Today I’m going to show you really interesting story about the place in Central Poland which before the Second World War was thought to be the chance for new petroleum province similar to Carpathians. The place is called Wójcza and now it is totally forgotten place from the point of view of geology and exploration. I think this place really needs more investigation but also more focus from the side of scientists as no one understand what happened there.
I found the first remarks about this place looking totally for something else but it seems for me like a really interesting place and story.
If you like similar stories about oil and gas history and locations you should also check:
Wójcza is a small village in Świętokrzyskie province, central Poland. It is situated on the southern margins of Holy Cross Mountains about 70km south from Kielce – the region capital. This region was always famous from the minerals exploration. Holy Cross Mountains are full of quarries or places where copper or other minerals has been explored. This area was never considered or described as an petroleum province however Wójcza village is surrounded by health resorts such as Solec Zdrój or Busko Zdrój where mineral waters are used for health purposes and it is quite common that very often such mineral waters with high sulfur content are accompanying the oil fields.
According to various literature first oil shows in Wójcza area are known approximately from the 1880 when farmers encountered natural oil seeps occuring on the fields. One of such oil seeps was called Smoczy Dół which means the Dragon’s Hole/Dragon’s Pit and for a long time it was considered by the farmers to be the place where unfortunate Dragon died one day.
This story was such interesting that first exploration works in Wójcza area begun in 1886. Engineer Michalski arrived there and made couple of shallow shafts. Seeing small oil amount he stated that there is no potential in this area for oil exploration.
However after 1919 when Poland became independent again, Polish state ordered research on Wójcza area. Many theories were produced on oil source and generation by the most famous names of Polish Geology and only one well was drilled in 1925-1926. This did not help to solve the Wójcza problem. Works again were interruped without any specific result.
Between 1931 and 1939 works were continued again by Polish Geological Institute using more extensive cartograhpy, gravity data and also results of the previous experiences. Again financing source was dried up quite fast but also Second World War interrupped the research project.
All the wells drilled until 1939 obtained very small oil flow (less than 1bbl/day) and this results were not satisfying at all.
After the war Wójcza project was continued and resulted in drilling one deep well Zaucze-1 (TD=2258m) but the well showed no result, no oil or gas shows and also did not match expected geological profile. Project again was stopped in 1951 and never continued. That was about 60 years ago! Such a good place and potential to make research with modern techniques:)
As you can read from the cross section the Wójcza structure is a small antiform made of Cretaceous and Miocene sediments. Those are Miocene shales and anhydrites underlied by Cretaceous marls – not very good conditions for oil accumulation. Also you can spot on a map and cross section E/W fault which separates this structure into two pieces and exposes the Cretacous in the southern part. Oil from Wójcza wells was encountered on very shallow depths, sometimes less than 50m and it was thought to be related to the sulfur waters level. It was also relatively heavy (0.95 SG = ~18API) probably because of the flushing in the shallow zone.
So what is the source of oil? There were couple of theories, for example:
- oil comes from the Permian zone surrounding Holy Cross Mountains from the West
- oil comes from Carpathian shales similarly as well known oil from fields of Bóbrka and Krosno migrating through the fault zones (distance about 100km)
Drilling deep well in 1950’s disproved the theory about Permian source of oil. No Permian formations were found and no oil shows were found in a deep well. On the other hand Carpathian source of oil was also never confirmed. It was only a guess that maybe deep fault zones ranging from Wójcza to Carpathians might have been migration routes for oil.
Generally all the major works were abandoned in 1950’s so more than 60 years ago. I think this area needs more research as it has some potential which with current state of knowledge is unknown. The puzzle is still unresolved!