Indonesia Conference Directory

Corresponding Author
Rizky Arif Putra

Institutions
a) Petroleum Engineering Department, Bandung Institute of Technology
Jalan Ganesha 10, Bandung 40132, Indonesia
b) Petroleum Engineering Department, Bandung Institute of Technology
Jalan Ganesha 10, Bandung 40132, Indonesia
c) Petroleum Engineering Department, Bandung Institute of Technology
Jalan Ganesha 10, Bandung 40132, Indonesia
d) Petroleum Engineering Department, Bandung Institute of Technology
Jalan Ganesha 10, Bandung 40132, Indonesia
e) Petroleum Engineering Department, Bandung Institute of Technology
Jalan Ganesha 10, Bandung 40132, Indonesia

Abstract
Gas lift has been successfully operated in many types of oil wells around the world. Many techniques have been derived to increase gas lift efficiency, not only from gas lift modeling but also technical designs of gas lift components have been tweaked to produce higher gas lift performance with less gas injected. Gas Lift Performance Curve currently holds as one of the most prominent evaluation method of gas lift performance. The method itself is derived as a subcomponent of Inflow Performance Relationship (IPR) curves that allows simple and robust GLP curve generation without having to perform procedural, iterative calculations. It is worth noting, however, that GLP curves cannot be held as a single culmination parameter in determining the efficiency of gas lift systems. This study introduces a new paradigm in modeling the performance of gas lifted wells by utilization of mechanistic fluid flow modeling. Mechanistic models, unlike conventional GLP curves, are generated from observations in full scale laboratory experiments, therefore complications in multiphase flow pattern, such as flow pattern transition can be fully acknowledged and incorporated into the calculations. Based on the previously stated hypothesis, this study offers a case study on marginal oil well where gas lift acts as the main extraction method. Observations done in the model has confirmed the functionality of Flow Pattern Map (FPM) derived from mechanistic modeling as a complementary check and balance tool for gas lift systems. It is also expected that the FPM will perform well in a multitude of gas lift case studies due to its versatility.

Keywords
Gas lift; Flow regime; Mechanistic model; Two phase flow; Optimum gas lift rate

Topic
Petroleum and Geothermal Engineering

Link: https://ifory.id/abstract/6dGykaYUK8fm

Corresponding Author
SEKAR UTARI

Institutions
1Balai Litbang Perumahan Wilayah I Medan, Puslitbang Perumahan dan Permukiman, Badan Penelitian dan Pengembangan, Kementerian Pekerjaan Umum dan Perumahan Rakyat.
2Subdirektorat Lingkungan dan Keselamatan Jalan, Direktorat Pengembangan Jaringan Jalan, Direktorat Jenderal Bina Marga, Kementerian Pekerjaan Umum dan Perumahan Rakyat.

Abstract
New road development, bridge, and toll road constructions will give impact to the environment. The road is a land transportation infrastructure which has an important role in the economy, society and culture, environment, politic, defense, and security. Besides, roads are goods and services distribution infrastructure, therefore, they become the lifeblood of society, the nation, and the country. Road and bridge development are essential needs for the society, therefore need to develop road design that can minimize the impact on the environment. Kelok 9 Bridge is a bridge that has applied green infrastructure design. The concept of Kelok 9 Bridge is Nature and Engineering in Harmony. The design of this bridge is one example that can minimize the impact on the environment. This study aims to determine the impact of this bridge construction on the environment and its compatibility to the sustainable road principle. The method used to determine the impact on the environment and compatibility with the sustainable road principle was using literature study. The results from this study are there are several environmental impacts from this bridge construction that can be reduced e.g., the changes in land use. On the other hand, this bridge has applied several principles of sustainable road.

Keywords
Kelok 9 Bridge; Green infrastructure; Environmental impact; Sustainable road

Topic
Disaster Management and Environmental Issues

Link: https://ifory.id/abstract/E2hbNfV8P6kp

Corresponding Author
Boni Swadesi

Institutions
(a) UPN Veteran Yogyakarta
(b) Institut Teknologi Bandung

Abstract
Polymer flooding is one of the methods to improve sweep efficiency and reduce water mobility when water channeling takes place in an oil reservoir. Theoretically, if the polymer viscosity increases, the mobility ratio decreases. Thus, the oil sweep becomes more efficient while the recovery factor (RF) becomes higher. However, there is a phenomenon in which polymer with higher viscosity does not always improve oil recovery. One of the factors that influence this phenomenon is the existence of Inaccessible Pore Volume (IPV), so this study is needed to determine the relationship between polymer rheology and the amount of IPV. Two commercial polymers with the same concentration, FP3630S and ChemEOR, were done by rheology testing and injected into a number of sandstone Berea cores. The effluents of salt tracer (potassium iodide) and polymer flood were collected, and their concentrations were measured using atomic absorption spectroscopy (AAS) and UV-Vis spectrometry, respectively. Based on Rheology test in the same concentration, polymer ChemEOR has a higher viscosity, but from the Coreflood test, ChemEOR has smaller oil recovery than FP3630S. The IPV of ChemEOR and FP3630S were 30.6 % and 23.12%, respectively. The size of IPV of a polymer is influenced by the ability of the polymer to increase viscosity, so that the greater the value of the viscosity given, the greater the value of IPV from the polymer. The FP3630S polymer can reach larger rock pores even though in terms of the water-oil mobility ratio is smaller than ChemEOR. With a smaller IPV, the result proves that FP3630 polymer displays an increase of oil recovery compared to ChemEOR polymer.

