NATURAL GAS

• Natural gas energy refers to the energy derived from natural gas, a fossil fuel composed mainly of methane along with other hydrocarbons. Natural gas is found in underground reservoirs and is extracted for various energy applications.
• Used domestically and industrially, it serves as fuel in power generation, heating in industries, and raw material in various sectors. Additionally, it’s employed in transportation and cooking.
• Major gas reserves are in Mumbai High, allied fields along the west coast, and the Krishna-Godavari basin. The Hazira-Vijaipur-Jagdishpur (HVJ) cross-country gas pipeline, spanning 1,700 km, connects Mumbai High and Bassein fields to western and northern industrial complexes. GAIL (India) constructed it, spurring India’s gas market development. The gas infrastructure, covering 18,500 km, is expected to expand to over 34,000 km, forming a Gas Grid connecting all sources and consuming markets nationwide, including the North Eastern states.
• TAPI Pipeline, also called Peace pipeline, is a 1,814km natural gas pipeline that originates from Turkmenistan and passes through Afghanistan and Pakistan to reach India.
• It aims to monetise Turkmenistan’s gas reserves and supply them to neighbouring countries to promote the use of natural gas and improve energy security.
• The project is being developed by TAPI Pipeline Company (TPCL), a consortium established by four individual state-owned gas companies Turkmengaz (Turkmenistan), Afghan Gas (Afghanistan), Interstate Gas Service (Pakistan), and Gas Authority of India and Indian Oil (India). The four countries signed an Inter Government Agreement (IGA) and Gas Pipeline Framework Agreements (GPFA) in December 2010 for the development of the pipeline.

Conventional natural gas:

• Conventional gas is accessible because it is trapped under a permeable layer of rock. In most cases, it occurs together with oil reservoir deposits and sometimes it floats on top of the oil, forming a layer on it.

Unconventional natural gas:

• Unconventional gas hiding deep below (4500 meters or more) the surface, making extraction difficult. Economically, it is not always viable to extract unconventional gas types, because it is not cost-effective. Yet, new technologies are developing every day to make natural gas extraction easier. Thus, today’s unconventional natural gas types will become conventional in the future.

Deep Natural Gas types belong to the unconventional category. These are hard to extract for different reasons.

• Shale: Shale is a fine-grained, clastic sedimentary rock, composed of mud and it is a massive mineral. It is so tough that drilling into it is a rather costly process.
• Tight gas: It can be extracted only by fracking and acidizing because tight gas is trapped underground in an impermeable rock formation.
• Coalbed Methane: It can occur aside seams of coal. Historically it was the waste product of coal mining, but in recent decades it has become an important source of energy.
• Gas in Geopressurized Zones: Geopressurized Zones form 3000-7600 meters below the surface. It is hard to extract, but gas processing can be viable because a high amount of natural gas hides in this zone.
• Methane Hydrates: It is trapped in places like the Arctic with low temperature and high pressure. Climate change incites the release of methane hydrates into the atmosphere.

Biogas: It contains less methane gas than natural gas, but still a reliable energy source. It is a type of gas that is produced when organic matter decomposes without oxygen being present.

Where does natural gas come from?

• Natural gas can be found beneath the ocean or the lands, close to the Earth’s surface or deep below the crust. It can be trapped alone or with oil: as we drill deeper, the possibility of finding natural gas instead of oil is getting bigger.
• Most of the reserves are in the Middle East (Iran, Qatar, Saudi Arabia, United Arab Emirates) and Russia. The Middle Eastern countries have over 40% of the world’s natural gas supply, Russia has 24% while the Unites States only possesses 5.3%.

Natural gas extraction: how is natural gas collected?

