Energy Policy Act of 2005 (Ultra-deepwater and Unconventional Resources Program)
Heavy Viscous Oil PVT, Ultra Deepwater Program
The objectives of this project include 1) Evaluation of current practice in heavy viscous oil PVT measurement, correlation and models; experimental validation of the models; 2) Development and recommendation of best practices of sample handing and laboratory measurement methods. 3) Study the impact of solvent and commingling of different fluids on viscosity change and asphaltene instability; examination of the existing models and mixing rules in handling the property change. 4) Report conditions where multiple phases exist.
The experimental program for the proposed heavy viscous oil PVT study includes the sample preparation and preliminary analyses such as dewatering/cleaning of live heavy oil samples (demulsification) with various techniques, GOR, composition and API measurement of clean oil samples etc. The best practice and sample preparation procedure will be documented. Before measuring the viscosities of heavy viscous oil mixture (HVO) with solvents, the asphaltene titration tests will be performed with each solvent in order to check the compatibility of solvent with original heavy oil with respect to asphaltene precipitation. The HVO and HVO mixture density will then be measured with electromagnetic viscometer (EMV) and capillary viscometer for various types of fluids. The density of each HVO and HVO mixture will be measured at the P-T and concentrations points as viscosity with HPHT Anton-Parr densitometer. The details of the experimental method and proposed technology are discussed in the following sections.
A consolidated report documenting the work performed in each task will be prepared. The deliverables for all technical work task report will include the following:
- Task 5 – Develop and verify “best practice” sample preparation document for cleaning and sampling heavy oils, while maintaining sample integrity, for analysis.
- Task 6 – Develop and validate procedures for determining the viscosity and density of a series of mixtures that will be used to test and validate existing mixture rules for viscosity and density for oils mixed with oils, gases mixed with oils, and solvents mixed with oils.
- Task 7 – Develop and validate a “best practice” document for measurement of heavy oil viscosity determination as a function of temperature and pressure from experimental example results.
- Task 8 – Develop a benchmarked database for HVO and its mixtures with other crude oils and solvents, and evaluate the performance of existing HVO viscosity correlations as well as mixture viscosity models/correlations.