scholarly journals PERHITUNGAN CADANGAN HIDROKARBON FORMASI TALANG AKAR MENGGUNAKAN ANALISIS PETROFISIKA DAN SEISMIK INVERSI AI DENGAN PENDEKATAN MAP ALGEBRA PADA LAPANGAN BISMA, CEKUNGAN SUMATERA SELATAN

2020 ◽  
Vol 4 (3) ◽  
pp. 3-14
Author(s):  
Egi Ramdhani ◽  
Ordas Dewanto ◽  
Karyanto Karyanto ◽  
Nanang Yulianto

As a potential field in hydrocarbon prospect, Bisma field, the part of south Sumatra basin, can be evaluated in order to mapping the hydrocarbon accumulation and total reserve calculation purpose. Petrophysical analysis is an analytic method to evaluate the formation which sensitive with vertical contrast. Main output of this analysis is the compilation of some property value that useful on reservoir quality justification. Seismic acoustic impedance inversion is a method that can be used to define the distribution of porous zone as a hydrocarbon reservoir. This inversion result is the distribution of prospect area map by using combination of interpretation in AI map, density map and P-wave map. Map algebra is a calculation method that used to map that has the same grid number. By using those three methods, the reserve of hydrocarbon accumulation on Bisma field can be calculated. Petrophysical analysis results the indication of hydrocarbon in target zone is oil on two main layer, S and W3. Meanwhile, seismic inversion interpreting the distribution of porous zone is between 7400 – 9315 m/s*gr/cc in AI value context. Then, the effective porosity, Sw value and isopach are spread laterally using picked horizon and seismic acoustic impedance result as a guide, also, calculating the reserve. Layer S accumulating 21.1 million barrel oil and W3 accumulating 50.2 million barrel oil. This value resulted by aplicating Original Oil in Place (OOIP) equation on property map with map algebra approachment.

Author(s):  
Neha Rai ◽  
Dip Kumar Singha ◽  
Rima Chatterjee

AbstractThe upper Assam shelf is a self-slope basin in north-east India, filled with nearly 7 km of sedimentary rocks of tertiary period with the granite basement and various oil fields along the border of the Naga thrust. The major producing fields are structural and strati-structural. The study area is placed in between the Mikir hills and Naga thrust. The objective of the study is to identify potential hydrocarbon reservoir zones in the geologically complex south upper of the Assam shelf using estimates of acoustic impedance and porosity derived by 3D post-stack seismic inversion. Well data, such as sonic velocity and density logs, from two wells (namely, KA and TE) are used in the inversion and validation of results. Inversion results are used to build a geological model in the form of acoustic impedance from which we derive 3D porosity cube which are used for hydrocarbon potential in the Paleocene to lower Oligocene sands, and the Precambrian basement. Although the amplitude maps provide an indication of potential reservoirs, the extent of these zones are much better identified in the inverted impedance maps and the corresponding estimated high-porosity zones. The analysis predicted the potential reservoir rocks in the Sylhet, Kopili and Barail formations, in which the Sylhet and Kopili appear to have good potential zones. Near the vicinity of the Naga thrust belt, the proximity of potential reservoir is predicted in the Kopili, Sylhet formation and in the fractured basement, respectively.


2020 ◽  
Vol 13 (36) ◽  
pp. 3738-3753 ◽  
Author(s):  
Aniefiok Sylvester Akpan ◽  

Aim/objectives: The aim of this research is, to use Time lapse (4D) seismic and investigate the influence of low frequency update in deterministic model-based seismic inversion employed in delineating a prospect saturated with bypassed hydrocarbon accumulation. Method: The dataset employed in this study incorporates 4D seismic volumes with fifteen (15) years production, interval between 2001 baseline and 2016 monitor seismic vintages. The inversion was carried out using full bandwidth of the updated low frequency and bandpass filtered low frequency approaches. The seismic vintages (baseline and monitor) were simultaneously inverted into acoustic impedance volumes for the two approaches. The formation fluid and lithology were discriminated through fluid replacement modelling (FRM) based on the colour separation between brine and gas saturation scenarios. Findings: The two inversion methods employed reveal six (6) zones suspected to be saturated with bypassed hydrocarbons. The delineated bypassed zones are masked in the full bandwidth approach,depicting the effect of the updated low frequency model. Meanwhile, the bandpass filtered approach result presents a better delineated bypassed reservoir as the zones are more pronounced when compared with the full bandwidth approach. Porosity estimate reveals that the bandpass filtered approach is characterized with excellent porosity in the suspected bypassed zones. The results equally gave more reliable and full delineated bypassed zones. Originality and novelty: The dataset employed in this study were obtained from a producing hydrocarbon field which, interest is to maximize the production of oil/gas. The study will bridge the inherent gab observed in using model-based seismic inversion approach to analyse and interpret seismic data in order to delineate hydrocarbon prospects. The research reveals that,the model-based seismic inversion method is still very effective in delineating hydrocarbon prospect when the updated low frequency is bandpass filtered to remove the model effect which influences the inverted acoustic impedance results. Keywords: Porosity; frequency; bypassed; reservoir and impedance


