GEOL. CROAT. 49/2 169· 170 ZAGREB 1996 

Professiollol papei' 

The Fu ndamental Economic Issues of Petroleum Geological 
Explorations in Croatia 

Boro VLASIC ' and Zvonimir HERNITZ' PROCEEDINGS 

The Section of Geology, Geophysics and Geochem­
istry of th e Scie ntifi c Cou ncil for Petroleum of th e 
Croatian Academy or Sciences and Arts has already 
o rgani sed scientific meetings on seve ra l occasio ns. 
These meetings were almost witholl t exception con­
cerning geological -geophysical aspects of explo rati on 
for oil and gas as we ll as the application of spec ifi c 
exp loration methods. Thi s was unde rstandabl e given 
the socia-economic conditions present a l those times. 
The change in social envi ronment gave the economical 

aspect of ex ploration and production far g reater impor­
tance for it can significantly influcnce the final resu lt as 
well as knowledge on gcologic-geophysical conditions. 
Bccause not many in Croatia have occu pied themselves 
wi th such and re lated matters it was our a im to inform 
[he broade r profess ional publi c wi th how thi s was 

applied in other oil -produc ing coulltries. T he parti ci pa­
tion o f inte rnational ex perts gave thi s sympos ium an 
international character. 

Approxi mate ly two years ago, the management o f 
the INA-Nn fLaplin company mentioned the possi bility 
of orga ni s ing an advi sory mccting to discuss the eco­
nomi c factors re levant to the exploration of petroleum. 
Both the Min istry o f Science and Technology and Min­
is try of Economic Affa irs showed the ir iIllerest. 

l NA-NafLap lin is the national oil -company of C roat ­
ia. It covers a wide spectrum of activ it ies expected of 
any such oil company from basic exploration and geo­
phys icalmeasuremenls to the drilling and production of 
hydrocarbons both inland and abroad. Numerous explo­
ration s have been carried o ut in foreign count ries such 
as Angola, Tunisia , Albania, Egypt, Libya, and a signi­
ficant ex pansion of th ese activi ties is ex pected in the 
future. Othe r bus iness agreement s wit h in ternational 
partners have been made, one example being the most 
recen t arrangement on gas production with the Italian 
company Agip. 

All o f these s llccess ful business re lations creatc a 
need fo r the Croatian petroleum economy to systemati ­
ca ll y enhance its bonds with the world and to be con­
necled to the world-wide ci rculation of scientific infor­
mation. Croatia is a counlry in tran sition. Not the only 

1 INA-Naflilplin . .subiceva 29, HR-lOOOO Zagreb. Croatia. 

one. This process has slart ed in all the countries of the 
form er eas tern block. It is also noted that in some west­
ern countries privati sa tion of the petro le llm economy 
occurs. 

T he Croatian pe troleum econom y has undergone 
rapid expansion aft er World War n, but under the con­
ditions of" a " plan economy". Of course, everything had 
it' s pri ce then as well as today. However the price in 
those times e ither d kln 't play an important role in dec i­
sion making, o r Ihe ex penditures were not transparent 
enough. It is hard to be lieve that the techno-econom ical 
param eters were conveni ently omitted from the reports 
on reserves although their importance was well-known. 
It is onl y in recent years that , according to the latest 
" By- law on the data acquisition , ev idenc ing and de te r­
mination of reserves or mineral deposits and balanc ing 
of reserves" from 1992 that the detailed analysis oj" the 
rentabi lit y of each and eve ry field is req uired. These 
matters were the basic reason fo r organising the sympo­
Sium. 

An optimal and rat iona l approach to the explorati on 
of minera l reso urces represents the ultimate scicntific 
goal in the field of economic geology. Initially, explo­
ra ti on makes poss ibl e the discovery of oil and gas 
pools. Th is is fo ll owed by exp lo ra tion carried out for 
the purpose of the realis tic es t imati o n of oil and gas 
reserves, and phase three comprises exp lora tion proce­
dures carried out in the course of product ion it self. All 
of these ex plorations ex hibit a multidisciplinary charac­
te r, in va rious port ion s they inc lude the res ults 0 1" a 
number of scient ifi c disc iplines, primarily geology, geo­
physics and petroleum engi neering. 

T he ai m is [0 follow the advance or exploration pro­
cedures across the world in Croatia. ObvioLisly, the pre­
sentation o f the results obtained in this sense is of great 
importance fo r our country, and that 's why the princ ipal 
objective of the symposium was to give a review of the 
possi ble solutions for a sys tem to intensify exploration 
for the purpose of increasing the recoverable oil and gas 
reserves. 

We ex pect the lec tures (o ral presen tations) and di s­
cussions to address th e prospectivity of exp loration 

2 Universit y o f Z1.grcb, Fac ulty o f Mi ning, Geology & Petroleum Engineering, Pierollijcva 6, P.O. Box I !:!6, HR -lOOOO Zagreb, Croatia . 



170 

areas with i.I rational way of carry in g ou t petrol eum ­
geologica l ex plora tions, thc techno-econom ic va luation 
of pc tro leum -gcol og ical projects, petroleum-re lated leg­
isla tion and problems of a petroleum economy in transi­
tion. 

The explo ration in Croatia, both in part of the Pan­
nonian basin and in the Adriatic off-shore is s till ineom­
plcte. In the Pannonian basin special atten tion has to be 
paid to non-s tructural , i.e. stratigraphic types of plays as 
well as to the rocks underlying Tertiary depos its. 

Th e re will be an interesting opportun it y to di sc li ss 
the suggestions on the possibility of acqui siti on of pre-

Gcologi;, CW;l lic;149{2 

viously de termi ned and explored o il reserves in foreign 
countries. A modernisat ion o f the men tioned By-law on 
Reserves will also be necessary in order to bring it in 
line wi th international standards. The contemporary by­
law, a lthough actually not old, is in fac t mere ly a mod i­
fi cation of one inherited from the old s tate in accor­
dan ce to the actual needs. Alternatively, the recently 
published es timation of va lue of hydrocarbon rese rves 
of the fi elds d iscovered in Croatia showed that we were 
too rigorous with these reserves, and that the oil and gas 
a re more va lu able than previously though t.