Abstract: 3D Modelling and Characterisation of Delta Reservoir in SE Hungary

Janos Geiger, Julia Komlosi

The Algyo field is the largest field of Hungary consisting of more than 40 oil and gas bearing layers. The upper part of this field developed in delta slope and delta plain units of a progradational delta system, the lower members are turbidity rock bodies of prodelta and deep basin fans.

As a type analogy of the reservoirs developed in Miocene-Pliocene progradational delta systems, the reservoir "Szeged-1" of the Algyo field has been chosen. It has been penetrated by 912 wells over an area of about 60 square km. This reservoir is interpreted as an alternation of distributary channels and inter-distributary swamp areas. About 40 cores with 100% core recovery was taken. The reservoir has been on stream since the late '60-s, the geological model can be controlled by the data of the reservoir engineering.

An integrated 3D reservoir description based on a grid-oriented 3D geostatistical visualisation of the internal lithological and petrophysical heterogeneity has been developed. This system integrates data of

-- core descriptions
-- standard and special core analyses
-- petrophysical well-log interpretations.

The reservoir geometry and lithological heterogeneity have been characterized by two models

-- Markov-model for the lithological transitions
-- 3D-grid-based geostatistical model for the visualisation.

The 3-D visualization of the petrophysical data expresses the dependence of recovery mechanism, and injection schemes on the real internal heterogeneity. These images may be generalised and used as conditional constraints for the simulation of internal heterogeneity of other Pannonian fields developed only by few wells.

AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France