Process for upgrading heavy hydrocarbon oils

Abstract

A process using supercritical water to upgrade a heavy hydrocarbon feedstock into an upgraded hydrocarbon product or syncrude with highly desirable properties (low sulfur content, low metals content, lower density (higher API), lower viscosity lower, residuum content, etc.) is disclosed. The process does not require external supply of hydrogen nor does it use externally supplied catalysts. Improved methods of mixing the reactants are also disclosed.

Description

FIELD OF THE INVENTION[0001]The present invention relates to upgrading of heavy hydrocarbons such as whole heavy oil, bitumen, and the like using supercritical water.BACKGROUND OF THE INVENTION[0002]Oil produced from a significant number of oil reserves around the world is simply too heavy to flow under ambient conditions. This makes it challenging to bring remote, heavy oil resources closer to the markets. One typical example is the Hamaca field in Venezuela. In order to render such heavy oils flowable, one of the most common methods known in the art is to reduce the viscosity and density by mixing the heavy oil with a sufficient diluent. The diluent may be naphtha, or any other stream with a significantly higher API gravity (i.e., much lower density) than the heavy oil.[0003]For a case such as Hamaca, diluted crude oil is sent from the production wellhead via pipeline to an upgrading facility. Two key operations occur at the upgrading facility: (1) the diluent stream is recovered ...

AI Technical Summary

Benefits of technology

"The present invention is about a way to upgrade heavy hydrocarbons by mixing them with heated water to form a mixture. This mixture is then reacted under supercritical water conditions without adding any extra hydrogen. The resulting product is a single-phase reaction product that can be separated into gas, effluent water, and upgraded hydrocarbon phases. The technical effect of this invention is the ability to upgrade heavy hydrocarbons to higher quality products without the need for additional hydrogen."

Problems solved by technology

Oil produced from a significant number of oil reserves around the world is simply too heavy to flow under ambient conditions.

This makes it challenging to bring remote, heavy oil resources closer to the markets.

1. The infrastructure required for the handling, recovery, and recycle of diluent could be expensive, especially over long distances. Diluent availability is another potential issue.

2. Hydrogen-addition processes such as hydrotreating or hydrocracking require significant investments in capital and infrastructure.

3. Hydrogen-addition processes also have high operating costs, since hydrogen production costs are highly sensitive to natural gas prices. Some remote heavy oil reserves may not even have access to sufficient quantities of low-cost natural gas to support a hydrogen plant. These hydrogen-addition processes also generally require expensive catalysts and resource intensive catalyst handling techniques, including catalyst regeneration.

4. In some cases, the refineries and / or upgrading facilities that are located closest to the production site may have neither the capacity nor the facilities to accept the heavy oil.

5. Coking is often used at refineries or upgrading facilities. Significant amounts of by-product solid coke are rejected during the coking process, leading to lower liquid hydrocarbon yield. In addition, the liquid products from a coking plant often need further hydrotreating. Further, the volume of the product from the coking process is significantly less than the volume of the feed crude oil.

It is well understood that solids in the system will pose significant challenges for reactor and process design.

Direct heating of oil feed may lead to over heating which in turn leads to more solid residue formation, lower desired product yield and lower product quality.

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