 We have been directly or indirectly talking about the introduction of the course, a scope of environmental geomechanics and in the previous lecture I gave you an idea about what are the current trends in environmental geomechanics or the subject as such and after listing several state of the art topics, I picked up energy geotechnics which is the need of the hour. Everywhere in the world the big crisis is how to harness sustainable energy. Go to the western world, 6 months of the year the entire country remains no bound and imagine the amount of energy they required for refrigeration heating up of their houses and infrastructure and so on. Come to the countries like India where we have temperate climate again the energy geotechnics plays a very important role. We have to talk about sustainable energy by which we can cool our infrastructure and the buildings alright. So imagine the parts of Rajasthan and northern India which remain under severe heat conditions you know for almost 4 to 5 months. Now this is where we have talked about what are the resources which can be exploited to generate more energy and I talked about a discussion on nuclear energy versus thermal energy and then we discussed about the volume versus concentration concept and then later on I took that concept to quantify like how to solve this type of problems for the philosophies by using the concept of THMC that is thermo hydro mechanical chemical coupling and then this is where I also talked about THMCB thermo hydro mechanical chemical biological coupling and how these type of couplings can help you in solving the issues which are related to production of energy and particularly the nuclear waste disposal and post disposal you know monitoring. I will go ahead with this concept of energy geotechnics in today's lecture and to just give you an idea about what is happening in the contemporary world and some of you who have already heard about the gas hydrates I will discuss a bit about what these gas hydrates are. So I have provided link over here if you click over the gas hydrates you will get lot of information about what is happening in the contemporary world. So this is a clipping which shows in a first natural gas hydrates discovered in the Indian ocean I mean like this is the source of energy in the days to come and people speculate when the fossil fuel is over this is the source of energy or this is the type of energy which can be exploited for sustenance of the society. So it is interesting report which you should go through most of the time these hydrates are available in the offshore regions or in the water bodies and I will discuss in details about these type of structures in today's lecture in details and what these structures have to do with the geomechanics. Now as far as the Indian scenario is concerned if you go through the current affairs this is what is happening. So India might hold world's second largest gas hydrate reservoirs and this is a very good news you know the regions which have been identified are the KG Basin, Andaman area and northeast. So KG Basin is a very rich area in which the hydrates are deposited. If you talk about the South Asia gas hydrates are the resources and this is a very interesting document which is available on the net this comes from Sark Energy Center Islamabad Pakistan gas hydrate resource potential of the South Asia. Well whenever you get time you should go through this this is how the hydrates looks like. So if I expose it to the atmosphere it catches fire because of the methane getting emitted in the environment. So basically what hydrates are these are basically ice like clathrates this is how they look like. So what you will notice is that this is the molecule of methane those of you who love chemistry there is a carbon attached with four hydrogen atoms. So this is a methane molecule which gets trapped into water and because of the pressure and temperature condition it gets trapped over there due to action of very high pressure and low temperatures. We call them as ice like cathrates and truly speaking this is a state of a material or a geomaterial which also is considered as a multi-phase Americans would call it as multi-phase alright. So many people are doing research nowadays on multi-phase geomechanics in conventional geomechanics if you remember you have talked about only mostly started with three phases but then very cleverly you brought it down to the two stages by saturating all the samples. So most of the tests which you did in the laboratory were under so condition whether it is CBR whether it is hydraulic conductivity whether shear strength triaxial consolidation you saturate the sample for enough time so that the air phase gets lost. So truly speaking the conventional geomechanics does not capture the real life response of the geomaterials and keeping this in view people have started working on unsaturated state of the material they talk about the three phases and here we are talking about the multi-phases. So the difference is we have solids we have liquids and in liquids we have let us say water we have gases, fluids alright a composition of the two and when you are lowering the temperature and playing with the pressure the state of fluid may also get changed very high pressures would cause dissolution of the gas which is present in the pores of the soil into the liquid phase alright. Similarly a very high low temperature might change a certain fraction of the liquid