Method for removing calcium from crude oil
View Patent ↗Methods for reducing calcium deposition along surfaces in contact with the water phase of a resolved water/oil emulsion are disclosed. High calcium crude oil and the like are contacted with a sequestrant to form a sequestered calcium containing complex that partitions to the water phase in the resolved emulsion. A specifically formulated polymeric deposit control agent is added to the water phase to inhibit calcium deposit formation therein and along surfaces in contact with the water phase.
1. A method for reducing calcium deposit formation along surfaces in contact with a water phase formed as a result of resolution of an emulsion from crude oil fed to a petroleum refinery desalter, wherein said crude oil has a high calcium content of 30 ppm calcium and greater, said method comprising:
a) contacting said crude oil with citric acid sequestrant and wash water thereby forming sequestered calcium citrate complexes in said water phase of said emulsion; and
b) contacting said water phase with from about 1 to 300 ppm of a deposit control polymer to inhibit the formation of calcium based scales and deposits along said surfaces, wherein said deposit control polymer is AA/AHPSE, AA/APES, AA/APES/AHPSE, or AA/MA/APES.
2. Method as recited in claim 1 wherein said crude oil comprises about 100 ppm calcium and greater.
3. Method as recited in claim 1 wherein said deposit control polymer is AA/AHPSE.
4. Method as recited in claim 1 wherein said deposit control polymer is AA/APES.
5. A method for reducing calcium deposit formation along surfaces in contact with a water phase formed as a result of resolution of an emulsion from a crude oil fed to a petroleum refinery desalter, wherein said crude oil has a high calcium content of 30 ppm calcium and greater, said method comprising:
a) contacting said crude oil with citric acid sequestrant and wash water thereby forming sequestered calcium citrate complexes in said water phase of said emulsion; and
b) contacting said water phase with from about 1 to 300 ppm of a deposit control polymer to inhibit the formation of calcium based scales and deposits along said surfaces, wherein said deposit control polymer is AA/AMPS.
6. Method as recited in claim 5 wherein said crude oil comprises about 100 ppm calcium and greater.