Methods of Transporting Various Bitumen Extraction Products and Compositions Thereof

PATENT
Methods of Transporting Various Bitumen Extraction Products and Compositions Thereof
United States Patent Application 20130006026
Inventors:
Kift, Julian (Reno, NV, US)
Joshi, Mahendra (Katy, TX, US)
Application Number:
13/524303
Publication Date:
01/03/2013
Assignee:
Marathon Oil Canada Corporation (Calgary, CA)
Abstract:
Methods for transporting bitumen extraction product include providing bitumen-laden aromatic solvent, providing bitumen-laden paraffinic solvent, and blending the two materials. The resulting mixture can be transported through existing pipeline infrastructure and can use existing separation processing equipment, and thereby avoids the need for separate infrastructure for each composition. Combining the two compositions can also avoid undesirable asphaltene precipitation.
BACKGROUND

Many traditional bitumen extraction processes, such as hot water bitumen extraction, use paraffinic solvent as a carrier liquid to transport extracted bitumen material. As a result, many bitumen extraction facilities are specifically designed for handling and processing compositions of bitumen and paraffinic solvent. For example, pipelines and distillation columns used in some traditional bitumen extraction facilities are tailored for being used with paraffinic solvent having bitumen dissolved therein.

The recent development of new bitumen extraction technologies, such as those described in U.S. Pat. No. 7,909,989, have resulted in the need for bitumen extraction facilities to have the capability to handle other solvents used as carrier mediums for bitumen. For example, the bitumen extracted in the methods described in the '989 patent are dissolved in an aromatic solvent. Accordingly, some modern bitumen extraction facilities must now consider ways in which different solvents having bitumen dissolved therein can be economically and efficiently transported and subjected to downstream processing.

Many of the proposed solutions to this issue are not economic or efficient. For example, one proposed solution is to provide an entirely new infrastructure designed for handling and processing the bitumen-laden aromatic solvent and which is used in conjunction with separate infrastructure designed for handling bitumen-laden paraffinic solvent. Such new and separate systems can include an entirely separate set of pipelines for and separate distillation towers used solely for the separation of aromatic solvent from bitumen. Such a solution is not desirable due to added cost and complexity of such a system. Another proposal has been to operate an existing system in shifts, whereby the existing equipment is alternated between processing the bitumen-laden paraffinic solvent and the bitumen-laden aromatic solvent. Not only does this proposed solution add expense and complexity to the system, but also slows down the overall rate at which the facility can operate. Still another proposal has been to separate the bitumen from the aromatic solvent and mix it with paraffinic solvent so that it can be joined with the bitumen-laden paraffinic solvent produced by the hot water extraction techniques. Such a solution would drastically increase the operating cost of the process and would have a negative impact on the environment due to the CO2 emissions associated with separating the aromatic solvent from the bitumen. Additionally, the asphaltene content in the bitumen separated from the aromatic solvent would subsequently precipitate when added with the paraffinic solvent, which can lead to equipment clogging and other issues.

SUMMARY

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary, and the foregoing Background, is not intended to identify key aspects or essential aspects of the claimed subject matter. Moreover, this Summary is not intended for use as an aid in determining the scope of the claimed subject matter.

In some embodiments, a method for transporting bitumen extraction products includes providing a first composition comprising bitumen and aromatic solvent; providing a second composition comprising bitumen and paraffinic solvent; and blending the first composition and the second composition.

In some embodiments, a blended bitumen extraction product composition is prepared by a method including the steps of providing a first composition comprising bitumen and aromatic solvent; providing a second composition comprising bitumen and paraffinic solvent; and blending the first composition and the second composition.

In some embodiments, a blended bitumen extraction product includes from 40 to 70 wt % bitumen; 2 to 50 wt % aromatic solvent; and 15 to 35 wt % paraffinic solvent.

Various advantages can be achieved from the methods and compositions described above. The embodiments summarized above use existing infrastructure, such as existing pipelines and distillation towers, rather than requiring dedicated equipment for the composition of aromatic solvent and bitumen. Accordingly, capital expenditures are minimized. Operating expenditures are also minimized by avoiding the need for separate distillation steps to separate aromatic solvent from bitumen. Correspondingly, CO2 emissions are minimized by avoiding the need for additional distillation steps. Additionally, because a relatively small amount of aromatic solvent and bitumen is blended with the composition of paraffinic solvent and bitumen, the pipeline transportation specifications (e.g., viscosity, API, stability) based on bitumen-laden paraffinic solvent are still met. The above described embodiments also adequately address any concerns related to asphaltene precipitation. The bitumen carried by the aromatic solvent includes asphaltenes. If the bitumen were separated from the aromatic solvent and then added to paraffinic solvent, the asphaltene content would precipitate and could lead to equipment clogging and other issues. However, when the bitumen material remains with the aromatic solvent, the subsequent addition to the bitumen-laden paraffinic solvent does not result in asphaltene precipitation due to the continuing presence of the aromatic solvent in the blended composition.

These and other aspects of the present system will be apparent after consideration of the Detailed Description and Figures herein. It is to be understood, however, that the scope of the invention shall be determined by the claims as issued and not by whether given subject matter addresses any or all issues noted in the Background or includes any features or aspects recited in this Summary.
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