into a solid phase say water getting frozen in the pores partially. So imagine a state of the material where you have soil skeleton where you have little bit frozen water you have completely frozen water where you have no frozen water and then you have different type of gases this could be fumes this could be chemicals that could be anything alright it could be methane gas. So this is the state of the geomechanics in the 21st century which people are trying to work on and these are going to be more realistic. So whether it is atomic waste disposal which we are discussing the other day or whether it is hydrates gas hydrates these are the good examples of how geomaterials when they come in contact with different environmental situations conditions they behave. In other words the response of the material when it is exposed to different environmental conditions yes please. Sir is this methane trapped in ice like a crystal or like a crystal solid crystal in ice. No gases cannot be crystallized. So methane molecule gets trapped into the crystal of water alright okay any other question. So I hope you have understood what is the state of the art on the subject yes please the geomechanics as such. So suppose if I ask you to find out the compressibility of this type of sediment which is a multi phase sediment or what is the hydraulic conductivity of a fluid which is passing through these sediments or what is the shear strength of these type of sediments clear. This becomes very very complicated. The simple thing would be you go out for the reconnaissance. So the way you the way the geophysicists were finding out the minerals location on the earth same way you have to go reconnaissance in a ship and find out where these type of reservoirs are or sometimes if you check on the net mid ocean fires clear. That is an indication that somewhere down below you have a reservoir of hydrograpes. So the methane gas is leaking and this catches fire and in the middle of the sea you will find there is a big fire alright. So these are the good indications. There are a lot of people who are working on resources. So geophysicists they were talking about location of water table, location of minerals clear and now the shift is on finding out hydrates. So where is the habitat of such type of elements? These are marine environment. This could be lakes, this could be water bodies and you know wherever you have sediments. So each molecule of hydrate would be having 180 meter cube of methane gas imagine. That means what is happening is as you are asking the more and more pressure which I apply on the system the lower the temperatures so many molecules of methane gas can be packed inside the matrix that once you take out this system and put it to the STP standard temperature pressure condition you can produce 180 meter cube of the methane gas. Imagine that would be the most wonderful thing. So when you fill your car you know diesel tank or petroleum tank what is the capacity of the car diesel tank? So early 27, 28, 30 liters, 50 liters trucks would be about 200 liters, 500 liters and so on. For an aircraft it would be in thousands of liters clear. So imagine one molecule of the hydrate crystal is capable of producing 180 meter cube of methane gas. So this is what is going to solve the energy crisis of the society the contemporary world. This is how they look like like a cauliflower or a cabbage you may say. I will show a lot of photographs today. So what are the different sources of the methane gas? The first thing is this is the question as you were asking. The second thing is types of methane gas are two. One is thermogenic alright. Thermogenic corresponds to the situation which is due to the chemical reaction which are occurring in the earth's crust alright. Thermal processes because of the temperature gradient of the sediments inside the sea. So what you are observing here is I have done an animation that the bubbles are coming out and this gas you know gets trapped into the sediments and under normal sorry not normal under varied conditions of pressure and temperature they will get trapped over there and they form hydrates. Normally thermogenic gases are methane C2S6 any idea what it is? Ethane you are right. So C2S6 is ethane and C3H8 propane perfect. So all these thermogenic gases are methane, propane, ethane it is a combination. Now our interest is mostly in the methane gas. So I can produce the methane gas, I can bring it to the refinery and I can filter out all those things. Normally this type of process occurs in the deep seas. So I have drawn a line over here which shows the depth of the water column alright. So under deep sea conditions normally thermogenic processes occur. There is a second situation which is known as biogenic methane gas. So biogenic methane gas is a pure form of the methane. We will be more interested in biogenic methane because thermogenic methane would require some sort of a refinery and microbial decomposition of the organic matter which is present in the sediments is the main cause of biogenic methane production and I hope now you can realize that why most of geotechnical engineers like us are venturing into the you know biogeointerface and what really happens when the sediments are attacked by the biotic activity, microbial activity. So this is a very interesting idea where people are trying to master becoming cross-disciplinary or interdisciplinary subject where we have to learn a lot from