterally shifts in response to said dimensional variation to determine the relative quantity of said dimensional variation.
Claim 2
Independent Claim
137 words
A method of measuring dimensional variations of a borehole comprising the following steps: spanning a dimension of said borehole with resiliently biased movable finger elements; mechanically linking the spread of said finger elements to a movable optical flat; directing light waves from a substantially monochromatic source through a stationary optical flat having a partially reflective surface and against a partially reflective surface of said moving flat; moving said partially reflective surface of said movable flat with respect to the partially reflective surface of said stationary flat a distance proportional to a dimension variation sensed by a change in the spread of said finger elements; and noting the number of spaces a particular fringe line seen above said stationary optical flat laterally shifts in response to said dimensional variation to determine the relative quantity of said dimensional variation.
Claim 3
Dependent Claim
170 words
Apparatus for measuring dimensional variations between oppositely facing surfaces, said apparatus comprising: resilientLy biased finger means for bearing respectively against said oppositely facing surfaces; stationary optical flat means having a partially light-reflective surface; movable optical flat means having a partially light-reflective surface disposed adjacent to and substantially parallel with said stationary flat means, said movable flat means having freedom of movement with respect to the light-reflective surface of said stationary flat means; light source means of substantially monochromatic wavelength propagation for emitting light waves to pass through said moving and stationary flat means, at least a portion of said light waves reflecting from each of said partially reflecting surfaces to form fringe lines; and linkage means interconnecting said finger elements and said movable flat means whereby dimensional variations between said oppositely facing surfaces which cause a change in the span between said finger elements are transmitted to said movable flat means to change the spacing between said light-reflective surfaces proportionately, thereby causing a relative lateral shift of respective fringe lines.
Claim 4
Dependent Claim
170 words
Apparatus for measuring dimensional variations between oppositely facing surfaces, said apparatus comprising: resilientLy biased finger means for bearing respectively against said oppositely facing surfaces; stationary optical flat means having a partially light-reflective surface; movable optical flat means having a partially light-reflective surface disposed adjacent to and substantially parallel with said stationary flat means, said movable flat means having freedom of movement with respect to the light-reflective surface of said stationary flat means; light source means of substantially monochromatic wavelength propagation for emitting light waves to pass through said moving and stationary flat means, at least a portion of said light waves reflecting from each of said partially reflecting surfaces to form fringe lines; and linkage means interconnecting said finger elements and said movable flat means whereby dimensional variations between said oppositely facing surfaces which cause a change in the span between said finger elements are transmitted to said movable flat means to change the spacing between said light-reflective surfaces proportionately, thereby causing a relative lateral shift of respective fringe lines.
Claim 5
Dependent Claim
50 words
Apparatus as described by claim 2 wherein the edge of the surface of said moving optical flat nearest to said stationary optical flat is slightly turned, thereby causing said fringes to appear, as viewed through said stationary flat, with ends turned in the direction of greatest proximity between said flats.
Claim 6
Dependent Claim
53 words
Apparatus as described in claim 2 having caging means to securely position said moving flat until said finger means are properly positioned between said oppositely facing surfaces, and slip joint means in said linkage means to allow said finger means movement independent of said moving flat means while said caging means is engaged.
Claim 7
Dependent Claim
23 words
Apparatus as described by claim 4 having timing means to disengage said caging means after the elapse of a predetermined period of time.
Claim 8
Dependent Claim
18 words
Apparatus as described by claim 5 wherein said timing means is spring-biased dashpot means having variable orifice means.
Claim 9
Dependent Claim
39 words
Apparatus as described by claim 4 having slip joint biasing means between said caging means and said linkage means to urge said moving flat means away from said caged position when said caging means disengages said moving flat means.
Claim 10
Dependent Claim
15 words
Apparatus as described by claim 2 having light source means of more than one wavelength.
Claim 11
Dependent Claim
26 words
Apparatus as described by claim 2 having recording means integral therewith for recording the position of a particular fringe line at some particular instant of time.
Claim 12
Dependent Claim
19 words
Apparatus as described by claim 9 wherein said recording means is photographic means having means for periodic film advance.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-03 | 1974-11-02 | 1975-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-03 | 1978-11-02 | 1979-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-03 | 1982-11-02 | 1983-05-04 | $7700.00 | Window Closed / Lapsed |