Steam-Assisted Gravity Drainage (SAGD)

What Is Steam-Assisted Gravity Drainage (SAGD)?

Steam-assisted gravity drainage (SAGD) is a drilling technique used to separate heavy crude oil which is covered too deep or generally difficult to access. Its location makes it monetarily inefficient to mine utilizing traditional methods. There are several varieties of the SAGD cycle, however Butler, McNab, and Lo developed the original in 1979. The cycle being used today was field tried by the Alberta Oil Sands Technology Research Authority (AOSTRA) as an efficient means of recuperating hard to-access oil reserves.

Understanding Steam-Assisted Gravity Drainage (SAGD)

SAGD is a enhanced oil recovery (EOR) process which utilizations steam to remove oil from a supply through primary or secondary recovery techniques. EOR methods change the compound structure of the oil itself to make it more straightforward to separate.

SAGD requires a pair of horizontal wells bored from a central well cushion. A horizontal well is dug at a point of 90 degrees to a vertical drag well. This type of well enjoys upper hands over traditional vertical drilling as changes can permit the bit to penetrate in non-vertical headings. It will empower one drilling cushion, or the opening shot point, to investigate a more extensive underground area.

Otherwise called the steam flooding process, steam generators produce steam, which goes through pipelines into the wells. As the fume gathers into hot water, it warms the oil to make it less thick, permitting it to flow by gravity to the lower part of the well. The oil transfers through a pipe from the creating great at the base to a plant for treatment.

Petroleum companies and researchers hope to steam-assisted gravity drainage for its capability to drag out the life of wells in proven or probable oil fields. Proven reserves are those with a higher than 90% chance of oil recovery, and probable fields have a more than half chance of petroleum recovery.

Modern Applications of Steam-Assisted Gravity Drainage

Canada is the biggest provider of oil to the United States, accounting for over 4.7 million barrels of imported crude each day in 2022.. This Canadian import is more than all oil imported from all of the Organization of Petroleum Exporting Countries (OPEC) countries combined. The majority of Canada's oil exports come from Alberta's oil sand deposits.

There are two common methods of recuperating product from oil sands. The first being SAGD, which is more proper for the deep deposits in Alberta. The subsequent method, all the more commonly known for coal recovery in the United States, is strip mining. In strip mining, the top layer of soil and rock are eliminated to access the oil below. The majority of future oil production from Alberta is expected to from SAGD gather.

With the rise in costs of oil production throughout the long term and the increased demand, the replacement of traditional oil drilling rigs with contemporary methods are the reason there has been a rise in SAGD recovery.

A few varieties of this method are Cyclic Steam Stimulation (CSS), High-Pressure Cyclic Steam Stimulation (HPCSS), Vapor Extraction (Vapex), Enhanced Modified Steam, and Gas Push (eMSAGP). These methods actually use steam to warm oil sand deposits for harvesting and recuperating purposes.

Hazards from SAGD

These methods are not without imaginable geo-hazards. As reported by Inside Climate News, in 2016, four wild breaks were confirmed by the Alberta Energy Regulators at destinations involving high-pressure steam injection methods in Alberta's tar sands patch.

Geologists are representing that there might be risks associated with this method, explicitly conceivable topographical risks across Alberta's sands region. With these locales, specifically, there were contributing factors of natural breaks in the bedrock and salt disintegration, a cycle where salt water flows through rocks making breaks and openings, which might have intensified the problem.

Features

• The cycle was made by the Alberta Oil Sands Technology and Research Authority (AOSTRA) as an efficient means of recuperating hard to-access oil reserves.
• Steam-assisted gravity drainage (SAGD), is a drilling technique used to separate heavy crude oil which is covered too deep or generally oppressive to access.
• With the rise in costs of oil production throughout the long term and the increased demand, there has been a replacement of traditional oil drilling rigs with SAGD.