biotechnologists, microbiologists and so on and to master the whole thing. So idea is to trap these type of gases alright. Now the whole realm of new or new geomechanics starts. So sometime back I said that I would be very eager to know how much is the migration of these type of gases in the sediments. So until now you have been doing only constant head test, falling head test to find out what is the permeability of the water which is seeping through the sediments or the soils. Now the situation is different. We are talking about gas migration through the sediments alright and when gas migrates through the sediments, pressure temperature conditions are peculiar, microbial activity is peculiar. So this is what has to be studied. Look at the work which is done by my research scholar Dr. Jeevan, he is a faculty member at NIT Trichy right now and he is the one who has established the entire setup himself and he has done wonderful work on deriving the gas permeability through saturated soils, unsaturated soils under different environmental conditions referred to as papers alright. So this is a big challenge how gas flow occurs rather than only the fluid flow you are talking about the water migrating to the. Normally the biogenic methane gases or the sediments are in the continental reefs very close to the onshore you know adjacent to the coastal area. So this is the differentiation between the types of gases which you get. Now coming back to your question I can always take a sample and I can do different types of analysis including carbon dating to find out what type of carbon is present and what type of sediment. So this subject now becomes absolutely interdisciplinary and this is the future of the geotechnical engineering alright. Any other question. Although sir biogenic methane is in the purest form but I think its quantity will be far, far less than thermogenic form because of that we do not have that much organic matter in the sea bed even near coastal bed. No, no, no, never say this because you have ignored the organic matter. See the marine clays typically have they can have anything up to 90% of the organic matter and that is the reason no wonder why the liquid limit is so high clear. So I think you have mistaken if you really want to understand a typical organic matter distribution in the clays please read it on net and particularly we have come across some place where you have more than 80-90%. No, quantity of methane is something like as long as the bacterial activity is there it has to happen. The simple thing is when you ferment something you know most of the pickles the way they have been formed this is fermentation process and that is how they give you a very different taste or you know tinge on your tongue when you put them. So volumes are not an issue because reservoirs of these deposits are enormous imagine we are talking about the marine conditions okay. Any other question. You have to create when you do these type of tests different types of pressure and temperature conditions in the laboratory. So I am happy to say that my laboratory is the only one right now in the country or maybe in Southeast Asia also we do not have many such facilities where you can simulate and you can do testing of hydrates. So this is how we are very unique and very recently we have acquired this environmental track shell setup we got it done ourselves and where you can simulate the conditions of pressure and temperature varied temperature pressure conditions and you can see how the sediments are going to behave. And then later on we like to find out their shear strength parameters and compressibility and the fluid flow and all these engineering properties. So Vinny is working on creation or synthesis of the hydrates in the lab condition and Liget is working on the geomechanical stability of the sediments which I will discuss subsequently. So you follow the papers which have been written by Vinny Rani and Liget Nambiar in from the literature we have published several papers two papers. Now it so happens that is a very tricky interesting subject. So morphology of the hydrates would depend upon the you know different types of freezing processes. So this is a subject which also deals with or interfaces with the frozen geomechanics. So what I have shown over here is the morphology of the hydrates which governs the geomechanical properties can be understood like this. This is the skeleton of the particles sediments and if you look at the animation carefully you will find that this is the pore filling you know. The crystallization of water takes place in the pores and this is where the methane gets trapped. Now these type of sediments are not going to be very good load bearing sediments. I hope you can understand because the bridging between the particles is not so good and the permeabilities are going to be extremely high as compared to the other situation if we call as load bearing. So what has happened? I think you missed this animation some of you so please do not write and see on the slides that is going to help you. So if I start from the pore filling the further growth of the crystals is going to now be like this. That means the particles are getting cemented and hence the system is becoming load bearing. So this system would have higher bearing as compared to the previous one and further what is going to happen is if I say cementing process all the particles get cemented and they become like cemented sands. So