Page 218 - Basic Well Log Analysis for Geologist

LOG INTERPRETATION CASE STUDIES

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from 16.325 to 16,370 ft. If, in fact, a loss of vuggy thickness (h) = 8 ft; gas gravity = 0.63 (estimated).
porosity has caused the abrupt change to lower resistivities, temperature (estimated) = 228°F; BHP (estimated) = 7,260
then the interval may not represent a zone above irreducible psi: recovery factor (RF) = 0.75; Z factor = 1.165. A
water saturation (i.e. “wet zone”). Unfortunately, without geothermal gradient of 0.014 x depth and a pressure
having a core to analyze, you can’t determine with any gradient of 0.445 x depth.
certainty whether or not the 16,325 to 16,370 ft interval will The Hunton was perforated from 16,306 to 16,314 ft with
be water or hydrocarbon productive, and so you decide to 27 holes. Completion was natural and the calculated open
avoid pertorating it in this well. flow (CAOF) of the well was 67,023 mefgpd and the
porosity (b) = 7%; water saturation (S,) = 11%; reservoir months of production, the Hunton produced 0.455 BCF
shut-in tubing pressure was 4.639 psi. During the first six
The estimated gas recovery is 2.76 BCE Parameters used
to arrive at this figure are: drainage area (DA) = 540 acres;
plus 2,030 barrels of condensate.