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"Air merupakan komoditas penting yang dimanfaatkan oleh masyarakat untuk memenuhi kebutuhan hidup sehari-hari. Salah satu daerah yang menggunakan air yang bersumber dari sumur gali untuk meningkatkan kualitas hidup masyarakatnya adalah Kecamatan Cipanas, Kabupaten Lebak, Provinsi Banten. Namun, resiko penggunaan sumur gali adalah kualitas air tanah yang kurang layak untuk digunakan. Penelitian yang dilakukan di sekitar daerah Kecamatan Cipanas memiliki tujuan untuk mengetahui persebaran fasies air tanah pada daerah penelitian. Metode yang digunakan merupakan metode hidrogeokimia. Dalam menentukan fasies air tanah menggunakan diagram Gibbs diagram Durov, diagram Stiff, dan diagram Piper. Tiga fasies air tanah yang tersebar, yaitu calcium magnesium sulfate, sodium bicarbonate, dan calcium magnesium bicarbonate. Proses kimia air tanah daerah penelitian didominasi oleh disolusi dan pertukaran ion sehingga mineral karbonatan cukup mendominasi. Kualitas air tanah daerah penelitian apabila mengacu Permenkes No. 37 Tahun 2017 untuk penggunaan higiene sanitasi tidak memenuhi syarat untuk digunakan.

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Water is an important commodity that is used by the community to fulfil the needs of daily life. One area that uses water sourced from dug wells to improve the quality of life of its people is Cipanas District, Lebak Regency, Banten Province. However, the risk of using dug wells is that the groundwater quality is not suitable for use The research conducted around the Cipanas District area has the aim of knowing the distribution of groundwater facies in the studied area. The method used is a hydrogeochemical method. In determining groundwater facies using Gibbs diagrams, Durov diagrams, Stiff diagrams, and Piper diagrams. Three groundwater facies are found, they are calcium magnesium sulfate, sodium bicarbonate, and calcium magnesium bicarbonate. The chemical process of groundwater in the study area is dominated by dissolution and ion exchange so that carbonate minerals dominate. The groundwater quality of the research area referring to the Minister of Health Regulation No. 37 of 2017 for the use of sanitation hygiene does not pass the requirements for use."

"Cekungan Air Tanah Jakarta merupakan CAT lintas provinsi yang meliputi Provinsi DKI Jakarta, Jawa Barat, dan Banten. Seiring dengan peningkatan populasi dan pembangunan, cekungan air tanah akan semakin rawan terhadap suatu isu permasalahan apabila tidak dilakukan konservasi. Tangerang merupakan daerah yang sebagian wilayahnya termasuk ke dalam CAT Jakarta yang memiliki jumlah kepadatan penduduk dan industri yang tinggi, sehingga berdampak kepada peningkatan pengambilan air tanah dan kualitas air tanah. Penelitian ini dilakukan untuk mengetahui fasies geokimia dan kualitas air tanah pada akuifer dangkal di Tangerang dan sekitarnya menggunakan metode indeks pencemaran dengan mengacu kepada Peraturan Menteri Kesehatan Republik Indonesia Nomor 492/MENKES/PER.IV/2010 tentang persyaratan kualitas air minum. Analisis dilakukan terhadap 30 titik sumur bor hingga kedalaman 40 meter. Berdasarkan analisis data bor didapatkan litologi penyusun daerah penelitian terdiri atas batulempung, batulanau, batupasir, dan tuf. Analisis geokimia air tanah menunjukan terdapat fasies CaMgHCO3 30%, CaMgSO4 13%, NaCl 30%, dan NaHCO3 27%. Evaluasi kualitas air tanah menghasilkan nilai sekitar 2.5 – 6.3. Dari data tersebut dapat disimpulkan fasies air tanah yang dominan merupakan fasies kalsium magnesium hidroksida dan natrium klorida serta air tanah pada akuifer dangkal memiliki tingkat pencemaran ringan – sedang. Oleh karena itu perlu dilakukan pengelolaan dan konservasi air tanah untuk mengurangi tingkat pencemaran air.

