SCIENCE & TECHNOLOGY
 

   Interstate gas network
Self-sufficiency of gas in India
N
atural gas is becoming the most popular fuel for use in cooking, transport, fertilisers and power generation. This is because of two reasons. First like coal and oil, burning of gas does not produce harmful and toxic gas oxides. Second, import of gas is cheaper than import of oil to develop a given amount of energy. If gas reserves are explored and developed within the country, the economic benefits are still higher. Therefore, the recent discoveries of gas in India and revival and resurgence of hydropower augur well for a great economic renaissance.

UNDERSTANDING THE UNIVERSE 

 
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Interstate gas network
Self-sufficiency of gas in India
by R.N. Malik and Mukesh Gupta

Natural gas is becoming the most popular fuel for use in cooking, transport, fertilisers and power generation. This is because of two reasons. First like coal and oil, burning of gas does not produce harmful and toxic gas oxides. Second, import of gas is cheaper than import of oil to develop a given amount of energy. If gas reserves are explored and developed within the country, the economic benefits are still higher. Therefore, the recent discoveries of gas in India and revival and resurgence of hydropower augur well for a great economic renaissance.

In order to fully understand the gas economics, some basic terms of gas usage need to be understood. Natural gas is primarily composed of methane (87%) with small quantities of nitrogen, oxygen, CO2, sulfur, water (2%) and higher hydrocarbon like ethane, propane and butane (11%). Under intense compression and cooling, gas assumes liquid state at - 162C and is called Liquified Natural Gas (LNG). The natural gas has to be liquified for the purpose of transportation from one country to another through sea vessels. CNG is the natural gas compressed to a pressure of 9-10 Kg/Cm2 in cylinders for use in vehicles. As a result of Supreme Court order in 1998, the Delhi Government had to set up Indraprastha Gas Limited (IGL), to promote CNG as a vehicular fuel in the city. The company laid a 23-km pipeline from Dhaula Kuan to G.T. Karnal by-pass road. 120 CNG stations were set up and CNG is being provided to all the three-wheelers and buses in Delhi. The number of CNG powered vehicles has increased to 90000 in March, 2003. Besides, 2300 vehicles are added every month to run on CNG. IGI has also expanded its network to provide PNG (piped natural gas) connections to 17000 households and 110 commercial organisations. LPG is liquified petroleum gas and consists of higher fraction of propane and butane.

Prospecting Gas Demand: Before recent discoveries, the Govt of India had a limited vision of gas usage in India. This was because of two reasons:

1. Import of natural gas by sea by first converting it into LNG followed by regasification is not very economical as compared to import of oil.

2. Bangladesh is not allowing laying of a pipeline from Agartala to Kolkata for transportation of gas from reserves in Tripura. Bangladesh is also not selling its huge reserves of gas to India or to any other country because of some irrational reasons.

Natural gas can be used copiously for five purposes. i.e power generation, domestic supplies (cooking) industry (captive power generator and heating of boilers), transport and fertiliser plants. These five uses can use any amount of gas provided. There is no limit to its supplies. Present discoveries indicate a gas reserve of 1800 BCM (Billion Cubic Meter) and 1000 BCM of coal bed methane (CBM) only. Present consumption of gas from existing resources (new discoveries have not been used so far) within the country is 80 MMS CMD (million standard cubic meter per day). Import of gas has started from January this year only. The indigenous resources (200 BCM) can run for 40 years @ 200 MMS CMD or @ 400 MMSCMD for 20 years. In fact the present consumption is also severely limited by the lack of distribution infrastructure from gas reserves to different parts of the country. PETRONET LNG Limited (a joint venture of public sector oil companies) has also purchased gas from Qatar (25 MMSCMD) and 9 MMSCMD supply will start this year (January, 2004) from Dahej terminal. Petro-dyine is also importing 9 MMSCMD gas from Holland to bring it to Hazira terminal. Gas Authority of India has been given the selling right of 70% of the PETRONET supplies and it is becoming difficult for GAIL to find customers.

