RE: Highly competent18 Jul 2020 18:33
Grey Panther,
I do agree that while Canadian geologists are experienced with carbonates reservoirs - you and I know these are 99% pinnacle reefs - not present in UKCS. Yes, there are fringing reefs in the North Sea, but there are various carbonate ramp features similar to the Cretaceous Sligo and Edwards plays in the the Gulf of Mexico. The West Newton Magnesian Limestones are not renowned for their permeability and the discovery of an oil leg was a bit disappointing because gas will flow much better than oil - time will tell. I suspect Deltic has grounds to question West Newton’s viability until more is known from the EWT. A poor well test is a distinct possibility and might undermine the commercial logic as seen by aDeltic shareholder
CLNR - now Deltic - kicked off its early UKCS applications with two play concepts. One was the unexplored Zechstein play and the other was the emerging carboniferous play.
The Zechstein play was based on legacy seismic, previous drilling and analogues overlooked by others. Many geologists brought up in the UKCS, view carbonate plays as ‘too difficult’ - which is odd, since 66% of global reserves are in carbonate rocks. But not Shell, which is what attracted them to CLNR farm in.
The whole point of the original CLNR strategy was to prove the Zechstein play was extensive and may even have another 5 or 6 tcf yet-to-find in the prospective trend. The other CLNR line of evidence for both oil and gas is an oil prone petroleum source deep in the Carboniferous, rather than the traditional Westphalian coals which generate dry gas.
In the recent gas/oil discovery at Darrach in 43/4 the ‘oil’ is probably retrograde condensate, similar to Breagh. Other companies such as Simwell have licensed the Zechstein play in Q42/43 and conducted 3D seismic.
While local examples of production from the Zechstein Carbonates in the SNS (Conoco well 41/24a-2z reported to have flows at 100 mmscfd from the Plattendolomite) and onshore UK (Eskdale and Lockton gasfields).
The best developed examples of the Zechstein Carbonate play are located in eastern Netherlands, Germany and Poland. The key proponent of the Zechstein Carbonate Play in the Netherlands is NAM (`Shell) which has discovered of 20 gas fields with cumulative gas reserves of approximately 2.5TCF over the last 40 years. The Drenth Zechstein Complex alone has over 3.5 TCF of gas in place excluding the Tertiary aged Coevorden and Permian Groningen fields. This experience has led to the development of a predictive model based on 3D seismic data which uses a combination of isochore mapping to define the transition zone between shelf and basin along with fracture mapping which indicates enhanced reservoir characteristics. Finding the pervasive fracture systems in Zechstein play is the key to commercial production which Deltic understands in detail.
https://www.cluffnaturalresources.com/wp-content/uploads/2016/01/5-Axis-CPR-on-Southern-North-Sea-Assets-02-Decemb