pH pS EARLY DETECTION OF H2S

Hydrogen and Sulphide Ion Monitoring:
• Advance warning of H2S breakout.
• Easy to install.
• Simple to interpret.
• Reliable electrode technology.
• Temperature compensated for direct result
   interpretation.

The drilling industry is well aware of the dangers posed by Hydrogen Sulfide (H2S) and the need to minimize its threat to workers. Gain valuable time for corrective action before a potentially dangerous and expensive situation occurs. 

Traditionally, ambient H2S detectors are positioned at strategic locations around the rigsite. This type of monitoring can leave the operator with a false sense of security!Detection of H2S in the atmosphere relays that a dangerous situation already exists. It is possible for large concentrations of H2S to be present in drilling fluid, but in a dissolved state and without actually being released to the atmosphere. Operators are unaware of a potential danger until it is too late.

The Facts:
• More than 10ppm is considered dangerous to
   humans if exposure is prolonged.
• Typical, OHS legislation prohibits any exposure to
   levels above 20ppm.
• Exposure to 1000ppm results in almost immediate
   death.

Decrease the Risk
Acidic H2S is “hidden” in the mud, in an ionic dissolved state, by the high alkalinity level of the drilling fluid. This state prevents H2S from forming into a gas and being released to the atmosphere.

Should the alkalinity drop the result could be a catastrophic release of the deadly gas.

The graph on the right shows the normal pH range is between 8pH and 12pH, for most drilling fluids. More than 90% of sulfide exists in the HS- ionic state. The H2S molecule is ionically split as H2S=HS-+H+ (Figure 1).

ILI’s pH/pS System reduces the possibility of such a catastrophic event by measuring the level of “S-2” and “H+” ions in the mud. This sensor provides a very early warning of H2S in water based drilling mud, long before it is released into the atmosphere or is still “hidden” by the mud alkalinity. Traditional ambient or hand held monitoring devices can not make the same claim. Use hydrogen and sulfide ion monitoring on any well where there is a possibility of encountering H2S. Ion monitoring minimizes the chance of H2S release from drilling fluid and avoids sulfide related corrosion problems.

The ILI pH/pS System calculates and displays critical parameters of pH and pHS-. These parameters are recorded in both time & depth databases. The user can view these parameters on printed or screen charts. (Figure 2)

The pH and pHS- parameters are temperature compensated for direct interpretation. ILI also calculates the amount of H2S when it is existing in a dissolved state in the drilling fluid.