Abstract
Simple interpretation models, which are fast and reliable, are usually used in traditional well test analysis for estimating well and reservoir properties. However, more sophisticated interpretation models are required for the identification, description and quantification of geologically complex reservoir systems. These complex models are often not readily available in the literature.
This paper presents a multi-disciplinary approach involving ‘history matching’ of well test data to seismic and geological information using a simple 2D numerical simulator.
The test case is a practical scenario where a long multi-rate test in a gas reservoir is history-matched (using the 2D numerical simulator) with geological and petrophysical data to obtain a test drainage radius. Then the deterministic (volumetric) estimates of hydrocarbon-initially-in-place based on the resulting geometry (from the numerical simulation) are compared with estimates of minimum tested volumes derived using the method of Whittle et al, 2008.
In the end it is shown that for single-phase systems with small pressure drops, the simple 2D numerical simulator can aid in the reduction of geological uncertainty thereby solving a complex problem through relatively simpler means.
