US3825752A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Log-injected-log system
Assignee: BP America Production Co
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Filing: 1973-08-09
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Granted: 1974-07-23
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Expires: 1993-08-09
Abstract
Abstract This invention relates to determining the oil saturation in the underground rock reservoir by use of a log-inject-log technique. The formation rock adjacent the well bore is prepared such that the saturation conditions there are representative of those in the interwell area. A thermal decay time log is then run. A chlorinated hydrocarbon oil mixture or blend miscible with the formation oil and having a chlorine content about the same as the formation water is used to displace all the formation oil from adjacent the well bore. A second thermal neutron decay time log is then run. These two logs are then used to determine reservoir characteristics.
Inventors
- 👤 R Murphy
- 👤 H Froning
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:28
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/04; G01V5/08; G01V5/10; G01V5/107
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
94 words
A method of logging a subsurface zone containing formation oil and formation water penetrated by a wellbore which comprises the steps of: a. injecting a driving fluid containing hydrocarbon which is miscible with the formation oil into the zone to displace the formation oil from the vicinity of the wellbore, and which driving fluid has essentially the same neutron capture cross section as that of the formation water, b. then running a thermal neutron decay time log immediately following Step (a), and then using the logs obtained in Step (b) to determine reservoir characteristics.
Claim 2
Independent Claim
94 words
A method of logging a subsurface zone containing formation oil and formation water penetrated by a wellbore which comprises the steps of: a. injecting a driving fluid containing hydrocarbon which is miscible with the formation oil into the zone to displace the formation oil from the vicinity of the wellbore, and which driving fluid has essentially the same neutron capture cross section as that of the formation water, b. then running a thermal neutron decay time log immediately following Step (a), and then using the logs obtained in Step (b) to determine reservoir characteristics.
Claim 3
Dependent Claim
16 words
A method as defined in claim 1 in which the driving fluid is 1, 2 dichloroethane.
Claim 4
Dependent Claim
14 words
A method as defined in claim 1 in which the driving fluid includes chloroform.
Claim 5
Dependent Claim
53 words
A method as defined in claim 1 which includes prior to Step (a): conditioning of the well so that the fluid content in the zone adjacent the wellbore is approximately the same as that present in the zone remote from the wellbore, and running a thermal neutron decay time log before Step (a).
Claim 6
Independent Claim
84 words
The method of logging a subsurface zone containing formation oil and formation water penetrated by a wellbore which comprises the steps of: a. injecting chLorinated hydrocarbon as a driving fluid to displace the formation oil from the vicinity of the wellbore, such chlorinated hydrocarbon having essentially the same neutron capture cross section as that of the formation water, b. then running a thermal neutron decay time log immediately following Step (a), and then using the log obtained in Step (b) to determine reservoir characteristics.
Claim 7
Independent Claim
84 words
The method of logging a subsurface zone containing formation oil and formation water penetrated by a wellbore which comprises the steps of: a. injecting chLorinated hydrocarbon as a driving fluid to displace the formation oil from the vicinity of the wellbore, such chlorinated hydrocarbon having essentially the same neutron capture cross section as that of the formation water, b. then running a thermal neutron decay time log immediately following Step (a), and then using the log obtained in Step (b) to determine reservoir characteristics.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |