Wettability is an important parameter that influences the petrophysical properties of reservoir rocks. When drilling is doing, the penetration of mud filtration into formation causes considerable wettability alteration and affects the oil displacement by water. Hence the enhanced oil recovery methods will be affected because of formation damage. In this study, the effect of three samples (a bentonite commonly used in oil well drilling, a purified bentonite, and nanoclay) on wettability of sandstone and carbonate rocks has been studied using the contact angle method. The modification of surface properties of montmorillonite sheets by hydrophobic plug reformer changed the wettability of the clay particles from water-wet to oil-wet. This change resulted in the suitable dispersion of nanoclay (organic) into oil phase (as hydrophobic phase). The contact angle measurements of the prepared suspension from each of three samples showed that common and purified bentonites altered the wettability of the sandstone and limestone rocks to water wet, whereas the nanoclay changed contact angle to oil-wet behavior. Based on these observations, use of nanoclay, as an oil-based drilling mud additive, is useful due to its compatibility with oil zone wettability and suitable dispersion in oil-based drilling fluid.

Increasing of world demand for energy requires the increase in production of crude oil. Therefore, innovative enhanced oil recovery (EOR) methods have been the subject of many different kinds of studies. The use of nanotechnology has recently gained momentum in the oil and gas industry for its potential applications in EOR processes. Nanoparticles affect the wetting conditions of porous media which is a key factor in displacement efficiency. However, the effect of nanoparticles on wettability of porous media remains still little understood in the available literatures. In this work, the effect of hydrophilic silica nanoparticles on wettability of reservoir rock has been investigated. Contact angle of oil droplets in oil/water/rock system was used as an index of wettability conditions of surfaces. Obtained results revealed that the wettability of oil-wetted rocks in presence of silica nanoparticles changes from oil-wet to water wet; moreover, by increasing temperature and concentration of nanoparticles, the wettability alteration occurred in much less time. Finally, using micromodel setup some flooding tests has been performed in one-quarter five-spot glass micromodel to evaluate the effect of silica nanoparticles on sweep efficiency of water flooding process.

The wettability at the metal -ceramic interfaces is important in many applications, such as metal matrix composites (MMCs). The objective of the present paper is to study wetting phenomenon of aluminium base on reactios at interfacial. The effects of alloy elements such as Mg and the processing temperature on wettability were investigated theorically. The reactive wetting is governed not only by the interfacial reaction intensity, ∆Gr, but also by the physical and chemical properties of the resulting interface, ∆δr. The calculated wetting contact angles from physical and chemical model are approximately in agreement with experimental values.

The determination of fluid saturation is vital for the estimation of hydrocarbon in place which is the base for economic decision making about reservoir production. Archie’s equations are the most prevalent equations used for saturation calculation. One of the important parameters in these equations is saturation exponent.Saturation exponent has fundamental difference comparing with other parameters which are cementation exponent and tortuosity. Cementation exponent and tortuosity mostly depend on rock type but saturation exponent depends on the distribution of fluids and therefore the hysteresis of saturation during imbibitions and drainage and also wettability. The purpose of this research is an investigation into the effect of saturation hysteresis and wettability on saturation exponent. The saturation exponent was measured from primary drainage to secondary drainage with a four-electrode system at reservoir temperature with reservoir fluids on some cylindrical core samples. Dynamic porous plate technique was used, for which full capillary pressure curves and wettability with combined Amott-USBM were determined simultaneously. It was concluded that the saturation hysteresis affects saturation exponent in different samples during imbibition and drainage and cause it to range from 0.1 to 0.66; the variations were higher in oil-wet samples than water-wet samples.