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Jakarta Groundwater Basin is a cross-provincial groundwater basin covering DKI Jakarta, West Java, and Banten Provinces. Along with the increase in population and development, groundwater basins will be more vulnerable to a problem if conservation is not carried out. This research was conducted in Tangerang, which part of its territory is included in Jakarta Groundwater Basin. Tangerang has a high population density and industry, which has an impact on increasing groundwater abstraction and groundwater quality. This research aims to determine the geochemical facies and groundwater quality in shallow aquifers in Tangerang and its surroundings. The method used in this research is using the pollution index method for drinking water quality based on the Regulation of the Minister of Health of the Republic of Indonesia Number 492. The analysis was carried out on 30 drilled well points to a depth of 40 meters. Based on the analysis of drill data, it was found that the lithology that composes the research area consists of claystone, siltstone, sandstone, and tuff. Geochemical analysis of groundwater shows that there are 30% CaMgHCO3; 13% CaMgSO4; 30% NaCl; 27% NaHCO3 hydrogeochemical facies. Evaluation of groundwater quality yields a value of about 2.5 – 6.3. From these data, it can be concluded that the dominant groundwater facies is the calcium magnesium hydroxide and sodium chloride facies, groundwater quality in shallow aquifers has mild to moderate pollution levels. Therefore, it is necessary to manage and conserve groundwater to reduce the level of water pollution."

"Lokasi penelitian ini berada di daerah Kecamatan Cimanggu dan sekitarnya yang secara geografis terletak pada koordinat batas timur laut UTM 262370 E 9198862 N serta batas barat daya UTM 256431 E 9192930 N. Wilayah ini mencakup Desa Cijati, Pesahangan, Desa Negarajati, serta desa sekitarnya, Kecamatan Cimanggu, Kabupaten Cilacap, Jawa Tengah. Daerah penelitian termasuk ke dalam Formasi Halang berdasarkan Peta Geologi Lembar Majenang (Kastowo dan Suwarna, 1996). Formasi Halang merupakan salah satu Formasi pengisi Cekungan Banyumas, terendapkan pada umur Miosen Tengah hingga Pliosen Awal, dengan dominasi batuan sedimen jenis turbidit yang terendapkan pada zona batial atas. Batuan sedimen jenis turbidit inilah yang menjadi fokus penelitian kali ini untuk mengetahui fasies endapan turbidit serta asosiasinya agar dapat menenentukan sub-lingungan pengendapan pada daerah penelitian. Bagian timur laut daerah penelitian didominasi oleh ukuran butir yang lebih kasar sedangkan pada bagian barat daya didominasi oleh butiran yang lebih halus. Daerah penelitian terbukti terendapkan dengan mekanisme turbidit dikarenakan jenis litologi yang beragam, dari yang berbutir kasar (breksi – pasir sedang) hingga berbutir halus (pasir halus – lanau). Didapatkan umur relatif Formasi Halang yang mencakup daerah penelitian pada Miosen Tengah (N11) berdasarkan analisis mikrofosil. Berdasarkan pengukuran measuring section, analisis makroskopis dan mikroskopis, didapatkan 5 lintasan log stratigrafi yang memiliki fasies dominan proksimal pada timur laut dan medial pada barat daya berdasarkan klasifikasi dekatnya dari sumber sedimen (Nichols, 2009). Diasosiasikan dengan sub-lingkungan pengendapan kipas laut dalam (submarine fan) dan diinterpretasikan merupakan bagian inner fan dan middle fan, dengan tiga fasies pengendapan channel dan levee serta depositional lobes berdasarkan Nichols (2009).

