Development of a High-Pressure Bubbling Sampler for Trace Element Quantification in Natural Gas

A high-pressure bubbling sampler has been developed to trap and preconcentrate metals and metalloids from natural gas. This high-pressure sampler was designed to work at pressures up to 100 bar and be directly plugged into distribution and transportation networks. It consists of three vials in series, which contain 50 mL of metal trapping solution and the gas flows at the network pressure with a flow rate up to 40 L/min. The trapping solutions for mercury and other metals are permanganate/sulfuric acid or nitric acid/hydrogen peroxide according to standards EN 13211 and EN 14385. The sampler design, development, and validation steps are presented in this work. First, the trapping vials were tested in the laboratory, where argon gas was spiked with mercury at two different pressures that represented the distribution and transportation networks. The results show that more than 96% of the metal was trapped from the gas phase into the solution for both tested pressures. Moreover, more than 90% of the trapped metal was found in the first vial, which shows the good efficiency of the traps. Finally, the high-pressure bubbling sampler was tested in three field campaigns of natural gas sampling from a transportation network at 60 bar. Each sampling was performed for 5 days with a flow rate of 20 L/min, which makes a total volume of 140 Nm³ of sampled gas. The gas flowed through three vials of 50 mL, which makes a final preconcentration factor of 3 × 10⁶. The trapping solutions were analyzed for trace metal concentrations using inductively coupled plasma mass spectrometry. The concentrations were 10^–1 ng/Nm³ for barium, from 10^–1 to 5 ng/Nm³ for tin, from 0.9 to 10 ng/Nm³ for arsenic and copper, and from 1 to 10¹ ng/Nm³ for aluminum, selenium, and zinc. The efficiency of the traps and the low measured concentrations make this high-pressure bubbling sampler a useful tool for trace element analyses in natural gas

New Passive Water Tracers for Oil Field Applications

We present the results of theoretical and experimental work on the development of new chemical passive water tracers for application in oil reservoirs. Fluorinated benzoic acids (FBAs) are currently used as chemical water tracers in oil field applications, and they were considered as “reference water tracers” in this study. The 15 newly proposed tracer molecules are halogenated derivatives of benzoic acid that are commercially available and have two halogenated substituents on the aromatic ring, either one fluorine (F) and one trifluoromethyl group (CF₃) or one fluorine (F) and one chlorine (Cl). Laboratory-scale experiments were conducted to evaluate the physicochemical properties (e.g., detection, stability, and toxicity) and performance of the molecules as potential water tracers. Both the new tracers and FBAs are simultaneously detectable using the same rapid analytical tool [ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC/MS–MS)] and can therefore be used in the same tracing campaign without altering the analytical technique for the detection in reservoir water samples, which is economically desirable. Recommendations for the storage step between sampling and analysis are also discussed

New Passive Water Tracers for Oil Field Applications

We present the results of theoretical and experimental work on the development of new chemical passive water tracers for application in oil reservoirs. Fluorinated benzoic acids (FBAs) are currently used as chemical water tracers in oil field applications, and they were considered as “reference water tracers” in this study. The 15 newly proposed tracer molecules are halogenated derivatives of benzoic acid that are commercially available and have two halogenated substituents on the aromatic ring, either one fluorine (F) and one trifluoromethyl group (CF₃) or one fluorine (F) and one chlorine (Cl). Laboratory-scale experiments were conducted to evaluate the physicochemical properties (e.g., detection, stability, and toxicity) and performance of the molecules as potential water tracers. Both the new tracers and FBAs are simultaneously detectable using the same rapid analytical tool [ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC/MS–MS)] and can therefore be used in the same tracing campaign without altering the analytical technique for the detection in reservoir water samples, which is economically desirable. Recommendations for the storage step between sampling and analysis are also discussed