WO2008094047A1 - Emulsion removal - Google Patents

Emulsion removal Download PDF

Info

Publication number
WO2008094047A1
WO2008094047A1 PCT/NO2008/000029 NO2008000029W WO2008094047A1 WO 2008094047 A1 WO2008094047 A1 WO 2008094047A1 NO 2008000029 W NO2008000029 W NO 2008000029W WO 2008094047 A1 WO2008094047 A1 WO 2008094047A1
Authority
WO
WIPO (PCT)
Prior art keywords
oil
storage cell
water
hot water
pollution
Prior art date
Application number
PCT/NO2008/000029
Other languages
French (fr)
Inventor
Jon Hermstad
Original Assignee
Aker Engineering & Technology As
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Aker Engineering & Technology As filed Critical Aker Engineering & Technology As
Publication of WO2008094047A1 publication Critical patent/WO2008094047A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B9/00—Cleaning hollow articles by methods or apparatus specially adapted thereto 
    • B08B9/08—Cleaning containers, e.g. tanks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B57/00—Tank or cargo hold cleaning specially adapted for vessels
    • B63B57/02—Tank or cargo hold cleaning specially adapted for vessels by washing

Definitions

  • the present invention relates to a method for cleansing oil storage cells in concrete platforms according to the ingress of the following claim 1.
  • the concrete platforms being operational today are gradually going to be shut down.
  • Several of these platforms are equipped with oil storage cells in the underbody of the platform, so called caisson cells. If these platforms are not going to be brought to land at phasing out the operation, but being left where they are placed today, it will be a need to remove pollution in the storage cells.
  • pollution can for instance be emulsion, in addition to unwanted sediments deposited on the bottom of the storage cells and sedimentary deposits up along the walls.
  • the pollution in the storage cells is thick and thus difficult to remove from the storage cells. Due to the thick consistence of the pollution material, it will choke inlet and outlet pipes.
  • the present invention concerns a method for removing possible occurrence of pollution and oil from the storage cells in a concrete platform by means of the existing systems of the oil storage.
  • a storage cell contains, in layers from the top: oil, pollution and ballast water.
  • On the top of the storage cell a first inlet/outlet is arranged, and in the bottom, a second inlet/outlet is arranged.
  • Hot water is supplied to the storage cell in such a way that the hot water lie above the ballast water. This leads to that the pollution is heated. Oil and pollutions is then pumped out of the storage cell through the first inlet/outlet.
  • the hot water is produced water from an oil well.
  • the hot water is ballast water heated with a heat exchanger.
  • the temperature is adjusted to the hot water on the basis of the density of the ballast water and the oil.
  • the hot water is added through the first inlet/outlet.
  • Fig. 1 shows how a storage cell can be arranged in principle.
  • Fig. 2 shows how removal of emulsion can happen according to the invention.
  • Fig. 1 shows oil 1 in a storage cell 6 in a platform underbody.
  • Several storage cells 6 are placed around the utility shaft 7 on a platform underbody.
  • An example on how storage cells 6 can be placed around a utility shaft 7 is shown in the American publication US 4,674,919.
  • the oil 1 flows on the ballast water 3.
  • the oil 1 has heavier precipitations called emulsion 2, and can comprise for instance wax and asphalt, and water- and mineral particles that have followed the well flow up from the oil reservoir.
  • This emulsion 2 floats between the oil 1 and the ballast water 3, and is cooled down by the underlying ballast water 3.
  • the emulsion layer 2 will have so high viscosity, i.e. is thick, that the emulsion 2 can not flow freely out through an oil pipe 4 without danger for clogging of the oil pipe 4.
  • the oil pipe 4 has been used for filling and tapping of the storage cell 6, and is as an example placed on top of the storage cell 6.
  • the oil pipe 4 can also be arranged differently, for instance with an inlet in the storage cell 6 through a side wall.
  • the ballast water 3 is pumped in and out of the storage cell 6 through the ballast water pipe 5 placed in the bottom of the storage cell 6. This is done to compensating for varying oil volume in the storage cell 6.
  • the ballast water 3 is usually cold sea water.
