Application of Cyclic Steam Stimulation by Horizontal Wells in Iranian Heavy Oil Reservoirs


1 Department of Petroleum and Natural Gas Engineering,University of Tehran

2 -------,The Research Center of Petroleum University


In Iran, there are a number of heavy oil reservoirs whose importance is growing as the
conventional resources deplete. This study concerns the numerical simulation of cyclic steam stimulation
of one of the heavy oil reservoirs. Results are encouraging and should be tested by eld pilots. Heavy oil is
characterized by its high viscosity. Thermal methods reduce viscosity and residual oil saturation to improve
mobility and achieve an economical recovery. Cyclic Steam Stimulation (CSS) which has faster production,
lower capital costs and lower pressure operations than steam-
ooding is of great interest in thermal
methods. Oil recovery with steam injection has been enhanced with horizontal wells by increasing sweep
eciency, the contact area opened to
ow, producible reserves, steam injectivity and also by decreasing the
number of wells required so that higher oil production is reached. K-Field is one of the Iranian fractured
heavy oil elds with low API of 7.24 and high viscosity of 2700 cp. Although steam injection in naturally
fractured heavy oil reservoirs provides extremely challenging issues, it can be considered as a potentially
e ective and ecient improved recovery method. In this study, using STARS, a thermal dual-porosity
model was constructed based on the available measured data to study CSS. Comprehensive and comparative
studies and a sensitivity analysis of various operational parameters were conducted in order to nd the
optimum conditions for a high RF. This work shows that oil recovery could be improved from 0.66% by
cold production to more than 10% by CSS during a 10 year period.