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The location of this research is in the Cimanggu region and its surroundings which is geographically located at the coordinates of the northeastern boundary of UTM 262370 E 9198862 N and the southwest boundary of UTM 256431 E 9192930 N. This area includes Cijati Village, Pesahangan, Negarajati Village, and the surrounding villages, Subdistrict Cimanggu, Cilacap Regency, Central Java. The research area is included in the Halang Formation based on the Geological Map of the Majenang Sheet by Kastowo and Suwarna (1996). The Halang Formation is one of the filling formations of the Banyumas Basin, deposited in the Middle Miocene to Early Pliocene age, with the dominance of turbidite sedimentary rocks deposited in the upper bathial zone. This turbidite sedimentary rock is the main focus of this research to determine the turbidite depositional facies and their associations in order to determine the sub-environment of the deposition in the study area. The northeastern part of the study area is dominated by coarser grain sizes, while the southwest is dominated by finer grains. The study area was proven to be deposited by a turbidite mechanism due to the various types of lithology, from coarse-grained rocks (breccia – medium sand) to fine-grained rocks (fine sand – silt). The relative age of the Halang Formation which covers the study area is in the Middle Miocene (N11) based on microfossil analysis. Based on measuring section measurements, macroscopic and microscopic analysis, obtained 5 stratigraphic log paths which have dominant facies proximal to the northeast and medial to the southwest based on the close classification of sediment sources (Nichols, 2009). Associated with sub-depositional sub-environment of submarine fans and interpreted as part of the inner fan and middle fan, with three depositional facies channel, levee and depositional lobes based on Nichols (2009)."

"Penelitian ini akan membahas mengenai pemodelan penyebaran fasies sedimen laut dalam di salah satu lapangan yang mengandung gas di Cekungan Kutai. Fasies pengendapan di lapangan Y dibagi menjadi 5 yakni Channel Axis, Channel Margin, Levee Overbank, Mass Transport dan Mud. Fasies pengendapan tersebut dibedakan satu dengan yang lain dalam penelitian ini melalui perbedaan cut-off vshale dan pola log GR. Korelasi antar sumur menggunakan ketentuan stratigrafi sikuen dibantu dengan data plot gradien tekanan dan data seismik. Interpretasi data seismik 3D pada interval pemodelan yaitu interval A bertujuan untuk membentuk kerangka pemodelan penyebaran fasies. Pemodelan penyebaran fasies pada penelitian kali ini menggunakan metode Multi Point Statistic Simulation (MPS). Modul pemodelan MPS dalam software Petrel menyediakan sarana untuk menyertakan berbagai macam input data geologi dan geofisika dalam pemodelan fasies. Data input tersebut antara lain training image, seismik vshale dan data peta medan azimuth. Penelitian ini juga mencoba membandingkan proses pemodelan fasies menggunakan metode MPS dengan salah satu metode stochastic lainnya yakni SIS (Sequential Indicator Simulation).

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This study describes about fasies distribution modeling of deepwater deposit in one of gas field at Kutai Basin.The deepwater depositional fasies in Y field can be divided into 5 fasies such as Channel Axis, Channel Margin, Levee Overbank, Mass Transport and Mud. Vshale cut-off and GR log pattern are used for dividing one depositional fasies to other depositional facies. Sequence stratigraphy concept is applied on well to well correlation supported with other data like pressure gradien plot and seismic section. 3D seismic horizon interpretation at A interval aim to build model framework for fasies distribution.

This research utilizes Multi Point Statistic Simulation (MPS) method to distribute the fasies. The MPS modeling modul in Petrel provides some options to use geology and geophysics data as modeling input. Thoose input data are training image, vshale seismic cube and azimuth field map. The study also tried to compare the facies modeling process using the MPS method with one of the other stochastic methods namely SIS ( Sequential Indicator Simulation )."

"Lokasi penelitian terletak di Desa Cihaur yang terletak di Kecamatan Simpenan, Kabupaten Sukabumi, Provinsi Jawa Barat. Secara Fisiografi Desa Cihaur termasuk bagian dari Zona Pegunungan Selatan Jawa Barat atau Pegunungan Andesit Tua yang disusun oleh Formasi Jampang dan Formasi Dasit Ciemas. Pada area penelitian terdapat endapan skarn dengan batuan induk berupa batugamping. Endapan skarn merupakan endapan yang terbentuk akibat adanya kontak antara batugamping dengan batuan intrusi. Berdasarkan data perusahaan, batuan intrusi tidak ditemukan diatas permukaan. Oleh karena itu diperlukan studi fasies Vulkanik dan keterkaitan dengan batugamping yang berperan sebagai host skarn pada area penelitian untuk mengetahui skarn yang terbentuk pada area penelitian merupakan hasil kontak intrusi dengan batugamping atau akibat faktor lainnya. Metode yang digunakan dalam penelitian ini adalah analisis petrologi dan petrografi batuan inti sebanyak 22 lubang bor, Data-data yang diperoleh selanjutnya divisualisasikan dalam bentuk kolom litologi yang kemudian digunakan untuk menginterpretasikan hubungan antara fasies Vulkanik dengan batugamping yang berperan sebagai host skarn. Berdasarkan analisis petrologi dan petrografi didapati 13 litofasies yang kemudian dikelompokkan kedalam 6 satuan diantaranya Breksi Vulkanik, Lapilli Tuf, Tufaan, Andesit, Batugamping, dan Dasit Porfiri. Berdasarkan asosiasi litologi dan karakteristik litologi yang telah mengalami ubahan hidrotermal (alterasi) maka dapat disimpulkan bahwa daerah penelitian berada pada fasies proksimal gunung api. Keterkaitan antara batugamping dengan fasies vulkanik diinterpretasikan berdasarkan korelasi stratigrafi, didapati jika batugamping yang terubah menjadi marmer ataupun teralterasi skarn disebabkan oleh adanya terobosan oleh satuan dasit porfiri.

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The research location is located in Cihaur Village which is located in Simpenan District, Sukabumi Regency, West Java Province. Physiographically, Cihaur Village is part of the Southern Mountain Zone of West Java or the Old Andesite Mountains which are composed of the Jampang Formation and the Ciemas Dacite Formation. In the research area there are skarn deposits with the source rock being limestone. Skarn deposits are deposits formed due to contact between limestone and intrusive rocks. Based on company data, intrusive rocks were not found above the surface. Therefore, it is necessary to study volcanic facies and their relationship with limestone which acts as a host for skarn in the research area to determine whether the skarn formed in the research area is the result of intrusive contact with limestone or due to other factors. The method used in this research is petrological and petrographic analysis of core rock from 22 drill holes. The data obtained is then visualized in the form of lithological columns which are then used to interpret the relationship between volcanic facies and limestone which acts as a skarn host. Based on petrological and petrographic analysis, 13 lithofacies were found which were then grouped into 6 units including Volcanic Breccia, Lapilli Tuff, Tufaan, Andesite, Limestone and Porphyry Dacite. Based on the lithological associations and lithological characteristics that have undergone hydrothermal change (alteration), it can be concluded that the research area is in the proximal volcanic facies. The relationship between limestone and volcanic facies is interpreted based on stratigraphic correlation, it is found that limestone is changed to marble or skarn alteration due to breakthroughs by porphyry dacite units."

"Lokasi penelitian berada pada Formasi Cinambo wilayah Daerah Jatinunggal, Sumedang Jawa Barat. Pada lokasi ini, tersingkap dengan baik beberapa singkapan sepanjang Anak Sungai Ci Jaweu pada Desa Cibuyung dan Desa Cimanintin yang terbagi menjadi dua lintasan. Litologi penyusunnya adalah feldspathic wacke, allochemic mudstone, foraminiferal-packstone, foraminiferal-wackestone, dan batulanau. Porositas batuannya memiliki rentang poor – excellent (>25%). Berdasarkan pengamatan lapangan, pengukuran stratigrafi, dan analisis petrografi, lokasi penelitian tersusun atas Kelompok Fasies B, C, D, dan G yang terbagi lagi menjadi 7 anggota litofasies. Kelompok-kelompok fasies yang saling berasosiasi kemudian dikelompokan menjadi 3 asosiasi fasies yaitu Sandy-silt lobe distal, distal levee, dan distal silt-mud lobe. Analisis mikrofosil yang dilakukan, menunjukan lapisan pada lokasi penelitian memiliki umur Miosen Tengah/Miosen Akhir dan terendapkan pada lingkungan upper-lower bathyal. FormasiCinambo yang tersingkap pada daerah ini diinterpretasikan berada pada lingkungan kipas laut dalam bagian tengah (middle fan).

