Page 202 - Handbook Of Multiphase Flow Assurance

DRA 199

• Active heating
• Emulsion breaker chemical to reduce emulsion viscosity
• Emulsifier chemical to form water-external emulsion.

Mercury management

Mercury content in produced fluids affects the environment and personal health through
discharge streams such as de-oiled filtered produced water. Mercury also can accelerate cor-
rosion of metals such as aluminum and cause integrity issues in process equipment compo-
nents made of aluminum.
Mercury in produced fluids is usually associated with production in North Sea and regions
near continental rim such as Northern Australia or Indonesia.
Mercury management aims to reduce the mercury impact on health, safety and environ-
ment and material integrity.
Technologies which could be considered for management of mercury in produced fluids
include:

• Mercury removal from gas unit including recommended location and technology
• Mercury monitoring system including sample locations and appropriate
equipment
Materials in production systems containing mercury should avoid aluminum, brass, nickel
alloys as suitable for the expected mercury level.

Sulfur deposition

Sulfur may be carried from reservoir in gas phase. As pressure and temperature in well-
bore change, sulfur may deposit in well tubing.
Sulfur deposition depends on both temperature and pressure.
Elemental sulfur solubility in gas decreases very roughly tenfold for every 25 °C or for
every 100 bar.

DRA

Drag reducing agents are long polymeric chains which help reduce turbulence at the pipe
wall by affecting turbulent eddy size and reducing fluid drag on pipe wall.
Being long chains, the DRA chemicals suffer from shear degradation when long mole-
cules get sheared and broken by the flow. The location of DRA chemical injection should be
downstream of any equipment which causes high shear such as valves, chokes, etc. to avoid
chemical degradation.
Typical dosage of DRA chemicals is described in Chapter 1.