A process train for a floating production storage and offloading installation includes a crude oil storage tank equipped with at least one set of electrostatic internals. The set of electrostatic internals are arranged to provide a treatment flow path within the crude oil storage tank oblique to a longitudinal centerline of the crude oil storage tank and through an electric field provided by the set of electrostatic internals. Employing these electrostatic internals within the tank permits an allowable inlet water content into the tank of up to 80%, significantly reducing the required topside processing equipment. The process and system also includes, upstream of the tank, two separator vessels arranged in parallel so each receives a portion of an incoming oil-and-water stream, a flash vessel arranged downstream of the two separator vessels, and a degasser vessel. Downstream of the crude oil storage tank is an electrostatic treater.

The electro-coalescer includes: a fluid inlet; a fluid outlet; a power source; and one or more pipes fluidly connecting the inlet and the outlet, each pipe having an electrode disposed therethrough. The electrodes are coupled to the power source. The pipes are configured to connect to an electrical ground and an electric field is generated between the electrode and the pipe through which it is disposed. An internal surface of each of the one or more pipes is configured to induce turbulence in a fluid flowing through the pipes.

A process train for a floating production storage and offloading installation includes a crude oil storage tank that is equipped with at least one set of electrostatic internals arranged to provide a treatment flow path isolated from a surrounding volume of the electrostatic separator section of the tank. An oil-and-water stream or mixture entering the set of electrostatic internals travels along the treatment flow path and is subjected to an electric field. The treatment flow path is in an upwardly direction toward the oil outlet section and in a downwardly opposite direction toward the water outlet section of the tank. Employing electrostatic internals within the tank permits an allowable inlet water content into the tank of up to 80%, significantly reducing the required topside processing equipment.

The invention relates to a device for electrostatic coalescence of liquid particles in a flowing fluid mixture, comprising: a tube having an feed opening located at the front side of the tube and a discharge opening located on the opposite side of the tube and a least one arrangement with flow guide vanes arranged in the tube, positioned in between the opened infeed side and an opposite opened outfeed side, for reducing the turbulence or for imparting a rotating movement to the fluid mixture flowing through the tube. The invention also relates to a method for electrostatic coalescence of liquid particles in a flowing fluid mixture.

A process train for a floating production storage and offloading installation includes a crude oil storage tank that is equipped with at least one set of electrostatic internals arranged to provide a treatment flow path isolated from a surrounding volume of the electrostatic separator section of the tank. An oil-and-water stream or mixture entering the set of electrostatic internals travels along the treatment flow path and is subjected to an electric field. The treatment flow path is in an upwardly direction toward the oil outlet section and in a downwardly opposite direction toward the water outlet section of the tank. Employing electrostatic internals within the tank permits an allowable inlet water content into the tank of up to 80%, significantly reducing the required topside processing equipment.

A process train for a floating production storage and offloading installation includes a crude oil storage tank equipped with at least one set of electrostatic internals. The set of electrostatic internals are arranged to provide a treatment flow path within the crude oil storage tank oblique to a longitudinal centerline of the crude oil storage tank and through an electric field provided by the set of electrostatic internals. Employing these electrostatic internals within the tank permits an allowable inlet water content into the tank of up to 80%, significantly reducing the required topside processing equipment. The process and system also includes, upstream of the tank, two separator vessels arranged in parallel so each receives a portion of an incoming oil-and-water stream, a flash vessel arranged downstream of the two separator vessels, and a degasser vessel. Downstream of the crude oil storage tank is an electrostatic treater.

A system and method for dehydrating crude oil on a floating production storage and offloading installation include a separator vessel to receive an incoming produced water stream, followed by a flash vessel, a treatment block, a crude oil storage tank, and an electrostatic treater. The treatment block includes a low pressure degasser followed by a compact electrostatic separator pre-treater or a compact electrostatic separator pre-treater followed by a low pressure degasser. The flash vessel and/or the low pressure degasser may employ an inlet cyclonic distributor and demisting cyclones, while the electrostatic treater may employ DUAL FREQUENCY technology. The separator vessel may be a single horizontal two-phase separator/degasser or two vertical two-phase separator/degassers that operate in parallel with each receiving approximately 50 percent of the incoming produced water stream. The final outlet stream preferably contains no more than 0.5 BS&W and 285 milligrams per liter salt.

An apparatus and method for separating water from an oil-water influx are provided. The apparatus includes a separation vessel having an inlet, an oil collection portion at its upper end, and a water collection portion at its lower end. Multiple high voltage tubes, each containing an electrode, are located within the oil collection portion. These high voltage tubes are staggered in length and held in place by perforated plates. The oil-water influx flows through the inlet of the vessel into the high voltage tubes, where it is subjected to an electrostatic field. The electrostatic field causes water droplets in the influx to coalesce and form a water out-flux which flows downwardly into the water collection portion of the vessel. The remaining stream of dehydrated oil flows upwardly to the upper outlet end. The oil collection portion of the separation vessel may be oriented vertically or at an angle.

A method for protecting coalescer elements is provided. The method comprises: providing a device comprising a vessel that contains at least two coalescer elements each including an electrode; feeding a mixture into the vessel; supplying AC voltage to the electrodes; and time-resolved determining an electrical impedance of at least one of the electrodes and determining whether the electrical impedance has been changed within a predetermined time period of at most 1 second by more than a predetermined threshold of at least 0.25%. If so, a voltage supplied to the at least one of the electrodes is quenched or reduced to at most 70% of the AC voltage supplied to the electrode at a time of determining a change of the electrical impedance until at least one of: the change of the electrical impedance lies within a first predetermined range and the electrical impedance lies within a second predetermined range.

The present invention seeks to decompose and remove various types of organic materials contained in oilfield water by one operation. To this end, this method for treating oilfield water is provided with: a step for obtaining primary treated water containing organic material by removing the solid content and oil content from oilfield water; and a step for decomposing the organic material by exposing the primary treated water to discharge plasma, wherein the discharge plasma is generated by a nanosecond pulse power source for outputting a pulse having a pulse width of 10 ns or less.