  • the oil 1 in the storage cell 6 will therefore normally have a substantially higher temperature than the underlying ballast water 3.
  • the oil will have a temperature determined by the geothermal condition in the reservoir.
  • the oil 1 will be stabilized by that it i.a. is cooled down to a certain temperature level to be able to be transported safely to land in for example a tanker.
  • a stabilized oil 1 will have a temperature in the range of 30 - 50°C when it is pumped down in the oil storage.
  • the temperature profile 8 shows that the layer of emulsion 2 has a marked temperature fall in relation to the ballast water 3, which is cold sea water.
  • the temperature profile can vary from a temperature level of 30 - 50°C in the upper part, to a temperature level of 8 - 10°C in the lower part.
  • Figure 2 shows how the removal of the emulsion 2 can take place according to a preferred embodiment of the present invention.
  • Hot water 10 with sufficient high temperature is pumped in through the oil pipe 4 on the top of the storage cell 6.
  • the amount hot water 10 being pumped in must be sufficient to establish persistent high water temperature immediately under the emulsion layer 2.
  • the thickness of the layer of hot water 10 can for example be 4 — 6 meters.
  • This hot water 10 is heavier than both the oil 1 and the emulsion material 2 floating on the ballast water 3.
  • the hot water 10 is also lighter than the ballast water 3, which normally lie under the emulsion layer 2.
  • the temperature of the hot water 10 is adjusted to the density of the oil 1 and the ballast water 3.
  • These temperature differences can for example be 20 - 60°C, and lead to that the hot water 10 stays as a layer on top of the original cold ballast water 3 and under the emulsion layer 2.
  • Supply of the hot water 10 which lies under the emulsion 2 and the oil 1, which is also hotter than the emulsion 2 leads to that the emulsion 2 is heated.
  • a new temperature profile 9 shows this changed temperature.
  • the emulsion material 2 is heated to a sufficient high temperature, for example 30 - 70°C, dependent on the specific composition of the emulsion 2, the emulsion 2 will be able to change its viscous qualities.
  • the emulsion 2 has originally an unwanted high viscosity at low temperature, but at heating, it will get a desired lower viscosity, i.e. becomes sufficient thin so that it can be removed by outflow though the oil pipe 4 without risk for clogging the oil pipe 4.
  • the emulsion 2 has become sufficient thin, it is pumped, together with the oil 1, out of the storage cell 6 via the oil pipe 4.
  • oil 1 and emulsion material 2 is pumped out of the storage cell 6, equivalent amount of ballast water 3 is filled in from the ballast water pipe 5.
  • ballast water 3 is filled in from the ballast water pipe 5.
  • the hot water 10 being pumped into the storage cell 6 can for instance be produced water from the oil wells being pumped into the storage cells 6 after it has been separated from the oil 1 in the ordinary way.
  • the hot water 10 being separated from the oil has, in basis, the same temperature as the oil 1 (typically 70 - 90°C).
  • ballast water 3 from the oil storage cells 6 heated via a heat exchanger can be used.
  • a heat exchanger can for example be placed on the platform deck, down in one of the platform handles or onboard a boat by the platform. In such a heat exchanger, one can for instance use said produced well water as heat source.
  • the ballast water 5 will then for instance be pumped out from the lower part of the storage cell 6 via the ballast water pipe 5.
  • ballast water 3 After the ballast water 3 is heated by use of a heat exchanger, it will be pumped in on the top of the storage cell 6 via the oil pipe 4.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Ocean & Marine Engineering (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
  • Lubricants (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Abstract

The present invention relates to a method for cleansing under water storage cells (6). The storage cell (6) comprises in layers from the top, oil (1), pollution (2) and ballast water (3). In the upper part of the storage cell (6), a first inlet/outlet (4) is arranged, and a second inlet/outlet (5) is arranged in the lower part of the storage cell (6). Hot water (10) is supplied to the storage cell (6) in a way that the hot water (10) lays over the ballast water (3) so that the pollution (2) is heated, and so that the oil (1) and pollution (2) afterwards is pumped out of the storage cell (6) through the first inlet/outlet (4).

