Croatian Pannonian Basin licence round hydrocarbon potential assessment
Karyna Rodriguez, Neil Hodgson and Howard Nicholls
Journal name: First Break
Issue: Vol 37, No 4, April 2019 pp. 69 - 73
Special topic: Passive Seismic & Unconventionals
Info: Article, PDF ( 2.59Mb )
Price: € 30
With a proven hydrocarbon system, numerous discoveries and up to 59 oil, gas and condensate fields, the Pannonian basin is one of the most important hydrocarbon provinces in central Europe. Covering an area of 26,000 km, it has one of the deepest sedimentary sections and since the 1940s has produced more than 700 MMBO of oil and more than 400 MMBOE of natural gas. The region has a long history of hydrocarbon exploration, with the first well drilled in 1855. More recently, the basin has suffered firstly from a decline in production which peaked in the early 1980s and secondly from much reduced exploration activity over the last 20 years. However, recent changes in Croatian national law are breathing new life into the basin with exploration drilling activity close to starting again as a result of the success of the 2014 First Onshore Licence Round, and now by holding the Second Onshore Licence round. This second round was opened on 7 November 2018, with seven exploration blocks being offered over the Drava, Sava and Mura Depressions and the more frontier Hrvatsko Zajorge Sub-depression (Figure 1), making it again possible for international oil companies to explore in this proven basin with existing infrastructure and in close proximity to ever increasing energy markets. Significant undiscovered reserves in stratigraphic/structural plays have been identified with 12,100 km of regional 2D seismic data acquired during the 1970s through to the 1990s, but, more importantly, reprocessed in 2014 through a Pre-STM sequence (Figure 1). This reprocessing project has provided a contiguous dataset, time and phase matched to a single datum and significant imaging uplift. This data is complemented by conditioned well logs, with reports translated into English, for 53 key exploration wells as well as reprocessed VSP data where available. An evaluation carried out using the enhanced dataset has revealed deeper potential within a proven Badenian hydrocarbon system, as well as in untested tight reservoirs and fractured basement. Additional exploration opportunities have also been found in the under-explored regions on the basin margins of the Sava and Drava basins and large untested structures have been observed in the South West Sava and Hrvatsko Zagorje Basins.