Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Transcript of Water Separation
Water affects every stage of oil field from exploration, production, and finally to abandonment.
As oil is produced from a reservoir, water from an underlying aquifer or from injectors eventually will be mixed and produced along with the oil.
This movement of water flowing is called ‘’Water Cycle’’
Water Separation in
Oil Industry The economics of water production throughout the water cycle depend on a number of factors such as total flow rate, production rates, fluid properties ( oil gravity and water salinity), and finally the water separation
Operational expenses, including lifting, separation, filtering, pumping and reinjection, add to the overall costs.
Reports vary from 10 cents per barrel when unwanted water is released into the ocean offshore to over $1.50 per barrel when hauled away by trucks on land.
Although the potential savings from water control alone are significant, the greatest value comes from the potential increase in oil production and recovery.
Given the world wide daily water production of roughly 210 millions [ 33.4 million m3] of water accompanying every 75 million barrels [ 11.9 million m3] of oil, many oil companies could almost be called water companies.
Water-handling costs are high-estimates range from 5 to more than 50 cents per barrel of water.
In a well producing oil with an 80% water cut, the cost of handling water can be as high as 4$ per barrel of oil produced.
Today, oil companies produce an average of three each barrel of oil barrels of water for each barrel of oil from their depleting reservoir.
Every year more than $40 billion is spent dealing with unwanted water.
In many cases, innovative water-control technology can lead to significant cost reduction and improved oil production barrels
Introduction Separating water from continuous flows of oil is commonly required in oil production applications.
Oil refineries and chemical plants as well as some places where it is essential that the hydrocarbons not be contaminated with water.
The problems in removing water from oil vary widely mostly because of the widely varying viscosity of hydrocarbons that must be treated.
Two Phase & Three Phase Separators Water from oil separators
Water from Oil where flow is mostly Oil
Oil from Water where flow is mostly Water
Non-Hydrocarbon oils Types of separations TWO PHASE SEPARATORS Three Phase Vessels having working pressures of 150 psig or less are considered low-pressure units.
Those with working pressures above 150 psig are considered high-pressure units.
Units are available at pressures in excess of 3000 psig. They are usually mostly empty vessels, sized based on empirical relationships.
Often provided with rudimentary baffles and / or mesh pads for mist elimination and heating arrangements to raise the temperature of the oil, thus decreasing the viscosity and aiding the separation.
Two phase separators may be used where only oil and gas are present with no aqueous phase
In situations where only small amounts of gas or no gas are present hydrocarbon phases
High pressure systems may be designed as spheres because this is the most economical shape to manufacture in a high pressure design. It requires a footprint area larger than a vertical one
At high liquid levels, the liquid entrainment rate progressively increases with the increase in liquid level. Disadvantages: The horizontal separators have a much greater gas-liquid interface area than other types, which aids in the release of solution gas and reduction of foam.
A special de-foaming section is used when severe foaming of the inlet stream is anticipated.
The horizontal configuration is best suited for liquid-liquid-gas, or three phase, separations because of the large interfacial area available between the two liquid phases.
In addition to being easier to hook-up, easier to service
Minimize horizontal space requirements. Horizontal separators are ideally suited to wellstreams having high gas-oil ratios, constant flow, and small liquid surge characteristics.
Horizontal separators are smaller and less expensive than vertical separators for a given gas capacity.
Liquid particles in the wellstream travel horizontally and downward at the same time
Therefore, higher gas velocities can be permitted in horizontal separators and still obtain the same degree of separation as in vertical separators. Horizontal Separators
Not suitable for three-phase separation
Less suitable for high liquid–vapor ratios Disadvantages
Vertical separators occupy less floor space than comparably sized other types.
This is an important consideration where floor space can be very expensive, as on an offshore platform.
Vertical separators may be larger and more expensive than a horizontal separator for the same gas handling capacity.
Vertical separators are capable of handling large slugs of liquid and are therefore most often used on low to intermediate gas-oil ratio well streams.
They are ideally suited as inlet separators to processing plants since they can smooth out surging liquid flows. They are well suited for handling production that contains sand and other sediment.
When excessive sand production is expected, a cone bottom is placed in the vertical separator to properly handle the sand. Vertical Separators
Heater treaters are designed to break wellstream emulsions, allowing the separation of crude oil from water and other foreign materials.
Gas is liberated prior to the filtering and settling sections, allowing liquid and sediment separation without the agitation of gas breaking out of the liquid. Heater Treaters
The free-water immediately separates from the oil and is discharged from the treater bottom section through the outside adjustable siphon.
The oil and emulsion is broken into small streamlets by the perforated tray spreader and moves up through the hot water section surrounding the firebox.
The final traces of water are separated by gravity in the quiet settling section.
The treated oil exits the treater through the oil outlet at the top of the settling section and passes through the oil valve to the storage tank.
A horizontal treater can handle large amounts of emulsion by utilizing a long "U" firetube.
This firetube has greater heating capacity, thereby allowing a higher treating rate.
The large horizontal interface area in the settling section allows for more efficient separation of emulsion and gas release.
Horizontal treaters must operate under pressure to boost oil to storage tanks.
Vertical treaters use a firebox to heat water to a specified temperature; oil then passes through the hot water in streamlets. This is commonly called the "hot water wash" method.
The wellstream mixture of oil, emulsion, water, and gas enter the gas separation section at the top of the treater.
The inlet diverter deflects the liquid outward against the treater shell and causes it to spread in a thin film so both free gas and solution gas are released quickly.
The oil, water, and emulsion are collected on the diaphragm plate and they then flow through the downcomer pipe to the spreader underneath the firebox.
. VERTICAL HEATER TREATERS
In the correct application, the horizontal treater has several advantages over the vertical.
Increased liquid capacity for a given size vessel is possible
The BTU/Hr rating is higher because a longer firetube can be used.
Settling time is enhanced because of the larger surface area of the oil/water interface, and the shorter distance that small suspended particles of water must travel to fall from the oil phase to the water phase. HORIZONTAL HEATER TREATERS Heater Treaters Water Cut Its The ratio of water produced compared to the volume of total liquids produced.
Its important to knw the water cut precentatge in order to knw which separato will be used and the total produced oil percentage of the production.
The current API naming of water cut meter is OWD or On-Line Water Determination. We use OWD to measure:
-the water cut of oil flowing from a well
-produced oil from a separator
-crude oil transfer in pipelines
-in loading tankers
How OWD works
There are several technologies used, The main technologies are:
-dielectric measurements using radio or microwave frequency
-less common are gamma ray based instruments. Roxar Watercut meter •The Roxar Watercut meter (WCM) Full Cut (FC) model is constructed as an open coaxial cable resonator.
•The pipe is used as the outer conductor of a coaxial transmission line, and a metal rod in the middle of the pipe acts as the centre conductor.
•An electric field propagating along the coaxial line will be reflected at both ends of the rod. •Oil/water mixtures flow in the space between the centre conductor and the pipe.
• Thus the mixture affects the frequency at which the sensor resonates. Thank you Prepared by Mohammed Ahmed Ahmed Mohammed (sec 3)
Mohanned Mohamed El-Tamalawy (sec 4)
Mostafa Hamdy Osman (sec 4)
Mohamed Mahdy Fadel (sec 4)