Keywords
Inaccessible Pore Volume, Polymer Flooding, Coreflood

Topic
Petroleum and Geothermal Engineering

Link: https://ifory.id/abstract/gVn7aJW3bYZF

Corresponding Author
Wahyu Asmoro Nursandi

Institutions
PT Kaltim Prima Coal - Hatari Pits Department

Abstract
ABSTRAK KONFERENSI INTERNASIONAL ILMU KEBUMIAN, MINERAL DAN ENERGI II Analisis Sensitivitas Produksi Liebherr R9800B dan Penerapan Metode Loading 2-1 Menunjang Produksi R9800B All Crew-Operation Section, HATARI Department, PT Kaltim Prima Coal Wahyu Asmoro Nursandi, ST.1 Harry Asjuhar, SE.2 1Superintendent Production Shift, Operation Section, Hatari Dept, PT. Kaltim Prima Coal 2Mining Statistician, Technical Section, Hatari Dept, PT. Kaltim Prima Coal Perkembangan dan persaingan industri pertambangan dunia semakin ketat, sehingga perusahaan pertambangan dituntut lebih kompetitif dan menerapkan praktek operasional tambang yang efektif, efisien, dan produktif tanpa mengesampingkan aspek safety. Unit Liebherr R9800B adalah salah satu alat gali muat terbesar di dunia dioperasikan oleh PT. Kaltim Prima Coal. PT. Kaltim Prima Coal mengoperasikan 3 unit Liebherr R9800B, 2 unit di Bintang Department (S601 dan S602) dan 1 unit (S603) di Hatari Department. Pengoperasian Liebherr R9800B mempunyai tuntutan dan ekspektasi produksi yang tinggi, sehingga peningkatan overburden yang dipindahkan selaras dengan batubara yang terbuka. Beberapa improvement dilakukan untuk meningkatkan produksi R9800B, mulai dari metode sistem pemuatan, kombinasi truck yang digunakan, metode penggalian, memaksimalkan waktu operasi digger (pembuatan access refueling, access pergantian operator), dll. Area operasional Hatari Department berada di sisi utara area PKP2B PT. Kaltim Prima Coal. Karakteristik area utara memiliki nilai UCS batuan rendah 1.71-2.37 Mpa dan kerapatan interburden batubara lebih rapat dibanding area selatan. Hal ini menjadi tantangan tersendiri jika mengoperasikan Liebherr R9800B dengan berat 800 ton dikombinasikan dengan truck Euclid EH5000 500 ton. Berdasarkan plan 2019, usage R9800B ditargetkan sebesar 60.02%, dengan productivity 3,069 bcm/hour, dan produksi 37,932.49 bcm/day. S603 berpindah dari area operasional Bintang Department ke area operasional Hatari Department pada pertengahan tahun 2017. Saat beroperasi di area Bintang department, S603 mencatatkan rata-rata produksi 54,012.49 bcm/day dengan pencapaian produksi maksimal sebesar 29,120.83 bcm/shift dalam periode 2 (dua) tahun. Kemudian saat berpindah area kerja Hatari Department, tercatat rata-rata produksi sebesar 62,229.15 bcm/day dengan produksi maksimal 33,108.32 bcm/shift dalam kurun waktu yang sama. Dengan karakteristik area operasional yang berbeda jauh dibandingkan area Bintang, S603 mampu berproduksi lebih baik saat beroperasi di area Hatari. Tetapi hasil produksi antar crew section operation Hatari Department di tahun 2018 menunjukkan variance yang terlalu tinggi, produksi didominasi oleh satu crew. Crew Alpha memimpin perolehan produksi R9800B, crew Bravo mampu bersaing, sedangkan crew Charlie tertinggal jauh. Berdasarkan review performance tahun 2018, maka operation dan technical section berkerja sama melakukan analisis terhadap performance R9800B mulai awal tahun 2019.

Keywords
Analisis Sensitivitas Produksi

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/Fcrw2vAeKYCy

Corresponding Author
Hidartan Hidartan

Institutions
1 Program Studi Teknik Geologi, FTKE,Universitas Trisakti, Jl.KyaiTapa No1 Grogol, Jakarta Barat
2 Lit Bang Jalan PUPR Bandung

Abstract
The geological condition of Indonesia consisting of various geological formation units, one of which is volcanic products with tropical climate with different characteristics, allowing the discovery of rock-mixed soil media conditions such as the construction of the Sumedang toll road tunnel, where the media has an average Vp 2015m / s and CF1.1403 which are included in the soft rock category (category D II) . The condition of the media can cause various instability problems when doing tunnel excavation, especially the collapse of the crown with a deformation value of 65.6 cm. Therefore, an initial reinforcement system is needed in the form of forepoling with fillers less than 5 meters in length and the distance between forepoling 0.5-0.8 m before excavation to increase the shear strength of the soil / rock on the crown so as not to collapse.

Keywords
Tunnels, initial reinforcement, mixed media

Topic
Geology

Link: https://ifory.id/abstract/CrWwZJtpVaME

Corresponding Author
Dwi Atty Mardiana

Institutions
a) Faculty of Technology, Earth and Energy, Universitas Trisakti.
Jl. Kyai Tapa No.1 Jakarta
dwi_atty[at]yahoo.com
b) Faculty of Technology, Earth and Energy, Universitas Trisakti.
Jl. Kyai Tapa No.1 Jakarta
burhan[at]trisakti.ac.id

Abstract
The new fiscal scheme in the upstream petroleum industry has been implemented in Indonesia since 2017. Combination split at each parameter might not reflective to the various economic conditions. The difference between well-developed and new frontier offshore categories is only two percent. Yet, field size for the offshore new frontier areas should have significant larger reserves to justify the new pipelines and other infrastructure compare with the next offshore field that might would utilized the well-developed offshore facilities. This study will analyze the fiscal model calibration for the variable component of infrastructure in one offshore field, through its economic indicator. Sensitivity of the infrastructure development would be applied, that would affect to the capital investment, the operating cost, and production scenario. The study found that the composition of the split is not reflective to the various development and economic conditions. It is suggests that the new gross split scheme should be designed to apply to different levels of infrastructure in the same certain working area.

Keywords
petroleum economic, gross split scheme, variable component

Topic
Petroleum and Geothermal Engineering

Link: https://ifory.id/abstract/e4haqDMvbkgR

Corresponding Author
Muhammad Zaki

Institutions
(1) Geophysical Engineering, UPN Veteran Yogyakarta, Jalan SKW 104 Lingkar Utara, Yogyakarta 55283, Indonesia
(a) wahyu.hidayat[at]upnyk.ac.id

Abstract
Wonogiri Dam is one of the largest dams in Indonesia, located ± 2 km south of the Wonogiri City, in the province of Central Java. Wonogiri Dam has a volume ± 400 million m3 with a surface area of 73,6 km2 which has many benefits such as for agriculture, tourism, and power plant. Wonogiri is a part of the East Java Southern Mountain Zone. There are many rocks types found at Wonogiri, such as volcanic breccias, andesite lavas, tuffs, and many igneous intrusive rocks of the Miocene Mandalika and Semilir Formations, unconformably underlie Quaternary volcanic rocks of Lawu and Merapi Volcanoes (Sutarto, 2013). This research aimed to determine Ground Shear Strain (GSS) value along main dam and the surrounding area and to predict phenomena based on GSS values. From dominant period (TG) value, we can predict site class based on the classification of Zhao et al (2004). The microtremor data was taken on 31 observation points which is divided from 14 observation points with 100 m spacing in main dam and 17 observation points with 1.000 m spacing in surrounding area from Wonogiri Dam. Microtremor data was analysed using Horizontal to Vertical Spectral Ratio (HVSR) method to get amplification factor and dominant frequency. Those data were used to determine the seismic vulnerability index (Kg). Kanai empirical equations was used to calculate Peak Ground Acceleration (PGA) value based on earthquake event on 27th of Mei, 2006 with a moment magnitude of 6,3 and and 11,8 km depth. Seismic vulnerability index and peak ground acceleration value are used to determine the GSS value. The results of this research showed that GSS value in research area was about 3,4 x 10-4 to 7,2 x 10-3. The phenomena that can happen were ground movement as the form of surface cracking and settlement. Seismic vulneribility index was below 20 (0,35 to 16,97) which means surrounding area from Wonogiri Dam and main dam have low-risk, but potential for damage to building is still possible. Along main dam area, we need to notice the point at 400m and 600m. The value of the dominant period in research area ranged from 0.07 to 1.11 second. Based on the classification of Zhao et al (2004), there are 3 classes of site class in the research area.

