## 1 Introduction  
The formation of asphaltene-resin-paraffin deposits (ARPD) on the wetted surfaces of downhole equipment and field oil pipelines is a frequent complication in the process of oil extraction [1, 2]. The worldwide and Russian experiences of oil field development and exploitation provide evidence for the urgency of this problem [3, 4, 5]. In Russian deposits, the problem of ARPD formation is representative, the number of oil-producing wells is abnormal, due to ARPD amounting to 70% of their total [6, 7].  
The new and improved methods and technology for preventing deposit formation and deposit removal have identified the necessity for the examination and acquisition of new data about the mechanism of ARPD formation. Likewise, one requires correct estimations of the influences of different factors on the rate of deposit formation along the path of well-product motion--from the bed to the vessels of the depot [8, 9].  
Factors which affect the process of ARPD formation and its rate include the presence of asphaltenes, resins and hard paraffins in oil; pressure; temperature; oil current evidence of an independent gas phase; water; and roughness of wetted surfaces [10, 11]. Pressure reduction via the associated petroleum gas below the saturation pressure of the oil unbalances the system pathologically. As a result, asphaltene-resin agents (ARA) dissolved in oil begin to separate, forming primary substrate on the wetted surfaces of the downhole equipment. When the current's temperature decreases to the temperature at which the oil can be saturated by paraffin (the temperature of paraffin crystallization), solid paraffinic hydrocarbons are also isolated from the oil and form particles of different sizes in the process of crystallization [12]. The larger particles are removed by the current, and the smaller ones in the process of mixing the fluid stick to the wetted surfaces under the influence of the adhesive strength and form the ARPD layer. The rate of the layer formation is substantially affected by the presence of the temperature gradient between the wetted surface and the current. As the temperature gradient rises, the intermolecular bonds between the microcrystals of paraffin and the surfaces are strengthened [13]. If the flow rate increases, shear stress affecting the ARPD layer can exceed the pressure defined by the adhesive strength [14]. In this case the particles of crystal paraffin are broken off the surface and removed by the flow [15].  
Asphaltene-resin agents, through the process of deposition on metal surfaces, including those which are covered with paraffin deposits, promote the surfaces' rugosity and make them hydrophobic [16; 17]. Along with the minute rock particles and corrosion products, they promote hardening of the deposits formed. It has been determined that ARA influences the temperature of oil saturation with paraffin as well [18].  
The presence of water in crude oil makes an impact on the character and the rate of ARPD [19; 20]. Water increases the specific heat of the fluid and increases the hydrophilicity of the wetted surfaces, weakening the effects of adhesive forces [21; 22]. In the process of water and oil emulsion (WOE) generation, minute globules armored by the crystals of paraffin, asphaltene and resin are involved in the process of ARPD initiation [23; 24]. Small particles of free water in WOE can be also involved in the process of ARPD initiation.  
The results of laboratory research concerning ARPD initiation, taking into consideration the water cut of crude oil and the degree of associated water mineralization, are presented in this work.