Gas discoveries: There has been virtually no new discovery of gas reserves in India since 1973 till 2000 A.D. Earlier discoveries were in Assam and Tripura. The latest major discovery of oil and gas reserves was in Bombay High (1972-73). Real breakthrough came in 1999 when the Government of India took a historic decision to open the prospective gas and oil reserves areas to private agencies (including the ONGC) for exploration under the New Exploration Licensing Policy (NELP) though competitive bidding. The award under NELP I,II, III, were given for 70 blocks covering an area of 7,15,000 sq km. These awards covered 16 inland, 30 shallow water and 24 deep water blocks over a period of three years. The fresh round i.e. NELP-IV, was launched on 8.5.2003 for 24 blocks and final awarding process completed in December, 2003. These 24 blocks comprised of 11 inland, 12 deep water and one shallow water blocks. As a result of exploration in 70 blocks (it is not yet complete), major discoveries of gas reported so far are as below:

1. A major discovery of gas was by Reliance in October, 2002, in Krishana Godavari basin (KGB) 150 km, off the Andhra coast with initial estimated reserves of 300 BCM equivalent to 1.7 billion bausels 232 million tonnes of crude oil. The find is estimated to come on stream in 2006-07.

2. CAIRN Energy (Scottish company) also discovered oil and gas in Sarswati, Guda and Rajeshwar wells in Barmer District of Rajasthan. These wells were of moderate yield and total reserves could be 100 BCM.

3. The CAIRN ENERGY, Tata Petro-dyne and ONGC consortium also discovered oil and gas in four wells in the Gulf of Khambata (Gujarat) in 2000. These four wells are Lakshmi, Gauri, Ambe and Parvati. These wells can supply 80 MMSCD of gas for five years.

4. CAIRN ENERGY also made five discoveries in K.G.Basin (2 gas, 2 oil and gas and one oil) with 200 millions barrels of oil equivalent.

5. Reliance Industries Limited (RIL) and Gujarat State Petroleum Corporation Ltd. (GSPCL) have made another significant gas discovery of oil and gas in an exploration block in the shallow water of the gulf of Cambay (January, 2003).

6. GAIL India has unearthed a new natural gas reserve in the off-shore block A-I in Myanmar. This discovery has a potential of peak production of 60 MMSCMD of gas for 20 years.

7. ONGC has launched a multibillion dollar deep water exploration programme in the Arabian Sea and Bay of Bengal code named Sagar Smiridhi. It plans to drill 47 exploratory wells to explore expected 11 billion tonnes of oil and gas equivalent.

Now equally important discovery of gas was in coal fields. The ONGC knew about the presence of Coal Bed Melhame (CBM) from long time but exploration started after 1999 only. It is estimated that there might be 1000 BCM (ITCM) of CBM in India. Therefore, the Government has expedited the process of awarding CBM blocks separately.

1. Reliance made the second largest gas discovery in two CBM blocks in Shahdol District of Madhya Pradesh. The gas reserve are estimated to give a yield of 7-10 MMSCMD.

2. ONGC discovered coal bed methane gas in exploratory wells (with a yield of 7000 m3/day each in Telgadia village) in Bokaro and Jharia blocks. The blocks promise significant reservoir of methane gas.

The real picture of gas reserves will be known in next 2-3 years after results of all the 94 exploratory blocks have arrived in full.

Natural Grid for Gas distribution: In order to transport gas from new discovery sites and Dahej and Hazira terminals, new gas pipelines need to be laid. The present HBJ pipeline has the capacity to transport 25 MMSCMD gas imported from Qatar. The total absence of secondary distribution lines has also come as a big road block for gas utilisation. Now, GAIL is also contacting state governments to take up the work of laying distribution lines within the cities to supply metered supply of gas to domestic consumers. In fact, Gujarat is the first State to set up a company known as Gujarat State Petronet Limited (GSPL). This company is building a 1200-km gas grid within the state and a 200-km pipeline is already operational. The GSPL grid is supplying around 5 MMSCMD of gas to various consumers in the power, fertilizers and other industrial sectors in the cities of Baroda and Surat.

Therefore, GAIL has formulated Natural Gas Grid Development Plan (NGGDP) to lay 7900-km long pipeline network by 2007-08 for linking various domestic and cross border sources to the demand centres across the country. (see map).