Keywords
Dam, Ground Shear Strain, Site Class.

Topic
Geophysics,Geomatics and Geochemistry

Link: https://ifory.id/abstract/VcXez6vJdmuH

Corresponding Author
muhammad bagaskoro

Institutions
a) ITNY Yogyakarta
b) Faculity Of Mining Enginering

Abstract
Activities can make the impact to a land, so that needs to be done reclamation in an effort to increase the quality of land and improvement of the condition the former land of the mine. Kulon progo has a lot of andesite reserves. The aim of this study are 1) assess the factor causing physical damage caused by mining of Andesite in Pengasih district of Kulon Progo, 2) analyse the extent of the damage. This research uses direct field observation method and survey. Data taken in CV. Elita Karya Pratama in districts Pengasih, in CV. Elita Karya Pratama taken eight sample of the mine site that is in the moor. Quantitive analysis is done by means of weighting and scoring and qualitative. Each parameter is weighted in accordance with standards set by the environmental damage in the DIY Govener Decree No 63 of 2003. The factor known to cause damage through interviews and questionnaires administration. As a result, the damage caused by mining in the area were severely damaged moor categorized as medium damaged. Factor that influence the damage is lack of socialization.

Keywords
Andesite, Enviroment, Mining

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/7BCN8QmpMzRq

Corresponding Author
Heri Prabowo

Institutions
Universitas Negeri Padang

Abstract
Based on observations in the field In the IUP 412 Ha area overburden (soil) found on the Tajarang hill, mining must be carried out first so that the next limestone mining process can be carried out, because the limestone is blocked by overburden (soil). On soil slopes in IUP 412 Ha area it has a height of 27 meters and a slope of 79˚. On this overburden (soil) slope, several laboratory tests were conducted to obtain the safety factor (FK) value from the soil slope with several tests. The analysis of the tests carried out was testing the original soil content, soil moisture content, direct shear angle and proctor testing. The results of the analysis of the calculations performed are obtained from: The average fill weight of the 10 soil samples tested was 1.9233 grams / cm3. The average soil water content of the 8 soil samples was 46.75%.

Keywords
soil, shear

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/H6xGZJbamdRK

Corresponding Author
Harry Budiharjo S

Institutions
1)Program Studi Teknik Perminyakan, FTM, UPN “Veteran” Yogyakarta
2)Program Studi Teknik Kimia, AKPRIN Yogyakarta

Abstract
Kawengan Field has reached the peak of its production and currently is being developed an Enhanced Oil Recovery (EOR). In this research bio-surfactants will be used as substance that will be injected into reservoir. Bio-surfactants are as surfactant from microorganisms and can work to reduce interfacial tension (IFT) so that it can be applied in EOR. The other advantages of bio-surfactant are being able to reduce oil viscosity in reservoir temperatures, higher biodegradation rates and low toxicity. This research used Kawengan Field oil samples before and after being given bio-surfactants. In laboratory test, the viscosity and IFT will be measured. Viscosity shows the phase changes and IFT shows bio-surfactants can reduce IFT between water-oil. The aim of this research is to provide an overview of the application of bio-surfactants as a good and viable alternative to expensive chemical surfactants in increasing oil recovery.

Keywords
Bio-surfactant, EOR, IFT

Topic
Petroleum and Geothermal Engineering

Link: https://ifory.id/abstract/Q2N8x7gymZf9

Corresponding Author
Reza Adhi Fajar

Institutions
a) Post Graduate Program in Mining Engineering, ITB, Ganesa 10 Bandung, Indonesia.
*reza[at]poliban.ac.id
b) Department of Mining Engineering, Poliban, Kayutangi Banjarmasin, Indonesia.
c) Graduate Program in Biotechnology, School of Life Sciences and Tech., ITB, Ganesa 10 Bandung, Indonesia.
d) Department of Microbiology, School of Life Sciences and Technology, ITB, Ganesa 10 Bandung, Indonesia.
e) Research Group for Earth Resources Exploration, ITB, Ganesa 10 Bandung, Indonesia.
f) Senior Hydrogeology, PT.BC, Pemuda 40 Tanjung Redeb Berau, Indonesia.

Abstract
Liquid waste with high amount of total suspended solid (TSS), is one of the significant environment issues from coal mining activities in Kalimantan island under high precipitation in of a very wide zone of coverage. The TSS concentration with Nano-sized particle in mine drainage caused by clay minerals which is dominated by montmorillonite type. Therefore, a huge chemical agent is usually used to treat TSS concentrations of the liquid waste less than 300 mg/L based on government regulation. However, in this case, the chemical flocculant triggers the onset of secondary pollutant because its carcinogenic and non-biodegradable. This study aims to observe specific fungi, Marasmius sp, as bio-flocculant for the treatment of mine drainage with extra high TSS. The fungi can produce biodegradable polymer that have ability to precipitate the montmorillonite with two mode action, they are bio-flocculant polymeration and mycelial trapping. A role model was running in laboratory scale less than 1 L in several graduated/measuring cylinders under 22-30 oC. The results of clarity test by using spectrophotometer shown a number of 86% clarity value averagely in one-hour treatment, while flocculation rate test indicated the amount of TSS concentrations became 110.1 mg/L. In this term, the minerals in the mine drainage samples from PT.BC mining excavation area, had been precipitated rapidly from previous measured TSS concentration at 11,000 mg/L.