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The research location is in the Cinambo Formation in the Jatinunggal Region, Sumedang, West Java. At this location, several outcrops along the Ci Jaweu River in Cibuyung Village and Cimanintin Village are well exposed and are divided into two tracks. Its constituent lithologies are feldspathic wacke, allochemic mudstone, foraminiferal-packstone, foraminiferal-wackestone, and siltstone. The rock porosity ranges from poor to excellent (>25%). Based on field observations, stratigraphic measurements, and petrographic analysis, the study site is composed of Facies B, C, D, and G which are further divided into 7 lithofacies. Facies groups that are associated with each other are then grouped into 3 facies associations namely distal Sandy-silt lobe, distal levee, and distal silt-mud lobe. The microfossil analysis performed showed that the layers at the study site are Middle Miocene/Lower Miocene and were deposited in an upper-lower bathyal environment. The Cinambo Formation exposed in this area is interpreted to be in the middle fan environment."

"ABSTRAKPemodelan fasies karbonat pada Formasi Kujung dan Formasi Ngimbang telah dilakukan dengan mengintegrasikan data geologi dan data geofisika. Penelitian ini difokuskan pada analisis seismik fasies dan lingkungan pengendapan. Formasi target pada studi ini adalah Formasi Kujung dan Formasi Ngimbang. Formasi Kujung merupakan Formasi yang terdiri atas batuan karbonat. Formasi Ngimbang mampu menjadi reservoar minyak yang baik seperti yang telah ditembus oleh sumur-sumur di lepas pantai Jawa Timur. Namun kajian mengenai Formasi Ngimbang masih terbatas dan belum komprehensif sehingga harus diangkat potensi-potensi pada formasi tersebut dengan pendekatan seismik stratigrafi, ditambah dengan data sumur yang telah menembus Formasi Ngimbang. Dengan menggunakan seismic fasies sebagai acuan diharapkan dapat mengetahui potensi-potensi baru Batuan Karbonat pada Formasi Kujung dan Formasi Ngimbang. Untuk itu pada penelitian ini, dilakukan pemodelan facies karbonat. Hasil analisis memperlihatkan tiga fasies pada interval target yaitu: Fasies wackstone-grainstone coraline reffal dengan arah relatif berarah barat-timur, Fasies mudstone-packstone lagoonal dengan arah relative barat-timur,fasies grainstone dolomite tidal, yang berarah relative barat-timur. Pada fasies wackstone-grainstone coraline reffal, merupakan transgresive reef system, dimana pertumbuhan reef mengikuti kenaikan muka air laut relative. Analisis lebih lanjut pada seismik fasies dapat disimpulkan bahwa Formasi Ngimbang didominasi oleh fasies reefal.

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ABSTRACTCarbonate rock is an important reservoir rock in Indonesia. North East Java Basin has several carbonate reservoir which still productive. This research focused on seismic facies analysis and depositional environtment. This study is conducted integrating geological and geophysical method for evaluating carbonate reservoir in Kujung and Ngimbang Formation. Kujung Formation consist of carbonate rocks. Ngimbang Formation capable of being good reservoir but the study of Ngimbang Formation is still limited and not comprehensible. Structure experience aggradation in the northern part and prograding unit to the south. Facies mapping of the Ngimbang and Kujung formation as presented in the study area suggested that the facies distribution is not as important as fault intensity to control the reservoir quality. Whereas facies modeling from well correlation suggested that towards western part, that is, from Well JPD in the eastern part to JPL in the western part, the facies become more basinal.From facies analyses in the Well JPD of Ngimbang Formation from top to bottom is mostly dominated by reefal facies but the presence of intensive micrite and stylolite suggested that late diagenetic process occurred and really influence reservoir quality. As also from facies analyses in the Well JPL indicated that Kujung Formation is having reefal to fore reef depositional environment. From this point of view, the area of interest is the area where fault intensity are high. The top structure of Ngimbang Formation at the present time is higher towards eastern part, Whereas facies modeling from well correlation suggested that towards western part, that is, from Well JPD in the eastern part to JPL in the western part, the facies become more basinal.From facies analyses in the Well JPD of Ngimbang Formation from top to bottom is mostly dominated by reefal facies. "

