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Yohanes Nuwara Rafif Abdus Salam Niken Dyah Arum Sari Irfani Sakinah Fara Yuniar Latifah Adisa Putri Utami Moh Hasyim Taufik Dzaky Irfansyah Dinda Putri P Azarine Nurfairuz K Defiska Andang N Laurent Juliani M Nabiel Husein Shihab
Tabina Joebhaar Karya S. Hendra Fatimah Az Zahra Arivia Dian Pertiwi Rizka Amalia Dimas Zulfikar Bagas Arya Regina Nathasa Jefri Bambang Andrian Martasuta
Suci Farissa Mahendra Dwi S Azhar Harisandi Tabina Joebhaar Tara Annisa Pangestu Soekarno Raisha Pradisti
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Person in Cahrge Dr. rer. nat Rachmat Sule S.T., M.T.
Editor in Chief Yohanes Nuwara
Managing Director Silvia Ayu Agatha
Layouting Director Dimas M. Zulfikar Head of Translators Diya Tabina Joebhaar
Publikasi
Photography & Videography
Najla Insyirah Firadila Ainunnisa Giovanni Pierre Jefri Bambang
M. Ardhya W Kevyn Augusta Giovanni Piere Dimas M. Zulfikar M. Ababil Akram M. Hafiyyan Fikri M. Devandra Ridho Pratama Z Nabiel Husein Shihab
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editor’s word
Yohanes Nuwara
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We are proud to publish our 11th La Terre edition. We wonder if you have already read the previous edition. Each of our publications has its own chosen theme. We still remember when the 11th edition had just been finished, a disastrous earthquake struck Palu. This mighty earthquake happened so fast that the whole cities faced its major destruction and people losses. You might be curious about what causes this big problem. The explanations are already wrapped in this issue. This edition also covers discussion about what so-called Urban Geophysics. Our readers should read because we will present you one of the most scenic tourist spots in the world and how geophysics plays its role here. Numbers of your best questions reach and trigger us to discuss if megatsunami had ever happened in Indonesia in the past and if carbondioxide can be injected back into the earth to reduce global warming. Most of these questions are topics in geophysics. All in all, happy reading!
CON TENT INDEX
PAGE
Vibroseismic Impact Technology
7
Paleotsunami Indonesia
11
Urban Geophysics
21
A Gift from God for Palu’s 40th Birthday
25
All about Geophysical Satellites
31
Peaks of Archipelago
41
Geo-modelling
45
Carbon Capture and Storage Gundih
53
Vibroseis truck generate the sound waves for the seismic survey
VIBRO SEISMIC IMPACT TECHNOLOGY By Yohanes Nuwara and Mohammad Hasyim
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V
ibro seismic impact technology (VSIT), is a method commonly used in the enhanced oil recovery (EOR) system to help increase in the rate of degassing due to applied vibration energy. This method is simply applied based on the basic theory of the use of vibration energy in shaking the ground to help the pore fluid migrate. The application of VSIT is also referred as hydrodynamical washing of the pores’ walls from the adhesive films and drops of oil by vibroseismically generated vortex movement involving of oil in macrodynamical flows.
Why is VSIT? VSIT is an imperative part in order to increase the EOR production and significantly increase oil/water ratio. The use of VSIT, economically, wont affect much, with the use of vibroseismic has now been more common in the early phase of oil and gas exploration. Some important points of this VSIT method are, the position of vibrosesimic source, the frequency of vibrosesimic waves, and the duration od stimulation.
History of VSIT This method was originally proposed by O.L. Kouznetsov et. al in 1998. During their research, VSIT was firstly applied in laboratorium, the result showed a remarkably good correlation with the hypothesis of VSIT to improve EOR process. This method though has some screening criteria (limitations) as described in table beside These findings later on are applied into some real cases, like the use if VSIT in Jirnovsky oilfield Russia.
VSIT in Indonesia Despite the fact that EOR in Indonesia has not yet been widely implemented, the VSIT method itself however, was first implemented by PT. Medco Energi International. The VSIT method is also applied in another case like in the Marebau Trend and Jene Oilfield (2005). The VSIT in Indonesia is also applied to the water coning reservoir (e.g. Eko Rukmono et. al., 2007).
“Could You Seep Oil Deep Inside by Knocking Your Feet onto the Ground?” Hey, have you ever imagined how to seep oil inside the ground with very little effort, for example knocking your feet onto the ground? That’s surely impossible. Well actually that’s just an allegory of what we gonna tell you about one emerging technology named Vibro Seismic Impact Technology (VSIT). The global oil is now depleting, hence the technology named Enhanced Oil Recovery is very useful to lift up oil that is still trapped beneath the Earth under.