Keywords
Total suspended solid; Mine drainage; Bio flocculant; Concentration

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/DGT29WhYaem8

Corresponding Author
Y Yatini

Institutions
(1)Departement of Geophysics Engineering, Universitas Pembangunan Nasional Veteran Yogyakarta, SWK (104) North Ring Road Street Condong Catur, Yogyakarta55283. Indonesia.
email: jeng_tini[at]upnyk.ac.id
(2)Geophysics Departemant, Universitas Gadjah Mada (UGM), Sekip Utara BLS 21 Yogyakarta 55281
(3)Geophysics Departement, Universitas Brawijaya, Jl. Veteran, Malang 65145

Abstract
Sileri Crater is a manifestation of the Dieng Volcanic Complex (DVC) which has a large geothermal prospect. The problem of subsurface conductivity distribution is very important in geothermal prospecting. The geothermal prospects indicated by the presence of manifestations have characteristics of high conducivity values. The conductivity parameters were obtained by the Very Low Frequency (VLF) method. Research in DVC prospect area, precisely around Sileri Crater area using the VLF method, aims to map the subsurface structure through the distribution of conductivity values. VLF data consists of tilt, ellipse, vertical and horizontal magnetic field. VLF data processing is done by using the filter of moving average, Fraser and Karous-Hjelt. Current Density Equivalent (CDE) results are correlated to simplify the interpretation of the conductive zone. The results show that the conductive anomalies on A, B C, and D lines in the east are influenced by the presence of geothermal pipes around the crater. Other conductive anomalies found on the E and F lines are estimated to be caused by the influence of lithological contact between andesite lava and volcanic deposits. Andesite lava responds to conductive anomalies on the measurement results of the VLF method while volcanic deposits lithology has a more resistive.

Keywords
DVC, VLF, conductivity, tilt, fraser and CDE

Topic
Geophysics,Geomatics and Geochemistry

Link: https://ifory.id/abstract/vUjT2dFEeYG8

Corresponding Author
Oktarian Wisnu Lusantono

Institutions
a) Universitas Pembangunan Nasional “Veteran” Yogyakarta, Yogyakarta 55283, Indonesia
b) Yayasan Emas Artisanal Indonesia

Abstract
Artisanal and Small-scale gold mining (ASGM) is an interesting issue in the development world related to the sustainable development goals in environmental topics. Mercury is a one of the several focuses related with ASGM and its usage has been limited by the implementation of Minamata Convention on Mercury. Indonesia as development country with quite significant number of ASGM miners has been ratified and forced the implementation of Minamata Convention since 2016. In this study, a typical ASGM operation located in Tobongon, East Bolaang Mongondow, North Sulawesi Province was selected as a site of study. Tobongon is one of the few people-s mining area (Wilayah Pertambangan Rakyat – WPR) that has been verified by Ministry of Energy and Mineral Resources (Kementerian Energi dan Sumber Daya Mineral – ESDM). This study is cover several topics such as current state of operation in relation with mercury usage, legal status, and couples of activity that has been done for capacity building in the area. The result of this study will provide an illustration about ASGM conditions in Indonesia with its complexity and challenges for improvement and development.

Keywords
Artisanal and small-scale mining, responsible mining, mercury reduction

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/gvumzYMxbTtw

Corresponding Author
Ika Wahyuning Widiarti

Institutions
Department of Environmental Engineering, Faculty of Mineral Technology, Universitas Pembangunan Nasional Veteran Yogyakarta 55293, Indonesia

Abstract
Kopi Luhur Dumpsite is a waste dump facility from area surrounds Cirebon City. The Kopi Luhur Dumpsite has 9 hectares area that implements an open dumping system that may cause the spread of flies and rat vectors, release unpleasant odors, and reduce environmental aesthetics. Also, the Kopi Luhur Dumpsite has inadequate leachate treatment plant and methane gas control system. The aim of this study was to assess environmental risk due to dumping activities at the Kopi Luhur Dumpsite using IRBA (Integrated Risk-Based Approach). IRBA examines 27 parameters under three classes, namely, site-specific criteria, waste characteristics at the dumpsite, and those related to the quality of leachate from the dumpsite. Data were obtained through mapping in the field, interviews with managers and communities surround and testing samples in the laboratory. The research results showed that the Kopi Luhur dumpsite has corresponded to moderate hazard level with a total risk index score 575.3536. Therefore, the recommendation actions are immediate rehabilitation of the dumpsite into sustainable landfill.

Keywords
Kopi Luhur Dumpsite, IRBA, risk assessment

Topic
Disaster Management and Environmental Issues

Link: https://ifory.id/abstract/J7PE9zNjdqWb

Corresponding Author
Ardian Novianto

Institutions
Universitas Pembangunan Nasional Veteran Yogyakarta

Abstract
Abstract. Jambakan is a village in Bayat District, Klaten Regency, Central Java Province, Indonesia. Even though it is located ±30 km from the sea, brackish water is found in its aquifers. In light of this, scientific discussion on where this water comes from is deemed necessary. Based on the groundwater quality analysis at the local wells, brackishwater was detected in shallow aquifers at the depths of 5-8 m. The geoelectrical method using the Schlumberger and dipole-dipole electrode configurations screened for any aquifers vertically and horizontally. The results showed that aquifers were distributed discontinuously, for which they were interpreted as fan alluvial deposits in shallow seas or molasses accumulations on the land. The interpretation also revealed that the brackishwater resulted from contacts with minerals in seawater sediments that composed the aquifers in this village.

Keywords
Schlumberger,dipole-dipole,electrode

Topic
Geophysics,Geomatics and Geochemistry

Link: https://ifory.id/abstract/68cGXzxy2JPQ

Corresponding Author
Rizki Amelia Sasqia Putri

Institutions
Sriwijaya Univerity
Jl. Srijaya Negara Bukit Besar, Palembang, South Sumatera, Indonesia 30139
*rsasqia[at]gmail.com

Abstract
The research area is located in Lubuk Tarok Village, Sijunjung Regency, West Sumatra and is geologically part of the Ombilin Basin. Previous researchers examined Sawahtambang Formation as part of Ombilin Basin stratigraphy on a regional basis. The purpose of this study is to characterize sediment deposition, interpret and model the depositional environment. The method carried out in this study is the making of outcrop stratigraphic profiles with detailed observations of lithofacies and architectural elements in eight observation locations divided in two north-south oriented segments. The observation location is positioned in a geological cross section to find out the stratigraphic position of the unconformity with the Sangkarewang Formation below it. Interpretation of the lithofacies and architectural elements characteristics are carried out to know the process and its depositional environment. The final stage is making comparative modeling, refers to Nichols (2009) to show the vertical and lateral relation of lithofacies. Both segments in the west and east of the research area showed similarities in types of litofacies, there are Scourfills (Ss), Sandy through crossbeds (St), Sandy planar crossbeds (Sp) and Sandy horizontal (Sh). Ss is sandstones that fill the scour surface. St is found in the channel migration part. Sp is found above the channel migration, and Sh is fine deposits at the top of the runoff flow deposits. The architectural element shows repetitions and combination of channel and sandy bedform sedimentary geometry. Litofasies changes show how the the deposition process changed by the cause of channels that intersect each other. The deposit formed by this channel activity is called multistorey channels which are interpreted as the result of braided river environmental deposits with paleocurrent direction to the west. The characteristics of the Sawahtambang Formation which has very thick sandstones are significant value for the study of reservoirs in Ombilin Basin.

Keywords
lithofacies, architectural element, multistorey, amalgamated sandstones, braided river

Topic
Geology

Link: https://ifory.id/abstract/hYM2A8etpHaV

Corresponding Author
mira meirawaty

Institutions
a) Lecturer of Geological Engineering Dept, Universitas Trisakti
Jl. Kyai Tapa No.1, Jakarta Barat-11440
b) PT. Star Energy Geothermal

Abstract
Epidote is a Calc-silicate mineral which is important in geothermal system because it shows high temperature reservoir when the reservoir in neutral pH fluids condition. The presence of epidote in the Wayang Windu geothermal field is very interesting because it comes in two forms, the epidote that replacing primary felsic minerals and the epidote that have been replaced by low temperature calcite-anhydrite minerals. This research is carried out by microscopic analysis (petrographic observation and XRD) of cutting samples from wells in southern area that represent liquid dominated system, and one in the northern that represent the vapor dominated system. The calcite and anhydrite overprinting epidote occur in all three reservoir-s wells, their occurance show abundance of CO2 and H2S gas in the reservoir. These type of epidotes occur right above the heat loss zone in reservoirs well with liquid dominated system, its being intrepeted associate with the boiling zone in the past. Whereas its occurrence in vapour dominated reservoir that present continuesly from certain depth was intrepreted associate with water condensate that move downward to the reservoir. The Calc-silicate minerals in vapour dominated reservoir reflects earlier alteration episodes when the system was more liquid-dominated. The vapor dominated system in the northern area is well indicated by a thick cap rock consist of smectite-cristobalite, whereas this zone is become thinner to the liquid dominated system in the southern. The reservoir of vapor dominated system are composed of acidic pyrophyllite and sericite-illite alteration, meanwhile the reservoir of liquid dominated composed of Calc-alkali mineral that show neutral pH fluids. This research is supported by fluid inclusion analysis to see further fluid evolution in the study area.

Keywords
Epidote, Geothermal, Wayang Windu, Vapour dominated, Liquid dominated

Topic
Geology

Link: https://ifory.id/abstract/KWpxrFaAm4zH

Corresponding Author
FX Delova Christama

Institutions
Universitas Pembangunan Nasional "Veteran" Yogyakarta

Abstract
The research area is located nearby Batutegi Dam in Batutegi Village, Air Naningan District, Tanggamus Regency, Lampung. This area is predominantly occupied by metamorphic rock, namely mica schist, which is part of Paleozoic Gunungkasih Complex. The geological fieldwork which has been conducted reveals the existence of mineralization potential. Altered rocks found in this area are an evidence of past hydrothermal activity during the orogeny tectonic event of Sumatra Island formation which might have deposited some ore minerals. The altered rocks have experienced argillic alteration type with the presence of illite and secondary quartz. This kind of rocks is mostly associated with iron oxide druzy quartz veins. The structures controlling this area are mainly oriented in NW - SE direction.

Keywords
gold mineralization, metamorphic rock, Sekampung River

Topic
Geology

Link: https://ifory.id/abstract/FVnqxXJhw9tj

Corresponding Author
Agus Harjanto

Institutions
Universitas Pembangunan Nasional Veteran Yogyakarta

Abstract
Based on the administrative location the research was located in Tomohon Selatan District, Tomohon, North Sulawesi Province. In the study area, there was a pattern of diverter that developed so that it could be of two types, namely the radial drainage pattern and parallel flow pattern. Through these drainage patterns and geomorphological aspects in the study area, one origin form is in the form of volcanic origin, which can then be grouped into five land forms. The research area is composed of volcanostratigraphic units arranged from old to young, namely, Khuluk Post - Tondano which is composed of Gumuk Lengkoan, Guml Panglombian, Gumuk Kasuratan, and Gumuk Linau. The presence of "Patriot" geothermal surface manifestations in the form of hot springs, warm springs, ponds / hot mud and fumaroles which have a temperature of 47 - 90⁰C. - Chloride waters have geothermal fluid equilibrium in the immature waters which is interpreted that the process is dominated by meteoric water and formed in a fluid forming environment in the form of riolytic and andesitic composition. It can be seen that the characteristics of surface manifestations are included in high temperature systemic manifestations. Fluid equilibrium in MNA-5 wells is in partial equilibrium which has a temperature of 260⁰ C so that it can be categorized as a high-temperature convective geothermal system with liquid domination. The "Patriot" geothermal system is interpreted by conducting petrographic analysis based on cutting and cores accumulated into mineral distributions that can be interpreted that the "Patriot" geothermal system has the characteristics of past and present reservoir temperature traces which are characterized by the presence of adularia, anhydrite, epidote, and mineral illite that forms at high temperatures and has an acidic pH and presence at different depths. So that based on data on mineral distribution of MNA-5 and MNA-23 wells there were three alteration zones consisting of the zone of argectic hematite + hematite alteration type, propylytic alteration zone chlorite + calcite + anhydrite so that the two zones can be interpreted as capillary rocks (caprock ), and epidemic zones + ilit ± wairakit as propylitic alteration types which are interpreted as top reservoirs. The presence of diorite intrusion in the MNA-5 well is interpreted as a heat source and magma body

Keywords
Goethermal, alteration, geochemistry

Topic
Geology

Link: https://ifory.id/abstract/weMAbnRhFY3K

Corresponding Author
Mau Lina

Institutions
a) University of Lampung, Lampung
*maulln197[at]gmail.com
b) Marine Geological Institute, Bandung

Abstract
Petrophysical analysis of well log data have been crucial for determination of reservoir prospect zone with lithology and hydrocarbon types based on petrophysical parameters. In addition, sensitivity analysis is carried out to determine elastic parameters that are sensitive of lithology variability and pore-fluid type. Based on the crossplot results, parameters such as Lambda-Rho, Mu-Rho, and VpVs ratio can detect lithology and pore-fluid types because they are sensitive to porosity and rock matrix characteristics. This study focuses on reservoir characterization of ‘MS- well on Late-Miocene N17 rock formation which was classified as a shelf carbonate matrix. The petrophysical parameters are carried out such as porosity ( ), water saturation (Sw), shale content (Vshale), and formation water resistivity (Rw) using density and neutron logs calculation, Indonesian-s equation, and qualitative analysis approcach. Based on the results of petrophysical analysis it is known that the reservoir zone is at 5003-5297 ft with total thickness 101 ft netpay. The reservoir has a limestone lithology with Gamma Ray-s value between 15-55 API. The hydrocarbon prospect zone is indicated by the separation of NPHI and RHOB curves with low value, porosity 18.5%, water saturation 37%, and water resistivity shows 0.12-0.13. The reservoir zone is indicated by the cut-off of Lambda-Rho <25 GPa*gr/cc, Mu-Rho <70 GPa*gr/cc, and VpVs ratio <2. Finally, both the petrophysical and sensitivity analysis show indication of fresh water biogenic gas reservoir.

Keywords
petrophysical and sensitivity analysis; reservoir characterization; lithology; carbonate; Nias basin

Topic
Geophysics,Geomatics and Geochemistry

Link: https://ifory.id/abstract/L794QjvweZEH

Corresponding Author
Tri Wahyuningsih

Institutions
1 Metallurgical Engineering, Mining Engineering Department, Mineral Technology Faculty, UPN "Veteran" Yogyakarta, Jl. SWK 104 (Lingkar Utara) Condongcatur Yogyakarta 55283 Indonesia
2 Metallurgy Engineering, FTTM, Bandung Institute of Technology (ITB), Bandung 40132, Indonesia
3 Laboratory of Geomicrobiology, Biomining & Biocorrosion, Research Center for Bioscience and Biotechnology, Bandung Institute of Technology (ITB), Jln. Ganesha 10, Bandung 40132, Indonesia
a)Corresponding author: tri.wahyuningsih[at]upnyk.ac.id
b)skchaerun[at]metallurgy.itb.ac.id
c)esanwani[at]mining.itb.ac.id;

Abstract
Abstract: Several studies have been conducted on the benefits of bacteria to replace chemical reagents in the bioflotation process of copper sulfide minerals. Most of the processing of copper sulfide minerals is carried out by flotation by adding reagents. Flotation is one of the mineral processing processes to separate valuable minerals and their impurities, by utilizing different mineral surface properties. In copper sulfide minerals there is a high sulfur content of pyrite impurities (FeS2) which must be separated or depressed (become more hydrophilic) to be separated with valuable minerals, while valuable minerals will remain hydrophobic (prefer air). However, not all bacteria can survive at high sulfur concentrations. In this research characterization of the interaction of biosurfactant-producing bacteria that can survive in environments with high sulfur content (Citrobacter youngae strain SKC-4) with pyrite minerals. The effect of bacterial and pyrite interactions is observed by analyzing the composition of mineral surface elements and the morphological changes of the sample with SEM-EDS (Scanning Electron Microscope - Energy Dispersive Spectrometer) showing the interaction of bacteria that is able to stick and make mineral particles into complex aggregates and from the EDS results show that in the presence of bacteria are able to change the components of the initial mineral elements, this is dominated by the element components Fe, S, and a little content of element C which is the main element of microbial activity. Sampling for functional group testing (FT-IR Spectroscopy) was carried out on days 0,7,14, and 30 when bacteria interacted with minerals, showing a peak of C = O carbonyl bonds and carboxylic acid formation on the 7th day. The contact angle value of interaction culture with pyrite minerals results in a decrease on the 7th day, this causes the pyrite minerals to become more hydrophilic. From the results of the interaction characterization, the Citrobacter youngae strain SKC-4 has the potential as an alternative to a depressant reagent in a more environmentally friendly copper sulfide mineral bioflotation process.

Keywords
interaction, biosurfactant, pyrite, depressant

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/V6rQbU9kj283

Corresponding Author
Stevanus Nalendra Jati

Institutions
Geology Study Program, Faculty of Engineering, Sriwijaya University

*s.nalendra[at]unsri.ac.id

Abstract
Observation on the Tanjung Enim coal outcrops has been conducted to evaluate coal and cleat characteristics, particularly those occurring at Suban and Air Laya Putih (ALP) sites. Tectonically, the region is located in the South Palembang Sub-basin. In this region, there are four to five coal seams dipping to the SW direction. The dips of coal beds in ALP are commonly steeper than those in Suban, implying that the ALP seams had been more deformed tectonically and hence underwent more shortening. The samples analyzed reveal that the coals are medium in rank with the ash content relatively constant along strike, but distinctive vertically. Most seams have high values of inherent moisture, fixed carbon, and volatile matter. Deformation of the seams has resulted in two types of fractures known as face and butt cleats. The present study employed a scanline method to measure cleat attributes such as spacing, aperture, and bedding orientation. A total of 3,241 face and butt cleats were measured from 12 scanlines. The face cleats are predominantly oriented to NNE-SSW, suggesting peleostress direction. The general trend of butt cleats is NW-SE, likely coincident with the releasing stresses. Face cleats have spacing and aperture more tightly than butt cleats. This suggests that face cleats developed in response to the maximum stresses, and butt cleats formed due to the minimum in situ stresses. Scanning Electron Microscope (SEM) analysis reveals that microcleats in seam show a number of apertures that are connected to form a network system within the analyzed samples.

Keywords
Coal properties, cleat attributes, face cleat, butt cleat

Topic
Geology

Link: https://ifory.id/abstract/ZQHjeXwYb7g4

Corresponding Author
Ekha Yogafanny

Institutions
(1) Environmental Engineering Department, Faculty of Mineral Technology, Universitas Pembangunan Nasional Veteran Yogyakarta
a) ekha.yogafanny[at]upnyk.ac.id
b) ardhiva.h.o[at]gmail.com
c) suharwanto[at]upnyk.ac.id

Abstract
Purwoharjo Village, Samigaluh Sub-district, Kulon Progo Regency is located at an altitude of 500 meters, lies on the Jonggrangan and Kebo-Butak Geological Formation, with a population of 3392 inhabitants. The most potential water source in the village is spring. The increasing number of population does not meet the availability of water in the area. The harmonization among the water sources, natural condition, and community are essential to achieve the optimal conservation strategy to sustain the good access of water in Purwoharjo Village. This research aims to analyze the characteristics of spring (spring-s type, water quantity, and water quality) and to investigate the community-based spring conservation in Purwoharjo Village. The methods used were quantitative and qualitative. The data used in these two analysis gained by survey, interview, and laboratory method. The study was conducted in five springs which have the highest discharge in Purwoharjo Village. Water quality was analyzed based on pH, COD, BOD, DO, TDS, TSS, CaCo3 turbidity and total coliform and compared to water quality standard class I Governor Regulation Of DIY Number 20 the Year 2008. The type of springs based on the flow consistency of these five springs was perennial spring because the water spring flowed both in rainy and dry season even though the discharge was fluctuated depend on the rainfall. Based on the discharge, these five springs were categorized as class VI ranging from 0.171 to 0.323 l/sec. Based on the gravitational power, the type of these five springs was fractured springs that are formed due to the rock cracks cut by the slope (topography). Springs conservation has been carried out by the community in Purwoharjo village in order to protect and preserve the water source, preserve the spring water, and manage the spring water quality as well as control the contamination in the spring.

