DBPapers
DOI: 10.5593/sgem2017/14/S06.127

WETTABILITY INVESTIGATION AS A PREREQUISITE DURING SELECTING ENHANCED OIL RECOVERY METHODS FOR SANDSTONE AND DOLOMITE FORMATIONS

R. Czarnota, D. Janiga, J. Stopa, P. Wojnarowski
Monday 11 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-00-3 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 14, 1013-1020 pp, DOI: 10.5593/sgem2017/14/S06.127

ABSTRACT

Wettability as a rock-fluid interaction property is well recognized to affect the multiphase flow in hydrocarbons reservoirs. It impacts on the petrophysical properties of reservoir rock including relative permeability, capillary pressure, electrical properties and enhanced oil recovery. The three most commonly states are differed of wettability for hydrocarbon fields, these include: water wet, oil wet and mixed. USBM and Amott- Harvey laboratory methods are proposed as petroleum industry standards to estimate rock wettability in laboratory conditions. The first technique is directly calculated from area under capillary pressure curves and the second is related to spontaneous and forced characteristics of drainage and imbibition processes. Most oil reservoir rocks are characterized by water-wet since they were formed in marine environments. Generally, carbonate rocks have a moderate to strong oil-wet character of wettability. During oil production reservoir rock can reverse from water-wet towards oil-wet condition because of the solid particles which attract negatively charged chemical compound contained in the migrating hydrocarbon phase. Laboratory measurement of wettability at reservoir conditions is a key factor for the success of EOR application on the oil field. In presented work, the determination of wettability at laboratory environment on standard sandstone and dolomite core plugs by Amott-Harvey test was carried out. These rock samples correspond to the main oil bearing formations which are taken into account as the potential EOR candidates. The obtained results show wettability for sandstone as water-wet and oil-wet for dolomite rock. In this paper determination of wettability is considered as a one of multiple preliminary factors considered as crucial parameter during selecting IOR and EOR method application for the Polish oil fields. For sandstone rocks IOR methods based on water flooding are recommended and EOR methods, especially gas injection are selected for dolomite formations. The proper understanding of the wettability of the reservoir is essential for determining the most efficient way of oil production.

Keywords: Wettability, EOR, Amott-Harvey, Sandstone, Dolomite