US3617868A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resistivity cell including a grounded shield for liquid-solid mixtures
Assignee: Marathon Oil Co
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Filing: 1969-06-09
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Granted: 1971-11-02
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Expires: 1989-06-09
Abstract
Abstract The resistivity of drilling fluid components, e.g. mud solution, mud cake, and mud filtrate water, are determined using a pressurized and heat controlled cylindrical cell to simulate bore hole conditions. The cell has an upper mud receiving portion separated from a lower mud filtrate receiving portion by a porous partition upon which mud cake deposits. Three sets of electrodes, preferably the four electrode type, extend into each of the mud, mud cake, and mud filtrate receiving portions, so that upon application of current, across the two outer electrodes in each of the three systems and upon taking a voltage reading across the two inner electrodes of each of the three systems, the resistivity of the mud, mud cake, and mud filtrate, may be determined. Knowledge of these resistivity values is helpful in further determining subterranean formation parameters, such as fluid saturation, porosity, and permeability.
Inventors
- 👤 James E Beitel
- 👤 Eugene Allen Breitenbach
- 👤 Charles R Bruce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:36
CPC Classifications
E; E21; E21B; E21B49/00; E21B49/005; G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/06
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
22 words
filter means connected to the chamber for receiving the substantially solid component as a deposit on a first side of said filter
Claim 2
Dependent Claim
21 words
The apparatus of claim 1 wherein the liquid-solid mixture is well-drilling mud and where the substantially solid deposit is mud cake.
Claim 3
Dependent Claim
25 words
a lower chamber for receiving liquid filtrate and current and electrode means for determining the potential difference across electrodes penetrating the liquid in the chamber,
Claim 4
Dependent Claim
8 words
a lowest chamber portion for receiving liquid filtrate,
Claim 5
Dependent Claim
37 words
a middle chamber portion, having filter means for receiving the substantially solid component as a deposit on a first side of said filter means connecting and being in fluid communication with the upper and lower chamber portions,
Claim 6
Dependent Claim
28 words
filter means between the said upper and lower chambers for receiving the substantially solid component as a deposit and allowing liquid to flow through to the lower chamber,
Claim 7
Dependent Claim
34 words
The apparatus of claim 1 wherein the electrode means are comprised of four electrodes wherein current is induced across the outer two electrodes and the electric potential is measured across the inner two electrodes.
Claim 8
Dependent Claim
29 words
a plurality of electrodes located in said chamber on said first side of said filter in spaced relationship with said filter, said electrodes penetrating the substantially solid deposit, and
Claim 9
Dependent Claim
45 words
a grounded shield located in said chamber on said first side of said filter and spaced further from said filter than are said electrode means penetrating the solid deposit so as to maintain current substantially entirely within the solid deposit for accurate resistivity determination, and
Claim 10
Dependent Claim
24 words
The apparatus of claim 2 wherein external pressure and heat control means simulate well bore hole conditions from which the drilling mud is taken.
Claim 11
Dependent Claim
32 words
electrode means located in spaced relation to said filter means and located on the first side of said filter means for determining the potential difference across electrodes penetrating the substantially solid deposit,
Claim 12
Dependent Claim
12 words
means for controlling the temperature in the upper and middle chamber portions,
Claim 13
Dependent Claim
15 words
means for controlling the differential pressure across the substantially solid deposit within the middle chamber,
Claim 14
Dependent Claim
39 words
a grounded shield locateD on said first side of said filter means and spaced further from said filter means than are said electrode means, so as to maintain current substantially entirely within the solid deposit for accurate resistivity determinations.
Claim 15
Dependent Claim
19 words
A filter cell for determining the resistivity of at least one component of a liquid-solid mixture said cell comprising:
Claim 16
Dependent Claim
10 words
electrical means for determining the electrical potential between said electrodes.
Claim 17
Dependent Claim
33 words
The apparatus of claim 5 wherein all three sets of electrodes comprise four electrode systems wherein the outer electrodes are current carrying electrodes and the inner electrodes are used for potential difference measurement.
Claim 18
Dependent Claim
66 words
three sets of electrode means in spaced relation penetrating respectively, the mixtures in the upper chamber portion, the substantially solid deposit in the middle chamber portion, and the filtrate in the lowest chamber, each of said sets comprises inner and outer electrodes and wherein the outer electrodes in each chamber portion function as current carrying electrodes and the inner electrodes function as potential difference measuring electrodes,
Claim 19
Dependent Claim
30 words
measuring means for connection to said electrodes for determining the resistivity of each of the mixture, substantially solid deposit, and filtrate by relating measured potential difference and known current values,
Claim 20
Dependent Claim
20 words
The apparatus of claim 5 wherein the upper chamber and middle chamber are thermally controlled separately from the lowest chamber.
Claim 21
Dependent Claim
15 words
The apparatus of claim 5 wherein pressure is maintained and controlled by nitrogen compression means.
Claim 22
Dependent Claim
39 words
a grounded shield located on said first side of said filter means and spaced further from said filter means than are said electrode means, so as to maintain current substantially entirely within the solid deposit for accurate resistivity determinations.
Claim 23
Dependent Claim
22 words
The apparatus of claim 5 wherein the liquid solid mixture is well-drilling mud and where the substantially solid deposit is mud cake.
Claim 24
Dependent Claim
24 words
The apparatus of claim 5 wherein external pressure and heat control means simulate well bore hole conditions from which the drilling mud is taken.
Claim 25
Dependent Claim
37 words
A filter cell for determining the resistivity of at least one component of a liquid-solid mixture wherein the natural temperature and pressure conditions in which the mixture is found are simulated within the cell, said cell comprising:
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |