Coking is to be the front-end process to upgrade the bitumen extracted from oil sand in Canada.
Coke calcining technology is unique; in fact it is considered more a metallurgical process than a refining process. StatoilHydro’s delayed coking and calcining know-how has proven invaluable during the last years positioning StatoilHydro’s coke as one of the European preferred for production of anodes for the aluminium industry.
A significant contribution is being made by StatoilHydro researchers to heavy oil upgrading in Venezuela.
StatoilHydro joined the Sincor partnership in the late 1990s to produce, upgrade and market heavy oil from the shallow Zuata bitumen field in Venezuela’s Orinoco Basin.
Although the field is currently producing about 200,000 barrels per day, and may continue to do so for the next 30 years or so, recovery will only represent five to 10 per cent of the heavy oil originally in place.
This leaves considerable room for substantially improving oil recovery and enhancing the upgrading facilities. However, considerable technical challenges are faced.
These include the high viscosity of the heavy oil and the considerable amount of naphthenic acid and trace metals it contains.
The heavy oil is upgraded to synthetic crude, which must be sold to refineries elsewhere in the world able to produce end products from this feedstock. These include naphthas, automotive diesel and heating oils.
The heavy oil is de-watered and diluted with condensate at Sincor’s main production plant (left) before being pumped 200 kilometres north to the upgrader on the Caribbean coast (right).
Although a relative newcomer to the heavy oil business, StatoilHydro has already had a significant impact on Sincor’s upgrading activities.
For example, all reactor catalysts used by Sincor today conform to StatoilHydro’s recommendations. These are based on a comparative evaluation of commercial varieties using a unique purpose-built test rig.
Repeated operational upsets caused when the reactor becomes clogged by solid particles have been explained with the aid of the group’s fundamental knowledge of naphthenic acids.
This made it possible to establish that iron released by acid corrosion of process equipment and pipework combines with hydrogen sulphide to form solid, granular pyrrhotite.
Remedial solutions have been recommended as an alternative to an immensely expensive changeover to sophisticated, corrosion-resistant materials. These include particle trapping technology or the adoption of StatoilHydro’s proprietary naphthenic acid removal (NAR) technology.
StatoilHydro is also evaluating the latest commercial technologies and technical developments, especially in Canada, with an eye to a possible second development phase in Venezuela (Sincor II). This includes both improved oil recovery (IOR) methods and enhanced upgrading processes.
Steam-assisted gravity drainage involves combining steam injection with horizontal wells, while “integrated processes” combine IOR techniques with wellhead upgrading in an energy-efficient manner.
