Study On The Properties Of Graphene Used In Continuous Tube Clearing Lubricating Additives

With the development of horizontal wells and large displacement wells,the problem of sand deposition and jamming in horizontal and large displacement wells has become a focus of attention,and sand cleaning has become a research hotspot.In this paper,graphene was used as an oil-based and water-based clearing liquid additive,respectively,under different conditions of GCr15 steel ball and CT80 steel plate grinding sample and GCr15 steel ball and granite grinding sample,respectively.The friction and wear lubrication law under the condition of speed and load was further analyzed by surface topographer and SEM and EDS after the experiment.Research indicates:(1)Using sodium cholate as a dispersing agent can make graphene stable in water-based clearing liquid.In water-based clearing fluid,the main lubrication mechanism is the formation of frictional lubrication film,the wear mechanism is mainly abrasive wear;under different load conditions,the main wear mechanism wears abrasive particles and is accompanied by chemical corrosion and wear;under different speed conditions,The wear mechanism is mainly abrasive wear,which may be accompanied by adhesive wear and oxidative corrosion wear.(2)In the oil-based clearing liquid,under the conditions of GCr15 steel ball and CT80 steel sheet sample,the wear mechanism is mainly abrasive wear under different graphene concentration conditions.Under different load conditions,the wear mechanism is mainly abrasive wear and is accompanied by oxidative corrosion wear.Under different speed conditions,the friction coefficient decreases with the increase of the rotational speed,and finally shows a steady trend.The reason may be analyzed.Due to the increase of the rotational speed,more graphene is drawn into the friction contact surface.As a result,the friction surface is more lubricated,showing that the friction coefficient decreases as the rotation speed increases,and the main wear mechanism is abrasive wear.(3)In the oil-based clearing liquid,under the conditions of GCr15 steel ball and granite sample,the main wear mechanism under different graphene conditions is abrasive wear and chemical corrosion wear.Under different load conditions,the main damage mechanism is mainly adhesive wear and may be accompanied by electrochemical corrosion.Under different speed conditions,the friction coefficient shows a process of decreasing first,then increasing,and finally stabilizing.The reason may be that as the rotation speed increases,graphene is drawn into the friction contact surface to form graphene/oil.Base lubrication film.The lubricating film has a large thickness and is stable.At this time,the friction coefficient is small.As the rotation speed increases,the graphene is “squeezed out” to the frictional contact surface,and the graphene lubricating film and the oil-based lubricating film both are damaged.As a result,the lubricating film is discontinuous,and finally the friction coefficient is increased.The wear mechanism at this time can be understood as abrasive wear and accompanied by chemical corrosion wear.