Seven-Spot Steam Injection Experiments in Heavy Oil Reservoirs Having a Bottom Water Zone

摘要

A 3-D scaled physical model was used to compare the performance of steam injection in reservoirs having a bottom water zone with the application of different well configurations. The model was triangular, designed to represent 1/12 of a seven-spot pattern in the Bati Kozluca field in Turkey. Nine experiments were conducted by using the triangular model with or without a bottom water zone. The well configurations were changed during the course of experiments to determine their effects on oil recovery. Bottom water thicknesses were changed to see the effects on oil recovery. The physical properties of a crushed limestone and crude oil (12.4° API) mixture were kept constant during the experiments. Steam was injected through a vertical well. Strings of thermocouples were used to observe the 3-D temperature distribution inside the model. The maximum oil recoveries were obtained by placing the horizontal producers along the hypotenuse of the triangular model. This well configuration provided better oil recovery than any other well configuration, even in the presence of a bottom water zone. Oil recoveries decreased with an increase in the thickness of the bottom water zone. The steam—oil ratio increased in the presence of bottom water.