Basic sediment and water (BS&W) is a both a technical specification of certain impurities in crude oil and the method for measuring it. When extracted from an

oil reservoir A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the presenc ...

, the crude oil will contain some amount of water and

suspended solids Suspended solids refers to small solid particles which remain in suspension in water as a colloid or due to motion of the water. Suspended solids can be removed by sedimentation if their size or density is comparatively large, or by filtration. It ...

from the reservoir formation. The particulate matter is known as sediment or mud. The water content can vary greatly from field to field, and may be present in large quantities for older fields, or if oil extraction is enhanced using water injection technology. The bulk of the water and sediment is usually separated at the field to minimize the quantity that needs to be transported further. The residual content of these unwanted impurities is measured as BS&W.

Oil refineries An oil refinery or petroleum refinery is an industrial process plant where petroleum (crude oil) is transformed and refined into useful products such as gasoline (petrol), diesel fuel, asphalt base, fuel oils, heating oil, kerosene, liquef ...

may either buy crude to a certain BS&W specification or may alternatively have initial crude oil dehydration and desalting process units that reduce the BS&W to acceptable limits, or a combination thereof.

Testing

ASTM ASTM International, formerly known as American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, a ...

method D4007 or

API An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how ...

Manual of Petroleum Measurement Standards chapter 10.4 are commonly used to measure BS&W. These methods both consist of mixing equal volumes of solvent and crude oil then centrifuging in order to separate any solids, free water, or suspended particles. More precise methods beyond BS&W are available to independently measure water or solids present in a sample of crude oil.

References

Sources

* Industrial processes Chemical process engineering Oil refining {{petroleum-stub