Abstract:
An acid gas purification system is described herein that includes a primary membrane system with a CO 2 - and H 2 S-enriched permeate stream effluent and a hydrocarbon stream effluent; a first compression stage arranged to receive the CO 2 - and H 2 S-enriched permeate stream and produce a compressed stream; and a cryogenic separation system to receive the compressed stream, the cryogenic separation system including a cooler followed by a fractionator, wherein the fractionator produces a CO 2 - and H 2 S liquid stream and a hydrocarbon gas stream.
Abstract:
A system and method for removing acidic species from a rich mono-ethylene glycol ("MEG") solution (21) does so by stripping the acid from the rich MEG solution (21) by contacting the solution with a gas (23), the gas being nitrogen or a fuel gas such as methane; and stripping the acid from the gas by contacting the gas with a caustic solution (41) such as a dilute sodium hydroxide solution. The stripping steps take place in respective stripping columns (25). A portion of the gas (27) exiting the gas acid stripping column (30) can be recycled to the MEG acid stripping column (25) to reduce total gas usage. A portion of the waste stream (35) exiting the gas acid stripping column (30) can be recycled back to the gas acid stripping column (30) to reduce the amount of caustic solution (41) used as well as the amount of waste.
Abstract:
A water injection process plant includes a catalytic deoxygenation unit (50) located subsea that makes use of a reducing agent (60) sent from topsides in liquid form. The catalyst is preferably a palladium catalyst or its equivalent. The reducing agent is an oxygen scavenger such as but not limited to hydrazine, carbohydrazide, sodium erythorbate, methyl ethyl ketoxime ("MEKO"), hydroquinone, diethylhydroxylamine ("DEHA"), formic acid (methanoic acid). A chemical umbilical (55) can be used to deliver the reducing agent to a mixer (51) located upstream of the deoxygenation unit, where the agent is mixed with seawater containing oxygen.
Abstract:
An apparatus and method for separating water from an oil-water influx are provided. The apparatus includes a separation vessel (10) having an inlet (15), an oil collection portion (20) at its upper end (25), and a water collection portion (30) at its lower end (35). Multiple high voltage tubes (40), each containing an electrode (45), are located within the oil collection portion (20). These high voltage tubes (40) are staggered in length and held in place by perforated plates (100). The oil- water influx flows through the inlet (15) of the vessel (10) into the high voltage tubes (40), 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 (30) of the vessel (10). The remaining stream of dehydrated oil flows upwardly to the upper outlet end (25). The oil collection portion of (20) the separation vessel (10) may be oriented vertically or at an angle.
Abstract:
A system and process to protect chlorine-susceptible water treatment membranes from chlorine damage without the use of chemical scavengers employs a catalytic deoxygenation system located upstream of the chlorine-susceptible membranes. The system and process not only achieves the required oxygen discharge levels, via reaction of the oxygen with hydrogen, but also dechlorinates the water, via reaction of the chlorine species with hydrogen.
Abstract:
A system and method to remove solids, liquid contaminants, or both from a process stream (15) does so in a liquid pool zone (21) of a vessel (20) as the stream comes into contact with a heating medium (23) that is less volatile than the process stream (15). To keep the pool hot, the heating medium (23) can be recirculated through a heater (41) of a pump- around loop (40) or a heater (41) can be placed in the liquid pool zone (21). As the process stream (15) is vaporized, solids and any remaining liquids present in the process stream (15) migrate from the process stream (15) into the heating medium (23), and may be further removed from the heating medium (23) in the pool or in the pump-around loop (40). The vaporized process stream (30) can be further condensed. Any heat recovered can be used to pre-heat the process stream or used in the pump-around loop's heater in case of mechanical vapor recovery.
Abstract:
A method to remove oil from an oily water stream (25) includes the step of pressure controlling a release of dissolved gases from the stream (25) as the stream (25) passes through two or more stages of gas flotation treatment. The operating pressure of the first stage of flotation (30) treatment is purposefully reduced relative to that of an upstream unit (20) so that a certain controlled percent volume of dissolved gases is released. The operating pressure of the second stage of flotation (40) treatment is then purposefully reduced relative to that of the first stage (30) so that another controlled percent volume of dissolved gases is released. Any subsequent flotation treatment stage is at a lower operating pressure than that of the previous stage so that the subsequent treatment stage releases a controlled percent volume of dissolved gases. By controlling the operating pressure in this way, overall separation performance is improved.
Abstract:
A system and method for dehydrating crude oil on a floating production storage and offloading installation include a separator vessel (20) to receive an incoming produced water stream (15), followed by a flash vessel (30), a treatment block, a crude oil storage tank (60), and an electrostatic treater (70). The treatment block includes a low pressure degasser (40) followed by a compact electrostatic separator pre-treater (50) or a compact electrostatic separator pre- treater (50) followed by a low pressure degasser (40). The flash vessel (30) and/or the low pressure degasser (40) may employ an inlet cyclonic distributor and demisting cyclones, while the electrostatic treater may employ DUAL FREQUENCY® technology. The separator vessel (20) 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.
Abstract:
A system and process for removing divalent ions from a MEG feed stream (15) is presented. The system includes a chemical treatment tank (25) where chemicals are mixed with the feed stream (15) to form insoluble carbonate and hydroxide salts. The system also includes a membrane-type solid-liquid separation unit (60) that receives the feed stream (35) from the chemical treatment tank (25) and separates it into a filtrate (90) containing MEG and a retentate (130) containing the insoluble salts. The system may also include washing the retentate (130) to remove additional MEG, which is then recycled to a MEG regeneration or reclamation process. The system may also include a dryer (140) that receives waste slurry (132) from the solid-liquid separation unit (60) and dries it to form a solid waste, thereby facilitating its handling, storage, and disposal.
Abstract:
A vessel (10) for treating an oil-in-water inlet stream houses an inlet flow distributor (21) arranged to direct an inlet flow toward a perforated baffle (31) of a coalescing section (30), the coalescing section (30) housing a packing and being arranged upstream of a second baffle (31); a flotation section (50) arranged to receive a flow exiting the coalescing section (30) and being divided by one or more perforated baffles (55); and an outlet water collecting pipe (61) arranged to receive a flow exiting the flotation section (50), the outlet water collecting pipe (61) having one or more openings located along its length. The coalescing section (30) may be divided into two sections (37/39), with one section preferably housing a different pre-selected sized packing than the other section. The flotation section (50) may include one or more gas-inducing devices (53). A solid baffle (43) may be arranged downstream of the second baffle (31) and ahead of the flotation section (50) to provide single or dual flow through that section.