Gas separation: processes – Degasification of liquid – Plural successive degassing treatments
Patent
1998-02-23
2000-10-17
Smith, Duane S.
Gas separation: processes
Degasification of liquid
Plural successive degassing treatments
95254, 95259, 95261, 96182, 96195, 210188, 2105122, 210788, B01D 1900
Patent
active
061324949
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention relates to a method for separating a well production flow consisting of a mixture of oil, water and gas, where oil/water/gas are subjected to a static separation process and are split into a light and a heavy phase, ie, a gas phase and a liquid phase.
BACKGROUND OF THE INVENTION
The invention also relates to an apparatus for separating a well production flow consisting of a mixture of oil, water and gas, comprising a static separator for separating a well production flow into a light and a heavy phase, ie, a gas phase and a liquid phase.
In connection with the growing need to recover oil from so-called marginal fields, there has been an increase in the need for light, compact, flexible and cost-effective processing equipment.
Many of today's known marginal fields would not be capable of providing a proper yield without the costs of the processing plants being reduced from today's level. A typical processing plant for an oil field consists of oil/water separation and stabilisation, water purification, a water injection unit and a gas reinjection unit.
As a rule, production from marginal fields will be carried out from ships or smaller vessels which are equipped with the most essential processing systems. It is therefore of great importance that the processing equipment also functions satisfactorily during quite large movements, eg, during surging, heaving and tilting.
Today, oil/water separation from an oil reservoir is carried out in large static gravitation separators where the separation takes place under the force of gravity. Drawing off takes place through respective overflows and underflows having great differences in height so that it is simple to draw off a pure phase which has been separated.
Static gravitation separators are large and heavy and not very serviceable for producing from marginal fields at great depths of water, from floating platforms or vessels in motion, from the seabed or directly in the reservoir. There is therefore a need for a reduction in the physical dimensions of the units, and it is thus one of the objectives of the present invention to propose measures which allow the physical dimensions of separation units to be greatly reduced.
SUMMARY OF THE INVENTION
According to the invention, a method is therefore proposed as mentioned above, said method being characterised in that the liquid phase, in a dehydration step, is subjected to a dynamic separation process and is split into a light and a heavy phase, ie, an oil phase and a water phase, and that the water phase, in a de-oiling step, is subjected to a dynamic separation process in order to produce pure, produced water and reject.
Similarly, according to the invention, an apparatus is proposed as mentioned above, said apparatus being characterised by a dehydration step after the static separator and comprising at least one cyclone for splitting the liquid phase into a light and a heavy phase, ie, an oil phase and a water phase, and a de-oiling step after the static separator and comprising at least one cyclone for producing pure, produced water and reject.
Today's established technology in the field of liquid/liquid cyclones consists of,cyclones having countercurrent spin, ie, the light phase flows countercurrent to the top reject and the heavy phase passes out in the bottom reject. One area of application for such cyclones is to purify produced water where the light phase (oil) is a small volume flow, maximum 5,000 ppm oil (0.5%), compared with the heavy phase (water), which is 99.5% of the volume flow.
If the portion of the light phase is increased in a countercurrent cyclone, the outlets will be crucial. A choice must be made as to which phase is to be given priority.
One of the specific aims of the present invention is to utilise the effect of the use of countercurrent and cocurrent spin in the cyclones. By varying the cocurrent spin portion, one can vary the duration and separation of the light phase so that the portion of the heavy phase increases along the axis of the cyclone
REFERENCES:
patent: 2730190 (1956-01-01), Brown et al.
patent: 2765045 (1956-10-01), Meyers
patent: 3704567 (1972-12-01), Engel
patent: 4369047 (1983-01-01), Arscott et al.
patent: 4424068 (1984-01-01), McMillan
patent: 4948393 (1990-08-01), Hodson et al.
patent: 4968332 (1990-11-01), Maher
patent: 5049277 (1991-09-01), Kalnins
patent: 5302294 (1994-04-01), Schubert et al.
Andersen Helge L.
Kjos Tore
Voigt Marius Fr.
READ Group A/S
Smith Duane S.
LandOfFree
Process and means for separation of a well production stream does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process and means for separation of a well production stream, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process and means for separation of a well production stream will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-464346