heron - the story continues, page-43

Iam
Love your posts but just wondering in the diagram of the Heron cross structure you terminated Heron 1 at a depth of 3900 RT when this well was drilled to 4209 mKB (meters below kelly bush is this the same as RT)

"The well penetrated a thick Cenozoic to Late Jurassic succession of sedimentary rocks and reached a total depth (TD) of 4209 mKB within the Petrel Formation [Flamingo Group]. Vertical closure for the structure is based on closure mapped at the Aptian unconformity (Shell Development (Australia) Limited, 1998a). The lower part of the well penetrated competent shales and minor sandstones. Due to slow penetration rates, lack of porosity (0.6-6.2%) and permeability (<0.1 mD) in the penetrated sandstones, and junk in the hole, drilling was terminated before reaching the programmed total depth of 4724 mKB. A high bottom hole temperature, approaching 204.5°C, was measured in Heron 1."

The thing of interest is that it finished in sandstone, could this be the top plover section. Another thing I never knew is a core sample was cut at 4101.4m to 4114.3m. Here are some comments on the core sample.

"One conventional core was cut from 4101.4 - 4114.3m with 100% recovery"

"Fluid saturation (% pore space): oil = 0.0%, water = 3.8%. See remarks."

Eni's first core was thought to be just abover the plover formation, 40 years ago in 1972 could they have made the same mistake and cut the core too early? Here's the Heron 1 report with depths and remarks

http://dbforms.ga.gov.au/pls/www/npm.well_wam.produce_detail_data?pWellHeaderEnos=&pOrgchemEnos=&pResfacsEnos=&pResfacsEnos=12062&pStratdatEnos=&pIsopachEnos=&pSummaryEnos=&pGraphEnos=&pTimescale=A&pAgeMin=0&pAgeMax=3000&pTotalAge=144.6&pStage=