Definition of Depositional Environment of Productive Series Based on Well Logging Data

Performed work aims to reconstruct the depositional environment of the main lithofacial types of geological section and to clarify the geological structure of Pirallahi field on Productive series (PS) lower division suites on the basis of processing and interpretation of geophysical well logging data.

The main electrometric lithofacial types for suites — Postkirmaky Clayey (PKC), Postkirmaky Sandy (PKS), Kirmaky (KS) and Prekirmaky (PK) have been distinguished as a result of aSP well logs analysis by application of V.S.Muromtsev’s methodology. The differentiation of layers at intervals has been carried out by matching them to a particular lithofacies types.

Two transgressive stages can be distinguished in the study area: from the PK base to the top of KS and from the base of PKS to PKC top.

The main role in the formation of objects with sufficiently good reservoir properties belongs to river channels. Sandy objects are mostly traps of facies substitutions and are confined to the limbs of brachy-anticline fold. The most perspective areas have been revealed in the north-eastern and central (near crest) parts of the field.

The detail review of lithofacial parameters variation will allow us to create more effective lithofacial models for further operation of Pirallahi field.