# Electrical resistance tomography using steel cased boreholes as electrodes

## Abstract

An electrical resistance tomography method is described which uses steel cased boreholes as electrodes. The method enables mapping the electrical resistivity distribution in the subsurface from measurements of electrical potential caused by electrical currents injected into an array of electrodes in the subsurface. By use of current injection and potential measurement electrodes to generate data about the subsurface resistivity distribution, which data is then used in an inverse calculation, a model of the electrical resistivity distribution can be obtained. The inverse model may be constrained by independent data to better define an inverse solution. The method utilizes pairs of electrically conductive (steel) borehole casings as current injection electrodes and as potential measurement electrodes. The greater the number of steel cased boreholes in an array, the greater the amount of data is obtained. The steel cased boreholes may be utilized for either current injection or potential measurement electrodes. The subsurface model produced by this method can be 2 or 3 dimensional in resistivity depending on the detail desired in the calculated resistivity distribution and the amount of data to constrain the models. 2 figs.

- Inventors:

- Issue Date:

- Sponsoring Org.:
- USDOE; USDOE, Washington, DC (United States)

- OSTI Identifier:
- 6158965

- Patent Number(s):
- 5914603 A

- Application Number:
- PPN: US 8-804163

- Assignee:
- Univ. of California, Oakland, CA (United States) PTO; EDB-99-081348

- DOE Contract Number:
- W-7405-ENG-48

- Resource Type:
- Patent

- Resource Relation:
- Patent File Date: 20 Feb 1997

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 47 OTHER INSTRUMENTATION; DATA ANALYSIS; ELECTRODES; EXPLORATION; MATHEMATICAL MODELS; RESISTIVITY SURVEYS; WELL CASINGS; ELECTRICAL SURVEYS; GEOPHYSICAL SURVEYS; 440400* - Well Logging Instrumentation

### Citation Formats

```
Daily, W.D., and Ramirez, A.L.
```*Electrical resistance tomography using steel cased boreholes as electrodes*. United States: N. p., 1999.
Web.

```
Daily, W.D., & Ramirez, A.L.
```*Electrical resistance tomography using steel cased boreholes as electrodes*. United States.

```
Daily, W.D., and Ramirez, A.L. Tue .
"Electrical resistance tomography using steel cased boreholes as electrodes". United States.
```

```
@article{osti_6158965,
```

title = {Electrical resistance tomography using steel cased boreholes as electrodes},

author = {Daily, W.D. and Ramirez, A.L.},

abstractNote = {An electrical resistance tomography method is described which uses steel cased boreholes as electrodes. The method enables mapping the electrical resistivity distribution in the subsurface from measurements of electrical potential caused by electrical currents injected into an array of electrodes in the subsurface. By use of current injection and potential measurement electrodes to generate data about the subsurface resistivity distribution, which data is then used in an inverse calculation, a model of the electrical resistivity distribution can be obtained. The inverse model may be constrained by independent data to better define an inverse solution. The method utilizes pairs of electrically conductive (steel) borehole casings as current injection electrodes and as potential measurement electrodes. The greater the number of steel cased boreholes in an array, the greater the amount of data is obtained. The steel cased boreholes may be utilized for either current injection or potential measurement electrodes. The subsurface model produced by this method can be 2 or 3 dimensional in resistivity depending on the detail desired in the calculated resistivity distribution and the amount of data to constrain the models. 2 figs.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {1999},

month = {6}

}