these are the three mechanisms which people are trying to study and these are the conceptual models you know remember in conventional geomechanics you talked about a rhombic structure and cubic structure if you remember is it not this is how you visualize the entire granular material. Now the same thing is being done over here with different mechanisms of the material and finding out the response at different environmental condition hope this point is clear. So a big challenge is how to differentiate between pore filling load bearing and cementing processes and the way you talk in conventional geomechanics the moisture content. Here people talk about what is the gas content in the sediments once the hydrates are formed all right. So we call it as gas hydrate concentration and the shear strength properties are going to be a function of gas hydrate, shear gas hydrate concentration and the type of morphology which the system is exhibiting. It remains same as what you have studied in conventional geomechanics as the Cardo structure floccular and dispersed and so on. It is easy said then done you know it is very difficult to simulate these type of situation and particularly I would like to see inside what is happening inside the cells you know how the system is getting altered from one state to another state and you can realize when you are working at such high pressures of let us say 3035 MPa of triaxial pressures you cannot look into the system because this is made up of a opaque steel all right. But still people are trying to see inside and where you have to learn lot of biopsy. Now look at this animation slightly carefully and this is where I have talked about the extraction process because after locating the places where the reservoirs are ultimately you want to harness this energy you want to tap this energy you want to extract it from the ground is it not from the seabed the way the petroleum is extracted. So when you extract the methane gas there are a lot of challenges you know the gas is going to get dissociated from the crystal which you were talking about Lavender. So the moment you bring it back to the normal standard temperature pressure conditions the methane gas will liberate this is what is known as dissociation there is a lot of science and mechanics behind this which you should study or you should attend the seminars by these guys ultimately what I want is I want to produce energy. So this is the hydrate and the moment you expose it to the environment it will catch fire and it produces heat and this is the whole purpose. So most of the time these expeditions are created by government of India all right very expensive expeditions the way there was a time when people used to go for you know Antarctica expeditions you must have heard about very scientists used to go there and they used to do a lot of stuff nowadays Mars moon expeditions are going on they call it as a mission. I do not know what is the difference between mission and expectation. Climbing upon the mountains is expedition is it not. So this is how it happens. So you know the place where the hydrate reservoirs are you go in a ship and then lower down a KC this is what is known as extraction value how to design the extraction value itself is a big challenge. So what legit is trying to do it is trying to simulate the whole process I will tell you how. Now once you start extracting something first of all extraction cannot be done as long as the system remains in the frozen state. So what you have to do is either you have to you have to dissociate it and for dissociation you have to do different types of techniques. So extraction is by depressurization release the pressure which the system has got the system has because of the natural conditions. And the natural conditions are because you have so much of water column the depth of the sediments is this much. So total height would be gamma water multiplied by this total stress is not height total stresses would be gamma water multiplied by the water column plus gamma saturated multiplied by this much depth of the sediments. So this much pressure are acting on the hydrate system which has to be depressurized by alloying vacuum so that the gas may come out. The second could be by thermal stimulation remember the hydrates are at lower temperature. So what you have to do is you have to go drill the well put heater wires and heat up the entire soil mass imagine. So just now he was asking about the volumes now I am giving you an idea that entire seabed is to be heated up and once you heat it up you are playing with the temperatures. So either you play with the pressure or you play with the temperature you can liberate the sediments. Now what is happening is once you are extracting something I am sure you must have heard about the you know subsidence process in geotechnical engineering. So the more and more water you extract from the wells or the aquifers what happens the entire system subsides it settles. So most of the cities are settling you know Highland is a good example the more and more mining you do the area is subsided subsiding all right. So these are the challenges people are trying to handle these days. So coming back to the point when I do this depressurization or thermal stimulation the chances are that you know what is going to happen there will be a heat migration through multi-phase system and this is how the entire thing gets liberated. So the methane is catching fire and