Fluid Composition Using Optical Analysis and Gas Chromatography

摘要

Methods and systems are provided for determining a gas/oil ratio using gas chromatography and optical analysis of a fluid sample obtained using a fluid sampling tool. In some embodiments, a gas/oil ratio may be determined from the mass fraction of each light component of the fluid, the mass fraction of each intermediate component of the fluid, a molecular weight of each light component of the fluid, a molecular weight of each intermediate component of the fluid, the density of stock tank oil, the vapor mass fraction of the intermediate components of the fluid, and the mass fraction of the plus fraction of the fluid. In some embodiments, a gas/oil ratio may be determined from the density of stock tank oil, the vapor mole fraction of the intermediate components of the fluid, and the molecular weight of stock tank oil.

主权项

1. A method for determining a composition and gas/oil ratio of a fluid, comprising:
quantifying a plurality of components of a fluid sample from measurements obtained from a gas chromatogram adapted to receive a first portion of the fluid sample and from an optical analyzer adapted to receive a second portion of the fluid sample, wherein the plurality of components comprises light components and intermediate components; determining a mass fraction for each light component of the plurality of components; determining a mass fraction for each intermediate component of the plurality of components; determining a gas/oil ratio of the fluid sample from the mass fraction of each light component, the mass fraction of each intermediate component, a molecular weight of each light component, a molecular weight of each intermediate component, the density of stock tank oil, the vapor mass fraction of the intermediate components, and the mass fraction of a plus fraction determined from the fluid sample.