"Cekungan Sumatra Selatan adalah salah satu wilayah yang memiliki potensi besar dalam cadangan minyak bumi dan gas, terutama di Formasi Talang Akar. Untuk mengoptimalkan eksplorasi dan produksi di cekungan ini, dibutuhkan studi yang melibatkan bidang geologi untuk menemukan dan mengembangkan potensi baru. Penelitian ini difokuskan pada Formasi Talang Akar Bagian Bawah, dengan menggunakan beberapa sumur bor di daerah penelitian. Penelitian ini bertujuan untuk menganalisis persebaran dari variasi litologi dan menganalisis fasies dan sistem pengendapan berdasarkan pola elektrofasies pada tiap sumur daerah penelitian dari batuan penyusun Formasi Talang Akar Bagian Bawah pada lapangan “X”. Metode yang digunakan dalam penelitian ini melibatkan data batuan inti dan data sumur. Kedua jenis data tersebut memiliki peran penting dalam mengkarakterisasi batuan penyusun yang terdapat di daerah penelitian. Analisis fasies dan sistem pengendapan digunakan untuk menggambarkan sifat dan lingkungan deposisi batuan, yang diambil dari data batuan inti yang akan digunakan sebagai validasi terhadap interpretasi data sumur atau elektrofasies. Hasil penelitian menunjukkan bahwa daerah penelitian dapat dibagi menjadi beberapa elemen yaitu, fluvial meandering channel, floodplain, tidal distributary channel, distributary mouth bar, dan delta front/marine shale. Elemen tersebut terendapkan pada dua sistem pengendapan yang berbeda, yaitu meandering system dan tide dominated delta system. Hasil interpretasi log gamma ray pada tiga sumur menunjukkan dua litologi utama: sandstone dan shale. Persebaran litologi dan pola penyusunannya dapat dikorelasikan antar sumur. Namun, satu tubuh sandstone tebal di dasar sumur B-1 tidak ada pada dua sumur lainnya. Secara vertikal, pola litologi dari log gamma ray menunjukkan beberapa tren, termasuk fase yang didominasi oleh sandstone dan fase yang didominasi oleh shale. Dalam penelitian ini, analisis fasies dan sistem pengendapan akan memberikan pemahaman yang mendalam tentang karakteristik batuan dan lingkungan deposisi di Lapangan “X”, Formasi Talang Akar Bagian Bawah. Penelitian ini diharapkan dapat memberikan kontribusi atau sudut pandang baru terhadap kegiatan pengembangan lapangan minyak dan gas bumi pada daerah penelitian.

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The South Sumatra Basin is one of the regions with significant potential for oil and gas reserves, especially within the Talang Akar Formation. To optimize exploration and production in this basin, a study involving the field of geology is needed to discover and develop new potentials. This research focuses on the Lower Talang Akar Formation, using several drilling wells in the research area. The objective of this study is to analyze the distribution of lithological variations and to analyze facies and deposition systems based on electrofacies patterns in each well within the research area of the Lower Talang Akar Formation in the "X" field. The methods employed in this research involve core rock data and well data. Both types of data play a crucial role in characterizing the constituent rocks present in the research area. Facies and deposition system analysis are used to depict the nature and depositional environment of the rocks, derived from core rock data, which will be used as validation for the interpretation of well data or electrofacies. The research results indicate that the research area can be divided into several elements, namely fluvial meandering channels, floodplains, tidal distributary channels, distributary mouth bars, and delta fronts/marine shales. These elements are deposited within two distinct deposition systems, namely the meandering system and the tide-dominated delta system. The interpretation results of the gamma-ray log in the three wells indicate two main lithologies: sandstone and shale. The distribution of lithology and its arrangement can be correlated between wells. However, a thick sandstone body at the base of well B-1 is not present in the other two wells. Vertically, the lithology pattern from the gamma-ray log indicates several trends, including phases dominated by sandstone and phases dominated by shale. In this study, facies and deposition system analysis will provide an in-depth understanding of rock characteristics and depositional environments in the "X" field of the Lower Talang Akar Formation. This research is expected to contribute new insights or perspectives to the development of oil and gas fields in the research area."

