US 4,428,841 AGranted

Offshore pollution prevention

AssigneeEngineering Specialties, Inc.

InventorUncas B. Favret, Jr.

Life of this patent

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Abstract

A complete system for removing oil from produced water and deck drain fluids in an offshore facility includes a surge settler which receives the produced water from a three-phase separator. In the surge settler, the produced water flows crosswise through a corrugated plate assembly to separate free oil and solids from the produced water. A portion of the produced water which is relatively free of solid particles (less than 50 microns) is then treated in a water washer with a portion which is relatively rich in solid particles further treated in a solids cleaner. In the water washer 90% or more oil droplets (less than 50 microns) is removed from the produced water and the relatively oil free water is then disposed by way of a skim pile. A portion of fluid from the water washer is further treated in a high efficiency skimmer. In the solids cleaner a conical corrugated plate arrangement having periodic agitation by sand cleaning eductors removes free oil from the solids rich portion of the fluid which is relatively rich in solid particles and passes a relatively oil free and solids rich portion to a skim pile for disposal. Drained fluids from exposed decks and elsewhere are supplied directly to the skim pile for oil removal prior to passage into the surrounding body of water.

Claims26

Dependent claims

A surge settler for removing solid particles of about 50 microns or more and free oil droplets of about 50 microns or more from a fluid, comprising:

a surge settler vessel having a first partition defining an entrance chamber and a second partition defining an exit chamber and said first and second partitions together defining an intermediate chamber;
inlet means for supplying said fluid to the entrance chamber;
first passageway means for conducting said fluid from the entrance chamber to said intermediate chamber;
means for treating said fluid within the intermediate chamber including a plurality of corrugated plates each arranged generally parallel to one another and generally equally spaced from adjacent corrugated plates oriented at an angle of about 60.degree. with respect to the horizontal, each of said corrugated plates being generally planar having first and second generally linear side edges and first and second saw toothed end edges, the first side edges of said plurality of corrugated plates defining a first side of said means for treating said fluid with the second side edges of said plurality of corrugated edges defining a second side of said means for treating said fluid, said plurality of corrugated plates being generally rectangular;
means for withdrawing oil above said means for treating, said oil being released from said fluid while passing through said means for treating;
means for withdrawing gas above said means for treating, said gas being released from said fluid while passing through said means for treating;
means for withdrawing solid particles beneath said means for treating, said solid particles being released from said fluid while passing through said means for treating;
second passageway means for conducting said fluid from the second side of said means for treating to the exit chamber;
said first passageway means including first guide means for supplying said fluid generally evenly about said first side, said second passageway means including second guide means for withdrawing said fluid generally evenly about said second side, said first and second guide means each being comprised of a plurality of parallel guide plates generally equally spaced with respect to one another;
outlet means for withdrawing said fluid from the exit chamber.

7 more elements

An arrangement for separating and cleaning solid particles from a fluid, comprising:

a surge settler vessel having inlet means for admitting said fluid and outlet means for withdrawing said fluid;
a plurality of corrugated plates arranged within said surge settler vessel, each of said corrugated plates being generally parallel to one another and generally equally spaced with respect to one another, each of said plates being oriented at about 60.degree. with respect to the horizontal with said fluid arranged to flow crosswise through said plurality of corrugated plates;
first means for removing free oil and gas from above said plurality of corrugated plates;
a solids cleaner vessel vertically beneath said surge settler vessel;
conduit means for supplying said solid particles from said surge settler vessel generally downwardly to said solids cleaner vessel;
means for cleaning said solid particles within said solids cleaner vessel including a plurality of generally conical corrugated plates arranged generally about a common vertical axis and generally equally spaced from one another, said plurality of generally conical corrugated plates defining a central inlet passageway for said fluid about said common vertical axis, each of said generally conical corrugated plates extending upwardly at an angle of about 60.degree. with respect to the horizontal,
said conical corrugated plates defining passageway means for said solid particles wherein said solid particles first flow upwardly between said conical corrugated plates and then flow downwardly along channels of said conical corrugated plates after said solid particles separate from said fluid;
second means for removing free oil and gas from above said plurality of generally conical corrugated plates;
and
second means spaced from said conical corrugated plates for removing solid particles from beneath said plurality of generally conical corrugated plates.

7 more elements

Apparatus for cleaning a fluid, especially produced water and collected deckdrainage on an offshore facility for oil or gas production, comprising:

surge settler means for separating the fluid into a first portion which is relatively free of solid particles and a second portion which is relatively rich in solid particles;
water washer means for removing oil from the first portion, said water washer means being operable to separate the second portion into a third portion which is relatively free of both oil and solid particles, and a fourth portion which is relatively rich in oil;
solids cleaner means for removing oil from the second portion, said solids cleaner means being operable to separate said second portion into a fifth portion which is relatively rich in solid particles and free of oil and a sixth portion which is relatively free of solid particles;
high efficiency skimmer means for further removing oil from the fourth and sixth portions, said high efficiency skimmer means being operable to supply said cleaned fourth and sixth portions as a seventh portion which is relatively free of both solid particles and oil;
skim pile means for still further removing oil from the third, fifth and seventh portions, said skim pile means being operable to supply an eighth portion which is rich in oil to said high efficiency skimmer for further oil removal thereby;
and
conduit means for supplying fluid directly to the skim pile means for oil removal.

4 more elements

A method for treating a fluid, especially produced water from a three phase separator in an offshore oil or gas production facility, comprising the steps of:

flowing said fluid crosswise through a passageway having a corrugated configuration, said crosswise flow of said fluid urging oil and gas to separate from the fluid and flow upwardly along peaks of the passageway, said crosswise flow of said fluid also urging solid particles to separate from the fluid and flow downwardly along valleys of the passageway, said peaks and valleys being oriented at about 60.degree. with respect to the horizontal;
periodically removing free oil from above the passageway;
periodically removing solid particles from beneath the passageway;
and
periodically removing relatively clean water from the passageway.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/237,976Filed 25 Feb 1981 · continuation in part
Priority: 27 Jan 1981
Granted: 31 Jan 1984
Term ends: Not estimatedThe source records don’t support an estimate.

Classification18 codes

B01D 21/2488
Feed or discharge mechanisms for settling tanks: bringing about a partial recirculation of the liquid, e.g. for introducing chemical aids
B01D 17/00
Separation of liquids, not provided for elsewhere
B01D 17/0208
Separation of non-miscible liquids: by sedimentation
B01D 17/0211
By sedimentation: with baffles