US4551154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas tracer composition and method
Assignee: COLUMBIA GAS SERVICE Corp A CORP OF OH
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Filing: 1983-03-02
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Granted: 1985-11-05
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Expires: 2003-03-02
Abstract
Abstract The invention provides a method for tagging methane by adding thereto one or more of the tracer compounds sulfur hexafluoride and chloropentafluoroethane. The methane being tagged is noramlly being stored in underground storage fields to provide identity and proof of ownership of the gas. The two tracer compounds are readily detectable at very low concentrations by electron capture gas chromatography apparatus which can be made portable and thus suitable for use in the field.
Inventors
- 👤 Norman D. Malcosky
- 👤 Greg Koziar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:58
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/22; G01N33/225; Y; Y10; Y10T; Y10T436/00; Y10T436/13
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
115 words
A method for tagging methane during underground storage of methane, said method comprising adding to said methane a tracer compound, said tracer compound having the properties of (1) not occurring in natural supplies of methane, (2) diffusing through any underground methane storage field in a manner very similar to methane, and (3) substantially insoluble in petroleum distillates, said compound being selected from the group consisting of sulfur hexafluoride and chloropentafluoroethane, and thereafter passing said methane in gaseous form into an underground gas storage field having petroleum distillates therein, the amount of tracer compound passage into the field being great enough that said tracer may be detected after said tracer is uniformly disbursed throughout the field.
Claim 2
Independent Claim
115 words
A method for tagging methane during underground storage of methane, said method comprising adding to said methane a tracer compound, said tracer compound having the properties of (1) not occurring in natural supplies of methane, (2) diffusing through any underground methane storage field in a manner very similar to methane, and (3) substantially insoluble in petroleum distillates, said compound being selected from the group consisting of sulfur hexafluoride and chloropentafluoroethane, and thereafter passing said methane in gaseous form into an underground gas storage field having petroleum distillates therein, the amount of tracer compound passage into the field being great enough that said tracer may be detected after said tracer is uniformly disbursed throughout the field.
Claim 3
Dependent Claim
13 words
A method according to claim 1 wherein said tracer compound is sulfur hexafluoride.
Claim 4
Dependent Claim
29 words
A method according to claim 2 wherein said sulfur hexafluoride is added to said methane in the form of a liquid solution of sulfur hexafluoride in a liquid solvent.
Claim 5
Dependent Claim
11 words
A method according to claim 3 wherein said solvent is methanol.
Claim 6
Dependent Claim
12 words
A method according to claim 3 wherein said solvent is carbon dioxide.
Claim 7
Dependent Claim
28 words
A method according to claim 2 wherein sulfur hexafluoride is added to said methane in the form of a gaseous mixture comprising sulfur hexafluoride and a carrier gas.
Claim 8
Dependent Claim
12 words
A method according to claim 6 wherein said carrier gas is nitrogen.
Claim 9
Dependent Claim
39 words
A method according to claim 2 wherein said sulfur hexafluoride is added to said methane in an amount not exceeding about 5 parts per billion by volume, when said methane and said sulfur hexafluoride are both in gaseous form.
Claim 10
Dependent Claim
13 words
A method according to claim 1 wherein said methane is in gaseous form.
Claim 11
Dependent Claim
41 words
A method according to claim 1 wherein said tracer compound is chloropentafluoroethane and is added to said methane in an amount not exceeding about 20 parts per million by volume, when said methane and said chloropentafluoroethane are both in gaseous form.
Claim 12
Dependent Claim
30 words
A method according to claim 1, further comprising recovering a sample of gas from said underground gas storage field, and testing said sample for the presence of said tracer compound.
Claim 13
Dependent Claim
20 words
A method according to claim 11 wherein said testing for said tracer compound is effected by electron capture gas chromatography.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-11-04 | 1989-05-06 | 1989-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-04 | 1993-05-06 | 1993-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-04 | 1997-05-06 | 1997-11-05 | $7700.00 | Window Closed / Lapsed |