Evaluation of geofiltration settings for Devonian terrigenous play in north-eastern part of Volga-Urals petroleum province

The authors discuss evaluation of geofiltration settings for filtration in the Devonian terrigenous play within the north-eastern part of Volga-Urals Petroleum Province/ Depositional settings of the Devonian sequence are reconstructed from the Emsian to the Timanian time. The deposits were formed in different lithofacies conditions under the influence of large tectonic elements. There are four lithofacies zones identified in the study area. A sample of almost 900 wells from the Perm Krai, the Udmurt Republic and the Kirov Region was used for the research. It was found that the reservoir rocks having very low, low and medium-reduced storage capacity predominate in the sequence of interest. In the column of the sequence, the most continuous reservoir zones with low and medium-reduced storage capacity are typical of the Vorobyovsky-Ardatovsky, Mullinsky, and Pashiisky deposits. The zones favourable in terms of hydrocarbon accumulation are predicted in these same intervals. The conductive units in the Vorobyovsky-Ardatovsky and Pashiisky deposits are considered to be the efficient elements of the sequence’s migration system in all the lithofacies zones. Conductivity of the Mullinsky deposits is predicted only in the zone of the southern part of the Verkhnekamsky-Chusovsky paleodepression and in the zone of paleoarches. The expert review of geofiltration settings of migration in the sequence is carried out using the calculated conductivity of the deposits, The most favourable hydrocarbon migration settings are found in the Vorobyovsky-Ardatovsky, Pashiisky, and Timanian deposits