Summary
This paper documents progress in the development of a numerical model to
predict the amount and rate of sand production at the scale of a wellbore or
perforation. The model uses a continuum hydromechanical description of the rock
mass, coupled with a superficial erosion scheme with evolving geometry.
Different modes of cavity evolution have been observed in laboratory
experiments to study sand production (uniform, dog-ear, and slit), and the
various modes have been associated with different rock failure types (tension,
shear, and compaction). In this work, the sand-production model (which can
accommodate tension and shear failure) is also expanded to account for the
combination of volumetric collapse (compaction band formation) and transport of
failed material by hydrodynamic forces. It is shown, using numerical
experiments, that those two basic ingredients can lead to the development of
the slit mechanism.
In this paper, we review the basic conditions for the compaction mode of
failure to occur by considering a simple cap constitutive law and give examples
of numerical simulations that illustrate band formation in a (dry) hollow
cylinder test. Also, using numerical experiments, we show that the
sand-production model, enhanced with a constitutive law featuring a volumetric
cap, is able to reproduce qualitatively the slit mode of cavity evolution that
has been observed in laboratory settings. One key feature of the computational
model is a sand-production curve giving sand-mass production versus simulation
time. With the documented enhancement, the model can generate sand-production
curves associated with tension, shear, and compaction failure. The
sand-production model needs to be developed and validated further, and
calibrated using laboratory experiments. However, at this stage, it shows good
potential as an engineering tool to help characterize the impact of rock
strength on sand production associated with oil production.
© 2009. Society of Petroleum Engineers
View full textPDF
(
993 KB
)
History
- Original manuscript received:
30 June 2008
- Meeting paper published:
21 September 2008
- Revised manuscript received:
5 January 2009
- Manuscript approved:
18 January 2009
- Published online:
2 July 2009
- Version of record:
22 December 2009
View Cart
