Отправлено: 21.06.07 03:51. Заголовок: Параметр насыщения карбонатов с двойной пористостью

Conductivity of Double-Porosity Carbonate
Formations Saturated with Water – Oil Mixtures
A. Mousatov* (Mexican Petroleum Institute), E. Kazatchenko (Mexican Petroleum Institute), M. Markov (Mexican Petroleum Institute) & E.Pervago (Mexican Petroleum Institute)
SUMMARY
The determination of water saturation from resistivity logs is an important problem in formation
evaluation required for the correct assessment of oil-resources. In carbonate formations this problem is
especially complicated because of the complex structure of pore space composed of the small-scale matrix
porosity and large-scale secondary pores of different shapes.
In this paper we introduce a new approach for calculating the conductivity of carbonate formations with
different wettability types. This approach is based on the double porosity model and computing the
conductivity of pore saturating fluid treated as a mixture of conductive water and non-conductive oil (gas)
inclusions. The non-conductive component is represented by spheroids embedded in the water (host). The
variation of inclusion shapes allows us to model the dependence of conductivity on the formation
wettability.
The calculations have shown that the effective conductivity of the double porosity formations significantly depends on the type of the secondary pores, rock wettability, and water saturation of the matrix and secondary pore-systems. This result indicates that the assessment of the water saturation in carbonate formations, using traditional approaches without considering the secondary-porosity and wettability types, may lead to erroneous oil reserve estimation.

Статья коллег из Мексики (Михаил Марков регулярно пишет на данном Форуме)
Авторы сопоставляют разнообразные расчетные кривые для сред с разной геометрией прооводящих включений и результаты экспериментов заимствованные ими из публикаций
Sweeney, S. A. and Jennings, H. Y. Jr., 1960, Effect of wettability on the electrical resistivity
of carbonate rock from a petroleum reservoir,Journal of Physical Chemistry,64,551-553.

Longeron, D. G., Argaud M. J., and Feraud, J.-P.,
1989, Effect of overburden pressure and the nature and
microscopic distribution of fluids on electrical
properties of rock samples, SPE Formation Evaluation,
June, 194-202.