Desalination of high salinity produced water using a ultra high pressure reverse osmosis membrane
AssigneeSaudi Arabian Oil Company
InventorsHasan Al Abdulgader, Duaa J. Al Saeed
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Abstract
The technology relates to the use of a high salinity produced water stream from a gas oil separation plant (GOSP), as a wash water stream for the desalter unit in a GOSP. The produced water stream is pretreated by a sequence of steps and subsequently desalinated by a ultra-high pressure reverse osmosis (UHP-RO) membrane. The UHP-RO produces a permeate stream and a reject stream. A portion of the permeate stream is reused as a wash water stream in the desalter unit of the GOSP.
Claims20
A method comprising:
- receiving a mixture of crude oil and water by a water oil separator;
- separating the water from the crude oil in the mixture to form a produced water stream and a recovered oil stream, wherein the produced water stream comprises a salinity;
- desalinating the produced water stream in a desalination unit which comprises an ultra-high pressure reverse osmosis (UHP-RO) membrane, wherein desalinating the produced water stream produces a permeate stream having lower salinity compared to the salinity of the produced water stream and a reject stream;
- flowing a portion of the permeate stream from the desalination unit to a wash water unit in a desalter;
- and
- desalting, in the desalter the crude oil using the portion of the permeate stream as a wash water.
An integrated system in a gas oil separation plant (GOSP) comprising:
- a high pressure and low pressure trap to separate crude oil, gas, and an untreated produced water stream that comprises suspended solids, emulsions, dissolved oil, and organics;
- a water oil separator that receives the untreated produced water and separates it into a recovered oil stream and a produced water stream of comprising of a salinity;
- a pretreatment unit that produces a pretreated produced water stream;
- a desalination unit that comprises an ultra-high pressure reverse osmosis (UHP-RO) membrane to receive the pretreated produced water;
- wherein desalination produces a permeate stream comprising a salinity lower than the produced water stream and a reject stream;
- a wash water system which receives a portion of the permeate stream from the desalination unit to produce a wash water stream;
- and
- a desalter that receives the wash water stream to reduce the salt content in the crude oil.
A method of reusing produced water in a gas oil separation comprising:
- flowing a mixture of crude oil and water into a water oil separator to separate the mixture into a recovered oil stream and a produced water stream;
- flowing a first portion of the produced water stream to an injection well and a second portion of the produced water stream to a pretreatment unit;
- pretreating the second portion of the produced water stream by a sequence of steps to remove suspended oils, emulsions, H2S gas, organics, hardness, total suspended solids, and dissolved oil;
- desalinating the second portion of the produced water by an ultra-high pressure reverse osmosis (UHP-RO) to produce a permeate stream and a reject stream;
- flowing a portion of the permeate stream to a desalter unit to use as a wash water to desalt crude oil.
Dependencies are inferred from the claim text.