CA2254490A1 - Method and apparatus for investigating earth formations - Google Patents
Method and apparatus for investigating earth formationsInfo
- Publication number
- CA2254490A1 CA2254490A1 CA 2254490 CA2254490A CA2254490A1 CA 2254490 A1 CA2254490 A1 CA 2254490A1 CA 2254490 CA2254490 CA 2254490 CA 2254490 A CA2254490 A CA 2254490A CA 2254490 A1 CA2254490 A1 CA 2254490A1
- Authority
- CA
- Canada
- Prior art keywords
- current
- formations
- signal
- monitor
- electrode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000015572 biosynthetic process Effects 0.000 title abstract 6
- 238000005755 formation reaction Methods 0.000 title abstract 6
- 238000000034 method Methods 0.000 title abstract 2
- 239000002184 metal Substances 0.000 abstract 1
Landscapes
- Geophysics And Detection Of Objects (AREA)
Abstract
Apparatus and method are disclosed for determining the resistivity of formations surrounding an earth borehole.
An electrically conductive metal body, such as a drill collar on a drill string, is movable through the borehole. A
transmitting toroidal coil antenna is disposed on the body and is energized to induce a current which travels in a path that includes the body and the formations. An electrode is disposed on the body, and a first signal which depends on the electrical effect of the current on the electrode is measured to obtain an indication of the resistivity of the formations.
In a form of the invention, a second transmitting toroidal coil antenna establishes a second current in the body that travels in a path that includes the body and the formations, and a second signal is measured at the electrode. A current monitor measures the axial current passing a monitor position on the body, to obtain a monitor current value. A compensated indication of formation resistivity can then be obtained as a function of the first signal, the second signal, and the monitor current value. A local communication system facilitates the ultimate communication of information to the earth's surface.
An electrically conductive metal body, such as a drill collar on a drill string, is movable through the borehole. A
transmitting toroidal coil antenna is disposed on the body and is energized to induce a current which travels in a path that includes the body and the formations. An electrode is disposed on the body, and a first signal which depends on the electrical effect of the current on the electrode is measured to obtain an indication of the resistivity of the formations.
In a form of the invention, a second transmitting toroidal coil antenna establishes a second current in the body that travels in a path that includes the body and the formations, and a second signal is measured at the electrode. A current monitor measures the axial current passing a monitor position on the body, to obtain a monitor current value. A compensated indication of formation resistivity can then be obtained as a function of the first signal, the second signal, and the monitor current value. A local communication system facilitates the ultimate communication of information to the earth's surface.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/786,137 US5235285A (en) | 1991-10-31 | 1991-10-31 | Well logging apparatus having toroidal induction antenna for measuring, while drilling, resistivity of earth formations |
US786,137 | 1991-10-31 | ||
US07/955,101 US5339037A (en) | 1992-10-09 | 1992-10-09 | Apparatus and method for determining the resistivity of earth formations |
US955,101 | 1992-10-09 | ||
CA 2081790 CA2081790C (en) | 1991-10-31 | 1992-10-30 | Method and apparatus for investigating earth formations |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA 2081790 Division CA2081790C (en) | 1991-10-31 | 1992-10-30 | Method and apparatus for investigating earth formations |
Publications (2)
Publication Number | Publication Date |
---|---|
CA2254490A1 true CA2254490A1 (en) | 1993-05-01 |
CA2254490C CA2254490C (en) | 1999-08-24 |
Family
ID=27169230
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002254490A Expired - Lifetime CA2254490C (en) | 1991-10-31 | 1992-10-30 | Method and apparatus for investigating earth formations |
Country Status (1)
Country | Link |
---|---|
CA (1) | CA2254490C (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10982529B2 (en) | 2017-01-31 | 2021-04-20 | Halliburton Energy Services, Inc. | Incorporating mandrel current measurements in electromagnetic ranging inversion |
-
1992
- 1992-10-30 CA CA002254490A patent/CA2254490C/en not_active Expired - Lifetime
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10982529B2 (en) | 2017-01-31 | 2021-04-20 | Halliburton Energy Services, Inc. | Incorporating mandrel current measurements in electromagnetic ranging inversion |
Also Published As
Publication number | Publication date |
---|---|
CA2254490C (en) | 1999-08-24 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
MKEX | Expiry |