So, yes the engineers that do the reserve determination will use all of  the data available. Seismic, gravity, logs, cores, flow tests etc. I would not say they will “average” the methods but that they will give what they consider to be the proper weight to each technique in determining their final number. I guess this is why there is such a wide spread between the companies that have given previous estimates.

About the only good news that I can think of is that most of the data obtained since GLJ gave their first estimate in 2009 has been positive.

• Wells have mostly come in higher than anticipate making the reservoir thicker.
• The good porosity rock has been better than expected in the last two wells, Antelope-4 ST-1 and Antelope-5.
• Antelope-3 was also a great well that was drilled since 2009.
• Now they think the western fault is further to the west making the area of the field larger.
• The results from Antelope-4 and Antelope-5 indicated that the gas/water contact may be lower than presently being used.
• The flow tests at Antelope-5 have shown how great the deliverability is with 60+ MMCFD and a drawdown of only 2 psi.
• And of course the minimum reservoir pressure loss (0.06 – 0.08 psi) during the first flow test which produced 152.9 MMCF is a positive indication.

One would think the present resource number should be larger than GLJ got in 2009 before they got all of this additional positive data.

Source: Where is the Gas/Water Contact and the Elusive Western Fault?