Vibroseismic Seismic Impact Technology has some screening criteria (limitations) Companies use steam flooding, water flooding, and CO2 injection. However, one truly crazy idea comes from geophysics, which can be summarized in a short statement: “How can one use seismic wave to lift up the trapped oil?” Hold on, buddy, is that even real? Yes surely it’s real. VSIT had been discovered long time ago by Russian scientist, but this technology is popularized by Prof. Tutuka Ariadji, a lecturer of petroleum engineering from Bandung Institute of Technology. He is the leading professor in this invention in Indonesia. Now, what’s going on with physics behind VSIT. It’s pretty simple. You have already known that a needle can float on the water if the water is mixed with glicerine, a chemical for soap. Why? Because of it’s surface tension that holds the needle on the water. Can we break the surface tension? Yes we can. Just give a little thrust on it to slightly disturb the needle, and the needle will sink down. Now the key is: Disturbance.
How do VSIT works Source : petroleum-uir
Prof. Tutuka Ariadji from Bandung Institute of Technology
Seismic wave is disturbance. When the wave propagates to the rock, it will disturb the mechanical property of the rocks. If the rock stores oil inside, the wave will also disturb the molecule of oil and under certain maximum disturbance, the oil molecule can move thus the oil will move. Just as simple as that! In the field, the seismic wave is generated by Vibroseis
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Truck. Now your eyes will open because now seismic wave is not just for interpretation of what is inside our earth, but it can also push the oil from beneath the earth.
Paleotsunami Indonesia by DWI JULIANTI and DZAKY IRFANSYAH
Earthquake and tsunami that struct Palu and Donggala on 28th September is a part of a series of disasters that happens in Indonesia since the year of 416. The National Oceanic and Atmospheric Administration (NOAA) stated there are up to 246 tsunami events happens from 416 until 2018 in Indonesia. Southern region of Java has historical evidence of tsunami, according to Eko Yulianto, an expert in paleotsunami from Indonesian Institute of Science (Lembaga Ilmu Pengetahuan, LIPI). In his research in Lebak, Banten, he found 331-year-old and 293-year-old evidence of what was assumed to be deposit traces caused by tsunami, in other words, tsunami that happened in the year of 1685 and 1723. In the southern region of Java and Bali also shows sedimentary layers which were assumed to be caused by tsunami from different time periods. All evidence shows recurrence interval of 675 years. Such phenomena were recorded in the Arthur Wichmann catalogue named “Die Erdbeben Des Archipelos� or the Earthquakes in Dutch East Indies, in which inscribed 61 reports of earthquakes and 36 reports of tsunamis in Indonesia between 1538 and 1877. According to Rahmat Triyono, Head of Earthquake and Tsunami Division of Indonesia Meteorological, Climatological, and Geophysical Agency, Indonesia has 18000 scenarios of tsunami. Out of all tsunami that
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has happened, 90% of which was caused by earthquakes in the oceanic region.Based on NOAA records, the first tsunami ever recorded in Indonesia happened in the year of 416, in the Java Sea. Later in 1608 until 1690, tsunamis happened 13 times, with one of the event in 1674 in the Banda Sea has the tsunami elevation up to 100 meters. One of the most well-known tsunami event caused by volcanic eruption happened in 1883, where Krakatoa eruption produced
tsunami elevation up to 41 meters. Krakatoa eruption also happened in 1930 which caused a tsunami as high as 500 meters and became the highest tsunami elevation ever recorded in Indonesia. Fast forward to the 20th century, since 1992 until 2018, there were 37 tsunami events recorded. Some of the events are the Flores tsunami in 1992 with tsunami elevation of 26 meters, Aceh tsunami in 2004 with tsunami
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A man standing on a crushed car when he saw rubble after tsunami hit the land on October 2th, 2018 in Palu, Indonesia. Taken by Carl Court/ Getty IMage
elevation of 51 meters, and the most recent one, the Palu-Donggala tsunami. So, how does one know the ancient tsunami phenomena? The main focus in paleotsunami research is the sedimentary layers around the beach area. This is based on the assumption where every tsunami-generated wave leaves material deposits. Just like fossil trail, tsunami deposits can be examined to reveal many things, such as the thickness of the deposit can be used to predict the relative magnitude of tsunami wave. Tsunami event reconstruction may include the tsunami elevation, estimation of earthquake magnitude, and the areas affected, all of which depends on the revealed data from observation. According to Eko Yulianto, these data can be used to predict potentially affected areas if and when tsunami happen in the future. Paleotsunami holds a significant role in disaster management, especially for areas without historical records of earthquake events. However, paleotsunami research requires high accuracy. One of many problems in paleotsunami research is material
identification. It is rather difficult to distinguished whether one material was caused by storm, flood, or tsunami. Recent development in paleotsunami is hoped to overcome such difficulties. Material deposits from tsunami is confirmed to contain high number of oceanic fossils. The distribution of paleotsunami deposits are more extensive and even compared to flood or storm deposits. Following paleotsunami deposits identification, this research can obtain the period when tsunami occurred in the past, including the interval between events. Radiocarbon can also be used to determine the age of a deposit, such as the surface dating techniques with thermoluminescence or the chlorine-36 dating. Despite all of the above, paleotsunami cannot be used as a tool to precisely predict recurrence of tsunami events. Four tsunami events for example, cannot be used as reference to predict future tsunami events. Even if time prediction of tsunami may be done, the error in its calculation ranges up to five to ten years.
A miracle happened. Mosque Baiturrahman in Aceh remained the same after tsunami hit the land. Taken by bebaslepas.com
Paleotsunami sediment characteristics: case study Cilacap and Pangandaran coastal region, Java, Indonesia. Cilacap and Pangandaran coasts was struck by tsunami on 17th July 2006 and these areas are damaged worse compare to other areas. Iron sand deposit containing anthropogenic fragments was found in Cilacap. These anthropogenic fragments originated from human activities mixed in sediments. Based on the grain size analysis, there is an evidence of sudden change in sediment transportation energy and no evidence of fossils. Such characteristics do not belong in tsunami deposits characteristics, thus the sediment deposit in Cilacap is not considered as tsunami deposits, but rather deposit of different process. In contrast of evidence found in Cilacap, two sedimentary layers were found in Pangandaran. Based on the grain size analysis and the evidence of Plankton and Foraminifera fossils, the deposit from Pangandaran is considered as tsunami deposit of the 2006 tsunami with thickness of 5-6 cm in the upper layer, and paleotsunami deposit in the lower layer with thickness of 5-10cm.
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Gambar 1
What’s Next?
Gambar 2
(1) Sediment deposit in Cilacap; (2) Stratigrafic layer in tsunami deposit in Karapyak, Pangandaran. (Source: Yudhicara, Zaim Y dkk. 2013. Characteristics of Paleotsunami Sediments, A Case Study in Cilacap and Pangandaran Coastal Areas, Jawa, Indonesia)
Paleotsunami research in northwestern Aceh
I
In the southwestern of Aceh, a province of Sumatera, a sedimentary deposit uncovered in limestone coastal cave where a group of tsunami deposit also existed and separated by or guano of bats. The by guano faecesor offaeces bats. The complete complete tsunamiwas deposit was to believed to tsunami deposit believed have age age around Holocene. around Holocene Some studies from Dura et al (2011) and Grand Pre et al (2012) documented a sudden change of sea level associated with tsunami drowning indication. Previous studies showed that the sudden change of sea level can only be proved if it happened in a constant sea level for a very long period of time. They found proofs of three tsunamigenic earthquakes (earthquake that triggers tsunami) which occurred between 4.5 and 7 thousands of years ago with interval between two occurrences of approximately 1 thousand year. Additionally, a more detailed investigation of lithological description and compilation of micro and macrofossils from Dura et al (2011), Kelsey et al (2011), and Horton et al (2005), showed lack of stratigraphic core preservation in the age of Holocene that started from 4.5 thousand years ago at the same time when the northwestern part of Sumatra was formed. Therefore, succeeding researches in southwestern part of Sumatra are more focused on coastal caves as an alternative to reconstruct complete paleoseismic records of Holocene age mainly from Sunda subduction. As a result, these researches highly preserve the tsunamigenic deposit inside protected coastal caves.
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(a) Map showing two major earthquakes occurred on 26 December 2004 and 28 March 2005 triggered by faulting of Sunda megathrust and the location of coastal caves (Subarya et al, 2006 )and late displacement vector from Bock et al., 2003) (b) Map showing location of coastal cave and previous sites studied by Grand Pre et al (2012). Map. Source: Gebco, NOAA, National Geographic, DeLome, and ESRI from www.earthobservatory.org
An ancient city of the Minoa civilization in the Island of Crete
Urban Geophyics A Modern Branch of Geophysics! By Yohanes Nuwara and Azarine
A
bout three thousand years ago, an ancient, thriving civilization called Minoa stood atop the island of Greece. During these times, the art industry was growing rapidly, especially in pottery and wall paintings that even transcends through time such as the Fresco. Today, the site of this once great civi-lization has become an island with modern cities we now know as the Crete Island. People from all across the globe gather here to enjoy the amazing tourist sites, such as the archeological site of Knos-sos, or the pink sanded beaches of Elafonisi and Balos, or even Samaria Valley, where Jesus Christ led the first Christian congregation in an effort to spread the holy Bible. Aside from its historical sites, traditional music performances and mouthwatering delicacies from villages like Rethymno, Her-sonissos, Heraklion, among others also spoils visitors who came to the Island of Crete. Looking to explore more of the Crete Island? Well, hold on! In this article we are not going to discuss the tourism side of the island, rather its urban geophysical properties. As an island with modern cit-ies, its preservation needs to be maintained even with the increase of population and the ever grow-ing age of the sites as it becomes more and more vulnerable to damages. We don’t want a city so rich in historical values to degrade right? It turns out, Geophysics play an important role in conserving this city. This is what is called Urban Geophysics. Next, we will discuss an interesting study about the application of Urban Geophysics in the Island of Crete
Electrical Tomography Method
Electrical Resistivity Tomography in Rethymnot
This method is used to identify the subsoil stratigraphy structure on varying depths, ranging from 10 to 50 km. Measurements were done in cities on the Crete Island which are Chania, Rethymno, and Heraklion using direct penetration of steel electrodes to the ground and injecting induced electrical currents indirectly using highly conductive materials. Data processing and interpretations were done using inverse algorithm from Constable, et al (1987). The resistivity model shows that at the center of Crete is covered with a thin layer of alluvial sediments from the Neogene period, with a layer of cohesive yellow marl – marl limestone di-rectly above it. At a depth of under 30 km, is a layer of marl limestone, whereas in Forteza Cas-tle just north of the city, carbonates can be found near the surface.
Electrical Resistivity Tomography in Heraklion City
In Heraklion City, the surface is enclosed by alluvial sediments while up north near the coast-line, we can find anthropological materials containing water intrusions. The geological proper-ties of Chania City is more complex. Its cover layer consists of quaternary sediments, anthro-pogenic substances, and sand. Beneath said layer, cohesive marls and marl limestone can be found.
Seismic Prospection Method
Comparison of tomography and Geoelectrical tomography results (top) and seismic refraction (bottom). Both shows appropriate results.
For the interpretations of the chosen sets of data, the deepest refraction of seismic waves are measured for each corresponding arrival inside a layer. With this, the first arrival (closest to the source) corresponds to the direct waves which gives information on the first speed structure (superficial). The first refracting wave fits the second layer. The same procedure is done on deeper layers. On the first layer, the layer speed is relatively moderate (957 m/s), in accordance to the formation of quantitative quaternary sediment. The second layer appears with a much higher speed (5395 m/s) which corresponds to the karstification of massive limestone.
Location of data acquisition in Chania City, Rethimo, and Heraklion Source : google maps
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Ambient Noise Measurements Method One of the alternative approach to characterizing the response in a certain location using low seismicity is through the comparison of horizontal spectrum with the vertical spectrum from the ambient noise measurements. Ambient noise is a low amplitude vibration from the ground which is caused by natural disturbances. This comparison commonly shows basic frequency from the research site. Chania City has an Eigen base frequency range of 0.20 to 0.50 Hz. This indicates the seismic contrast between marl limestone and lime stone at a depth of 300 meters in certain locations. It is different with the measurements from Rethymno and Heraklion City, wherein the acquired data tends to scatter so the results were inconclusive. The mentioned data is integrated with information regarding the environment, topography, and the statistics on the EMERIC-I shell. The dissemination of data is realized through the availabil-ity of reports which explains the methodology, instrumentation, as well as the results from said measurements. Compilations of earth related information including field measurements, geolog-ical maps, and historical or statistical data corresponding to urban context is crucial to its appli-cation to wider spectrums. On top of that, these measurements contributes significantly to dis-trict and city planning, as well as developments of main cities in Crete, especially in disaster management fields or mitigation of geological dangers in urban areas.
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Geophysical Structure result underneath Herakleion City
Distribution Map of Eigen base frequency values in Chania City
A SURPRISE GIFT FROM GOD For Palu’s 40th Birthday
By : Irfani Sakinah dan Nabiel Husein Shihab
Tanjung Pinang, Indonesia Taken by Yulia Agnis
The City of Palu, is estimated to have been populated by over than 370.000 people. As the city celebrates its 40th anniversary by helding Nomoni Palu’s Charm Festive 2018, Earthquake, Tsunami, and liquefaction hit the city. The big earthquake with magnitude 7.5, followed by tsunami, happened on 28th of September 2018. That date will be remembered as terrifying moment for its destructions and terrible experiences for people of Palu
Tectonic Configuration Based on its geological setting (tectonism), Sulawesi is located in the triple junction of Australian, Philipines, and Sunda plate. In addition, it is convergent to the continental fragment with the sunda plate boundary. Furthermore, the western part of Manado block and the middle part of North Sula Block moves with orientation NNW and rotates clockwise; meanwhile the East Sulawesi is located between Northern Sula block and Makassar block.
Tatanan tektonik Lempeng Sunda-Australia-Filipina-Pasifik. Panah menggambarkan kecepatan lempeng relatif terhadap Eurasia. Gambar diambil dari Socquet, dkk. (2006)
Aftershock distribution (red circle) in 4 days after earthquake in Palu. Depth of hipocenter and magnitude is shown in colorbar and circle size. Palu Koro Fault is shown in the picture with black line. Source : Global Earthquake Monitoring Processing Analysis (GEMPA).
The Earthquake The main shock hits the Palu-Koro fault, which type is left-transcurrent, and it is known as the most active structure in Sulawesi. The Epicenter was located in the 27 km from South-East Donggala with the depth of 10 km. By analyzing the aftershock distribution in 4 days (after main eq 7.5 MW), It can be predicted that the fracture has abrupt wider up to several kilometers north until 200 km south. The inflicted areas is estimated roughly 200 x 20 km, with the main destruction happened from the southern of the hypocenter until Palu city. Palu Koro Fault which has a lateral-left orientation is the most active structure in Sulawesi. This fault divides two island and related to
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Minahasa Trench, where the subduction happened. This Palu-Koro fault accommodates roughly 42 mm/year and shows transtensive complex behavior. The deformation can be explained by the presence of the structure which is localized in the area near Palu.
Tsunami Dr. Hamzah Latief, as seismologist expert, told about the facts of tsunamis that hit Palu City. Based on his analysis, Tsunami that happened in palu bay is caused by sediment avalanche in the ocean floor because of the earthquake. Furthermore, by seeing the record of tidal station BIG, tsunami happened when tidal reach its maximum while the height of the
tsunami wave reached 4 meters. This tsunami then is resonated in the Palu bay which area covers 30km in length and 7km in width, with the depth reached almost 600 until 800 meters.
categorized as local tsunami. At least, he mentioned there were four places that he identified undergoing sediment avalanche, they are Talise, Tondo-Taipa, Donggala, and Balaesang..
Moreover, he added, it can be concluded that the height of the tsunami waves is about 3-4 meter above sea level yet it spread over quickly after hit the bay. It means that the wavelength of the tsunami wave is categorized as short wave.
Liquifaction
Beside that, the deformation made by the earthquake wasn’t capable of generating tsunami with the estimated height so it made sense that the tsunamis was generated by sediment avalanche, said Dr. Hamzah. This is indicated by the impact of tsunamis that
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The other main cause of thus many victims and massive damage in the Palu City is a phenomena called liquefaction.. Liquefaction happened when the water saturated soil and silt is rocked by the earthquake, as a result it behaves like fluids (liquid). In Balaroa, Palu, approximately 1700 houses “sunk� in the soil where liquefaction happened. This number is confirmed by the satellite images from National Disaster Mitigation Agency, evenmore, the
(a)
(b)
(c)
(d)
(a) Petobo before liquifaction; (b) Petobo after liquifaction;; (c) Balaroa before liquifaction;; (d) Balaroa after liquifaction; Source : Planet Labs
picture from Petobo Area, shown the other impacted area caused by this liquefaction. “When earthquake happened, the soil layer below the surface became muddy and soggy” Told Sutopo Purwo Nugroho, the spokesman of National Disaster Mitigation Agency. “The mud with such big volumes sunk and dragged the houses in Petobo. We estimated there are 744 houses in Petobo. Furthermore, the Satelite images from Balaroa and Petobo reveals the scale of destruction. “We don’t know for sure the number of buried victims there, probably hundreds.” said Sutopo Purwo Nugroho.
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The experts claimed that the liquefaction is normally happened in the big earthquakes. For example, Liquefaction happened in the big earthquake that hit Japan with the magnitude of 9.0 M.W in 2011 and it had become the “feature” in the other earthquakes that hit Indonesia recently. Some of this is already confirmed in some of the earthquakes that already happened in Indonesia.
Sumbori Island, Central Sulawesi Taken by ig : @dzh_hrp
La Terre Journal
all about geophysical satellites Yohanes Nuwara, Suci Farissa, Laurent Juliani
Satelit untuk pengambilan citra bumi dalam ilmu geofisika Gambar dari Frogtech Geoscience
Let’s imagine a satellite, surrounding the earth and collecting those amazing images of the earth. Oftentimes, it captures unimaginable things we least expect. Look at the picture below. That is an image of the earth taken by Russian’s Electro-L No.1 satellite. Not only the blue or the green color, but also the red color beautifies the image, which is rarely seen. How about image (a) ? The satellite imagery can even indicate an “oil pond” that is supposed to occur way below the surface of the earth. We are familiar with the capability of a satellite to collect surface images. But never have this ability of a satellite—capturing what lies under the surface---ever been innovated. This advanced technology exists now. Currently, the technology is being developed by Terra Energy & Resource Technologies, Inc. Last Thursday, October 23th, as La Terre magazine’s reporters, the three of us attended a guest lecture “STeP (Sub-Terrain Prospecting: Advanced Satellite-Based Technology)” held by Society of Exploration Geophysicist Bandung Institute of Technology Student Chapter (SEG ITB SC). Prof. George Barber, the honorable keynote speaker, is best known as the Country Manager from Terra Energy & Resource Technologies, Inc. that serves the current satellite technology for the oil and gas explorations. He is an expert in Hydrography, and was an alumnus of Royal Navy Hydrographic School in England. His presentation surprised and inspired the audiences. Without further ado, let’s check out what this technology does. The technology is called Sub Terrain Prospecting or STeP®. It is a remote sensing technology that enables processing and interpreting many phenomenon and manifestations under the surface of the earth. Its applications range from the geological oil and gas, the geothermal, up to the mineral exploration. For the most part, we know the gravity method delineates oil and gas potentials in a sedimentary basin. However, this method never depicts the amount of oil contented inside the basin. Likewise, with a seismic method, oil and gas explorations are costly. The risk is high and the assumptions used in this method need a careful attention. Hence, sometimes, the ratio of the risk over the result is no-account. Not to mention, the magnetotelluric (MT) method for a geothermal exploration cannot portray deep under the cap rock. Shockingly, a satellite imaging with STeP overcomes these dilemmas. The STeP® technology is a breakthrough innovation; radical and smart. It competes against those well-established geophysical methods, such
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Satellite imagery taken by Russian’s Electro-L No.1 satellite in 2012
(a)
An oil pond is spotted in the satellite imagery. Source : Terra Energy & Resource Technologies, Inc.
Map of potential resources appears like an ice cream cone.
as seismic, gravity, also magnetotelluric method.
(a)
At its core, every rock has a unique value of density, waveform, and chemical composition. These characteristics result in a pattern. The pattern appears as a light waveform; indicated by a wavelength and a light color spectrum. Different rock means different light wave, thus different pattern. This method—recognizing a different pattern by the rock characteristic—is called Pattern Recognition. Subsequently, the satellite captures the varying pattern. As a result, the STeP® technology utilizes this method to illustrate different lithology in the satellite imagery. Its result, map of potential resources resembles ice cream cone shape. (b)
Above all, choosing the remote sensing is crucial. Of course, we want it to outcome an accurate and high-resolution image of the earth. So, should we capture the image from satellite or aircraft? There’s an interesting comparison between Satellite Imagery (satellite-based imaging) over LiDAR (Light Detection and Ranging carried by aircraft). Although, both technology: 1) use light detection and raging basis, and 2) create digital terrain model (DTM), but Satellite Imagery is 10 cm more accurate than LiDAR. Consequently, STeP® technology uses Satellite Imagery with multispectral satellite data coming from remote 1.0 (cloud data) and remote 2.0 (reflection data light wave). The display is as follows. Above all, choosing the remote sensing is crucial. Of course, we want it to outcome an accurate and high-resolution image of the earth. So, should we capture the image from satellite or aircraft? There’s an interesting comparison between Satellite Imagery (satellite-based imaging) over LiDAR (Light Detection and Ranging carried by aircraft). Although, both technology: 1) use light detection and raging basis, and 2) create digital terrain model (DTM), but Satellite Imagery is 10 cm more accurate than LiDAR. Consequently, STeP® technology uses Satellite Imagery with multispectral satellite data coming from remote 1.0 (cloud data) and remote 2.0 (reflection data light wave). The display is as follows.
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(a) image was taken by an aircraft; (b) image was taken by satellite. Source: Photosat Information Ltd
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This picture was taken in the afternoon, where the sun went down. Hikers was enjoy the wonderful sunset peacefully.
GEOMODELLING PADUAN SENI DAN GEOFISIKA by Rafif A.S dan Defiska A.N is a type of applied science that creates computerized representations of parts of the earth's crust based on geophysical and geological observations made in relation to the subsurface image of the earth. Geomodelling can integrate into numerous sub-disciplines of studies including structural geology, sedimentology, stratigraphy, and paleoclimatology. In 2 dimensional models the geological model is limited to eomodelling
polygons while in 3 dimensional geological models, triangulation mesh are used which arr equivalent to polygons ina fully enclosed geological unit. For the purpose of liquid modeling, this volume can be further separated into the cell arrangement, which is often referred to as voxel (volumetric element). These 3D grids are equivalent to 2D grids used to express properties of a single surface.
Subsurface Mapping and Spatial Geomodeling Laboratory gambar dari www. galaxy.agh.edu.pl
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Geomodelling was initially developed in the 1970s, and was still limited to 2D automatic cartography techniques such as contouring with FORTRAN. The emergence of workstations with 3D graphics capabilities during the 1980s gave birth to a new generation of geomodelling software with a graphical user interface that are developed during the 1990s. Geomodelling is generally used to manage natural resources, identify natural hazards, and measure geological processes, with the main applications for oil and gas fields, groundwater aquifers, and ore deposits. For example, in the oil and gas industry, geological models are needed as inputs for
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reservoir simulator programs, which predict rock behavior under various hydrocarbon recovery scenarios. A reservoir can only be developed and produced once. Therefore, making a mistake by choosing a site for development will result in losses. Using geological models and reservoir simulations makes it possible to identify which options offer the safest and most economical, efficient, and effective development plans. In geomodelling raw data can be classified into two categories, namely spatial data and property data. Spatial data is useful for creating 3D geometry models while property data is used to create predictive models.
Dalam geomodelling data mentah dapat diklasifikasikan dalam dua kategori yaitu data spasial dan data properti. Data spasial berguna untuk membuat model geometri 3D sedangkan data properti digunakan untuk membuat model prediktif. Pemodelan geometri dilakukan dalam dua tahap. Pertama pembuatan framework geologi atau gambaran geologi dibawah permukaan contohnya pembuatan perlapisan batuan, ketidakselarasan dan sesar. Kemudian dilanjutkan dengan membagi tubuh batuan pada framework tersebut menjadi satuan lebih kecil (discretization) yang akan digunakan dalam komputasi model prediktif. Pemodelan prediktif diawali dengan menetapkan properti batuan yang akan ditinjau, kemudian dilakukan perhitungan analisis dalam model numerik pada model geometri yang telah dibagi menjadi satuan kecil. Hubungan antara perhitungan analisis dan discretization ditunjukkan dengan hubungan panah horizontal pada diagram alir. Hasil dari pemodelan prediktif ini adalah visualisasi dari bawah permukaan baik geometri maupun properti batuan. Geomodelling biasa dilakukan oleh seorang ahli geologi dalam suatu perusahaan. Dari awalnya hanya dapat menampilkan model dua dimensi sampai akhirnya berkembang menjadi tiga dimensi dengan berbagai user interface baru yang memudahkan. Perkembangan dalam profesi ini didukung oleh industri minyak dan gas, karena geomodelling sangat dibutuhkan dalam industri tersebut.
Seismic Attribute Analysis and Quantitative Interpretation gambar dari www.geomodelling.com
Ilustrasi produksi gas Pertamina EP Gundih di Blora, Jawa Tengah. Sumber : Antara Foto/Zabur Karuru
carbon capture and
What is Carbon Capture and Storage? Carbon Capture and Storage (CCS) is a process of capturing CO2 waste from a source like fossil-fueled power plant (also includes the production activity of natural gas) and stores it in a geological formation underground so it will not enter the atmosphere. The usage of Carbon Capture and Storage (CCS) technology to reduce the greenhouse gas emission has been an attention of Indonesia and one of the ways
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to do so is making the Gundih field as the pilot project of CCS Development. This project starts with the proposal that was proposed by one of the Geophysical Engineering lecturers in ITB, Dr. Rer. Nat. R. Mohammad Rachmat Sule, ST, MT for the SATREPS (Science and Technology Research Partnership for Sustainable Development) research. “I was the one making the proposal, helped by Mr. Fatkhan, Ms. Santi, and Ms. Ningsih. The idea is from the seniors in Geophysical Engineering of ITB, Mr. Djoko and Mr.
d storage By Niken Dyah Arum Sari
Indonesia is planning to reduce the emission of CO2 by 26% in 2020. However, CO2 emission keeps on growing every day because of production. This problem could be solved by creating a system to capture and store CO2 or what we usually called Carbon Capture and Storage or CCS.
Wawan, and also Prof. Toshifumi Matsuoka from Kyoto University” says Mr. Rachmat Sule.