Description

EMULSION REMOVAL
The present invention relates to a method for cleansing oil storage cells in concrete platforms according to the ingress of the following claim 1.
The concrete platforms being operational today are gradually going to be shut down. Several of these platforms are equipped with oil storage cells in the underbody of the platform, so called caisson cells. If these platforms are not going to be brought to land at phasing out the operation, but being left where they are placed today, it will be a need to remove pollution in the storage cells. Such pollution can for instance be emulsion, in addition to unwanted sediments deposited on the bottom of the storage cells and sedimentary deposits up along the walls.
The patent publications GB A 2 101 475 and US 4,195,653 describes method for pumping components ((ballast-)water, oil, pollution) out from a tank or a cell by supplying hot water to the tank/cell so that the pollution is heated and pumped out.
The pollution in the storage cells is thick and thus difficult to remove from the storage cells. Due to the thick consistence of the pollution material, it will choke inlet and outlet pipes.
The present invention concerns a method for removing possible occurrence of pollution and oil from the storage cells in a concrete platform by means of the existing systems of the oil storage. A storage cell contains, in layers from the top: oil, pollution and ballast water. On the top of the storage cell, a first inlet/outlet is arranged, and in the bottom, a second inlet/outlet is arranged. Hot water is supplied to the storage cell in such a way that the hot water lie above the ballast water. This leads to that the pollution is heated. Oil and pollutions is then pumped out of the storage cell through the first inlet/outlet.
In an embodiment of the invention, the hot water is produced water from an oil well.
In an alternative embodiment of the invention, the hot water is ballast water heated with a heat exchanger. In an embodiment of the invention, the temperature is adjusted to the hot water on the basis of the density of the ballast water and the oil.
In an embodiment of the invention, the hot water is added through the first inlet/outlet.
The invention and related embodiments of this will be described by reference to the figures 1 and 2.
• Fig. 1 shows how a storage cell can be arranged in principle.
• Fig. 2 shows how removal of emulsion can happen according to the invention.
Fig. 1 shows oil 1 in a storage cell 6 in a platform underbody. Several storage cells 6 are placed around the utility shaft 7 on a platform underbody. An example on how storage cells 6 can be placed around a utility shaft 7 is shown in the American publication US 4,674,919.
In principle, the oil 1 flows on the ballast water 3. The oil 1 has heavier precipitations called emulsion 2, and can comprise for instance wax and asphalt, and water- and mineral particles that have followed the well flow up from the oil reservoir. This emulsion 2 floats between the oil 1 and the ballast water 3, and is cooled down by the underlying ballast water 3. As a result of the cooling, the emulsion layer 2 will have so high viscosity, i.e. is thick, that the emulsion 2 can not flow freely out through an oil pipe 4 without danger for clogging of the oil pipe 4. The oil pipe 4 has been used for filling and tapping of the storage cell 6, and is as an example placed on top of the storage cell 6. The oil pipe 4 can also be arranged differently, for instance with an inlet in the storage cell 6 through a side wall.
The ballast water 3 is pumped in and out of the storage cell 6 through the ballast water pipe 5 placed in the bottom of the storage cell 6. This is done to compensating for varying oil volume in the storage cell 6. The ballast water 3 is usually cold sea water.
