US4052662A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for investigating earth formations utilizing microwave electromagnetic energy
Assignee: Schlumberger Technology Corp
•
Filing: 1976-02-19
•
Granted: 1977-10-04
•
Expires: 1996-02-19
Abstract
Abstract A method and apparatus for investigating earth formations surrounding a borehole by injecting microwave electromagnetic energy into the formations and then taking measurements which relate to the propagation of such energy in the formations. In the preferred form of the invention, the injected microwave energy establishes a lateral wave which travels in the formations adjacent the interface between the mudcake and the formations. Energy signals from the lateral wave are received at first and second receiving locations. The phase difference between signals received at the first and second receiving locations is measured. Also measured is the relative attenuation as between signals received at the two receiving locations. The loss-corrected dielectric constant associated with the formations surrounding the area between the first and second receiving locations is then obtained by judiciously combining the phase and attenuation measurements.
Inventors
- 👤 Rama N. Rau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:49
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/18; G01V3/30
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
118 words
Apparatus for investigating earth formations surrounding a borehole comprising: a. a pad member adapted for engagement with the borehole wall; b. means for generating microwave electromagnetic energy; c. a transmitting antenna mounted on the wall-engaging face of said pad member for receiving said microwave electromagnetic energy and injecting said microwave electromagnetic energy into the surrounding formations; d. first and second receiving antennas mounted in spaced relation on the wall-engaging face of said pad member, said antennas being spaced apart by a distance of the order of 4 cm., for receiving the microwave energy from the surrounding formations; and e. means for detecting differences in the characteristics of the microwave energy received at said first and second receiving antennas.
Claim 2
Dependent Claim
118 words
Apparatus for investigating earth formations surrounding a borehole comprising: a. a pad member adapted for engagement with the borehole wall; b. means for generating microwave electromagnetic energy; c. a transmitting antenna mounted on the wall-engaging face of said pad member for receiving said microwave electromagnetic energy and injecting said microwave electromagnetic energy into the surrounding formations; d. first and second receiving antennas mounted in spaced relation on the wall-engaging face of said pad member, said antennas being spaced apart by a distance of the order of 4 cm., for receiving the microwave energy from the surrounding formations; and e. means for detecting differences in the characteristics of the microwave energy received at said first and second receiving antennas.
Claim 3
Dependent Claim
26 words
Apparatus as defined by claim 1 wherein said transmitting antenna is spaced from the closer receiving antenna by a distance of the order of 8 cm.
Claim 4
Dependent Claim
16 words
Apparatus as defined by claim 1 wherein said transmitting and receiving antennas are cavity-backed slot antennas.
Claim 5
Dependent Claim
23 words
Apparatus as defined by claim 3 wherein said microwave electromagnetic energy has a frequency within the range of 500 MHz. and 2.0 GHz.
Claim 6
Dependent Claim
18 words
Apparatus as defined by claim 3 wherein said microwave electromagnetic energy has a frequency of about 1.1 GHz.
Claim 7
Dependent Claim
120 words
Apparatus for investigating earth formations surrounding a borehole, comprising: a. a pad member adapted for engagement with the borehole wall; b. means for generating microwave electromagnetic energy; c. a transmitting cavity-backed slot antenna mounted on the wall-engaging face of said pad member for receiving said microwave electromagnetic energy and injecting said microwave electromagnetic energy into the surrounding formations to establish a lateral wave in the surrounding formations; d. first and second receiving cavity-backed slot antennas mounted in spaced relation on the wall-engaging face of said pad member for receiving the microwave energy from the lateral wave in the surrounding formations; and e. means for detecting differences in the characteristics of the microwave energy received at said first and second antennas.
Claim 8
Dependent Claim
120 words
Apparatus for investigating earth formations surrounding a borehole, comprising: a. a pad member adapted for engagement with the borehole wall; b. means for generating microwave electromagnetic energy; c. a transmitting cavity-backed slot antenna mounted on the wall-engaging face of said pad member for receiving said microwave electromagnetic energy and injecting said microwave electromagnetic energy into the surrounding formations to establish a lateral wave in the surrounding formations; d. first and second receiving cavity-backed slot antennas mounted in spaced relation on the wall-engaging face of said pad member for receiving the microwave energy from the lateral wave in the surrounding formations; and e. means for detecting differences in the characteristics of the microwave energy received at said first and second antennas.
Claim 9
Dependent Claim
17 words
Apparatus as defined by claim 6 wherein said cavity-backed slot antennas are filled with a dielectric material.
Claim 10
Dependent Claim
23 words
Apparatus as defined by claim 6 wherein said microwave electromagnetic energy has a frequency within the range of 500 MHz. and 2.0 GHz.
Claim 11
Dependent Claim
18 words
Apparatus as defined by claim 6 wherein said microwave electromagnetic energy has a frequency of about 1.1 GHz.
Claim 12
Dependent Claim
124 words
Apparatus for investigating earth formations surrounding a borehole comprising: a. a pad member adapted for engagement with the borehole wall; b. means for generating microwave electromagnetic energy; c. a transmitting antenna mounted on the wall-engaging face of said pad member for receiving said microwave electromagnetic energy and injecting said microwave electromagnetic energy into the surrounding formations; d. first and second receiving antennas mounted in spaced relation on the wall-engaging face of said pad member for receiving microwave energy from the surrounding formations, the receiving antenna closest said transmitting antenna being spaced from said transmitting antenna by a distance of the order of 8 cm. e. means for detecting differences in the characteristics of the microwave energy received at said first and second receiving antennas.
Claim 13
Dependent Claim
124 words
Apparatus for investigating earth formations surrounding a borehole comprising: a. a pad member adapted for engagement with the borehole wall; b. means for generating microwave electromagnetic energy; c. a transmitting antenna mounted on the wall-engaging face of said pad member for receiving said microwave electromagnetic energy and injecting said microwave electromagnetic energy into the surrounding formations; d. first and second receiving antennas mounted in spaced relation on the wall-engaging face of said pad member for receiving microwave energy from the surrounding formations, the receiving antenna closest said transmitting antenna being spaced from said transmitting antenna by a distance of the order of 8 cm. e. means for detecting differences in the characteristics of the microwave energy received at said first and second receiving antennas.
Claim 14
Dependent Claim
25 words
Apparatus as defined in claim 10 wherein said first and second receiving antennas are spaced apart by a distance of the order of 4 cm.
Claim 15
Dependent Claim
16 words
Apparatus as defined by claim 10 wherein said transmitting and receiving antennas are cavity-backed slot antennas.
Claim 16
Dependent Claim
23 words
Apparatus as defined by claim 12 wherein said microwave electromagnetic energy has a frequency within the range of 500 MHz. and 2.0 GHz.
Claim 17
Dependent Claim
18 words
Apparatus as defined by claim 12 wherein said microwave electromagnetic energy has a frequency of about 1.1 GHz.
References Cited (Backward Citations)
SU272450A1
Cited
US2139460A
Cited
US2334475A
Cited
US2455941A
Cited
US2963641A
Cited
US3114875A
Cited
US3398356A
Cited
US3391334A
Cited
US3551797A
Cited
US3412323A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |