Several mechanisms can be responsible for the compositional modification of
a hydrocarbon fluid in a reservoir. One of them is related to its contact
with a large amount of connate water. This water-washing phenomenon has bee
n simulated in model laboratory conditions. A compositional analysis of bot
h water and hydrocarbon phases at every stage allows for a direct visualisa
tion of the effect of water-washing. Volumetric measurements have been perf
ormed simultaneously. Henry's law is used to describe the hydrocarbon solub
ility in water. This approach is validated with a global mass balance. (C)
2001 Elsevier Science B.V. All rights reserved.