Reliance is also upbeat to lay 2600 km of pipelines to solve the transport problems. Once the grid plan becomes a reality, the gas utilisation scenario in the country will be totally changed in the next five years.

Self Sufficiency: India is consuming only 80 MMSCMD of gas. The recent gas discoveries are no doubt heartening but fresh discoveries do not indicate huge reserves (2800 BCM only) as in the Arab countries or in Bangladesh we can at best consume 300 MMSCMD of gas for next 30 years which is four times the present level of consumption. But 80 MMSCMD rate is hardly significant because it serves a limited population of 10% to meet cooking and vehicular requirement of fuel. The government has not precisely calculated so far the rate of gas consumption required to meet cooking and vehicular needs in total. Because of limited reserves, gas should be exclusively used for catering to the cooking and vehicular needs and not for generation of power. Power can be generated more cheaply from coal and hydropower projects. Assuming that national grid is ready by 2008 simultaneously with secondary distribution lines in towns, the level of gas consumption at the rate of 400 MMSCMD (300 MMSCMD from domestic supplies and 100 MMSCMD from imports) will be fairly close to self-sufficiency level during 30-40 years. But real self-sufficiency will come when Bangladesh allows transportation of gas from Tripura to West Bengal through its territory and starts selling gas to India from its own huge reserves in Indian currency.

This is because the gas coming from Bangladesh will be utilised right in the adjoining states and liquification (followed by regasification) will not be needed.

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UNDERSTANDING THE UNIVERSE 
Prof Yash Pal

Prof Yash PalWhy does the earth rotate in a clockwise direction: why not anticlockwise?

First of all, I will like to point out that in actual fact the West to East rotation of the earth would appear to be anti-clockwise when viewed from top of the North pole and clockwise when viewed sitting on the South pole. (You might be able to check it by looking at a rotating ball from the top and then from the bottom). You may still ask why it is not the other way around. There is no law that it has to be only the way it is. It just happened that in the formation of the sun and the earth the rotation of the initial dust cloud happened to be so. The angular momentum of the cloud was so directed. There is nothing very deep in this happening.

We can balance a two-wheeler while riding. But we are unable to do so when it is not moving. Why?

If we push a standing bicycle with a great force it can go quite some distance before it topples. It acquires a degree of stability because of the angular momentum of the rotating wheels. The need for conservation of angular momentum gives the bicycle some stiffness against tilt. But this is not enough. The bicycle does topple after a while. It is clear that a bicycle rider and the bicycle together become a system capable of dynamic equilibrium not accessible to a rider-less bicycle. In my view learning to ride a bicycle is like becoming a coupled system with your bike. You become involved, subconsciously, in correcting the tilts. This is not very different from what you do while standing, walking or running. You keep ensuring that your centre of gravity does not wander far outside the vertical plane through the line joining the two support points on the ground. When standing your support points are the places where your two legs touch the ground. When pushed by someone to the left your left foot shoots out to the left to keep your centre of gravity in the middle. Similar movement of the right leg occurs when pushed to the right. Thus you can go on walking and running without realising that you are using a pretty sophisticated control system you discovered when, as a baby, you learnt to stand and walk. So what do you do when you have learnt to ride a bicycle? What you have learnt is that if you are tilting to the right you turn the handle bar slightly to the right and to the left when you are tilting to the left. This action, coupled with the forward motion of the bicycle moves the front wheel sideways to ensure that the composite centre of gravity of you, the rider and the bike, falls between the two points of support where the wheels touch the ground. This is a dynamic process and you are not even aware of what you are doing. The corrections required are larger when moving slowly and miniscule when going fast the slightest tilt of the bar can move the support point sideways if you are going fast. I do not know how the inventor of the bicycle knew that riders would be able to master this skill only after a few falls! I still remember that while learning to ride a bike more than 65 years ago my first few falls occurred when I kept trying to correct a rightward tilt by trying to turn the handle bar to the left.

I cannot help drawing a lesson from what happens to us when we acquire the automatic capability of control after learning to ride a bicycle. We become a single organism without bicycle and the control is only dynamic. This is also needed if we want to control an institution, corporation or a country. True stability cannot be static we need to keep moving to achieve it.

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