Abstract
The Bach-01 reservoir has one of Heavy Oil Reserves (12° API) the most importan West Venezuela with an OOIP 6621 MMSTB. Stratigraphically the reservoir is comprised of Miocene sediments (Member Bachaquero, Lagunillas Fm) with a thickness of 750ft, the product of sedimentation prograding fluvial-deltaic domain, being divided into 8 intervals informal (AP, H, G, F, E, D, C, AB), which are marked differences in thickness, rock quality, facies and distribution of fluids. On the other hand, the development plan of the field horizontal wells has been based only on exploiting the upper sand (AP unit), which represents 75% of the OOIP. In this research, we have visualized and conceptualized new opportunities for development of heavy oil reserves, by optimizing steam injection in horizontal wells, through gas injection during the soaking period (CSS+GAS).
The work integrates geological and reservoir of upper-lower sands and thermal evaluation of the optimal parameters of steam injection and rock-fluid characterization. In this research were used field data for making model pit that is the representation of the behavior of production wells, subjected the process of css+gas and weighted data reservoir, for performing a pseudo-compositional thermal simulation black oil system, through which were evaluated the effects caused in the reservoir, by css+gas process. The most outstanding results concerning this process were: increase oil accumulated by cycle, increased volume of the steam chamber in horizontal wells and, decreased viscosity.