CO2, such as where would the CO2 go inside the formation and is it possible to have a leak back into the surface.
The proposal of the research of SATREPS (Science and Technology Research Partnership for Sustainable Development) was made the first time in 2010 and then it was submitted to The Ministry of Research and Technology, and then they selected 6 best proposals to be submitted to JICA. The purposes of the research are: (1) To determine the best location to inject CO2 into the earth. (2) To monitor the injected
In 2011 this research was announced as the winner of the SATREPS competition. After that in 2012, this project was started. Mr. Rachmat Sule appointed himself as the Project Manager. “ I was the one doing the busiest tasks, and then I appointed myself as the project manager, while the project director is Mr. Wawan. Mr. Djoko acts as the head of the advisory board. It’s just to make ourselves cool” says him jokingly.
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Mr. Rachmat Sule says that the main task of a project manager is to maintain this project to be sustainable. Even when the funds from SATREPS is a lot of money, up to 300 million Yen for 5 years, The money can’t be used to be given as a salary for the researchers of the projects. Because of that, they need to find additional funds as the accompanying funding of this project. “That’s why I travel a lot in order to expand my network. We can say that this project was funded 95% by foreigners, while 5% was locally funded by the research funds of the Ministry of Research, Technology, And Further Education.” Aside from being the project manager, Mr. Rachmat Sule was a part of the geophysics team with a couple of the other lecturers of Geophysical Engineering ITB. Initially, Mr. Rachmat Sule thinks that the geophysical engineering portion in this CCS Project will be more dominant. However, after this project has been held, this project needs integration between other disciplines, such as reservoir engineering, Chemical Engineering, and Production Engineering. So, Geophysical Engineering is not the only one that has an important role in this project.
Is CCS can become the main solution for reducing carbon emission? Is the CCS project has full support form the government?
According to Mr. Rachmat Sule, the sector that has the main impact of Reducing carbon emission in Indonesia is still from the Forestry sector. From the energy sector, energy conservation and renewable energy are the main sectors, however, the percentage is still small. Even though this CCS project can lift Indonesia’s reputation as a country that cares about carbon emission reduction from the energy sector. Unfortunately, the government can’t help fund the establishment of this pilot project, because the country’s commitment to reducing the carbon emission to 29% in 2030 is not from CCS. CCS was a part of our country’s commitment to reducing the carbon emission if we have international support. So, even though nowadays the Gundih CCS Pilot Project is a national project, Our Country couldn’t
Dr.rer.nat. R. Mohammad Rachmat Sule ST,MT
afford to fund it. The government, of course, is supportive of CCS, as long as it did not burden the selling price of fossil energy. We need to know that CCS only add cost. This country allowed the dirty coal power plant to operate without combining it with CCS. Mr. Rachmat Sule also says that the possibility of CO2 Enhanced Oil Recovery would be interesting in Indonesia because of the injection of CO2 into the reservoir for pressure maintenance and retracting hard to pumped oil in place. CO2 that was mixed with oil made oil easier to lift into the surface. Nowadays the organization in ITB was known as National CoE (Center of Excellence) of Carbon Capture and Storage (CCS) and Carbon Capture, Utilization and Storage (CCUS), that also works to promote CCS and CCUS in Indonesia. Even nowadays It was promoted to be ASEAN CoE of CCS and CCUS. Mr. Rachmat Sule added that the point of view subsurface is not too special like Carbon Capture and Storage (CCS) and Carbon Capture, Utilization and Storage (CCUS). The process is like in Oil and Gas Exploration, but it gives assurance that there will not be any leak during the injection is the main issue, if it fails, the CCS effort is no use. According to him, Drilling,
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Material Engineering and Chemical engineering is a very challenging sector, because by playing with these new techniques which mastery of these technologies in Indonesia is still far behind. “For me, the biggest challenge is how to manage the human resources in ITB to its maximum, which comes from multiple academic disciplines. For me, being able to work with experts from chemical engineering, mechanical engineering, petroleum engineering, geological engineering, civil engineering, communication studies and Law studies in one integrated project is a rare experience that’s very valuable to me“. This pilot project has been successfully operated in Gundih field for CCS and maybe another pilot project about CCUS in Beringin or Sukowati field. The full-scale form of this CCUS Project in Sukowati Field will be held in 2028 by Pertamina. However, this pilot project will be held in 2022. After that, there would be a lot of CCUS Project that would be operated in Indonesia so we can maintain the oil production while reducing the carbon emission. After that, the capturing technology should be able to be mastered so we can lower the cost and the dependency of foreigner’s technology would be decreased.
VOLUME XI