scholarly journals The model of gas pool formation in Frakulla area, Albania

2001 ◽  
Vol 34 (3) ◽  
pp. 1247
Author(s):  
R. KOCI ◽  
A. GJIKA ◽  
Q. AVDULAJ ◽  
S. KOCI

Frakulla diapir is one of the studied diapirs in Albania. It is located in the western part of Albania. The Serravallian to Pliocene sediments belongs to the uppermost part of the Adriatic Basin, which is included in the central Mediterranean Basins group. Some anticline and syncline structures are indicated in the western part of Albania. These structures are placed in a linear way forming some structural ranges with SSE-NNW axis direction. Frakulla is one of these structures as a part of Vlora-Panaja-Frakkull range (Fig. 1). Based on the surface geology, well data and the interpretation of the seismic sections results that this structure is formed as a consequence of the mud diapir growth. This diapir is complicated with tectonic faults in both western and eastern flanks, which dip with angle 45-90° The southern and northern ends of the structure are clearly seen in the seismic sections and a number of wells penetrated these ends. We think that the Frakulla structure is a typical mud diapir surrounding in all directions by many gas sandstone beds. These sandstones are formed in a deltaic environment during the Messinian (Globorotalia conomiozea zone). Some factors affected the quantity of hydrocarbon accumulation are discussed in this paper like: structural character of the area, pattern and complexity of faulting around and over the mud diapir, depositional environment, rate of growth of the diapir and time of uplift. We think that the presence of gas accumulation in Frakulla area is as a consequence of a favorable interrelation of these factors

Author(s):  
Luhut Pardamean Siringoringo ◽  
Dardji Noeradi

Northern part of Masalima Trench Basin is located in the southern part of the Strait of Makassar, which includes Masalima Trough and Massalima High. The area of research is an extension of the South Makassar Basin which extends from South Makassar Basin to the Northeast part of Java Sea. Subsurface data are used such as 2D seismic sections (21 lines) and data drilling wells (2 wells) to understand the tectonic structure in the basin formation and understand the stratigraphic order of basin. Based on well data can be known that Northern part Masalima Trench Basin is aborted rift because marked by post rift phase. Northern part Masalima Trench Basin was formed by normal faults which have trend northeast-southwest with  pre rift, early syn rift, late syn rift, and post rift sediment geometry. Early syn rift sediment was Middle Eocene, late syn rift sediment was Middle Eocene till Early Oligocene and post rift sediment was Early Oligocene till Early Miocene. The Depositional environment of early syn rift phase such as beach, shallow marine, and land. The Depositional environment of late syn rift phase such as beach till deep marine, and the depositional environment of post rift is deep marine.


Author(s):  
A. Livsey

South Sumatra is considered a mature exploration area, with over 2500MMbbls of oil and 9.5TCF of gas produced. However a recent large gas discovery in the Kali Berau Dalam-2 well in this basin, highlights that significant new reserve additions can still be made in these areas by the re-evaluation of the regional petroleum systems, both by identification of new plays or extension of plays to unexplored areas. In many mature areas the exploration and concession award history often results in successively more focused exploration programmes in smaller areas. This can lead to an increased emphasis on reservoir and trap delineation without further evaluation of the regional petroleum systems and, in particular, the hydrocarbon charge component. The Tungkal PSC area is a good example of an area that has undergone a long exploration history involving numerous operators with successive focus on block scale petroleum geology at the expense of the more regional controls on hydrocarbon prospectivity. An improved understanding of hydrocarbon accumulation in the Tungkal PSC required both using regional petroleum systems analysis and hydrocarbon charge modelling. While the Tungkal PSC operators had acquired high quality seismic data and drilled a number of wells, these were mainly focused on improving production from the existing field (Mengoepeh). More recent exploration-driven work highlighted the need for a new look at the hydrocarbon charge history but it was clear that little work had been done in the past few year to better understand exploration risk. This paper summarises the methodology employed and the results obtained, from a study, carried out in 2014-15, to better understand hydrocarbon accumulation within the current Tungkal PSC area. It has involved integration of available well and seismic data from the current and historical PSC area with published regional paleogeographic models, regional surface geology and structure maps, together with a regional oil generation model. This approach has allowed a better understanding of the genesis of the discovered hydrocarbons and identification of areas for future exploration interest.