By operation of the platform, the oil 1 in the storage cell 6 will therefore normally have a substantially higher temperature than the underlying ballast water 3. As a basis, the oil will have a temperature determined by the geothermal condition in the reservoir. On the platform, the oil 1 will be stabilized by that it i.a. is cooled down to a certain temperature level to be able to be transported safely to land in for example a tanker. Typically, a stabilized oil 1 will have a temperature in the range of 30 - 50°C when it is pumped down in the oil storage. The temperature profile 8 shows that the layer of emulsion 2 has a marked temperature fall in relation to the ballast water 3, which is cold sea water. The temperature profile can vary from a temperature level of 30 - 50°C in the upper part, to a temperature level of 8 - 10°C in the lower part.
Figure 2 shows how the removal of the emulsion 2 can take place according to a preferred embodiment of the present invention.
Hot water 10 with sufficient high temperature, for example 30 - 70°C, is pumped in through the oil pipe 4 on the top of the storage cell 6. The amount hot water 10 being pumped in must be sufficient to establish persistent high water temperature immediately under the emulsion layer 2. The thickness of the layer of hot water 10 can for example be 4 — 6 meters. This hot water 10 is heavier than both the oil 1 and the emulsion material 2 floating on the ballast water 3. The hot water 10 is also lighter than the ballast water 3, which normally lie under the emulsion layer 2. The temperature of the hot water 10 is adjusted to the density of the oil 1 and the ballast water 3. These temperature differences can for example be 20 - 60°C, and lead to that the hot water 10 stays as a layer on top of the original cold ballast water 3 and under the emulsion layer 2. Supply of the hot water 10 which lies under the emulsion 2 and the oil 1, which is also hotter than the emulsion 2, leads to that the emulsion 2 is heated. A new temperature profile 9 shows this changed temperature. When the emulsion material 2 is heated to a sufficient high temperature, for example 30 - 70°C, dependent on the specific composition of the emulsion 2, the emulsion 2 will be able to change its viscous qualities. The emulsion 2 has originally an unwanted high viscosity at low temperature, but at heating, it will get a desired lower viscosity, i.e. becomes sufficient thin so that it can be removed by outflow though the oil pipe 4 without risk for clogging the oil pipe 4. When the emulsion 2 has become sufficient thin, it is pumped, together with the oil 1, out of the storage cell 6 via the oil pipe 4. When oil 1 and emulsion material 2 is pumped out of the storage cell 6, equivalent amount of ballast water 3 is filled in from the ballast water pipe 5. When no more oil 1 and emulsion 2 comes out of the oil pipe 4, i.e. only water 3 comes, the storage cell 6 is emptied for oil 1 and emulsion material 2.
The hot water 10 being pumped into the storage cell 6 can for instance be produced water from the oil wells being pumped into the storage cells 6 after it has been separated from the oil 1 in the ordinary way. The hot water 10 being separated from the oil lhas, in basis, the same temperature as the oil 1 (typically 70 - 90°C). Alternatively, ballast water 3 from the oil storage cells 6 heated via a heat exchanger can be used. A heat exchanger can for example be placed on the platform deck, down in one of the platform handles or onboard a boat by the platform. In such a heat exchanger, one can for instance use said produced well water as heat source. The ballast water 5 will then for instance be pumped out from the lower part of the storage cell 6 via the ballast water pipe 5. After the ballast water 3 is heated by use of a heat exchanger, it will be pumped in on the top of the storage cell 6 via the oil pipe 4. Alternative methods with other energy sources, as for instance oil or gas burning, could also be used at heating of water to be pumped into the upper part of the storage cell 6.

