engleski

Mechanical Properties of Sandstone Rocks from Some Mature Gas and Oil Reservoirs in Sava Depression

This work presents the results of a pore-compressibility study, performed on reservoir rock samples, representative of main reservoir lithology in Okoli gas field as well as Ivanić, Lipovljani, Crnac, and Pavljani oil fields. Pore volume (Vp) vs. effective stress (pe) data were measured under hydrostatic load conditions in the pe range from 0 to 700 bar. The results were subsequently grouped according to lithology and analysed in terms of porosity reduction and pore compressibility coefficient (cp) correlations with pe and initial porosity. Poroelastic behavior of sanstones studied was found to be similar to that found in literature, characterised by compressibility decrease with increasing EOB pressure. Several analytical models incorporating different number of parameters were examined to obtain adequate description of stress dependence for rock type studied and the results compared with theory and published data. Experimentally determined pore compaction features are discussed in terms of possible impact on both Fetkovich-type material balance (re) calculations and the use in reservoir simulators.

rock; compressibility; pore; sandstone; porosity; mature

nije evidentirano