"ABSTRAKBatugamping Formasi Kais merupakan reservoar utama penghasil hidrokarbondilapangan Asmorom yang berumur Miosen Tengah. Lapangan ini berada diCekungan Bintuni Papua Barat dan merupakan bekas peninggalan Belanda.Penelitian ini bertujuan untuk melakukan detail fasies pengendapan dan prosesdiagenesis serta rock typing diharapkan dapat memberikan hasil yang lebih baikuntuk melihat karakteristik reservoar karbonat dan potensinya. Batugamping Kaisdiidentifikasi menjadi tiga unit yaitu lapisan Kais Atas, Kais Tengah, dan Kais Bawah yang berasosiasi menjadi lima fasies yaitu fasies shelf, front reef, interreef, back reef, dan core reef. Asosiasi fasies ini diinterpretasikan sebagai fasieskarbonat platform. Kualitas reservoar ini direview dari asosiasi fasies, analisispetrografi dan biostratigrafi, memperlihatkan bahwa lapisan atas dan bawahdikontol oleh proses diagenesis kompaksi dan porositas rekahan sedangkanlapisan bawah dikontrol oleh proses diagenesis dolomitisasi, pelarutan, danporositas rekahan.

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ABSTRACTKais Formation limestone is the main reservoar that produce hydrocarbon inAsmorom field in Middle Miocene. This field is located at Bintuni Basin WestPapua and used to run by Ducth company. The researchs proposed to do detaildepositional facies and diagenesis process with rock typing to characterize thepotential of carbonate reservoir. Kais Limestone can be identified in to threemembers namely Upper Kais, Middle Kais, and Lower Kais which are associatedin five different faciesnamely shelf, front reef, inter reef, back reef, and core reeffacies. The facies associations are interpreted as reefal platform carbonate. Thereservoir quality, which is reviewed from facies association, petrography andbiostratigraphy analysis shows that the Upper and Middle kais are controlled bycompaction diagenesis and fractures porosity, in another hand the Lower Kais iscontrolled by dolomitization diagenesis, dissolution, and fractures porosity."

"konang district has a problem on fresh water supply particularly in dry season. Two villages in the district, namely Pakes and Konang, are densely populated areas having agriculture activities, so available of sufficent fresh water in necessary. A fresh water source that can be developed in this area is deep groundwater source from potential aquifers. A geological study has been conducted to identify potential aquifer based on lithological aspect and geological structure. According to the regional stratigraphy, the study area consists of Tawun Formation and Ngrayong Formation. They compose of carbonaceous claystone (the oldest rock unit), carbonaceous claystone with sandy limestone intercalations, sandy limestone interbeded with carbonaceous claystone, tuffaceous sandstone with claystone intercalations, and reef limestone (the youngest) respectively. Strike and dip positions of the rocks layers are N110oE/22o - N150oE/26o, located on the south anticline axis with wavy plan to gentle slope of hilly morphology. Among the rock unit, only sandy limestone has fine sand with subangular in shape and open pack. Qualitatively, this rock has good porosity and parmeability and is enables to save and to flow subsurface water. Thrus, the sandy limestone is considered as a potensial zone for fresh water resources. Whereas, carbonaceous claystone with clay grainsize has low porosity and permeability, so it is potential as a cap rock"