Abstract
Exploratory well tests typically require timely, yet accurate log analysis from the responsible formation evaluation specialist. A rapid turnaround in the analysis is demanded due to economic considerations and decisions that are routinely made from log-derived, in-place reserve estimates. In general, in-place estimates are quickly expanded to include the reservoir's areal extent that was likely conceived from prior seismic and geological studies. Wireline data usually provide the porosity, saturation, pay thickness, and evidence of producibility that are input into reserve calculations. Core data are seldom available on exploration tests, especially in carbonate reservoirs.
A flexible algorithm defines formation resistivity factor (FR) boundaries within which log measurements from carbonates occur. Evidence shows the n exponent in carbonate reservoirs to be strongly affected by wettability characteristics and porosity type, but tolerable estimates of n can be made to obtain relatively accurate and timely estimates of saturation.
