Honour You have mentioned that Kuldana formation is present all over Dhulian area iam pasting your published word "This formation is present all over the Dhulian field and ranges in thickness from 90 to 120 feet"
"Due to its impermeable character Kuldana Formation forms an
effective seal over the Eocene reservoir of the Dhulian
Field." But Honour the well tops data i have acquired for dhulian oil field have no kuladana formation..they have mentioned Mamikhel clay instead of kuldana... but according to my knowledge mami khel clay is presnt in KOHAT Sub basin not in potwar plateau...so sir plzzzz properly guide me that what formation i should mentioned in my stratigraphic column.... u have visited the place by yourself so u know better that whether kuldana are present or mamikhel clay at Dhulian area????? plzzzz guide me in this regards
AZEEM KHAN (M.S Geophysics)
Thanks a lot for sending me your question.
First of all you have to realize that first well in Dhulian field was drilled in 1918 and first oil producing well was found in 1936 from well Dhulian 5. During that time the names of the formations and reservoir zones had not been standardized as you found now as all the stratigraphic formations names have been duly approved by Stratigraphic Committee of Pakistan (SCP)and usually are being published in Geological Survey of Pakistan (GSP)memoirs for the benefit of geological community. But, its also true that several names of the geological zones and formations were proposed by several geologists but without being acknowledged widely throughout the community.
The Attock Oil Company (AOC) had coined several names of the various geological zones which were based on the well cuttings and their age determination was made on biostratigrapic analysis. many names are no longer used in the industry any more and majority of the new wells in Potwar basin are being followed the standard formation names. Once in Khaur and Dhulian Eocene carbonates was known as Laki and Kirthar formation whereas Paleocene carbonates as Ranikot Formation. Also, it was reported Bhadrar fr Chorgali formation in many wells drilled in Khaur and Dhulian fields. Perhaps you won't find many new Potwar wells with that kind of naming scheme and it has long been abandoned.
As far as Tope seal in Dhulian is concerned majority of the wells in the field were reported presence of Red Clays overlying the Chorgali and underlying Murree Formation. There are three formations in Potwar which are chronostratigraphically equivalent; Kuldana, Red Clays and Mamikhel and these names can be used interchangeably. Various oil companies have been working in this area have used various names for Eocene shale beds overlying Chorgali. For example Oxy are being used Mamikhel for Dhurnal field whereas POL has used Kuldana formation for Meyal oilfield.
I hope, you know what is the real secret behind the Red Clays, Mamikhel and Kuldana formation.
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