Abstract
Proper reservoir characterization is the key to successful implementation of improved oil recovery programs. The recovery efficiency of any reservoir is mainly controlled by its heterogeneity. Interwell connectivity is considered as a direct measure of reservoir heterogeneity. This study uses a hydraulic interwell connectivity concept to characterize sandstone reservoirs. It defines and investigates the Interwell Flow Capacity Index (IFCI) to quantitatively characterize the reservoir connectivity. This approach is an integrated study of reservoir characterization, geostatistics, production performance and reservoir engineering. In this study IFCI is quantitatively defined as the ratio of observed fluid flow rates in any two adjacent wells in a producing unit. Geostatistics and fluid dynamics are used to evaluate the reservoir connectivity. The spatial variation of IFCI can be used to describe the degree of communication between injectors and producers, to evaluate the reservoir rock quality and to describe the production-injection performance. The spatial distribution of IFCI can also serve as a guide to modify water injection patterns, select infill well locations, define workovers and other operational strategies for waterflooding. A Colombian (South America) sandstone producing unit, La Cira Field "C Zone", is used to illustrate the application of IFCI concept. This zone has been subdivided into 16 genetic units. The CIC genetic unit (average reservoir permeability of 31 md and sand thickness of 6 feet) is used as an example to illustrate the application of this approach. The geological model is improved by incorporating the IFCI, which helps to define the flow units. IFCI model is a practical approach to evaluate the injection and production performance of existing waterflood patterns. The IFCI approach should be useful for interpreting the variability of oil recovery and improving the implementation of optimized waterflood process and targeted infill drilling.
Canas, Jesus Alberto (1993). Use of a hydraulic interwell connectivity concept for sandstone reservoir characterization. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1993 -THESIS -C213.