the water is coming out during the extraction process. So there are couple mechanisms which are associated with this first is the heat migration into the system. Once you are heating the sediments you have to study what happens to the sediments when they get heated up. So later on in the course we will be talking about you know thermal properties of geomaterials it is a big section which I will be discussing. I will be talking about electrical properties of the geomaterials and that is the reason you know why we are discussing these type of topics in geomechanics because live example is here you have to heat the sediments to liberate the methane gas and then only you can utilize it for your purpose. Remember one more interesting thing now we are talking about multi-phase porous media alright. So we are not the porous media is not devoid of microbial activities. In conventional geomechanics we never bothered about we thought about only three phases solids liquid gases microbial activity also comes organic matter also comes in the play and whatever fluid flow is taking place is a coupled phenomenon that means water and gas are travelling together through the porous system at environmental or sub environmental temperatures and pressures. So this becomes a complicated scheme. So what is going to happen when you are extracting things water will come out and I am sure you must have heard in your conventional geomechanics whenever discharge takes place through the body of the dam because of the critical gradients what is going to happen quick sand condition of piping action. So the more and more water comes out what it does it takes out all the fines along with it. So this is what is known as washing out of the fines from the sediments. If the fines get washed out from a sediment what is going to happen the voids of the cavities will get created and the chances are that the bearing capacity of the system is going to decrease hydraulic conductivity is going to increase gas permeability is going to increase and so on. So look at the whole geomechanics is now changing in the conventional geomechanics you thought that everything is constant volume inflow is equal to outflow all the time you derived this your control volume never deformed here we have all challenges. So migration of fines causes loss of strength. So all these problems are time and space dependent pressure strength is a function of x, y, z and t time cohesion is a function of x, y, z and t pressure angle is a function of x, y, z and t hydraulic conductivity itself is a function of x, y, z and t depending upon the fluid whether the gas phase you are talking about or whether the fluid phase sorry water phase you are talking about. So this problem becomes very complicated which people are trying to solve right now. So these challenges lead to what? The first thing is the piping and all whatever you have installed in the system you know it gets unstable. So well bore instability becomes a big issue. That means the chances are that the well bore itself may become unstable all the methane gas may bypass the extraction well and then what is going to happen? It will get liberated into the environment and if that happens what is going to happen? Green house gas are you realizing? This is a very intricate and sophisticated process. You do not want methane gas to enter into the atmosphere because of the extraction process. I am sure you must be getting an idea these extraction wells are nothing but you know straws which you use for drinking the cold drinks from the cans or the bottles. So the more and more you suck all right what happens? We are applying a negative pressure inside the pressure was positive high pressure and then you depressurize it or you apply a bit of suction then you can suck all the gases. So this is something which people are trying to simulate in laboratory including us. Now when well bore instability occurs this is one issue. The second issue is seabed subsidence. I hope you saw this animation or not you missed it. How many of you saw this? Good that is what I say there is no point in writing things it should be all written in the mind you know these are the mechanics problems. So look at this again. So when you are taking out the fluids from this type of systems what is going to happen? Concentrate here seabed subsidence all right. So the collapse of the seabed takes place. Now imagine whatever paraphernalia you have created on the seabed because of this collapse is going to get destroyed. So this could be a man made disaster. So this is the subject which also deals with disasters associated with offshore systems. In case tsunami comes the chances are that there is you know there could be a dislocation of the sediments and the methane gas may get liberated into the atmosphere. Earthquakes what is going to happen? Because of the relative movement of the seabed chances are that if you have reservoirs along the slip line the gases will enter into the atmosphere and that is what causes mid-ocean fires. So these are the issues like if you have identified that these are the places where hydrates are it is a good idea to extract them as soon as possible because now sorry nowadays you have lot of tsunamis affecting the system you have earthquake affecting the system you have lot of human activities affecting the system you never know tomorrow somebody might be putting a you know offshore pipeline cross-country pipeline for data communication