Throughout the various processes involved in natural gas refining, the end result frequently involves excess water being captured and removed. Water removal is an important part of ensuring the purest natural gas product possible, but the water cannot be simply drained away. Produced water, wash-down water or collected rainwater requires treatment, whether the water is reused for reservoir flooding or disposed of. Water collected from process operations contains hydrocarbon concentrations too high for safe discharge. Suspended hydrocarbon droplets in water also hinder well-injection.
In order to ensure safe, treated water that can be properly reused or discharged, water processing is necessary. The byproduct or captured water is processed to remove residual oil, excess hydrocarbons, and other contaminants. Once this process is complete, the water can be safely drained or used elsewhere.
Level Measurement Challenges and Considerations
Treatment equipment for water processing is similar to three-phase separators, except that water is the main product. Level control is found on skim tanks, precipitators, coalescers, flotation units, and collection tanks and sumps. Interface level measurement is essential for proper draining of clean water and removal of the residual oil. Instrumentation used for water processing must be reliable and capable of detecting interface and high/low level.
Level Measurement Solutions
Magnetrol has produced level measurement solutions for water processing:
For point level: Echotel Model 940/941 ultrasonic switch; Thermatel TD1/TD2 thermal dispersion switch; or float- or displacer-actuated switch
For continuous level: Eclipse Model 706 guided wave radar transmitter or E3 Modulevel displacer transmitter
For visual indication: Atlas or Aurora magnetic level indicators