H2S control in crude oil and condensate production
H2S is present in several wells around the globe. It will gradually increase over the lifetime of an oil and gas field in cases of water injection and sulfate-reducing bacteria. Control of the H2S partial vapor pressure, or H2S concentration, is in many cases safety-critical or required for process optimization. Hobré Instruments can provide the analyzer, or a complete solution to achieve the online measurement as required. The HLT Hilase Tunable Diode Laser (TDL) analyzer, with robust, easy-to-maintain photoacoustic analyzer technology, is at the heart of our solutions. Its major advantage over UV absorption technology is that TDL with IR absorption using the Photo Acoustic technology is not affected by BTX content. In cases where the BTX content of the oil is considerably more than the H2S content, UV is not suitable due to the interference of these aromatics. There are also numerous benefits over the lead acetate method, including lower OPEX costs, and the fact that inherent HSE risks associated with lead acetate are eliminated by design.
- H2S in Multi-Phase Crude
- H2S in Wet Gas
- H2S in Stabilized Petroleum Product
- H2S in Produced Water
- H2S in Gas Applications
This solution for three-phase water/oil/gas mixtures measures the H2S partial vapor pressure under process conditions. This can be used to verify contractual requirements and/or control scavenger injection into the well.
The HLT Hilase H2S partial vapor pressure analyzer in the gas phase of a production, test or second stage separator. Using Henry’s Law, and the parameter separators P and T, the H2S vapor pressure in the gas phase can be used to calculate the H2S concentration in the oil and water phase. The combination with the HIFISC sample conditioning system has been proven to work on such wet gas applications with a maintenance interval of 6-12 months. Analyzing the gas phase, and correlating to H2S in oil and water, is a lower-cost, faster-responding, and more accurate solution than a liquid phase analyzer. This design can also be applied in a crude oil stripper system by installing the analyzer on the flash vessel outlet.
Our solutions for oil and condensate processing
For applications in stabilized and treated crude oil, the HLT Hilase gas phase analyzer is combined with a counter current-based stripper system. The crude injection in the stripper is achieved using a fixed-volume injection system, mounted in the analyzer fast loop. The resulting stripping efficiency greater than 98%. The filtered gas phase from the stripper system is analyzed by the HLT Hilase H2S in-gas analyzer. The analyzer is calibrated with a calibration gas. The injection volume, and the carrier gas and H2S gas concentrations, are then used to calculate the H2S content in the oil phase.
Downstream: H2S analysis in hydrocarbon liquids
In the sulfur removal processes of the refinery fuel, the sulfur components are converted to H2S. The H2S is then fully removed, as traces of H2S in liquid fuels can cause corrosion problems and H2S issues during transportation and usage. To measure H2Sin liquid fuels, the gas phase H2S analyzer is combined with a counter current-based stripper system which gives an H2S stripping efficiency of greater than 98%. Accurate flow control of the fuel and the stripping gas, in combination with the gas-phase analyzer, enables an accurate and repeatable analysis of H2S in liquids. The filtered gas phase from the stripper system is analyzed by the HLT Hilase H2S in-gas analyzer, which is calibrated with a calibration gas.
For applications in process and waste water streams, the HLT Hilase gas phase analyzer is combined with a countercurrent-based stripper system. The water flow into the stripper is controlled. The stripping efficiency of the sulfides is then enhanced by an acid buffer dosing system. With the acid buffer addition, all H2S and HS in the water is converted to H2S and then stripped from the water. The filtered gas phase from the stripper system is analyzed by the HLT Hilase H2S in-gas analyzer. The analyzer is calibrated with a calibration gas. The injection volume, and the carrier gas and H2S gas concentrations, are used to calculate the H2S content in the oil phase.
Both in natural gas fractionation and in the refinery processes removal of moisture and H2S, on-line analyzers are used to monitor and control process units.
Ppm-level measurement of the H2S and moisture, in combination with possible contaminants in the gas, require a combination of a well-designed sample conditioning system and a reliable analyzer. Combining the HIFISC sample conditioning system with the HLT Hilase analyzer offers the industry a powerful tool for controlling the moisture and H2S removal process.
The HIFISC sampling system provides an excellent response time, minimum flow to flare, and low maintenance, as all contaminants from the process are returned back to the process.The analyzer has no moving parts, an expected lifespan of more than 10 years for both the laser and detector, and a typical drift of less than 5% over a year. For these low-ppm applications, a differential method is used which makes the instrument suitable for wide gas matrix variations. Additionally, a power supply is the only utility required. The analyzer is available for H2S, CO2, and moisture, as well as a combination of these parameters. Dual-cell and dual-stream analyzers are available.