Published August 2012
The research of the influence of core structure and filtrational oil volume on wetting
Sh.M. AliyevaThe estimation of wetting on reservoir rocks surface is necessary either in the phase of oil displacement process modelling, or for well geophysical survey data interpretation and fields development analysis. In connection with this has been investigated the influence of core surface oil hydrophobization, selected from terrigenous and carbonate rocks. The level of hydrophilicity and hydrophobization was viewed according to M index which shows integral characteristics of wetting according to capillary penetration data in sample of heterogeneous liquids in atmospheric conditions and in heavy gravitation field while centrifugation. The rock samples with total hydrophilic surface is characterized M=1 wetting index value, and with total hydrophobized surface M=0. The wetting index M is the immeasurable size and is calculated according to sample weight definition data in experiment different phases. As an investigation object served the rock samples of cylindric form made from natural core with diameter and length not less than 2.5 cm. The samples were previously exhausted with alchohol-benzol mixture. As a hydrocarbon liquid was used oil from Guneshly field with viscosity in 872 kg/m3 and interfacial tension in the layer alkaline water boundary in 22 mN/m. The experimental studies were carried out while filtration next core of 1; 5; 10 and 15; porous volume of oil. It was established that depending on oil capacity pumped through the oil sample the wetting index changes. It testifies the change of rock matrix surface changes. While going through the core the oil from 1 to 15 pore capacities the hydrophobization of core rock matrix grain surface increases which are verified with its electrical resistance increase. As a result of conducted experimental investigations it was defined that depending on oil capacity and contact time of terrigenous and carbonate cores porous medium surface with oil their wetting ability changes towards hydrophobization.