Author(s):  
P.J. Lee

A basin or subsurface study, which is the first step in petroleum resource evaluation, requires the following types of data: • Reservoir data—pool area, net pay, porosity, water saturation, oil or gas formation volume factor, in-place volume, recoverable oil volume or marketable gas volume, temperature, pressure, density, recovery factors, gas composition, discovery date, and other parameters (refer to Lee et al., 1999, Section 3.1.2). • Well data—surface and bottom well locations; spud and completion dates; well elevation; history of status; formation drill and true depths; lithology; drill stem tests; core, gas, and fluid analyses; and mechanical logs. • Geochemical data—types of source rocks, burial history, and maturation history. • Geophysical data—prospect maps and seismic sections. Well data are essential when we construct structural contour, isopach, lithofacies, porosity, and other types of maps. Geophysical data assist us when we compile number-of-prospect distributions and they provide information for risk analysis.


2013 ◽  
Vol 53 (2) ◽  
pp. 483
Author(s):  
Marcus Lemberger ◽  
James Stockley ◽  
Tim Gibbons

After an initial 2010 stratigraphic, depositional environment and facies determination study of 75 wells in the Browse Basin, TGS has pushed this high-resolution project north into the Bonaparte Basin area. The study incorporates a further 165 wells located across the Ashmore Platform, Vulcan Sub-basin, Londonderry High, Malita and Calder Grabens, Sahul and Flamingo synclines, Laminara and Flamingo highs, Sahul Platform, Troubadour Terrace, and offshore Petrel Sub-basin areas. This multi-basin project has combined all the selected relevant public data into one interpretation study and is delivered in an integrated environment—wells are standardised and sequences interpreted. Once depositional environment and facies are allocated, multi-element maps are produced showing how the basin environments change through time and structural evolution. Stratigraphic interpretation has determined 37 sequences and 32 associated facies maps. Both Browse Basin (140,000 km2) and Bonaparte Basin (270,000 km2) are relatively less explored and at different ages in their exploration life-cycle. Both have proved to be oil and gas bearing across numerous different stratigraphic ages with a wide range of trapping and reservoir methods. This study aims to further aid North West Shelf exploration by delineating, among other facets, the presence or otherwise of rocks with reservoir and seal potential and by identifying structural elements such as the Petrel Sub-basin salt diapirs. This regional well data stratigraphic approach has been used across all the UK and Norway continental shelf hydrocarbon provinces. TGS sees the Australian North West Shelf as a province where this approach will further assist sub-surface understanding, and hence exploration success.


1995 ◽  
Vol 42 ◽  
pp. 34-46
Author(s):  
Kim Gunn Maver

Zechstein carbonates in Southern Jutland, Denmark, have been explored by 10 wells since 1952, and a total of more than 2000 km of 2D seismic data has been acquired by various contractors. Seismic modelling, based on all the well data, is used as an aid to predict the lateral distribution of porous Zechstein carbonate intervals from the seismic data. ID seismic modelling is used to define the maximum number of intervals detected by the seismic sections at well locations. The ID seismic modelling results are also used to derive 2D acoustic impedance models and corresponding synthetic seismograms. The seismic modelling results illustrate a number of diagnostic reflection patterns associated with the porous carbonate intervals. The predicted distribution of porous carbonate intervals is, however, found to be uncertain, as thickness and porosity variations of each interval cannot be distinguished. Furthermore, thin porous carbonate intervals are not detected by the seismic sections, and the seismic reflection patterns indicating the presence of porous carbonate intervals can be associated with other lithologies. Porous Ca-la, Ca-lb, Ca-2 and Ca-3 carbonate intervals are found to be detected by the seismic sections only in the Zechstein platform area, and only the porous Ca-2 carbonate interval can be mapped


EKSPLORIUM ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 125
Author(s):  
I Gde Sukadana ◽  
Heri Syaeful

