How is heavy oil produced?

Crude oil becomes heavy after considerable degradation, after entrapment and during devolatilization. Degradation occurs through chemical and biological processes when oil reservoirs become contaminated by bacteria through subsurface water.

What is heavy oil?

What is Heavy Oil and How is it Formed? As defined by the U.S. Geological Survey (USGS), heavy oil is a type of crude oil characterized by an asphaltic, dense, viscous nature (similar to molasses), and its asphaltene (very large molecules incorporating roughly 90 percent of the sulfur and metals in the oil) content.

What is the meaning of heavy oil and why is the nature of heavy oil such a problem for recovery operations and refining?

Chapter 1 – Definitions The nature of heavy oil is a problem for recovery operations and for refining – the viscosity of the oil may be too high thereby rendering recovery expense and/or difficult and the sulfur content may be high which increases the expense of refining the oil.

What are the technical issues with heavy oil production?

The outstanding technical issues involve sand handling problems, field development strategies, wormhole plugging for water shutoff, low ultimate recovery, and sand disposal. Originally, cold production mechanisms were thought to apply only to vertical wells with high-capacity pumps.

How is cold production related to heavy oil?

The basis of cold production is that the oil production and recovery improve when sand production occurs naturally. Field production data indicates that heavy oil flows more efficiently when sand is produced from unconsolidated reservoirs.

Why is heavy oil called extra heavy oil?

It is also known as heavy crude oil or extra heavy crude oil. Due to its high viscosity, heavy oil cannot flow easily to production wells, not unless favorable conditions are provided using artificial means. Apart from its high density and API gravity level, heavy oil also contains heavy molecular arrangement.

Where does heavy oil come from in the world?

Field production data indicates that heavy oil flows more efficiently when sand is produced from unconsolidated reservoirs. In the Elk Point and Lindberg reservoirs, sand production from wells occurs regularly ( Loughead, 1992; McCaffrey and Bowman, 1991 ).