US4035289A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purifying treatment for effluents of mineral oil drillings
Assignee: Societe Nationale Elf Aquitaine Production SA
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Filing: 1975-11-25
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Granted: 1977-07-12
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Expires: 1995-11-25
Abstract
Abstract Purification of the effluents from mineral oil drillings, carried out on land, for permitting the discharge of the residual waters into the natural surroundings. First, microorganisms are cultivated on a volume of the effluent, in order to make them capable of digesting the impurities of the effluent. The culture, thus obtained, is then developed in the mass of the effluent to be treated until the BOD is reduced to the required limit. This treatment is preferably followed by a flocculation with chemical agents in the known manner. This anti-pollution treatment permits the regulations in force to be applied in all locations where the drillings are undertaken, whatever may be the auxiliary fluids used in the drilling operation.
Inventors
- 👤 Michel Guillerme
- 👤 Jaime Gratacos
- 👤 Andre Sirvins
- 👤 Bernard Tramier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:57
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/34; C02F3/344; C02F1/00; C02F1/52; C02F1/5236; C02F3/02; E; E21; E21B; E21B41/00; E21B41/005; Y; Y02; Y02W; Y02W10/00; Y02W10/10; Y02W10/40
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
177 words
A method of purifying effluent from oil well drilling in order to degrade polysaccharide and lignosulfonates drilling adjuvants contained therein which comprises: (a) acidifying said effluent to precipitate clay contained therein; (b) separating the precipitate thus formed; (c) bringing the liquid separated from the clay to about neutral pH; (d) mixing said neutralized liquid with a bacterial culture obtained by aerobic growth of sewage or soil bacteria in an aqueous medium which contains oil well drilling additive and nutrient substances bearing only nitrogen and phosphorus exclusive of carbon; (e) adding additional nitrogen and phosphorus bearing nutrient substances necessary for bacterial growth to said mixture and allowing the resulting mixture to stand in aerobic condition until the bacteria have substantially grown and until the biochemical oxygen demand of the mixture is decreased to below a predetermined limit; (f) separating the purified liquid produced in (e) from the mixture, and recovering a fraction of the remaining bacteria mycelium; and (g) mixing the purified liquid separated in step (f) with conventional chemical flocculating agents and separating the precipitate formed thereby.
Claim 2
Independent Claim
177 words
A method of purifying effluent from oil well drilling in order to degrade polysaccharide and lignosulfonates drilling adjuvants contained therein which comprises: (a) acidifying said effluent to precipitate clay contained therein; (b) separating the precipitate thus formed; (c) bringing the liquid separated from the clay to about neutral pH; (d) mixing said neutralized liquid with a bacterial culture obtained by aerobic growth of sewage or soil bacteria in an aqueous medium which contains oil well drilling additive and nutrient substances bearing only nitrogen and phosphorus exclusive of carbon; (e) adding additional nitrogen and phosphorus bearing nutrient substances necessary for bacterial growth to said mixture and allowing the resulting mixture to stand in aerobic condition until the bacteria have substantially grown and until the biochemical oxygen demand of the mixture is decreased to below a predetermined limit; (f) separating the purified liquid produced in (e) from the mixture, and recovering a fraction of the remaining bacteria mycelium; and (g) mixing the purified liquid separated in step (f) with conventional chemical flocculating agents and separating the precipitate formed thereby.
Claim 3
Dependent Claim
29 words
Method according to claim 1, wherein the growth of the bacteria (e) is allowed to continue until the biochemical oxygen demand of the liquid does not exceed 40 mg/l.
Claim 4
Dependent Claim
24 words
Method according to claim 1, wherein the growth of the bacteria (e) is allowed to proceed for 5 to 10 hours at ambient temperature.
Claim 5
Dependent Claim
41 words
Method according to claim 1, in which the acidifying (a) is carried out to bring the pH of the effluent to a value of about 5, while in the subsequent neutralization (c) the pH is adjusted to about 6 to 8.
Claim 6
Dependent Claim
48 words
Method according to claim 1, in which the nutrient substances, added to the liquid of said bacterial culture, are mixed in an amount such that there be about 5 mg of nitrogen and about 1 mg of phosphorus added per liter, per 100 mg/l of biochemical oxygen demand.
Claim 7
Dependent Claim
30 words
Method according to claim 5, in which 40 to 60% of the nitrogen of the nutrient substance added is in nitric form and respectively 60 to 40% in ammonia form.
Claim 8
Dependent Claim
40 words
A method according to claim 1, in which said flocculating agents are a ferric salt or an aluminum salt, and chalk, and are employed in an amount sufficient to bring the biochemical oxygen demand to a value below 20 mg./l.
References Cited (Backward Citations)
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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) | 1980-07-11 | 1981-01-10 | 1981-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-11 | 1985-01-10 | 1985-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-11 | 1989-01-10 | 1989-07-12 | $7700.00 | Window Closed / Lapsed |