Water treatment is an essential equipment for operation of steam injection boilers in oilfields.

The raw water is treated by the water treatment device into the softened water with stable and qualified quality, and then the dissolved oxygen of the softened water is removed by the deaeration system, which can be used as the water source of the steam injection boiler.

The quality of treated water is especially critical to the safe and economical operation of the steam injection boiler in oil field.

Water Treatment Device Composition

Water treatment device includes ion exchange system, saline water system, dosing system, vacuum deaeration system, automatic control system, etc. It can realize unattended automatic control, and is easy to operate.

1. 1. Ion Exchanger

Pressure vessel for exchanging Ca2+ and Mg 2+ ions. This type of ion exchanger is designed for downstream operation and countercurrent regeneration. There are two ion exchangers, the primary ion exchanger handles most of the hardness and the secondary ion exchanger handles the remaining hardness.

2. 2. Water Treatment System Flow

Water Treatment System Flow includs force lift pump, pipeline, pneumatic diaphragm valve, butterfly valve, check valve, etc. The process flow of water treatment includes operation, backwashing, salt feeding, replacement, first-stage positive washing and second-stage positive washing.

3. Concentrated Salt Water Tank

It is a salt storage tank contacting with the atmosphere, which is used to dissolve salt particles and provide concentrated brine for softener regeneration.

4. 4. Dosing System

If the water quality does not meet the requirements during operation, chemicals such as EDTA, Na₂SO₃ and NaOH must be added to remove the leakage and the PH value of the water should be adjusted between 8 and 12.

5. 5. Vacuum eaerator

The oxygen content of softened water is reduced to the minimum after it is deoxidized twice in the first and second tanks of vacuum deaerator. The oxygen content is adjusted by adding deoxidizer to ensure that the dissolved oxygen content of softened water reaches the standard.

6.Control system

The control system has two control modes: manual and automatic. Automatic control mode is generally used in normal operation, manual control mode can be used in initial operation, overhaul or failure.

Water Treatment Device Parameter

1. Rated water yield:      15m³/h.
2. Rated working pressure: 0.6MPa.
3. Water hardness:

When hardness of raw water is less than 400 mg/l, hardness of primary outlet is less than 3 mg/l and that of secondary outlet is 0.

4. Vacuum deaeration:

Vacuum: -0.095~0.098 MPa; rated outlet water pressure ≥0.3MPa; residual oxygen content in outlet water: ≤0.15mg/l.

5. Index of total outlet of water treatment (boiler feed water):

hardness 0, oxygen content ≤0.007mg/l (after dosing), PH value: 8-9.

6. Utilization ratio of clean water (ratio of yield to intake): ≥90%