Appraisal and exploration in this case is a subjective distinction. Subsequent to the Lockyer Deep-1 discovery well, many people would call every well drilled in the Lockyer structure, an appraisal well. These guys, who have been "erring" on the side of conservatism from the onset...(and thus keeping the share price in check)...spin it their way and call NED-1 an exploration well. They "did" this after the LD-1 well test results came out. NED-1 was also relegated to second cab off the rank in this current 2 well drilling campaign. I questioned this at the time.
They introduced the term "exploration well" for NED-1 after they did the flow test analysis and saw just how much gas there could be. I would speculate the main reason they introduced the designation "exploration well" and the "compartmentalisation" concept is because the numbers they got back from LD-1 point to such a large resource, everyone (except CE and his mate) "got scared" of the number. They also have an obligation to drill an exploration well, so calling NED-1 an exploration well kills two birds with one stone...You could also argue, this narrative also helped downplay the significance of the discovery, thus keeping the lid on the share price...
The arguments for NED-1 being an
appraisal well are many and patently obvious. The 2D seismic has allowed mapping of the reservoir unit across the entire structure. Remember this little beauty below? This seismic line (cross section) was
pre-drill Lockyer Deep.
It is located near NED-1. The red arrow (my annotation, their interpretation!!) shows the Top Kingia. Its a pretty prominent reflector. It sticks out like DBs.
@OldGeo pointed out at the time, other than the prominent reflector being clearly visible, one of the most important things for him, was the Top Kingia reflector "truncated" up against the fault (left), pointing to the fault forming a competent reservoir seal. The other thing we see below is a small "fault" near the words TopKingia. This is one of those "compartmentalising" faults. And in this case, we can see the Kingia reflector extending to the east, beyond that fault (second red arrow). So it tells you compartmentalisation, may be there, but it does not look like it has prevented the gas from getting there, because the Top Kingia reflector, indicative of gas saturated sands..is still present beyond the fault.
The reservoir is there, the seal is there, and after drilling LD-1, the gas is there and the pressure is there. The gas pressure gradient was
measured in LD-1 (i.e top of reservoir is P1, 10m in its P2, 20 m in its P3, 30m in its P4 etc - put these together and you get a pressure gradient) - and the water table gradient (extrapolated from a measured water table gradient in a gas field to the west) indicate an 800m gas column in the Lockyer structure. This tells you its odd on to hit gas in most of the Lockyer structure. Why are they (NWE) calling NED-1 an exploration well? who knows. Why are they flagging compartmentalisation as a risk? Who knows. Compartmentalisation in this case, means you may need more wells to access the entire gas field.
But you can look back at the history and make your own judgement.
in the following years it will be interesting to see where the PB is and who the players are ? thanks again to everyone on this thread for the wealth of information, individual's have contributed their own time and management on a regular basis ,and for that I thank you
