Abstract: A filtering process is disclosed for obtaining a clear effluent filtrate from a turbid oil or gas well treatment fluid contaminated with solid particulates comprised of drilling and formation debris having particle sizes in the range of from about 0.1 to about 30 micrometers comprising passing the treatment fluid through a surface filter having an absolute pore rating of about 40 micrometers or less at a flow density of from about 0.05 to about 0.5 gallons per minute per square foot of filter surface such that (1) initially at least a portion of the particulates is collected on the upstream surface of the surface filter and begins forming a filter cake with enhanced capability for removing particulates smaller than the absolute pore rating of said surface filter and (2) thereafter the treatment fluid is filtered through a filter composite of the surface filter and the filter cake whereby a clear effluent substantially free of solid particulates having particle sizes in the range of from about 0.

Abstract: A process is provided for filtration of aqueous oil-containing brines that are substantially free from viscosity-increasing agents, which comprises adding to the aqueous oil-containing brine having a tendency to contaminate and plug a filter a sufficient amount of an oxidizing agent capable of reacting with plugging contaminants present in the brine to alleviate the plugging tendency, thereby extending filter life.

Abstract: A fused salt thermal device having two spaced electrodes to provide an active thermal cell space therebetween, a reservoir containing an inorganic fusible salt electrolyte which is solid at a temperature below a predetermined activation temperature and which is molten at or above the activation temperature, and means permitting circulation of the fused salt electrolyte between the active thermal cell space and the reservoir during the generation of electricity in order to replenish spent electrolyte. Preferably, the fused salt thermal device has a metal electrode and an electrically conductive porous electrode spaced therefrom to provide an active thermal cell space with a reservoir containing an inorganic fusible salt electrolyte in fluid communication with the porous electrode so that upon activation of the thermal device the molten salt electrolyte circulates between the active thermal cell space and the reservoir through the porous electrode.