most of your fiber optic cables are running on the seabeds I do not know whether you are aware or not all right. So how undermans are connected with India mainland India read this whole story. So these are the geotechnical engineering jobs which people are into. Now if you want to learn more about the seabed subsidence and what it does please read this PDF file where people are trying to simulate these type of conditions. Santa Marina is number one in this subject so read the papers written by him and I wish some of you should get a chance to work with him in the you know Saudi Arabia he has established his own lab he is what you know in the American University of Sharjah. So mechanical and numerical modelling of gas-headed bearing sediments this is what legit is working on very intricate subjects no doubt but very satisfying and very you know if you have to contemplate a lot to understand how things happen yeah coming you have something to ask no all right any questions. So you read this text whatever is written over here and you may get a feel of what is going on right now. So I hope you realize that again THMC or TSCM is coming in the picture these are hydrate bearing sediments and worth reading whenever you get time all right legit has published an interesting literature review paper on geomechanical aspects of gas hydrates very recently over 3-4 months back. So moving on to the discussion when water flows out of the sediments migration of fines occurs loss of strength occurs well bore instability takes place seabed subsidence occurs foundation instability occurs. So the rigs which have been installed on the seabed are bound to collapse and as I discussed uncontrolled methane release is going to cause a greenhouse effect all right how does the whole story appears to be so he comes I think I was supposed to completely different realm of geomechanics today. Yes sir interesting. Yeah it is very interesting no doubt but apart from interesting. Work learning. Yes and quite intriguing very difficult to handle your samples at the conditions which prevail in the ocean beds but I wish that people like you should be working and contributing in these areas which are the most recent areas of geomechanics any questions yes please. The two methods of extraction is like you told just depressurization and thermal insulation and how we will find which is more suitable what is the difference between. Sorry well you have you know this is me not you. So yeah it is a very good question you are asking that how would you make sure whether depressurization works or thermal simulation works most of the pumps which are available in the market they produce positive pressures or negative pressures. So what is it. Most of the pumps which are available in the market they produce positive pressures or negative pressures answer this question if you can then your first question is answered. So idea is how much suction you can apply imagine you know simple thing what you do I mean you take a dropper and you press it and put it in the ink bottle and release the suction what is the height of the water column which you get in the dropper alternately. So certain few centimeters it is very difficult to make suction pumps very soon you will realize that negative pressures cannot be created by pumps but look at the nature you know it has produced different types of varieties of cactus which can survive in deserts also how come they can lift water up to 220 meter deep also this much pressure these plants can apply. So all the plants which are living in the arid regions they can apply so much of suction on the soil to take out the moisture. Very interesting geomechanics subject hope you will realize ultimately the entire thing is moisture migration through porous media or vapor migration through porous media. So repressurization is a difficult task and where would you install these type of big pumps on a boat or in a ship and that too you are lifting it from a depth of 200, 250, 110 meters imagine clear. So it is a big question number 2 thermal very easy to write on the piece of paper that do thermal destabilization and just now I said what you have to do is you have to insert heater wires in the ground and you have to heat it. So in the middle of the sea how would you do all these things how much area of the soil can be heated. So what is the confusion what is your answer what is that you are going to recommend. So if you appoint a consultant who is an expert from Japan who are already into the production stages they will charge you what fortunes India cannot afford. So what they have to do Indians and developing nations they have to develop their own technology nobody is going to help you. So this question is in everybody's mind what should I do A or B unfortunately there is nobody to give the answer. As a nation you have to decide what should be done do more R and D and then people like you should answer after few months years that well this is what is valid for kg basin because they are the type of soil is this depth of water column is this the pressure temperature conditions are these. What do under months the pressure conditions are different types of soils are different. So one medicine cannot be used everywhere also are you getting the complexities and ideas. So this is a trade-off between A and B I do not know which one is going to work. So in laboratory we are still in a stage where I want to synthesize them first because imagine