Field Deployment of a Portable Optical Spectrometer for Methane Fugitive Emissions Monitoring on Oil and Gas Well Pads

Abstract

We present field deployment results of a portable optical absorption spectrometer for localization and quantification of fugitive methane (CH4) emissions. Our near-infrared sensor targets the 2ν3 R(4) CH4 transition at 6057.1 cm−1 (1651 nm) via line-scanned tunable diode-laser absorption spectroscopy (TDLAS), with Allan deviation analysis yielding a normalized 2.0 ppmv∙Hz−1/2 sensitivity (4.5 × 10−6 Hz−1/2 noise-equivalent absorption) over 5 cm open-path length. Controlled CH4 leak experiments are performed at the METEC CSU engineering facility, where concurrent deployment of our TDLAS and a customized volatile organic compound (VOC) sensor demonstrates good linear correlation (R2 = 0.74) over high-flow (>60 SCFH) CH4 releases spanning 4.4 h. In conjunction with simultaneous wind velocity measurements, the leak angle-of-arrival (AOA) is ascertained via correlation of CH4 concentration and wind angle, demonstrating the efficacy of single-sensor line-of-sight (LOS) determination of leak sources. Source magnitude estimation based on a Gaussian plume model is demonstrated, with good correspondence (R2 = 0.74) between calculated and measured release rates.

Handheld near-infrared spectrometers: Where are we heading?

“…Panel (b) reproduced from Zhang et al. 3 under CC-BY 4.0 license. Panel (c) reproduced from Hutengs et al.…”

Advanced Leak Detection and Quantification of Methane Emissions Using sUAS

“…In contrast, ref. [185] utilized a portable TDLAS-based instrument and the PSG method to quantify emissions. Lastly, ref.…”

“…As well as, Can new technologies provide more cost-effective leak detection compared to existing approaches? [185] using a static on-site portable TDLAS and PSG method, (b) [186] using the dual frequency comb spectrometer and non-zero minimum bootstrap (NZMB) method [187] with Gaussian plume model, reprinted (adapted) with permission from [186], © 2019 American Chemical Society (c) Bridger Photonics' group white paper using Gas Mapping LiDAR [190], used with permission, © 2019 Bridger Photonics, Inc., and (d) [121] using the bs-TDLAS and PI-VFP methods.…”

Operation of a Single-Frequency Bismuth-Doped Fiber Power Amplifier near 1.65 µm

“…However, in some spectral regions, the availability of proper gain medium, fiber chemical composition, and manufacturing issues are still critical problems. One of the research gaps is the spectral range beyond 1650 nm, which can potentially be used not only to extend existing telecommunication windows, but also in applications such as laser eye surgery [1,2] and the chemical sensing of hydrocarbons such as methane [3][4][5] and ethane [6]. Thulium-doped fiber amplifiers (TDFAs) can be used in this spectral region.…”