Reservoir Enhancements and Production Technology Sequencing

摘要

Reservoir processes involving massive sand production, high temperatures, or high pressures cause changes in physical parameters (porosity, permeability, compressibility) and breach or shear barriers such as thin shale laminae, clay dustings on bedding planes, and shale beds up to several meters thick. These changes are beneficial to various production technologies as they will reduce the flow path length in gravity drainage processes improve flux rates, and accelerate thermal processes (reducing energy losses). New extraction processes are summarized, then the reservoir scale changes associated with CHOPS and with steam injection (high p, T) are reviewed. Then, the concept of formal sequencing of production technologies to take advantage of these changes will be presented As an example, the combination of CHOPS with horizontal cyclic steaming is attractive because of the process acceleration. Once communication is established, the CHOPS production approach is ceased, and wells converted to steam injection to achieve a process of SAGD using single wells rather than pairs. This is continued until steam injection is no longer economical, then inert gas injection (supercritical CO<,2> if possible) is used to strip another 10% of the oil from the hot reservoir. Also, combustion processes are far more likely to be successful in a case where the reservoir properties have been massively improved, and where the reservoir is hot. The concept of sequencing is explored for other configurations. It is believed that careful sequencing, planned in advance, can have major benefits on recovery factors and project economics. In good viscous oil reservoirs, systematic achievement of recovery factors greater than 0.75 seems feasible.