WCP -
I would suggest updating your model to account for at least comparable pay as those encountered immediately adjacent to the Kawa well location in Block 58 (Maka Central and Kwaskwasi). These are the closest and direct analogues to CGX's Kawa well.
Maka Central upper santonian = 240ft of pay
Kwaskwasi = 423ft of pay
Note, during the CGX/Frontera Operational update held in October 2021 - Jennifer Budlong referenced that they are expecting to encounter thicker and coarser santonian based reservoirs then those announced by the block 58 venture group (Apache / Total). That's not only based on CGX/Frontera seismic interpretation of H23 - but, also the geophysical assessment given Kawa's location being immediately adjacent to the mouth of the giant Bernice Canyon feeder system. The berbice canyon feeder system being the source for all sandstone reservoirs deposited in Block 58 as well in the South-Eastern Area of the Stabroek license (Haimara, Pluma, and the broader Turbot area).
H23 or H25 pay (Maka comparable - 240ft):
STOOIP = 7758 * 10,000 * 240 ft * .25 * (1-.30) / 1.2; or, 2.7 billion barrels in place.
Recoverable resource = 2.8 * 25% = ~680mmboe
H23 and H25 pay (Maka comparable - 240ft):
STOOIP = 7758 * 10,000 * 480 ft * .25 * (1-.30) / 1.2; or, 5.4 billion barrels in place.
Recoverable resource = 5.4 * 25% = ~1,350mmboe
H23 or H25 pay (Kwaskwasi comparable - 400ft):
STOOIP = 7758 * 10,000 * 400 ft * .25 * (1-.30) / 1.2; or, 4.5 billion barrels in place.
Recoverable resource = 4.5 * 25% = ~1,100mmboe
H23 and H25 pay (Maka comparable):
STOOIP = 7758 * 10,000 * 800 ft * .25 * (1-.30) / 1.2; or, 9.0 billion barrels in place.
Recoverable resource = 9.0 * 25% = ~2,300mmboe
Unfortunately, CGX/Frontera did not reveal specific P10, P50, or P90 figures for Kawa. Nor did they reveal their internal view on Kawa's probability of success.
What they did share was a proximate amplitude area of the campanian, upper Santonian, and lower Santonian features of Kawa. Both upper and lower santonian features (H23 and H25) appear to be larger then the size of two US GoM blocks.
If we generally take the net pay inputs of those direct analogues in Block 58 (Maka and Kwaskwasi) - and incorporate the possibility of stacked reservoirs - you can come up with more a billion barrels of recoverable resource using the model you provided.
Happy New Year - we are close to entering the auspicious year of the Tiger.
Hold on to your chair!