Steam assisted gravity drainage

As ofAmerican petroleum production not limited to SAGD generates over 5 billion gallons of produced water every day. The method involves injecting high-pressure steam, well above the ambient reservoir pressure, into a reservoir over a prolonged period of time.

Another drawback of very high sub-cool is the possibility of steam pressure eventually not being enough to sustain steam chamber development above the injector, sometimes resulting in collapsed steam chambers where condensed steam floods the injector and precludes further development of the chamber.

This is an idealized situation. In SAGD wells steam is injected to the upper wall, and the heated heavy oil and condensed steam are produced from the lower well.

There are two common methods of recovering product from oil sands. HPCSS differs from steam assisted gravity drainage SAGD operations where steam is continuously injected at lower pressures without fracturing the reservoir and uses gravity drainage as the primary recovery mechanism.

As Steam assisted gravity drainage specific example of an underlying data weakness, this figure excludes the increasingly important steam-assisted gravity drainage technique SAGD method.

The upper well injects steam, and the lower one collects the heated crude oil or bitumen that flows down due to gravity, plus recovered water from the condensation of the injected steam.

In SAGD operations, pairs of stacked horizontal wells are drilled into the reservoir about metres beneath the surface. This technology requires one well bore and the production consists of the injection to fracture and heat the formation prior to the production phases.

With these sites, in particular, there were contributing factors of natural cracks in the bedrock and salt dissolution, a process where salt water flows through rocks creating cracks and holes, which may have compounded the problem. In a million cp tar sand, the spacing would be 5 to 6 m [16 to 20 ft].

As reserves become harder to recover projects using Steam Assisted Gravity Drainage SAGD are becoming increasingly common because of challenging production demands and a wish to maximize reservoir deliverability.

Combined with the higher oil recovery rates achieved, this means that SAGD is much more economic than cyclic steam processes where the reservoir is reasonably thick. Though to offset the drastic reduction in fresh water use, industry has begun to significantly increase the volume of saline groundwater involved.

With horizontal wells stretching more than a kilometre beneath the surface, a large area can be developed with minimal impact to the land. There is a 60 m to m spacing for horizontal wells. Historically, natural gas has been used as a fuel for Canadian oil sands projects, due to the presence of large stranded gas reserves in the oil sands area.

Its first facility was owned and operated by ten industrial participants and received ample government support Deutsch and McLennan [2] including from the Alberta Heritage Savings Trust Fund. Real-time monitoring of SAGD wells provides operators with increased understanding of the overall development of the steam chamber and the operation balance that must be achieved between injector and producer wells.

Description[ edit ] The SAGD process of heavy oil or bitumen production is an enhancement on the steam injection techniques originally developed to produce heavy oil from the Kern River Oil Field of California.

In the past, heavy-oil production was expensive and ineffective but with the introduction of SAGD wells efficiency has been significantly improved and SAGD wells even emit significantly lower amounts of greenhouse gas than traditional drilling techniques.

SAGD allows development in stages, helping to manage costs and workforce peaks. In strip mining, the top layer of dirt and rock are removed to access the oil below.

Corporate Officers

Traditionally close to 70 million cubic metres of the water volume that was used in the SAGD process was fresh, surface, water. The condensed water and crude oil or bitumen is recovered to the surface by pumps such as progressive cavity pumps that work well for moving high-viscosity fluids with suspended solids.

The process is relatively insensitive to shale streaks and other vertical barriers to steam and fluid flow because, as the rock is heated, differential thermal expansion allows steam and fluids to gravity flow through to the production well.

The coatings of the optical fiber and the extrusion can be tailored to optimally suit the required resistance to temperature conditions and mechanical impacts. Steam is re-injected to begin a new cycle when oil production rates fall below a critical threshold due to the cooling of the reservoir.

All of these methods still use steam to heat oil sand deposits for harvesting and recovering purposes. As a consequence many operators, when faced with uneven stunted steam chamber development, allow a small quantity of steam to enter into the producer to keep the bitumen in the entire wellbore hot hence keeping its viscosity low with the added benefit of transferring heat to colder parts of the reservoir along the wellbore.

Use of water for steam generation[ edit ] A source of large amounts of fresh and brackish water and large water re-cycling facilities are required in order to create the steam for the SAGD process. The top well injects steam to heat the bitumenwhich separates from the sand and collects with the produced water in the lower well, approximately five metres below.

The steam and associated gas rise because of their low density compared to the heavy crude oil below, ensuring that steam is not produced at the lower production well, tend to rise in the steam chamber, filling the void space left by the oil.

Our special single mode high temperature fiber has the advantage that it is unaffected by hydrogen usually causing the darkening of the fiber.

Steam-Assisted Gravity Drainage (SAGD)

The CSOR is 3. Vertical wells are spaced at 2 to 8 Acre spacing for vertical wells. There has been a significant reduction in fresh water use as ofwhen approximately 18 million cubic metres were used. There is no steam migration to offset vertical wells.Steam-assisted gravity drainage (SAGD) is a drilling technique used to extract heavy oil that cannot be mined using traditional methods.

Steam-assisted gravity drainage (SAGD; "Sag-D") is an enhanced oil recovery technology for producing heavy crude oil and bitumen. It is an advanced form of steam stimulation in which a pair of horizontal wells is drilled into the oil reservoir, one a few metres above the other.

As reserves become harder to recover projects using Steam Assisted Gravity Drainage (SAGD) are becoming increasingly common because of challenging production demands and a wish to maximize reservoir deliverability. assessing and improving steam-assisted gravity drainage: reservoir heterogeneities, hydraulic fractures, and mobility control foams a dissertation.

Steam assisted gravity drainage or SAGD is a method that is widely used to extract bitumen from underground oil sands deposits. This method involves forcing steam into sub-surface oil sands deposits to heat the bitumen locked in the sand, allowing it to flow well enough to be extracted.

Steam assisted gravity drainage (SAGD) is an outstanding example of a steam injection process devised for a specific type of heavy oil reservoir utilizing horizontal is widely used in Alberta, Canada for recovery of heavy oil and tar sand resources.

Steam assisted gravity drainage
Rated 5/5 based on 2 review