Keywords
Community Based Springs Conservation, Fracture Spring, Perennial Spring

Topic
Disaster Management and Environmental Issues

Link: https://ifory.id/abstract/c8hgmvVYuJDr

Corresponding Author
Wiji Raharjo

Institutions
Geophysical Engineering, Universitas Pembangunan Nasional Veteran Yogyakarta, Jl. SWK 104 Condongcatur, Depok, Sleman, Yogyakarta, Indonesia 55283
* wiji.raharjo[at]upnyk.ac.id

Abstract
Geomagnetic 3D modelling can be done by varying inclination angel for each layer and Talwani method to build the initial model as forward modelling formulation. In modelling process, random noise distribution is always needed to build synthetic data from observation data. There are two kind of random noise distribution used in this research. They are uniform distribution and Gaussian distribution. This concept then applied in satellite data of magnetic intensity in Sintang, West Borneo. Sintang is chosen because it is rich of mineralization and off course has big potential of susceptibility. Based on modelling inversion result, uniform distribution is better in separate big and low anomaly of susceptibility contrast than Gaussian distribution in this research-s data

Keywords
3D modelling, geomagnetic, Talwani method, uniform and Gaussian distribution

Topic
Geophysics,Geomatics and Geochemistry

Link: https://ifory.id/abstract/7cyPZn2Kmdeh

Corresponding Author
Diah Rini Ratnaningsih

Institutions
* Pertamina
** UPN Veteran Yogyakarta

Abstract
The Ogan Komering Working Area has an area of 1,155 km2 located in the Ogan Komering Ulu District of South Sumatra Province. The Ogan Komering Working Area is currently operated by Pertamina Hulu Energi (PHE) Ogan Komering with a Gross Split Contract Agreement as of May 20, 2018. Waterflood project has implemented since 2006 in NEASD and GRH field. Ogan Komering Block has reached second peak production with 5,980 BOPD on early 2011. Because of plugging, the injection rate nowadays is only 16,000 BWPD when once it reached 40,000 BWPD. Remaining reserves in NEASD and GRH field is 4.04 MMBO based on updating GGR study in 2019. With enhancement injection rate, NEASD and GRH field are expected to increase 2-3 MMBO reserves. The further study about waterflood subsurface condition is conducted related to connectivity between injection well and production well also the injection performance in NEASD and GRH field to complete the target. From connectivity analysis supported with geophysic and geology interpretration, waterflooding in NEASD and GRH field consists of 4 areas which are A, B, C, and D. This analysis will be one of the guideline study for mature waterflood optimization. The connectivity between injection and production wells are important thing to optimize mature waterflood project. This paper report the tracer running result on 2006 and injection-production wells performance plot to evaluate reservoir connectivity. Tracer analysis was conducted to analyze the connectivity between injection and production wells. The tracer is injected to the several injection wells and will be expected to flow to the monitor wells considered as production wells. Several type of tracers were injected into 11 injection wells on June, 23rd until 27th 2006 and September, 10th 2006. The 11 injection wells are ASDJ-27, GRH-4, ASDJ-34, GRH-10, GRH-16, GRH-7, ASDJ-41, ASDJ-36, GRH-6, ASDJ-31, dan ASDJ-33 which is located in different section area which the injection wells has pattern peripheral. The tracer were expected to flow to the monitor wells (production wells) nearly located to the corresponding injector well. In Area A, tracer 158a in the amount of 100 liters was injected to ASDJ-34 and it was detected to ASDJ-22 after 453 days. However, performance plot shows that injection rate did not affect the liquid production rate. From geology interpretation, it is confirmed that there is minor fault in 1 km which is considered as minor leaking. Tracer 140c was injected to ASDJ-31 in Area B. In the span of time 553 days, tracer 140c was detected in ASDJ-74. The performance plot also confirmed that liquid production rate and oil production rate have a tendency of increment when injection well was started on June 2007. Several types of tracer were injected to Area-C but there were no tracer detection in monitoring wells. In Area D, Tracer 140c which was injected to GRH-6 was detected in GRH-22 after 70 days and Tracer 140a from GRH-10 was detected in GRH-13 after 927

Keywords
Connectivity Analysis, Tracer Wells

Topic
Petroleum and Geothermal Engineering

Link: https://ifory.id/abstract/daP2kjh7E3ZH

Corresponding Author
joko mulyono

Institutions
- UPN (Magister Teknik Perminyakan)

Abstract
Connectivity Analysis Using of Tracer or Injection-Production Wells Performance Plot In NEASD And GRH Field PHE Ogan Komering Authors : Joko Mulyono, S.T., Firman Edi, S.T., and Dr. Ir. Dyah Rini Ratnaningsih, M.T. 2)Petroleum Engineering Magister Universitas Pembangunan Nasional “Veteran” Yogyakarta, Indonesia Corresponding author: a) joko.mulyono@pertamina.com; b)firman.edi@pertamina.com c)rini_diah@yahoo.com Abstract. The Ogan Komering Working Area has an area of 1,155 km2 located in the Ogan Komering Ulu District of South Sumatra Province. The Ogan Komering Working Area is currently operated by Pertamina Hulu Energi (PHE) Ogan Komering with a Gross Split Contract Agreement as of May 20, 2018. Waterflood project has implemented since 2006 in NEASD and GRH field. Ogan Komering Block has reached second peak production with 5,980 BOPD on early 2011. Because of plugging, the injection rate nowadays is only 16,000 BWPD when once it reached 40,000 BWPD. Remaining reserves in NEASD and GRH field is 4.04 MMBO based on updating GGR study in 2019. With enhancement injection rate, NEASD and GRH field are expected to increase 2-3 MMBO reserves. The further study about waterflood subsurface condition is conducted related to connectivity between injection well and production well also the injection performance in NEASD and GRH field to complete the target. From connectivity analysis supported with geophysic and geology interpretration, waterflooding in NEASD and GRH field consists of 4 areas which are A, B, C, and D. This analysis will be one of the guideline study for mature waterflood optimization. The connectivity between injection and production wells are important thing to optimize mature waterflood project. This paper report the tracer running result on 2006 and injection-production wells performance plot to evaluate reservoir connectivity. Tracer analysis was conducted to analyze the connectivity between injection and production wells. The tracer is injected to the several injection wells and will be expected to flow to the monitor wells considered as production wells. Several type of tracers were injected into 11 injection wells on June, 23rd until 27th 2006 and September, 10th 2006. The 11 injection wells are ASDJ-27, GRH-4, ASDJ-34, GRH-10, GRH-16, GRH-7, ASDJ-41, ASDJ-36, GRH-6, ASDJ-31, dan ASDJ-33 which is located in different section area which the injection wells has pattern peripheral. The tracer were expected to flow to the monitor wells (production wells) nearly located to the corresponding injector well. In Area A, tracer 158a in the amount of 100 liters was injected to ASDJ-34 and it was detected to ASDJ-22 after 453 days. However, performance plot shows that injection rate did not affect the liquid production rate. From geology interpretation, it is confirmed that there is minor fault in 1 km which is considered as minor leaking. Tracer 140c was injected to ASDJ-31 in Area B. In the span of time 553 days, tracer 140c

