| dc.description.abstract | Unconventional shale and tight reservoirs have contributed over a half of oil and gas of total U.S. production these years. As well known, phase behavior of the fluid in unconventional reservoir is quite different from that in conventional reservoir. And the variation of the thermodynamic and transport properties of fluids has a significant impact on the well performance and ultimate recovery of unconventional reservoirs. Therefore, an effective and reliable method to investigate and predict the impact of confinement on well performance and ultimate recovery of unconventional reservoirs is necessary and of great importance. In this study, a mechanistic model of both depletion and injection for well performance prediction of unconventional reservoirs was developed, incorporating capillary pressure and pore size distribution, to provide a comprehensive approach to simulate the effect of confinement in unconventional reservoirs. With the developed mechanistic model, fluid model and pore size distribution models, a series of sensitivity analysis were conducted to investigate the impact of the variables including: capillary pressure, production modes, pore size distribution, pressure decline steps, wettability angle, injection dose per step, bottom-hole pressure (BHP) and injection fluid distribution. The developed mechanistic model gives a rapid prediction and estimation of the production performance especially for unconventional reservoirs by incorporating the capillary pressure and pore size distribution. It also can predict the production performance changing with different operation conditions, which is of vital importance in the field operation to optimize production. Furthermore, this mechanistic model provides the best and the worst extreme boundaries of the production performance, and two different injection fluid distribution models, which can be used as a guidance for other reservoir simulation methods. | en |
