History in the fold belt
The Carpathians started the modern oil and gas industry, with first drilling in Poland in 1854 and Romania in 1857. As of today, the Carpathians is the sixth largest hydrocarbon bearing thrust belt in the world behind those in the Middle East, Mexico and the Caspian. Discovered reserves from the Carpathians to date total 14 billion barrels of oil equivalent. Published sources give a total of 2.6 billion barrels of oil equivalent “yet to be found”. One of the key attractions of the region is the high impact nature of the prospects – relatively low cost of drilling with significant value potential. Aurelian considers the Carpathian thrust belt analogous to Llanos in Columbia where the application of 2D seismic led to significant discoveries.
Unlocking value
- Largely overlooked by major oil companies post 1989
- USGS yet-to-find resources of 3 bn boe
- Field size distribution shows gaps in the 100-425 mmboe range
- Little seismic has been acquired in the region
- Using techniques and equipment developed in other thrust fold belts structures at deeper than 1,000 metres are made visible
The Carpathian thrust fold belt
The Carpathians are a range of mountains forming an arc roughly 1,000 miles long from the Czech Republic in the northwest through Slovakia, Poland, Hungary, Ukraine and Romania in the east, to the Iron Gates on the Danube River between Romania and Serbia in
the south.
The old fields are almost entirely very shallow, discovered from surface geology and the presence of seeps. The deeper section is largely unevaluated because of the extremely limited amount of seismic acquired to date. Given new seismic, and the processing and interpretation technology developed in other more explored thrust belts (e.g. Columbia Llanos) significant discoveries can be expected at greater depths of 2,000-6,000 metres.
As a result of the long history of oil and gas activity in the region there is a good infrastructure of pipelines and a strong service industry.
With GDP increasing substantially over recent years, the demand for oil and gas has increased accordingly. The supply however has been almost exclusively from the former Soviet Union. Security of supply is increasingly being recognised as extremely important, and any increase in indigenous production is encouraged.
Accordingly, the fiscal terms in Central Europe are very favourable to the producer. Drilling costs are modest, and chances of geological success are estimated to be approximately 16%
on our licences.
We are funded to drill nine high-impact wells in this very promising area over the next two years.
Technology
High quality 2D seismic and modern processing and interpretation techniques
Surprisingly little seismic has been acquired in the past and as a result deep drilling is almost nonexistent. In our Bieszczady licence, for example, in an area of 3,520 km2 there were only eight regional lines available and these vintage lines were poor quality. Application of techniques and equipment developed in other thrust belts will allow us to visualise the subsurface and target wells below the restriction (c. 1,000m) imposed by surface mapping.
Acquisition of seismic in the Carpathians is a challenge. The terrain is rugged and access is difficult for large vehicles. In addition the variation in surface conditions can make it difficult to acquire good data and significant effort is required to optimise the combination of source and receivers to geological features. Extensive processing is often required to identify and remove side effects.
Finally when a structure is mapped in time, conversion to depth can be problematic. The Carpathians are the surface expression of massive earth movements which have resulted in large blocks of rock of different properties being thrust over one another. Extensive processing is required to convert from time to depth and place the blocks in the correct position to each other. Here we will benefit from the industry’s extensive experience in other areas of the world and the techniques and processing software that are available to us.