Roumanian Crude Oils

After a short geological description of the Roumanian oil province, the chemical composition of the crudes, based on almost 300 Hempel analyses, is represented by various tables and graphs. Depth and type of structure do not have any influence on the chemical composition. The upper Pliocene (Dacian) crudes are mostly of naphthene and naphthene-intermediate base, the lower Pliocene (Meotian) crudes and the few small occurrences in the Miocene are mostly of paraffin to intermediate base. Some exceptions are explained by invasion of crudes from other formations. Of the few Oligocene occurrences some belong to the naphthenic, some to the intermediate group. In the writer’s opinion the Dacian oils originated in the Dacian or Upper Pontian, the Meotian and most of the Miocene oils in the Meotian, the Oligocene oils in the Paleogene. Various transformation hypotheses are discussed; none of them seem applicable to Roumanian crudes. The cyclic compounds are therefore thought to be derived from cyclic compounds of the source material, namely, ligno-humic substances which may be partly continental in origin.