What Is Steam-Assisted Gravity Drainage (SAGD)?
Steam-assisted gravity drainage (SAGD) is a drilling technique used to extract heavy crude oil which is buried too deep or in a different way burdensome to access. Its location makes it economically inefficient to mine using common methods. There are a variety of diversifications of the SAGD process, on the other hand Butler, McNab, and Lo complex the original in 1979. The process in use at the present time was field-tested during the Alberta Oil Sands Technology Research Authority (AOSTRA) as an efficient manner of getting better difficult-to-access oil reserves.
Key Takeaways
- Steam-assisted gravity drainage (SAGD), is a drilling technique used to extract heavy crude oil which is buried too deep or in a different way burdensome to access.
- The process was created during the Alberta Oil Sands Technology and Research Authority (AOSTRA) as an efficient manner of getting better difficult-to-access oil reserves.
- With the rise in costs of oil production through the years and bigger name for, there used to be a selection of standard oil drilling rigs with SAGD.
Working out Steam-Assisted Gravity Drainage (SAGD)
SAGD is an enhanced oil recovery (EOR) process that uses steam to extract oil from a reservoir by way of primary or secondary recovery ways. EOR methods keep watch over the chemical composition of the oil itself to help you extract.
SAGD requires a few horizontal wells drilled from a central well pad. A horizontal well is dug at an standpoint of 90 ranges to a vertical bore well. This kind of well has advantages over common vertical drilling as adjustments can allow the bit to drill in non-vertical directions. It will allow one drilling pad, or kickoff degree, to find a broader underground area.
Incessantly known as the steam flooding process, steam generators produce steam, which travels by way of pipelines into the wells. Since the vapor condenses into scorching water, it heats the oil to make it a lot much less viscous, allowing it to flow via gravity to the bottom of the well. The oil transfers by the use of a pipe from the producing well at the bottom to a plant for treatment.
Petroleum corporations and scientists look to steam-assisted gravity drainage for its attainable to increase the life of wells in showed or imaginable oil fields. Showed reserves are those with a greater than 90% probability of oil recovery, and imaginable fields have an over 50% probability of petroleum recovery.
Stylish Applications of Steam-Assisted Gravity Drainage
Canada is an important supplier of oil to the US, accounting for over 4.7 million barrels of imported crude in step with day in 2022. This Canadian import is bigger than all oil imported from all the Workforce of Petroleum Exporting World places​​​​​​​​​​​ (OPEC) world places combined. The majority of Canada’s oil exports come from Alberta’s oil sand deposits.
There are two now not peculiar methods of getting better product from oil sands. The principle being SAGD, which is additional appropriate for the deep deposits in Alberta. The second way, additional steadily identified for coal recovery in the US, is strip mining. In strip mining, the perfect layer of filth and rock is removed to access the oil underneath. The majority of longer term oil production from Alberta is predicted to be from SAGD harvesting.
With the rise in costs of oil production through the years and the bigger name for, the other of standard oil drilling rigs with non-traditional methods is why there used to be a upward thrust in SAGD recovery.
Some diversifications of this system are Cyclic Steam Stimulation (CSS), High-Pressure Cyclic Steam Stimulation (HPCSS), Vapor Extraction (Vapex), Enhanced Modified Steam, and Fuel Push (eMSAGP). All of the ones methods however use steam to heat oil sand deposits for harvesting and getting better purposes.
Hazards From SAGD
The ones methods don’t seem to be without imaginable geo-hazards. As reported via Inside Native climate Knowledge, in 2016, 4 uncontrollable leaks had been confirmed during the Alberta Energy Regulators at internet sites using high-pressure steam injection methods in Alberta’s tar sands patch.
Geologists are posing that there may be risks associated with this system, particularly imaginable geological risks right through Alberta’s sands house. With the ones internet sites, specifically, there were contributing parts of natural cracks inside the bedrock and salt dissolution, a process where salt water flows by way of rocks creating cracks and holes, which may have compounded the problem.​​​
