Rice University scientists have developed a nanoscale detector, a type of nanotechnology that enables them to check crude oil and natural gas wells for the existence of hydrogen sulfide (H2S) within the wells and then report on what is found.
Nanoreporters can tell the difference between “sour” and “sweet” oil.
According to James Tour, the lead chemist of the Rice labs research project and Rice University professor, Hydrogen sulfide naturally exists within crude oil and natural gas. It is responsible for the “rotten egg” aroma that comes from these substances. All that it takes is a 1% trace of sulfur to transform oil into what is called “sour crude”.
Oil that is “sour” is toxic and eats away at transportation vessels and pipelines. Converting “sour” oil into the favored “sweet” is a costly process. Therefore, “it’s important to know the content of what you’re pumping out of the ground, and the earlier the better,” Tour said.
Aside from Tour, the other chief group members involved in the nanoreporters project include researcher Amy Kan and two other Rice professors, Mason Tomson and Michael Wong. The scientists developed carbon material the size of a nanometer to create the innovative nanoreporter, which has the ability to collect information from oil wells and report on data that would be difficult to evaluate by any other means.
Nanotechnology helps to make the detection of H2S contamination a safer process.
According to the researchers, hydrogen sulfide is highly toxic. Even limited exposure to it can cause humans to experience dizziness, sore throats and breathing difficulties. Moreover, it does not take long for humans to become desensitized to the smell, which makes it next to impossible for people to notice higher concentrations of H2S. Prolonged exposure to high concentrations of this chemical compound may not only lead to more health problems, but could also be fatal.
On the other hand, H2S does have some biological importance as a signaling molecule. Tour mentioned that chemist have found a way to detect it in the human body by using fluorescent probes. The Rice University research team used this technology to their advantage and applied it to the probes they created to be sent down holes and act as oil field detectors.
Now, the group of Rice scientist, along with chemist Angel Marti, are using carbon black-based nanoreporters that have been modified and designed to be soluble, very mobile and thermally stable, to seek out hydrogen sulfide and report what has been found right away once out of the well. With this nanotechnology, the hope is that the level of H2S contamination in oil and gas can be determined with greater ease and efficiency.