2020 ◽  
pp. 3294-3307
Author(s):  
Ahmed S. Al-Banna ◽  
Nowfal A. Nassir ◽  
Ghazi H. Al-Sharaa

A comparison was conducted between two wells, Kt-1and Kt-2, in Kumait and two wells, Du-1and Du-2, in Dujaila oil fields that belong to Mishrif formation, southern Iraq.  Seismic inversion method was employed to detect oil and water reservoirs. The comparison included the behavior of acoustic impedance (AI) of fluids and the lithology with related petrophysical properties. The values of water saturation, Shale volume (Vsh), and effective porosity were compared between the AI,  two fluid reservoirs. It was found that the AI value for the oil reservoir unit is relatively low to medium, whereas it was relatively medium for the water reservoir. Effective porosity value showed, in general, an increase in the oil reservoir and a slightly decrease in the water reservoir. The Vsh and water saturation (Sw) values of the oil reservoir unit were in general lower than those in the water reservoir, which indicates the presence of hydrocarbons accumulation. The lithology and porosity are the main factors affecting the acoustic impedance values. Despite the small difference in density between oil and water, these two fluids still show perceptible variation in their properties.  


2013 ◽  
Vol 477-478 ◽  
pp. 1088-1091
Author(s):  
Xu Tao Li

Seismic inversion includes different methods. Acoustic impedance inversion is an ordinary method to find reservoir in oil and gas exploration, but in some area the Acoustic impedance inversion is not effective on different geologic setting. In this paper we found the Gamma Ray is effective on distinguish the sand and shale bed by using P-wave and Gamma Ray crossplot analysis. The final Gamma Ray seismic inversion results show that Gamma Ray seismic inversion can improve the vertical resolution. A satisfactory inversion effect is obtained in HM area.


2021 ◽  
Vol 36 (1) ◽  
Author(s):  
Daffa Dzakwan Shiddiq ◽  
Eleonora Agustine ◽  
Tumpal Bernhard Nainggolan ◽  
Imam Setiadi ◽  
Shaska Zulivandama

Tarakan Basin area of Bunyu Island Waters is known to have hydrocarbon potential with complex geological structures. This study aims to determine reservoir characterization and to obtain prospect of hydrocarbon reservoir zones based on petrophysical and seismic stratigraphy analysis with reference to Well DDS-1 and 2D seismic Line S88. Petrophysical analysis results 3 zones that have potential as hydrocarbon reservoirs. Based on petrophysical quantitative analysis, Zone 1 has values of 52.25% for shale volume, 18.48% for effective porosity, 39.84% for water saturation and 13.03 mD for permeability. Zone 2 has values of 54.66% for shale volume, 10.27% for effective porosity, 40.9% for water saturation and 1.14 mD for permeability. Zone 3 has values of 49.22% for shale volume, 9.33% for effective porosity, 56.33% for water saturation and 0.22 mD for permeability. Out of these three reservoir zones in Well DDS- 1, Zone 1 has the prospect of hydrocarbons which is supported by the net pay value. Based on seismic stratigraphy interpretation, the reservoir zone is correlated to the Tabul Formation, which comprises calcareous clay and limestone.