Keywords
Tracer, Waterflood, Connectivity,

Topic
Petroleum and Geothermal Engineering

Link: https://ifory.id/abstract/Jyc76BFRvj9w

Corresponding Author
Wisnu Aji Dwi Kristanto

Institutions
Universitas Pembangunan Nasional Veteran Yogyakarta

Abstract
The hydrogeological system of Menoreh Hills, Purworejo Regency area is generally built by fissure aquifers consisting of volcanic pyroclastic breccia, lava, intrusion, and laharic breccia intensively jointed. On the other hand, there are also semi karstic and intergranular aquifer systems compiled by carbonate clastic sedimentary rocks of the Sentolo Formation. Hydrogeologically, the presence of groundwater is inserted in rock crevices (fissure aquifers), and occupying either cavities or inter-granular pores (semi karstic - intergranular aquifer). In general, the value of groundwater pressure is relatively high, proven from the fact that the hydraulic head in volcanic fissure aquifer ranges 150 m – 400 m, while in carbonate aquifer is about 110 m – 150 m above sea level. Groundwater pressure is one of the triggerring factors for landslides. Influenced by hilly topography with moderate to steep slope inclination of 4o – 35o (13% - 70%), thick soil (2m - 5m), high rainfall (>2000mm/year), and saturated soil (water content = 13% – 39%), the Menoreh Hills represents a high potential for landslides. The potential grades can be grouped into low, medium, and high categories. Based on hydrogeological studies, there is a correlation between the hydrogeological system represented by the types of aquifer with the potential of landslides. Volcanic fissure aquifer type indicates higher landslide potential than the carbonate intergranular aquifer type.

Keywords
hydrogeological system, aquifer types, landslide potential, correlation

Topic
Geology

Link: https://ifory.id/abstract/fHtQEDTFJx9B

Corresponding Author
Tiara Ayu Ningratri

Institutions
a) University of Lampung, Lampung
*tiaraayuratri[at]gmail.com
b) Marine Geological Institute, Bandung

Abstract
Cross plot analysis of well log data and its calculated elastic atributes are one of the most effective methods to discriminate lithology and fluid type, because the geophysical rock properties analysis is relatively less time and cost compare to other method such as geological core sample analysis. This study uses well log data analysis based on cross plot, lithology separation, fluid type distribution map of 5 (five) wells at Nias Waters. The inverse of the interval transit times of the sonic logs are used to generate computed compresional velocities and Castagna-s formula for predicting S-wave data. Employing rock physics algorithms, rock properties including elastic attributes such as LambdaRho, MuRho, and Vp/Vs ratio are also extracted from the well log data. Cross plotting is carried out and plots with the most outstanding results are LambdaRho - Vp/Vs, MuRho - Vp/Vs, LambdaRho - Density, MuRho - Density, and AI - Vp/Vs. For the one well considered, the MT-1 well and its formation N10-N11 interest zone, those cross plots can identify lithology and fluid type. It determines formation N10-N11 as a gas carbonate reservoir with average porosity 23% which indicates that proper gas flow in the reservoir. Finally, the cross plot analysis are suitable to characterize reservoirs lithology and fluid type.

Keywords
cross plot analysis; Castagna-s formula; carbonate reservoir; Nias Waters

Topic
Geophysics,Geomatics and Geochemistry

Link: https://ifory.id/abstract/EW2r7U6Nfvwp

Corresponding Author
Tiara Ayu Ningratri

Institutions
a) University of Lampung, Lampung
*tiaraayuratri[at]gmail.com
b) Marine Geological Institute, Bandung

Abstract
Cross plot analysis of well log data and its calculated elastic atributes are one of the most effective methods to discriminate lithology and fluid type, because the geophysical rock properties analysis is relatively less time and cost compare to other method such as geological core sample analysis. This study uses well log data analysis based on cross plot, lithology separation, fluid type distribution map of 5 (five) wells at Nias Waters. The inverse of the interval transit times of the sonic logs are used to generate computed compresional velocities and Castagna-s formula for predicting S-wave data. Employing rock physics algorithms, rock properties including elastic attributes such as LambdaRho, MuRho, and Vp/Vs ratio are also extracted from the well log data. Cross plotting is carried out and plots with the most outstanding results are LambdaRho - Vp/Vs, MuRho - Vp/Vs, LambdaRho - Density, MuRho - Density, and AI - Vp/Vs. For the one well considered, the MT-1 well and its formation N10-N11 interest zone, those cross plots can identify lithology and fluid type. It determines formation N10-N11 as a gas carbonate reservoir with average porosity 23% which indicates that proper gas flow in the reservoir. Finally, the cross plot analysis are suitable to characterize reservoirs lithology and fluid type.

Keywords
cross plot analysis; Castagna-s formula; carbonate reservoir; Nias Waters

Topic
Geophysics,Geomatics and Geochemistry

Link: https://ifory.id/abstract/UZHAmBK6P9gh

Corresponding Author
Steven Chandra

Institutions
Petroleum Engineering, Institut Teknologi Bandung

Abstract
Field X is an offshore field that is included in the deep-water area managed by an oil and gas company in Indonesia. From a number of tests conducted it was found that are presence of sand problems in this field especially in well G1 so that several studies were conducted. From the results of the study, it is determined that the use of Frac pack is one of the most appropriate ways, besides controlling sand problems, it also increases gas production on field X. The Frac pack method is a well stimulation by combining gravel pack to control the sand problems with hydraulic fracturing which is designed to have high conductivity to increase productivity over the well. In this paper, a calculation model is developed to find out the optimum fracture half length, fracture width and also the pumping schedule of the Frac pack with sensitivity of proppant concentration. Then the results will be compared with existing commercial software. The challenge faced in frac pack modeling for well G1 is large permeability so that the possibility of leakage occurring is greater and then handled by increasing the injection rate. Based on the calculations and analyzes that have been done, for the well G1 on field X it will be optimum to operate if frac pack is installed with the type of brady sand 20/40 proppant and dynafrac HT 30 as fracturing fluid, so that half fracture length, X_f 76.8 ft is obtained with fracture width, w_f 0.4355 ft and 5 times fold of increase in the production. From this study it can be concluded that the calculation model made can be accepted and used commercially.

Keywords
Frac pack, fracture half length, fracture width, fold of increase

Topic
Petroleum and Geothermal Engineering

Link: https://ifory.id/abstract/vD4FupBJyHRg