ABSTRAKUranium di alam dapat terbentuk dalam berbagai tipe cebakan, sesuai dengan sumber, proses, dan lingkungan pengendapannya. Keterdapatan uranium di Sibolga pada batuan sedimen Formasi Sibolga merupakan suatu potensi yang layak untuk dikembangkan tetapi hingga saat ini belum diketahui pola pengendapan dan proses mineralisasi uranium tersebut. Penelitian bertujuan untuk mengetahui pola sebaran batuan dan keterdapatan anomali kadar uranium berdasarkan data geologi, radiometri permukaan, dan data log bor untuk mengetahui proses pengendapan batuan dan mineralisasi uranium. Keterdapatan mineralisasi berdasarkan data log bor tersebar dari satuan konglomerat alas (Kgl 1), satuan batupasir 1 (Bp 1), satuan konglomerat 2 (Kgl 2), dan satuan batupasir 2 (Bp 2) dengan ketebalan dan sebaran semakin ke atas semakin menipis. Sebaran mineralisasi pada bagian timur pada satuan batuan konglomerat 1 lebih didominasi oleh mineral detrital hasil pengendapan epigenetik berupa monasit yang terbentuk pada saat pembentukan granit sebagai batuan sumber. Pada satuan batuan di atasnya mineralisasi berbentuk pola alur (channel) yang berarah timur laut-barat daya, yang terbentuk secara syn-genetic dengan mineral berupa uraninite, carnotite, dan coffinite. Pengendapan batuan Formasi Sibolga berasal dari timur ke arah barat dan pengendapan uranium terjadi akibat perbedaan kondisi lingkungan pengendapan dari oksidasi di bagian timur menjadi lebih reduktif di bagian barat daya. Peningkatan kandungan material organik yang cukup tinggi pada lingkungan pengendapan bagian barat daya menyebabkan lingkungan pengendapan dalam kondisi reduksi.ABSTRACTUranium in nature formed in various deposit type, depends on its sources, process, and depositional environments. Uranium occurrence in Sibolga, hosted in sedimentary rocks of Sibolga Formation, is properly potential to develop; nevertheless, the depositional pattern and uranium mineralization process so far had not been recognized. The research aim is to determine the rock distribution patterns and the existence of uranium grade anomalies based on surface geology and borehole log data. Mineralization occurrences from borehole log data distributed from basalt conglomerate unit (Kgl 1), sandstone 1 unit (Bp 1), conglomerate 2 unit (Kgl 2), and sandstone 2 unit (Bp 2) with their distribution and thickness are thinning to the top. Mineralization distribution in the eastern area, mainly on Kgl 1 unit, dominated by detritus materials from epi-genetic depositional in the form of monazite which is formed along with the formation of granite as its source rock. Meanwhile, mineralization on the upper rocks units formed a channel pattern trending northeast-southwest, which formed in syn-genetic process consist of uraninite, carnotite, and coffinite. Sibolga Formation deposition originated from east to west and uranium deposit formed because of the differences of depositional environment from oxidation in the east to the more reductive in the southwest. The increasing of organic materials in southwest basin caused the reduction condition of depositional environment.


2021 ◽  
Vol 325 ◽  
pp. 08013
Author(s):  
Mawar Towan Lestari Ramli ◽  
Hendra Amijaya ◽  
Akmaluddin

Research on the Late Miocene of Pandua Formation shale in Andowia area, Southeast Sulawesi is fundamental because it is considered to have the potential as a source rock in Manui Basin. This study aimed to determine the lithofacies and its potential as petroleum source rock using megascopic, petrographic, and total organic carbon analyses in Pandua Formation shale. Based on the megascopic and petrographic analysis of outcrops, the shale can be subdivided into 11 lithofacies consists of clayey shale, massive claystone, clastic detritus-rich claystone, massive mudstone, mica-rich mudstone, iron oxide-rich mudstone, low-angle laminated mudstone, massive siltstone, carbon-rich massive siltstone, laminated siltstone, and carbon-rich laminated siltstone. The results of the analysis of 19 samples of shale showed that the total organic carbon (TOC) content was classified as poor to excellent (<0.5%- >4%). The lithofacies with a high concentration of TOC are carbon-rich massive siltstone and carbon-rich laminated siltstone. Both lithofacies were categorized as potentially excellent source rock which the TOC value content is 5.78% and 5.74%.The result implies the better understanding of the depositional environment and hydrocarbon accumulation potential of the Manui basin for future exploration.


1995 ◽  
Vol 35 (1) ◽  
pp. 296
Author(s):  
J. S. Rasidi

The Late Cretaceous Withnell Formation has attracted very little exploration attention because of the perception that it has poor hydrocarbon potential. This unfavourable perception has arisen from the fact that very little is known about its depositional environment and lithofacies and therefore, its petroleum prospectivity.A sudden fall of relative sea level occurred at the end of the Santonian, and was followed by the deposition of the siliciclastic Withnell Formation. The occurrence of a number of channels and canyons at the base of the formation, over the old shelf and slope on the southern margin of the sub-basin, supports the hypothesis that the Withnell Formation began as a lowstand systems tract. The thickness distribution of the formation and the progradation direction of seismic packages suggest a southeasterly provenance. Correlation of seismic data and well logs, and rock descriptions demonstrate the presence of units deposited during increasing water depths and subsequent highstand systems tract.Much more information, both seismic and well data, is required to establish the facies distribution within the Withnell Formation which may contain sand-prone lowstand facies such as basinfloor or slope fans. The presence of such reservoir facies would enhance the petroleum prospectivity of the Withnell Formation.


