US4008775A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of using a porous Fe3 O4 drilling mud additive
Assignee: Ironite Products Co
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Filing: 1976-03-12
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Granted: 1977-02-22
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Expires: 1996-03-12
Abstract
Abstract An iron oxide having the ideal composition Fe 3 O 4 has a unique high porosity, substantially spherical particle structure. Used in oil and gas well drilling muds, it scavenges hydrogen sulfide. It also improves the rheological properties of the mud, maintains its stability under high temperatures, and functions as a mud weighting material. Upon completion of drilling, the drilling mud containing the porous Fe 3 O 4 additive may be left in place between the inner casing and the formation wall or the outer casing as a packer fluid.
Inventors
- 👤 Irwin Fox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:15
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/54; C01; C01G; C01G49/00; C01G49/02; C01G49/08; C01G49/12; C09K8/02; E; E21; E21B; E21B41/00; E21B41/02; C01P; C01P2004/00; C01P2004/30; C01P2004/32; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/12; Y; Y10; Y10S; Y10S166/00; Y10S166/902
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
148 words
A method of scavenging hydrogen sulfide from drilling mud, which comprises the following steps: a. adding to drilling mud porous iron oxide particles having an ideal composition of substantially Fe 3 O 4 and having a surface area at least 10 times as great as magnetite particles of equal size, the greater part of which particles are no longer than 60 microns, in a quantity sufficient to react such hydrogen sulfide as may be encountered, b. circulating the drilling mud down the interior of the drill pipe, through the drill bit and up the annular space between the drill pipe and the formation wall to the surface, c. entraining in the circulating drilling mud such hydrogen sulfide as may be encountered, and d. reacting the entrained hydrogen sulfide with the said porous iron oxide particles under the pressure there present to form a stable pyrite FeS 2 .
Claim 2
Independent Claim
148 words
A method of scavenging hydrogen sulfide from drilling mud, which comprises the following steps: a. adding to drilling mud porous iron oxide particles having an ideal composition of substantially Fe 3 O 4 and having a surface area at least 10 times as great as magnetite particles of equal size, the greater part of which particles are no longer than 60 microns, in a quantity sufficient to react such hydrogen sulfide as may be encountered, b. circulating the drilling mud down the interior of the drill pipe, through the drill bit and up the annular space between the drill pipe and the formation wall to the surface, c. entraining in the circulating drilling mud such hydrogen sulfide as may be encountered, and d. reacting the entrained hydrogen sulfide with the said porous iron oxide particles under the pressure there present to form a stable pyrite FeS 2 .
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein at least 95% of said particles are no larger than 60 microns.
Claim 4
Dependent Claim
47 words
The method of claim 1, together with the additional steps of screening the circulated mud containing the FeS 2 so formed and thereby removing agglomerated particles thereof, re-circulating the mud, and adding to the mud so re-circulated additional said iron oxide to replace the amount so reacted.
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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) | 1980-02-22 | 1980-08-23 | 1981-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-22 | 1984-08-23 | 1985-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-22 | 1988-08-23 | 1989-02-22 | $7700.00 | Window Closed / Lapsed |