US4312052A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for identifying weak sands
Assignee: Shell USA Inc
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Filing: 1980-04-21
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Granted: 1982-01-19
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Expires: 2000-04-21
Abstract
Abstract A method and apparatus for obtaining improved measurements of shear waves in low-velocity lossy formations surrounding a borehole. The method comprises forming an interface between the borehole wall and a solid homogeneous material having a lower velocity than the formation. The geometry and velocity of the homogeneous material provide enhancement of the shear waves at the interface and thereby minimize the effect of interference from undesired compressional waves. Further improvement is obtained by using shear waves whose particles move perpendicular to the travel of the wave, parallel to the plane of the waves and perpendicular to the surface of the material. These are commonly referred to as SV shear waves.
Inventors
- 👤 Charles B. Vogel
- 👤 Robert A. Herolz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:14
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/40; G01V1/52; G01V1/02; G01V1/04; G01V1/047; G01V1/053; Y; Y10; Y10S; Y10S181/00; Y10S181/40; Y10S181/401; Y10S367/00; Y10S367/911; Y10S367/912
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
109 words
An apparatus for measuring characteristics of SV shear waves in an earth material comprising: a pair of prisms formed of a low shear velocity material, said prisms being disposed on a flat surface of said earth material in spaced positions; a transducer mounted on each prism, one of said transducers being mounted to produce SV shear waves in one of said prisms and the other transducer being mounted to receive the SV shear waves; filter means coupled to said other transducer to reject low frequency noise and high frequency compressional waves; and recording means coupled to said filter to record the SV shear waves received by said other transducer.
Claim 2
Independent Claim
109 words
An apparatus for measuring characteristics of SV shear waves in an earth material comprising: a pair of prisms formed of a low shear velocity material, said prisms being disposed on a flat surface of said earth material in spaced positions; a transducer mounted on each prism, one of said transducers being mounted to produce SV shear waves in one of said prisms and the other transducer being mounted to receive the SV shear waves; filter means coupled to said other transducer to reject low frequency noise and high frequency compressional waves; and recording means coupled to said filter to record the SV shear waves received by said other transducer.
Claim 3
Dependent Claim
17 words
The apparatus of claim 1 wherein said prisms form approximately a 45° angle with said flat surface.
Claim 4
Dependent Claim
27 words
The apparatus of claim 1 or 2 wherein the shear velocity of said prisms is approximately equal to or less than the velocity of the earth material.
Claim 5
Dependent Claim
14 words
The apparatus of claim 1 wherein an acoustic absorber is disposed between said prisms.
Claim 6
Dependent Claim
22 words
The apparatus of claim 1 wherein said filter passes a band of frequencies between 2000 and 25000 Hz and rejects other frequencies.
Claim 7
Dependent Claim
144 words
A logging tool sonde having a plurality of flexible elongated arms extending along the axis of said sonde and means for extending and retracting said arms, said sonde in addition having: a plurality of prisms formed of a low shear velocity material, a pair of said prisms being mounted on each of said arms for movement into contact with the earth when said arms are extended; a transducer mounted on each of said prisms, one of said transducers being mounted to produce SV shear waves in one prism of each pair, another of said transducers being mounted on the other prism of each pair to receive SV shear waves; filter means coupled to said other transducer to reject low frequency noise and high frequency compressional waves; and, recording means coupled to said filter to record the SV shear waves received by said other transducer.
Claim 8
Dependent Claim
144 words
A logging tool sonde having a plurality of flexible elongated arms extending along the axis of said sonde and means for extending and retracting said arms, said sonde in addition having: a plurality of prisms formed of a low shear velocity material, a pair of said prisms being mounted on each of said arms for movement into contact with the earth when said arms are extended; a transducer mounted on each of said prisms, one of said transducers being mounted to produce SV shear waves in one prism of each pair, another of said transducers being mounted on the other prism of each pair to receive SV shear waves; filter means coupled to said other transducer to reject low frequency noise and high frequency compressional waves; and, recording means coupled to said filter to record the SV shear waves received by said other transducer.
Claim 9
Dependent Claim
44 words
The logging tool sonde of claim 6 wherein said prisms are triangular prisms that are oriented to form approximately a 45° angle with the wall of the borehole in which sonde is lowered when said arms are extended and the prisms contact the wall.
Claim 10
Dependent Claim
21 words
The logging tool sonde of claims 6 or 7 and in addition an acoustic absorber disposed between each pair of prisms.
Claim 11
Dependent Claim
36 words
The logging tool sonde of claim 7 wherein said transducers are flat transducers having their flat surface in contact with a surface of the prism whereby they produce and receive SV shear waves in said prisms.
References Cited (Backward Citations)
US2525861A
Cited
US2784325A
Cited
US2943694A
Cited
US3775739A
Cited
US3949352A
Cited
US3542150A
Cited
US3720098A
Cited
US3883841A
Cited
US3973152A
Cited
FR2321709A1
Cited
SU681401A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-01-18 | 1985-07-20 | 1986-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-18 | 1989-07-20 | 1990-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-18 | 1993-07-20 | 1994-01-19 | $7700.00 | Window Closed / Lapsed |