Numerical Simulation of Laboratory Steamflood Experiments
Authors: Hayashitani M. , Davis W. , Novosad J. , Batycky J.P. 
Published: March 2010

The Petroleum Recovery Institute has operated a scaled steamflood physical model since 1975. The objective of this work was to define and to evaluate the capabilities and limitations of Intercomp Ltd. "s numerical steamflood simulator and the Petroleum Recovery Institute"s physical model.

Three different types of laboratory experiments were selected for numerical history matching-waterflood, hot-waterflood and steamflood. The objective was to match oil, water and steam production as well as the energy balance and temperature profiles, using a single set of physical and petrophysical parameters. In addition, sensitivity studies were computed for three different grid systems, specifically a coarse cross-sectional grid (8xlx4), a fine cross-sectional grid (l6x1x8) and a three-dimensional grid (9x5x4).

Excellent matching was obtained for the fluids production and for the energy balances. However, some, difficulties were encountered during attempts to match some of the temperature profiles, especially those associated with the flow of hot water along the bottom of the reservoir. As a result of the simulations, new measurements of thermal conductivity between the model and the underlying concrete bed were performed. A more complete interpretation of the physical model was obtained.

The results indicate that physical model experiments offer useful data which can enable testing and calibration of numerical models, while the latter can help in obtaining a more precise description of the former. Therefore, the physical and numerical models should be used in a mutually complementary manner.

INTRODUCTION

Numerical simulators for steam injection oil recovery processes are being used frequently by reservoir engineers especially in the three areas of history matching(1–6), sensitivity studies(6–7) and field design and prediction(8–10). However, numerical simulators are complicated reservoir engineering tools and one has to realize their capabilities and limitations in order to use them properly.

The successful design of any enhanced oil recovery process requires that one be equipped with a reliable set of reservoir data which includes geological, physical and petrophysical properties. History matching with a numerical simulator is often used to verify the parameters that have been obtained from laboratory measurements, well logs or by correlation. Typically, it is difficult to obtain a unique result from history-matching studies of field-derived performance data because a large number of parameters, involved in the calculations, must be either estimated or determined indirectly.

History matching of laboratory steam flood experiments provides a better insight into the numerical simulator"s capabilities, because one has better control over most of the parameters defining the system. An additional advantage of history matching laboratory data is that more experimental data, usually of higher quality, are available to enable comparison with numerical results.

The PRI Research Division has been studying steamflood oil recovery processes using a one-twelfth of an inverted seven spot, partially scaled physical model(ll.12.l3) since 1975. Some sixty experimental runs have been made to date for various steam injection rates, steam qualities, initial water saturations and oil characteristics. Three of these runs were chosen for this study – a cold-waterflood, a hot-waterf1ood and a steamflood.

(Figure in full paper)

Physical Model Apparatus

The experimental apparatus is shown schematically in Figure 1.