Claims

1. Method for cleansing of under water storage cells (6), where the storage cell (6) in layers, from the top, comprises oil (1), pollution (2) and ballast water (3), said storage cell (6) has a first inlet/outlet (4) arranged in the upper part of the storage cell (6) and a second inlet/outlet (5) in the lower part of the storage cell (6), c h a r a c t e r i z e d i n that hot water (10) is supplied to the storage cell (6) in such a way that the hot water (10) lies over the ballast water (2) so that the pollution is heated, and that oil (1) and pollution (2) then is pumped out of the storage cell (6) via the first inlet/outlet (4).
2. Method according to claim 1, wherein the hot water (10) is produced water from an oil well.
3. Method according to claim 1, wherein the hot water (10) is ballast water (3) heated by a heat exchanger.
4. Method according to the preceding claims, wherein the temperature of the hot water (10) is adjusted on the basis of the density of the ballast water (3) and the oil (1).
5. Method according to one of the previous claims, wherein the hot water (10) is added through the first inlet/outlet (4).
PCT/NO2008/000029 2007-01-29 2008-01-29 Emulsion removal WO2008094047A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NO20070540 2007-01-29
NO20070540A NO325382B1 (en) 2007-01-29 2007-01-29 Emulsjonsfjerning

Publications (1)

Publication Number Publication Date
WO2008094047A1 true WO2008094047A1 (en) 2008-08-07

Family

ID=39363990

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NO2008/000029 WO2008094047A1 (en) 2007-01-29 2008-01-29 Emulsion removal

Country Status (2)

Country Link
NO (1) NO325382B1 (en)
WO (1) WO2008094047A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2101475A (en) * 1981-07-15 1983-01-19 British Petroleum Co Plc Method for cleaning storage tanks
GB2180255A (en) * 1985-07-16 1987-03-25 Marlborough Technical Manageme Hydrocarbon recovery
EP0976461A2 (en) * 1998-07-30 2000-02-02 Matsushita Electric Industrial Co., Ltd. Method of and apparatus for removing oil from a waste object
EP1281445A1 (en) * 2001-08-01 2003-02-05 H.C.I., naamloze vennootschap Method of emptying and cleaning an oil tank

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2380968A2 (en) * 1976-12-13 1978-09-15 Inst Francais Du Petrole Recovery of products esp. oil unsuitable for pumping - by injecting hot water and extracting products with the aqueous phase

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2101475A (en) * 1981-07-15 1983-01-19 British Petroleum Co Plc Method for cleaning storage tanks
GB2180255A (en) * 1985-07-16 1987-03-25 Marlborough Technical Manageme Hydrocarbon recovery
EP0976461A2 (en) * 1998-07-30 2000-02-02 Matsushita Electric Industrial Co., Ltd. Method of and apparatus for removing oil from a waste object
EP1281445A1 (en) * 2001-08-01 2003-02-05 H.C.I., naamloze vennootschap Method of emptying and cleaning an oil tank

Also Published As

Publication number Publication date
NO20070540A (en) 2008-04-14
NO325382B1 (en) 2008-04-14

Similar Documents

Publication Publication Date Title
DK176940B1 (en) Method and system for transporting a stream of fluid hydrocarbons containing water
US4896725A (en) In-well heat exchange method for improved recovery of subterranean fluids with poor flowability
CA2662942C (en) Sub sea processing system
NO318393B1 (en) Method and system for transporting hydrocarbon drums containing wax and asphaltenes
US9771701B2 (en) Hydrocarbon production and storage facility
Yao et al. Enhance flows of waxy crude oil in offshore petroleum pipeline: A review
CA2639851C (en) A method of controlling growth and heat loss of an in situ gravity drainage chamber formed with a condensing solvent process
Bacati et al. How technology enables a lower cost for subsea tiebacks
US9062525B2 (en) Offshore heavy oil production
WO2008094047A1 (en) Emulsion removal
McClimans et al. Status and new developments in subsea processing
US3596674A (en) Submarine piping system for transferring liquids
CA2806967A1 (en) Method and apparatus for heating a stored liquid
RU2637915C2 (en) Method for prevention of formation of bottom deposits in reservoirs for storage and/or transportation of oil
GB2514934B (en) Offshore heavy oil production
Davalath et al. Flow assurance management for Bijupira and Salema field development
KR102276218B1 (en) A gas treatment system and marine structure having the same
Zhao et al. Flow assurance during deepwater gas well testing: Addressing hydrate associated problems at reduced cost
Wang et al. A Thermal Study of the Subsea Bundled Pipelines for Offshore Marginal Oilfields
Titley Wheatstone development-Challenges and solutions in formation water treatment and disposal
Walsh et al. Produced water treating systems-comparison between North Sea and deepwater Gulf of Mexico
KR820000863B1 (en) Method of storing heavy hydrocarbon oil
Kildibaeva et al. Mathematical model of a device for the elimination of deep-water leaks accompanied by hydrate formation
Rocha et al. Technological Innovations on FPSO P-63 for Operation at Papa Terra Field-Offshore Brazil
Bon Pazflor, A World Technology First in Deep Offshore Development

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08712654

Country of ref document: EP

Kind code of ref document: A1

DPE1 Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101)
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 08712654

Country of ref document: EP

Kind code of ref document: A1