In Brazil, there are several offshore oil fields with horizontal oil-density
variations. API tracking, which is available in some commercial finite
difference simulators, can deal with such cases by allowing the definition of
an initial oil-gravity distribution and tracking variations of oil density,
owing to the movement of oil.
Streamline-based simulators can be much faster than conventional
finite-difference simulators when applied to large and heterogeneous models.
However, this approach is most accurate and efficient when it is assumed that
the rock and fluids are incompressible. In previous work, Beraldo et al. (2007)
presented an incompressible formulation for streamline simulation with an API
tracking option using two components in the oleic phase.
This paper presents a compressible formulation for streamlines that also
considers API tracking. It has an approach similar to the one presented by
Cheng et al. (2006) and Osako and Datta-Gupta (2007). However, cumulative
volume is used in the streamline solution, instead of time of flight, which
reduces mass-conservation errors.
The method was implemented in a 3D two-phase streamline-based simulator.
Tests based on a Brazilian oilfield model demonstrate that the implementation
can reproduce the results of a conventional simulator, even when significant
liquid compressibilities are considered. Another test, using the SPE 10th
Comparative Case, indicates that it can be substantially faster for finely
© 2009. Society of Petroleum Engineers
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- Original manuscript received:
7 July 2008
- Meeting paper published:
21 September 2008
- Revised manuscript received:
21 May 2009
- Manuscript approved:
5 June 2009
- Published online:
24 November 2009
- Version of record:
31 December 2009