Determining resistivity of a formation adjacent to a borehole having casing using multiple electrodes and with resistances being defined between the electrodes
Methods of operation are disclosed for different types of multiple electrode apparatus vertically disposed in a cased well to measure information related to the resistivity of adjacent geological formations from inside the cased well. The multiple electrode apparatus have a minimum of three spaced-apart voltage measurement electrodes that electrically engage the interior of the cased well. Measurement information is obtained related to current which is caused to flow from the cased well into the adjacent geological formation. First compensation information is obtained related to a first casing resistance between a first pair of the spaced-apart voltage measurement electrodes. Second compensation information is obtained related to a second casing resistance between a second pair of the spaced-apart voltage measurement electrodes. The measurement information, and first and second compensation information are used to determine a magnitude related to the adjacent formation resistivity. 13 figs.
- Research Organization:
- Paramagnetic Logging Inc
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG06-84ER13294; FG22-88BC14243; FG22-90BC14617; FG22-93BC14966
- Assignee:
- Paramagnetic Logging, Inc., Woodinville, WA (United States)
- Patent Number(s):
- US 5,570,024/A/
- Application Number:
- PAN: 8-083,615; CNN: Contract GRI 5088-212-1664
- OSTI ID:
- 392633
- Resource Relation:
- Other Information: PBD: 29 Oct 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Determining resistivity of a formation adjacent to a borehole having casing by generating constant current flow in portion of casing and using at least two voltage measurement electrodes
Determining resistivity of a formation adjacent to a borehole having casing by generating constant current flow in portion of casing and using at least two voltage measurement electrodes