another problem is I have to bring out a sample by UDS from the seabed first of all it has to be a specialized UDS where after taking out the sample also the pressure temperature conditions remain constant transporting them to the lab then you should have a facility over here which again can assimilate the sample under those pressure temperature conditions. So these are very, very expensive experiments and more than that exploration itself is expensive find out the cost of the each exploration with government of India has done until now all right and this is the might of the nation nobody is going to help you why they want to sell things so if I have developed a technology I like to sell it to you rather than help you out in developing a technology are you getting this idea. So it is a good question keep thinking like this but then more than thinking you have to work and you have to get a solution so that people can utilize it is this okay. So yes please. One has to simulate the. It is okay yeah it is okay fine. One has to simulate the conditions in the lab how do if this is in 200 meters so how do we create that? I know the pressure conditions over there I know the temperatures also I can do different types of investigations try to read on this what type of investigations are done to establish you know offshore reconnaissance to establish the thermal regime and thermal regime and pressure regime and to establish what type of x-rays are done in the deep wells I just gave you an idea about endoscopic cameras you can lower down the camera and you can see what is happening in the design so you can see over here also. So this interesting area is you know very intriguing is this okay. By depressurization will there be a how we deal with the problem of cavitation so. Cavitation of. That while pumping the negative pressure may reach to. In the pipe or in the in the reservoir. In the pipe or that kind of that I can control no so in your fluid mechanics course you must have studied what causes cavitation total pressure so that can be regulated that is a pipe flow but your question can be more complicated imagine this pipe is also a part of the frozen sediments so that is a very big challenge that how fluid will pass through the frozen conditions of the steel casings and the pipes so there are lot of people mechanical engineers who work in this area they try to see what is the transmissivity of the gases through sub ambient temperature conditions I hope you are getting the point. Check it out on net after you go to hostel today or tomorrow. Good what message you are getting bigger picture apart from environmental geomechanics course are you getting a message what is the message you are getting. First of all the country is expecting you to give the answers to these questions because there are not many geotechnical engineers in the world or the country so you are the people who are supposed to give these answers to the ministries when you know your petroleum ministers ask a question the parliament what is happening to a program of hydrate modeling so they will ask they will send you a question mark question parliamentary questions tell what is happening so all this happens we are a part of this. So many times the subject does not remain the books and the papers it has to be delegated to the national activities as well alright anything else sure okay so you know when you do extraction there is a possibility of triggering tsunamis also these are manmade tsunamis geohazards if you remember we were talking about so any type of collapse of bed might result into a wave form creation of waves and depending upon how much volume of the sediments is getting destabilized that much would be the surges which you are going to create okay sorry. Alright so this type of expeditions have been taken up by ministry of petroleum and natural gas government of India I hope you are aware of what is going on in the world these days and there is a special directorate of director general of hydrates hydrocarbon which is known as BGH until now there have been 3 expeditions and as NGHP 1, NGHP 2 and NGHP 3 what is known as national gas hydrate program and they are heavily dealing with the sample collection and onboard testing on the ships and the regions which have been identified in Indian margins we call that is the KG basin, Mahanadi and Andaman basins clear and it is very interesting to see that the types of soils which you get are totally different so people who want to study the gas hydrates Indians they have beautiful natural laboratory waiting for them and you just go and start your career in this. So coming back to the point we have been talking about energy geotechnics I have taken you too much into the intricacies of the subject and I have given you an idea about you know how these type of problems can be studied and sorted out under the realm of multi-phase geomechanics. So you have to deal with lot of chemical engineers you have to deal with petroleum production scientists, reconnaissance guys, petrophysicists, government officials definitely fluid flow, gas flow, condensation, cavitation, subsidence, mineralogy, biotechnology because they are the guys who will be telling you what type of bacteria you have and what type of gases are going to come whether it is feasible and useful to drill over here or not. So if you are having more of you know pentane and butane and whatever so this is of not much of use I want to get