Abstract
Heavy-oil occurring in thick reservoir is an important resource world-wide. Heavy-oil recovery from such reservoir using cyclic steam is an efficient solution due to very high oil viscosity. However heavy oil recovery at later cyclic steam soaking is a real challenge, yet no direct analogues exists as an efficient solution.
We proposed a new method called stereoscopic network development and needed for efficient heavy-oil recovery from thick reservoir, consisting of ten vertical wells and two horizontal wells in the following manner:
1. Stereoscopic network: adding two superposed horizontal wells between vertical wells in rectangular pattern.
2. Operation: steam injection through the upper horizontal well and production through the lower and all vertical wells.
Field practices of managing a steam flood with stereoscopic network in thick reservoir has shown that oil production and oil-steam ratio increased obviously, and water cut decreased sharply.
In this work, the field results obtained early and parameters were needed for field scale simulation. The numerical model has been developed by CMG simulation software and was validated with field data. Using field results and numerical simulations study on stereoscopic network development, the mechanism of stereoscopic network to enhanced heavy-oil recovery in thick reservoir has been studied theoretically and with field test results. And field scale simulations were performed to identify the efficiency of the new method and the optimal injection/production schemes. Specific conclusions as to how to apply the method in thick reservoir considering the effect of the method were reported.
