Chevron U.s.a. Inc.

Ian Phillip Benson

Cesar Ovalles

Michael Moir

Estrella Rogel

Ajit Ramachandra Pradhan

Toni Zhang Miao

Eddy Lee

Ronald A Behrens

Cesar Francisco Ovalles

In-situ upgrading of heavy hydrocarbons includes injecting into a reservoir solvent, an asphaltene precipitant additive and optionally steam, at a ratio of solvent to heavy hydrocarbon between 0.1:1 and 20:1 under reservoir conditions. The additive has C&#x2014;H, C&#x2014;C and/or C&#x2014;O bonds that thermally crack to generate free radicals in the vapor phase after injection. Formed downhole are a blend containing an upgraded hydrocarbon, and precipitated asphaltenes. The upgraded hydrocarbon is produced such that the precipitated asphaltenes remain in the reservoir. The upgraded hydrocarbon has a greater API gravity, lower asphaltene content, and lower viscosity than the heavy hydrocarbon. The precipitated asphaltenes are present in a higher amount than a similar blend not containing the additive. A method for selecting the additive includes identifying candidate additives having bonds that crack to generate free radicals in the vapor phase at the operating temperature, and calculating percent increase of asphaltenes precipitated for each.

Method of selection of asphaltene precipitant additives and process for subsurface upgrading therewith

A method is provided for producing upgraded heavy oil from a subterranean reservoir by producing a steam chamber within the reservoir by the action of steam and flowing a liquid phase additive into a near wellbore region of the steam chamber to control asphaltenes mobility within the near wellbore region. Build-up of asphaltenes, which derive from the heavy oil, in the near wellbore region has the potential of affecting heavy oil production rates from the reservoir. The additive is formulated to mobilize the asphaltenes within this region.

Method for upgrading in situ heavy oil

A method of estimating the relative concentration of at least two components contained in a mixture of the components is disclosed. At least two mixtures are produced by combining the at least two components, each of the at least two mixtures having different concentrations of the at least two components. NIR mixture spectra are acquired from each of the at least two mixtures. The NIR component spectra and the NIR mixture spectra are input into a computer utilizing chemometrics software and the spectra are analyzed to produce a calibration model for each component and each of the mixture NIR spectra. NIR monitored spectra for a monitored mixture of the components having an unknown concentration of the components is acquired. The calibration models are applied to the NIR monitored spectra to thereby estimate the concentration of at least one of the components in the monitored mixture.

Method and system for NIR spectroscopy of mixtures to evaluate composition of components of the mixtures

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The Woodlands, TX, United States of America

Ian Phillip Benson