2016 ◽  
Vol 5 (3) ◽  
Author(s):  
Faturachman Faturachman ◽  
Siti Marina

Pengambilan data seismik pantul dangkal di Perairan Sumenep dan pemboran inti sedalam 42 meter di pesisir selatan Sumenep dilakukan untuk memperlihatkan keadaan lapisan batuan dangkal. Profil seismik pantul dangkal memperlihatkan runtunan seismik A berumur Pra Kuarter dan runtunan seismik B berumur Kuarter – Resen. Runtunan A telah mengalami perlipatan dan pensesaran di mana di beberapa tempat diterobos oleh diapir lumpur, bahkan sampai ke permukaan laut. Runtunan B memperlihatkan pantulan transparan dan di beberapa tempat diterobos oleh diapir lumpur. Bor BH-2 memperlihatkan lempung hitam berumur Holosen – Resen yang ditemukan di atas Formasi Pamekasan yang berumur Pleistosen. Lempung hitam ini tersebar pada kedalaman 13.5 - 41 meter dengan kandungan gas metan sekitar 0.1 % mol yang terdeteksi pada kedalaman 17 – 18.5 meter dan 35.85 – 38.15 meter, serta didominasi oleh bakteri metanogenik Methanosarcina frisia yang menunjukkan lingkungan pengendapan estuaria. Kadar gas biogenik dangkal pada lempung hitam berjumlah kecil sehingga tidak potensial untuk dieksplorasi lebih lanjut. Kurangnya potensi gas biogenik dangkal di Perairan Sumenep kemungkinan disebabkan oleh proses tektonik, kondisi stratigrafi (sistem estuaria) dan struktur (rembesan gas ke atmosfer melalui patahan-patahan minor dan diapir lumpur) yang berpengaruh pada jalur migrasi dan akumulasi gas biogenik. Kata kunci: gas biogenik dangkal, migrasi, akumulasi, estuaria, diapir lumpur, lempung hitam Shallow seismic data acquisition in Sumenep waters and coring to 42 meter depth in shouthern coast of Sumenep were carried out to investigate a shallow sediment layers. The shallow reflection profiles indicate seismic sequence A of pre Quaternary and seismic sequence B of Quartenary Recent. Seismic sequence A was folded and faulted, whre in some places were intruded by mud diapirs which expose above water surface. Seismic sequence B indicates transparency reflection and in some places was intruded by mud diapirs. Core BH-2 indicates Holocene-Recent blacky clay that rest on the Pleistocene Pamekasan Formation. This blacky clay distribute at 13,5 – 41,5 meters depth with methane content about 0.1 % mol that detected at 17 – 18,5 meters depth and 35.05 – 38.15 meters depth, which is also dominated by metanogenic methanosarcinafrisia that indicates an estuaria depositional environment. The content of shallow biogenic gas within black clay is small, therefore it is inpotential to be futher explored. The lack of shallow biogenic gas in Sumenep waters. Key word : Shallow Biogenic Gas, Migration, Accumulation, Estuary, Mud diapir, Black clay.


2021 ◽  
pp. 4779-4790
Author(s):  
Marwa H. Shehab ◽  
Kamal K. Ali

     A seismic study was conducted to re-interpret the Qasab and Jawan Oil fields in northwestern Iraq, south of the city of Mosul, by reprocessing many seismic sections of a number of field surveys by using the Petrel software. Two reflectors, represented by the Hartha formation, deposited during the Cretan age, and the Euphrates formation, formed during the Tertiary age, were delineated to stabilize the structural picture of these fields. The stratigraphic study showed that the Qasab and Jawan fields represent areas of hydrocarbon accumulation. Seismic attribute analysis showed low values of instantaneous frequency in the areas of hydrocarbon accumulation. Instantaneous phase was used to determine the limits of the sequence, the nature of sedimentation, and the type of vanishing, i.e. onlap vs. toplap. Low instantaneous amplitude values were recorded, indicating hydrocarbon reservoirs in the studied area. Various other seismic stratigraphic features were studied , including the distribution mound, flat spot, and channels in the two formations, but they were discontinuous because of the tectonic effects. These activities explain reasonably the distribution of hydrocarbons in the studied area.


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