• First, a test well confirms that the deposit has enough natural gas and extracting it can be cost-effective. Then new production wells will be drilled.
• Oil extraction often comes with natural gas extraction. There are also examples of natural gas being pumped back into the well for future extraction. After drilling the well, a concrete and metal casing is installed into the hole, and a collection pump is built above this.
• Depending on the types of natural gas, collecting this fossil material can be different. Methods:
• Vertical drilling
• Horizontal drilling
• Hydraulic Fracturing / Fracking
• Acidizing

Vertical drilling: the most common method

• This natural gas extraction process was the first and only type of natural gas production until 1980. Vertical drilling is efficient when natural gas is close below the surface, so it is efficient in the freeing of conventional natural gas.
• The average depth of vertical wells is only 300-800 meters, then they reach the natural gas deposit and the gas can start flowing to the surface. Vertical drilling is therefore limited to the gas reserves it encounters from above, thus it can be the perfect solution in some cases.

Horizontal drilling

• Horizontal drilling is a flexible and cost-effective solution to broaden the possibilities of drilling. This way drilling companies can install less drilling sites because after reaching the required depth, the drill can change its way horizontally. With the steerable drill bit, it becomes more productive and can go horizontally through the natural gas deposits.

Hydraulic fracturing / Fracking

Hydraulic fracturing is the exciting side of gas production. This way drilling starts with a generated ‘micro-earthquake’. With high-pressure streams of water, sand, and chemicals it breaks up the formation of rocks. After that, natural gas can flow up to gathering gas pipelines and wells on the surface.

However, this method is banned in some places, because:

• It needs huge quantities of water, which can overwhelm the environment
• Has heavily toxic or even radioactive wastewater which can affect nature if mismanaged.

Hydraulic fracturing or fracking is used to extract unconventional natural gas.

Acidizing

• It is a side-operation to any drilling methods, but mainly to fracking. With acid dissolving the rocks that may be on the way of the natural gas, it can flow up to the well.

Key issues associated with natural gas extraction:

1. Environmental Impact:
   • Water Contamination: Hydraulic fracturing, commonly known as fracking, involves injecting large volumes of water, sand, and chemicals into the ground to release natural gas. There have been concerns about the potential contamination of groundwater due to the chemicals used in this process.
   • Air Pollution: The extraction, processing, and transportation of natural gas can release pollutants into the air, including methane, a potent greenhouse gas. Methane leaks during production contribute to climate change.
2. Land Use and Habitat Disruption:
   • Drilling Footprint: Extracting natural gas requires well pads, roads, and other infrastructure, leading to habitat disruption and fragmentation. This can impact local ecosystems and wildlife.
   • Deforestation: Clearing land for drilling sites can result in deforestation, further affecting biodiversity.
3. Induced Seismicity:
   • Earthquakes: Injection of wastewater into disposal wells, a byproduct of natural gas extraction, has been linked to induced seismicity (human-induced earthquakes). The disposal of wastewater into deep wells can alter subsurface pressures and trigger seismic events.
4. Water Usage:
   • High Water Consumption: Hydraulic fracturing requires large amounts of water, which can strain local water supplies, particularly in water-scarce regions.
5. Community and Social Concerns:
   • Community Disruption: Local communities near extraction sites may experience disruptions due to increased traffic, noise, and changes in the local landscape. Some communities also report adverse health effects they attribute to nearby natural gas operations.
   • Economic Dependency: Regions heavily reliant on natural gas extraction may face economic challenges when gas prices fluctuate or when resources are depleted.
6. Regulatory and Oversight Challenges:
   • Regulatory Gaps: In some cases, there may be regulatory gaps or lax enforcement, leading to inadequate oversight of natural gas extraction operations. Strong regulatory frameworks are essential to mitigate environmental and social impacts.
7. Methane Emissions:
   • Methane Leakage: Methane, the primary component of natural gas, is a potent greenhouse gas. Methane leakage during extraction, transportation, and processing contributes to global warming.
8. Waste Management:
   • Wastewater Treatment: Managing and treating wastewater generated during the extraction process is a significant challenge. Disposal methods, including injection into disposal wells, can have environmental implications.