mostly. How deep the subsidence can be? Seabed subsidence how deep can be? I mean it is a question I think I answered just now or sometime back that it depends upon the thickness of the seabed. So suppose if I ask you a question how much the one-dimensional consolidation would be in marine clays in Kerala you construct a building you remember the Kochin case next to the Lulu building. So what happened the entire building settled down and then the first floor and the second floor they were the part of the basements. So this is an undeterministic process depends upon so many parameters mainly the thickness of the sediments and how unstable they may become. I hope you are aware of the fact that one-dimensional consolidation theory of Terzaghi cannot predict very precisely how much marine clays that consolidate it. I might show you some examples where I have seen 2-2 meter 2 and a half meter of settlement in the pre-loading stages right now I am doing a lot of work for Indian railways in the coastal region and there are the settlements are of this order so subsidence could be hundreds of meters. So if hundreds of meters of subsidence is taking place look at the height of the tsunami which I will look at that is the logic. What about the fact on the marine life did they also study that thing? Yeah so I am sure when you see and there is something known as IEOT there is a laboratory at Panvel you know they talk about all these subjects but we have to pick up our subjects which is geotechnical geophysical modeling and geotechnical modeling and all those things rather than going into the details of the marine life and aquatic life which is the job of maybe scientists who are dealing with fisheries and offshore environment. So at the time of extraction can we like extract the methane directly from gas hydrates? That is the whole idea because you cannot process it. So just like you know many times what do you do aquifers or geysers you know geysers natural geysers so you just puncture over there and the water comes out there is something like that so this is what actually we will like to have. So you just put a drill casing destabilize the hydrates, regulate the flow by putting some valves and all and then you get the direct gases that is what is the production processes and in the process you get the fresh water. So you can fill up your mineral bottles in the offshore environment imagine. So two industries you can run together in the offshore environment itself we are getting the fresh water H2O the molecular water this is what we are planning at a landfill also by the way. So for me these situations are universal they may exist in the offshore and they may exist in a landfill. So in landfill also if I just like open the bottle of a drink you know what you want to do you want to take out all the flits. So for me the landfill is nothing but a container in which the entire thing is contained inside and I would like to extract only one phase of the flit is what is known as selective filtration of flits. It is an interesting subject in chemical engineering which we are trying to learn as a geotechnical engineer why? The hydraulic conductivity of the water and the hydrocarbons and the gases is going to be different so I can regulate. So for me the landfill becomes an industry the ocean bed becomes an industry and I will be able to take out only one phase or otherwise I can have separators you must have come across in chemical engineering courses. So there is a mixed air contaminated I want to separate out oxygen carbon dioxide nitrogen and so on. So they use separators see present day science and technology is different you cannot be myopic that this is what I am studying. The first thing is you have to train your mind to think multidisciplinary I hope you can realize I give you so many examples is it not. Suppose somebody comes to you for a consulting that in a basement of a mall shopping mall a beautiful problem which I was dealing with sometime back. There are a lot of cars which are parked and most of the time these cars engines remain on why because the drivers sit in AC room AC cars they do not put off their engines. So what is getting emitted in the entire area imagine and the whole thing is getting saturated with these fumes and that is why they say in stationary cars you should not put on ACs because CO is maximum. So if you do not flush out all this into the atmosphere what is going to happen now why a geotechnical engineer is required to solve this problem we will discuss this later on though this is the pollution of the air but geotechnical engineering plays a very important role here my materials can be utilized to solve different types of gases yes please. Sir can you please explain that process which took took place in that steel can the extraction of gas hydrates when impedance and all comes into picture. Impedance yeah those are the tricks to see what is happening inside. So that is the reason we will be talking about electrical properties of geomaterials in details how electrical properties thermal properties should be utilized to sense something to see something to visualize something to feel something to quantify something clear a process yeah. Is it possible to protect the steel when we take the methane replace it with something. Yeah very good excellent so that is what sequestration is so you do simultaneously two processes why not so there is one inflow one one x flow in the system balance the two.