Summary
The successful design of a polymer flood relies on the ability to properly
model the in-situ distribution of polymer concentration while accounting for
its effects on fluid properties such as increasing water viscosity as a
function of polymer concentration and loss of polymer caused by adsorption.
Despite advances in numerical techniques and computer hardware, the numerical
modeling of polymer floods using Eulerian-based approaches such as finite
difference (FD) remains a challenge: Coarse grids tend to excessively smear
concentration fronts, masking the true impact of polymers; yet introducing
finer grids inevitably leads to excessive run times, making the use of modern
reservoir-engineering workflows unrealistic. This problem was already outlined
in 1978 by Lake et al. (1981). We revisit the same problem 30 years later in
the context of modern streamline (SL) simulation techniques.
We present the extension of modern SL simulation to field-scale polymer
flooding, which represents a step change from the hybrid, 2D steady-state
models used in the 1970s. We apply well-established physical models for polymer
flooding to capture the displacement efficiency in 1D, and couple it with a 3D
SL simulator to capture the interpattern sweep efficiency caused by well rates,
reservoir architecture, and reservoir heterogeneity. Because modern 3D SL
simulators account for changing well rates, nonuniform initial conditions, and
gravity, adding polymer functionality means that real-field polymer floods can
be modeled efficiently using SLs so as to be useful in modern
reservoir-engineering workflows that center on assessing uncertainty and risk
associated with design parameters and geological scenarios.
In this paper, we proceed to outline the basic architecture of a SL
simulator with a polymer option. The physics of polymer flooding is the same as
that being used in established FD codes. We discuss advantages and
disadvantages of the formulation and present in numerical experiments 1D, 2D,
and 3D to illustrate our results.
© 2010. Society of Petroleum Engineers
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History
- Original manuscript received:
26 June 2008
- Meeting paper published:
22 September 2008
- Revised manuscript received:
20 January 2009
- Manuscript approved:
6 August 2009
- Published online:
19 April 2010
- Version of record:
20 April 2010
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