In 2014, I have involved in multi-billion dollars EPC project in Indonesia. The project handled gas and condensate. For condensate, it was stated that the quality shall meet certain RVP (Reid Vapor Pressure) value. In this post, I want to share what RVP is.
Definition of RVP (Reid Vapor Pressure)
Stabilized condensate generally has a vapor pressure specification. Its specification is usually identified by its Reid Vapor Pressure (RVP) or True Vapor Pressure (TVP).
Reid Vapor Pressure (RVP) is related to the vapor pressure of a petroleum product, which measures its inherent tendency to evaporate at 100oF with vapor:liquid ratio of 4:1 (ASTM D323). RVP is a function of hydrocarbon’s composition and is independent of operating temperature and pressure. The value of RVP lies below the true vapor pressure.
The higher the RVP, the more quickly the condensate or oil will vaporize into the air.
RVP Specification
RVP is usually set by local emissions authorities to limit hydrocarbon emission during storage and transportation. Typical RVP specification ranges from 4 to 8 psia. For hydrocarbon storage in high elevation, the atmospheric pressure is lower, consequently a low RVP as low as 4 psia may be necessary, allowing some safety margins.
In other reference [3], RVP specification is a function a climate. It is because increase in temperature will increase volatility of gas condensate component. Thus, the stability of condensate is climate-dependent.
Based on this reference [3], during winter, RVP should not be higher than 13.5 psia and not higher than 9.7 psia during summer.
The New York Mercantile Exchange (NYMEX) specify RVP of crude oil to be less than 9.5 psia. While Baken crude oil has an RVP of at least 8.75 psia up to 15 psia [4].
In addition to RVP specification, other specification for commercial grade condensate includes the following component:
References:
- Mochatab, Saeid, et al., “Handbook of Natural Gas Transmission and Processing”, Gulf Professional Publishing, 2015
- Arnold, Ken and Maurice Steward, “Surface Production Operations”, Gulf Professional Publishing, 2008
- Methods of Stabilization of Gas Condensates, Ibukun Makinde, Ph.D
- Steve Buschang State SSC Academy