Lab-simulated downhole leaching of formaldehyde from proppants by high performance liquid chromatography (HPLC), headspace gas chromatography-vacuum ultraviolet (HS-GC-VUV) spectroscopy, and headspace gas chromatography-mass spectrometry (HS-GC-MS)

Abstract

Different methods to analyze formaldehyde from proppants was investigated under lab-simulated downhole conditions.

Characterization of ethoxylated alcohols in friction reducers using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

“…The weight average molecular weights tended to be higher (more polymerization) in water than in other complex sample matrices. This phenomenon has been observed previously when dealing with these matrices, and is probably due to competing reactions taking place that result in less polymerization of the ethoxylated alcohol. Although the complex sample matrix tended to hinder polymerization when tested immediately at room temperature compared with the water matrix, upon heating for 24 h, a trend was observed in most cases where polymerization occurs in all matrices.…”

“…PWI, PW, and PW + shale), the ethoxylated alcohols tended to have lower weight average molecular weights and lower dispersity values. As previously discussed, this could be due to competing reactions occurring among the contents of the more complex sample matrices …”

“…Produced water was collected near Midland (TX, USA). Furthermore, a surrogate for produced water (termed here as produced water inorganic (PWI)) was prepared in house and consisted of BaCl 2 (1.88 mmol/L), CaCl 2 (39.63 mmol/L), MgCl 2 (9.51 mmol/L), SrCl 2 (2.97 mmol/L), Na 2 SO 4 (0.02 mmol/L), NaHCO 3 (15.19 mmol/L), and NaCl (1,896.31 mmol/L) with a salinity of 12% . α‐Cyano‐4‐hydroxycinnamic acid (99%), 2,5‐dihydroxybenzoic acid (98%), trifluoroacetic acid (99%), and BrijC10 (M n ~683) were purchased from Sigma‐Aldrich (St Louis, MO, USA).…”

“…Friction reducer (approximately 250 μL) was added to a 3‐dram screw‐capped vial with 1750 μL of solvent. The solvents included deionized water (DIW), produced water inorganic (PWI), or produced water (PW). Experiments were performed to also examine the behavior of ethoxylated alcohols contained in friction reducers in the presence of shale core and produced water.…”

Identifying Thermal Decomposition Products of Nitrate Ester Explosives Using Gas Chromatography–Vacuum Ultraviolet Spectroscopy: An Experimental and Computational Study

“…The VUV spectra of oxygen, carbon monoxide, and water using the benchtop GC–VUV have been previously reported. 1,32,33 Formaldehyde and nitric oxide are available in the VUV reference library; however, experimental acquisition of these compounds have not previously been published in an academic journal with wavelength acquisition down to 125 nm. 31 To the best of our knowledge, the VUV spectra of formaldehyde and nitric oxide have not been previously reported, nor has the use of TDDFT to predict spacing between vibronic transitions in the VUV.…”