Thermal SAGD process.

SAGD PROCESS Steam Assisted Gravity Drainage is an advanced form of steam stimulation in which a pair of horizontal wells are drilled into the oil

reservoir, one a few meters above the other. High pressure steam is continuously injected into the upper wellbore to heat the oil and

reduce its viscosity, causing the heated oil to drain into the lower wellbore, where it is pumped out. Fluor’s patented 3rd Gen

Modularization Execution can reduce the required plot area as much as 30% and significantly reduce TIC by as much as 20%.

CA20140133

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STEAMSTEAMGENERATIONGENERATION

PRODUCING WELLSPRODUCING WELLS

INJECTION & RECOVERYINJECTION & RECOVERY

WATER TREATMENTWATER TREATMENT

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Steam is created using

steam generators. It is

transported through

pipes to injection wells

which pump the steam

into the oil sands

reservoir.

Steam injected into the upper injection well rises and

heats the oil sand, enabling the bitumen to flow.

Condensed steam, bitumen and gas flow to the lower

production well and then flow to the surface.

Water is treated, mixed with make-up water

and sent back to the steam generators to be

used again as Boiler Feed Water.

Well pairs (one steam injector

and one produces) are located

at well pads. The injector well

controls the rate of steam into

the reservoir. Produced fluids

from the reservoir flow through

the production well to the

surface, and then through the

pipelines to the plant.

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INLET SEPARATION & TREATINGINLET SEPARATION & TREATINGBitumen, produced water (as emulsion) and gas are separated into

separate phases. Diluent is added to the emulsion to facilitate oil

and water separation. Produced gas is sent to the fuel gas system.

Produced water is sent to deoiling for oil removal prior to water

treatment. Dilbit is sent to storage.

DEOILINGDEOILINGOil in Produced Water needs to be removed

prior to Water Treatment. Combinations of

gravity settling, gas flotation and filtration are

used to reduce the oil content to required levels.

STORAGESTORAGEStorage is provided for

1) diluent received by pipeline, which is

used in oil/water separation, and

2) Sales Oil product which is shipped by

pipeline or rail.

PRODUCED GAS COLLECTIONPRODUCED GAS COLLECTION

STEAMGENERATION

PRODUCING WELLS

INJECTION & RECOVERY

WATER TREATMENT

INLET SEPARATION & TREATING

DEOILING

STORAGE

PRODUCED GAS COLLECTIONProduced vapours from the well are

collected and cooled to condense water

vapour. Condensed water is sent to

Deoiling. Wet Produced gas from the

condensing step is mixed with natural gas

and used as fuel for steam generation.

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steel. These gaskets were subsequently silver-plated to take advantage of the softer plating material’s ability to provide a tighter seal. The constant load on the gasket minimized the potential for leakage and the iron/soft steel, silver- plated pressure seal gasket was replaced with one made of die-formed graphite.

During SAGD operations, due to weather cycles in Canadian oilsands – Things to take care of on pressure seal valvesLike thermal binding, the phenomena of center cavity over-pressurization and pressure locking can result in an inability to stroke the valve. The potential of these concerns must be carefully evaluated and addressed in the design phase of the project. ASME B16.34 and MSS-SP-144 state that it is the user’s responsibility to determine the potential for, and provide a means to protect against, Center cavity over-pressurization and pressure locking.The closure element of double-seated valves (wedge gates, parallel slide gates) may become locked in place by either a buildup of pressure in the center cavity or an increase in the differential pressure upstream, downstream, or both of the seats in a closed valve as a function of decreased line pressure (pressure locking). Fluid trapped in the center cavity at ambient temperatures will expand when heat is introduced (e.g., during startup) and, depending on the fl uid type and temperature, this could reach a pressure where insuffi cient torque is available (manually or actuated) to overcome the pressure and open the valve. Pressure locking occurs in double-seated valves where the line pressure drops (during plant operation or through accident) on either the upstream, downstream, or both sides of the valve seats, creating a suffi cient differential pressure to preclude opening the valve. As in thermal binding, there are several methods to guard against center cavity over-pressurization and pressure locking.

However, the historical data for the industry’s water usage reveals that withdrawals from rivers for surface mining represent only a very small percentage of river fl ows and in-situ projects (SAGD, CSS) do not use any water from rivers.Further in this article we will discuss Pressure Seal Valves and the benefi ts of those used in SAGD and CSS technologies:In the tough and high pressure, high temperature valve applications, pressure seal gate, globe and check valves provide a safe, leak free, pressure-containing valve. The main difference between a bolted bonnet and pressure seal valve is the body/bonnet connection confi guration. The pressure seal design bonnet uses take-up bolts to pull the bonnet up and

seal against the pressure seal gasket, which creates a seal between the gasket and the inner diameter of the valve body and a segmented thrust ring maintains the load. The higher the pressure the better the seal in a pressure seal valve, i.e. the higher the pressure the more the leakage through the body/bonnet joint is decreased/eliminated. This design has advantages over bolted bonnet valve design mainly in steam, feed water, bypass and higher pressure sealing safety and integrity requirements.

Pressure seal gasketsOne of the primary components involved in sealing the pressure seal valve is the gasket. When the pressure seal valve was invented the pressure seal gaskets were manufactured from iron or soft

CO L U M N

www.valve-world.net94 May 2014