Permeable rocks have traditionally been considered as resources of natural gas and oil. They’re generally drilled to release the entrapped oil and gas. However, the natural gas and oil are present in relatively lower quantities in certain rocks. But several companies in the oil and gas industry have uncovered the possibility of the existence of huge amounts of oil and natural gas in shale and other tight rock formations. Nevertheless, the natural resources entrapped in these rocks were initially inaccessible due to the rocks’ low permeability properties. Thus, a revolutionary technology was invented combining hydraulic fracturing and horizontal drilling. This new technique was able to release a massive amount of entrapped oil and natural gas from shale and other tight rocks in a commercially feasible way.
This boom in oil and natural gas production undoubtedly strengthened the economic stability of countries like the United States, bringing in more revenue and allowing them to become less dependent on oil imports from other countries. At present, many power plants across the globe are run by natural gas instead of coal, resulting in reduced coal usage and lowered emissions of hazardous particulate matter in the atmosphere. For instance, the power generation by coal in the United States is expected to be reduced to 27.6% in 2022, while it was 32.7% in 2017. In 2018, 39.4% of the United Kingdom’s electricity came from natural gas, while only 5% came from coal.
Controversies:
The large-scale release of natural gas and oil from shale by hydraulic fracturing undoubtedly brought a huge economic fortune but also raised major environmental and community health concerns. For instance, traces of ground and surface water contamination were found, along with methane leakages, while releasing the entrapped gas. Additionally, several studies demonstrated that hydraulic fracturing was associated with a decrease in crop productivity and an increase in seismic activity, triggering tremors and earthquakes in the fracturing areas. In order to control these issues, statutory authorities formulated some stringent norms for the companies working in this field to abide by.
Hydraulic fracturing – Case studies and innovations:
From the technical perspective, hydraulic fracturing has multiple challenges to tackle, for example, better fracture design for heterogeneous rocks, increasing well productivity, minimizing formation damage, and simultaneous propagation of non-planer hydraulic fractures from multiple perforation clusters, which would reduce the possibility of tremors and earthquakes. To better deal with these challenges, the companies working in the oil and gas field are putting out tremendous efforts to make this technology more economical and environmentally sustainable, in collaboration with research foundations and academic institutions.
Halliburton Corporation conducted multiple case studies for coming up with better ways of solving these problems. They suggested the application of fracturing fluid that can be used with brackish water and recycled water in order to reduce the consumption of fresh water.
“For all intent and purposes we can reuse water for fracking without doing any significant form of filtration,” says Steve Ingram, Halliburton’s Manager of Technology and Marketing for North America.
Schlumberger Limited also made significant contributions through several case studies and is now offering a family of fluid additive systems called OpenFRAC that are well suited for recycling and reuse. GE is also currently working on technologies to lower water consumption. One of their key projects is to pressurize gases like propane or carbon dioxide into foams or gels for replacing the water used in fracking.
Computer simulations and 3D modeling programs made by certain academic institutions are also contributing towards the advancement of drilling and hydro fracturing techniques. A research group from the University of Texas at Austin used modeling to study fracture growth and other aspects of fracking.
Mukul M. Sharma, the group leader and professor of petroleum, geo systems, and chemical engineering, claimed, “Combine this with geo mechanical modeling and the picture becomes even clearer. Before we had these tools we had very little idea where the fractures were actually going.”
And MIT has performed the detailed 3D imaging of kerogen, a source of petroleum and natural gas that could potentially improve the estimates of recoverable amounts.
According to a recent study conducted by the scientists of Bristol University, it is now possible to predict the seismic activity at fracking sites and carry out the fracking procedures safely to prevent potential earthquakes.
Next-generation technologies:
There are several new major technologies developing in the fracking field.
- Raytheon combined radio frequency (RF) energy with critical fluid (CF) technology to demonstrate a promising way of economically extracting oil from shale in 2006. Steam generation and reduced water consumption were the main advantages of this technology, which was acquired by Schlumberger in 2008.
- In 2015, researchers from the University of New Mexico developed an environmentally friendly and cost-effective fracking fluid that uses less water and chemicals. It is able to frack bedrock, which could not be previously penetrated.
- A research team from the Department of Energy’s Oak Ridge National Laboratory is trying to develop a safer and more efficient fracking technique with the use of acoustic energy. They are combining neutron and X-ray scattering to efficiently blast well surfaces, or bores, which can potentially improve the penetrating power of fracking and cut down on the required water and chemicals.
- A new technology called microwave fracking was launched in 2017 by Qmast LLC as a novel way to harvest petroleum units from oil shale. We are yet to conclude whether or not this next-generation advancement of fracking technology is truly environmentally friendly and cost effective, as there are many variables to consider. Peter Kearl, cofounder and CTO of Qmast hopes it will possibly start an energy revolution. Further research and applications of this process will give us an answer.
