Gas Management Solutions In Oil Production

As a supplier of advanced versatile solutions to oil field operators, Wärtsilä participates in the Global Gas Flaring Reduction Partnership (GGFR), a public-private partnership supporting the efforts of the petroleum industry and national governments to reduce the flaring of gas. In June, the company joined GGFR as an associated partner.

Oil production generally involves the processing of upstream fluids into a crude oil that meets certain specifications. This is typically done at a field processing facility and involves a number of operations in different processing systems within the facility. One primary function of this processing is “phase separation” to remove water, solids and gas from the produced fluid, thereby producing crude oil that meets the specifications and provides the main source of income for the operator.

The gases, i.e., the volatile hydrocarbons in oil, are the main technical focus of attention throughout the oil production process from the underground oil reservoir to the refinery gates. The amount of gas in the reservoir fluid usually dictates the oil field recovery methods, and the production planning stages of the hydrocarbons.

The relative amount of gas varies during the lifecycle of the field. The amount of gas in the reservoir fluid is usually expressed as the gas-oil ratio, GOR, and is mainly given in U.S. standard units: scf/bbl (standard cubic feet per barrel). Volatile components in the oil will also mean “shrinkage” during transport and decreased volume at the delivery point, despite being stabilized according to specifications. Vaporized hydrocarbons, i.e., fumes around the processing equipment and throughout the operations, are - besides being an environmental concern - the source of hazardous explosive conditions, and are, therefore, a key safety issue.

The major concern in oil production has been the removal of the separated gas from the process in the field processing facility. Traditionally the gas has been considered a waste and utilized only occasionally. Gas has not even been considered as an item in the production sharing agreements (PSA), because the profit and cost calculations of the oil production process have been based on oil, not on gas. Usually, the gas has simply been flared as an unwanted by-product of oil, due to various reasons that constrained its utilization.

During the last decade, global institutions and organizations, as well as the world’s energy industry, have awakened to the realization that huge amounts of energy are being wasted in flaring. At the same time, flaring also poses a severe threat to the environment.

The World Bank-led Global Gas Flaring Reduction partnership (GGFR) estimates that globally, around 150 Bcm of gas are flared or burned every year, causing some 400 million tons of carbon dioxide in annual emissions. That is equivalent to 30% of the European Union’s gas consumption.

Gas flaring not only harms the environment but also deprives developing countries of an energy source that is often cleaner and cheaper than others available. During the drilling for crude oil, gas usually comes to the surface as well and is often vented or flared instead of used, particularly in countries that lack effective regulations, gas markets and the necessary infrastructure to utilize the gas.