Author(s):  
Oluwatoyin Khadijat Olaleye ◽  
Pius Adekunle Enikanselu ◽  
Michael Ayuk Ayuk

AbstractHydrocarbon accumulation and production within the Niger Delta Basin are controlled by varieties of geologic features guided by the depositional environment and tectonic history across the basin. In this study, multiple seismic attribute transforms were applied to three-dimensional (3D) seismic data obtained from “Reigh” Field, Onshore Niger Delta to delineate and characterize geologic features capable of harboring hydrocarbon and identifying hydrocarbon productivity areas within the field. Two (2) sand units were delineated from borehole log data and their corresponding horizons were mapped on seismic data, using appropriate check-shot data of the boreholes. Petrophysical summary of the sand units revealed that the area is characterized by high sand/shale ratio, effective porosity ranged from 16 to 36% and hydrocarbon saturation between 72 and 92%. By extracting attribute maps of coherence, instantaneous frequency, instantaneous amplitude and RMS amplitude, characterization of the sand units in terms of reservoir geomorphological features, facies distribution and hydrocarbon potential was achieved. Seismic attribute results revealed (1) characteristic patterns of varying frequency and amplitude areas, (2) major control of hydrocarbon accumulation being structural, in terms of fault, (3) prospective stratigraphic pinch-out, lenticular thick hydrocarbon sand, mounded sand deposit and barrier bar deposit. Seismic Attributes analysis together with seismic structural interpretation revealed prospective structurally high zones with high sand percentage, moderate thickness and high porosity anomaly at the center of the field. The integration of different seismic attribute transforms and results from the study has improved our understanding of mapped sand units and enhanced the delineation of drillable locations which are not recognized on conventional seismic interpretations.


2021 ◽  
Author(s):  
David Freire-Lista ◽  
Bruno Campos ◽  
Patricia Moreira da Costa

<p>Granite is the most important building stone in the north of Portugal. The importance of the stones in this region is evidenced by the pre-Roman roots Mor (r), Mur (r) and Mour of place names such as Montemuro, Moreiras, Mouçós, and Mourelhe. These roots indicate the existence of building stones used since ancient times in these places.</p><p>The quarries of the main building stones of historical buildings were generally in the vicinity of the buildings. Formerly, stonemasons carved mason's marks on ashlars. The mason's marks are lapidary signs to indicate the work carried out by each one. The mason's marks are generally symbolised by the initial of the stonemason's name. They are often found on dressed stones in buildings and in other public structures.</p><p>Nossa Senhora de Guadalupe church of Mouçós (possibly 16<sup>th</sup> century) has typical characteristics from the late Romanesque. It is located in Vila Real (North of Portugal). It is made up of three volumes: a single nave, a lower rectangular apse, and a sacristy attached to the apse. The exterior of this church is preserved almost unaltered in its original state. Each of the granite ashlars that make up this church has a mason's mark in the center of its face.</p><p>The mason's marks of the church have been identified; all the ashlars with visible mason's marks have been mapped, and a glyptographic study has been carried out. This has made it possible to calculate the number of stonemasons that worked in the construction of the church and the number of ashlars that were transported in each carriage, and to determine the construction phases of the church.</p><p>Eight cubic samples have been cut to calculate the granite’s hydric properties (effective porosity, water absorption and bulk density) according to UNE-EN:1936. Ultrasound wave velocity was measured according to UNE-EN:14579. Furthermore, three thin sections have been made to characterise the granite petrographically under a polarisation microscope Leica DM-4500-P. A mosaic of photomicrographs has been made to evaluate the petrographic properties.</p><p>There are six main types of mason's marks in Nossa Senhora de Guadalupe Church. All quarrymen extracted the stones from the same quarry, or from nearby quarries. The mean effective porosity of the building granite is 3.2%±0.3, and the mean water absorption is 1.2%±0.1. Its mean bulk density is 2566 kg/m<sup>3</sup>±61.0 and its ultrasound P wave velocity is 2920 m/s±98.3.</p><p>The mason's marks are preserved because of the excellent petrographic and petrophysical properties of Mouçós granite. Further, Nossa Senhora de Guadalupe church was protected with lime plaster during the past centuries, and the plaster was not removed with the projection of abrasive particles.</p><p>The use of analytical techniques such as petrography, ultrasonic P wave velocity and the determination of hydric properties will guarantee the quality and durability of a sustainable restoration.</p><p>The historical quarries, forms of traditional stone extraction and uses of Mouçós granite constitute a heritage that must be safeguarded.</p><p>Acknowledgements: The Fundação para a Ciência e a Tecnologia (FCT) of Portugal. CEECIND/03568/2017.</p>


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