Researchers from University of Nicosia recorded new information regarding the multi-scale flow processes that occur during shale gas extraction
Fossil fuels form continuously via natural processes. However, these sources are considered to be non-renewable as they require millions of years to form. Moreover, the known viable reserves are being depleted much faster than new ones are being made. Therefore, extracting gas, one of the majorly used source for producing fuels, from new sources is important to supplement the depleting conventional supplies. Shale reservoirs contain gas that is trapped in the pores of mudstone that contains a mixture of silt mineral particles of various sizes ranging from 4 to 60 microns and clay elements as minute as 4 microns. However, the mechanism behind effects of pore space and geological factors on gas storage and the ability of gas to flow in the shale is less understood.
Now, a team of researchers from University of Nicosia reviewed the current state of knowledge about flow processes that occur at scales ranging from the nano- to the microscopic during shale gas extraction. According to the researchers, the findings can help to improve gas recovery and lower shale gas production costs. The method of extracting gas from shale has gained traction in North America along with growing interest in South America and Asia. Majority of natural gas reservoirs display microscopic or larger scale pores. In contrast to conventional reservoirs, the pore structures of shale gas reservoirs range from the nanometric to microscopic scale.
In the research published in the journal The European Physical Journal E on November 20, 2018, the team demonstrated the latest insights on the effect of pore distribution and geometry of the shale matrix on the mechanics of the gas transport process during extraction. To determine how gas pressure and gas speed vary throughout the shale, the team developed a model based on a microscopic image that were acquired with the help of scanning electron microscopy. The team found that the model was in agreement with experimental evidence and the orientation, density, and magnitude of rock bottlenecks can affect the volume and flow in gas production.