scholarly journals Assessment of Paleocene to lower Oligocene formations and basement to estimate the potential hydrocarbon reservoirs using seismic inversion: a case study in the Upper Assam Shelf, India

2021 ◽  
Author(s):  
Neha Rai ◽  
Dip Kumar Singha ◽  
Rima Chatterjee
Keyword(s):  
Acoustic Impedance ◽  
Seismic Inversion ◽  
High Porosity ◽  
North East India ◽  
Hydrocarbon Reservoir ◽  
North East ◽  
Lower Oligocene ◽  
Potential Reservoir ◽  
Well Data ◽  
Granite Basement

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.

scholarly journals Pore Type and Porosity Distribution of Carbonate Reservoir Based on 3D Seismic Inversion in “P” Field Salawati Basin

2019 ◽  
Vol 125 ◽  
pp. 15002
Author(s):  
Avishena Prananda ◽  
Mohammad Syamsu Rosid ◽  
Robet Wahyu Widodo
Keyword(s):  
Acoustic Impedance ◽  
Carbonate Rock ◽  
Sedimentary Rock ◽  
Seismic Inversion ◽  
Carbonate Reservoir ◽  
High Porosity ◽  
3D Seismic ◽  
Impedance Distribution ◽  
Pore Types ◽  
Type Classification

Overall, carbonate rock has complex and more heterogeneous physical characteristic, compared to siliciclastic sedimentary rock. One parameter, which distinguishes carbonate rock and siliciclastic is pore structure/pore type. The heterogeneity and complexity of carbonate reservoir pore type are affected by the sedimentation process and the diagenesis process. Pore type classification is divided into three: interparticle, stiff, and crack. Therefore, carbonate pore type determination becomes important to enhance drilling success. This paper explains pore types prediction, porosity, and acoustic impedance on carbonate reservoir. The Differential Effective Medium (DEM) method to analyze carbonate reservoir pore type has been applied. DEM method generates bulk and shear modulus parameters to create carbonate Vp and Vs model based on pore type. We also do a 3D seismic inversion to create acoustic impedance distribution, porosity, and pore type. Afterward, we made cube porosity and pore type cube by using geostatistics method to provide a better result. Moreover, this study shows low impedance value correlates with high porosity value and enhancement of porosity value correlates with crack and interparticle pore type on “P” field, Salawati Basin.

High-resolution acoustic impedance inversion to characterize turbidites at Marlim Field, Campos Basin, Brazil

2014 ◽  
Vol 2 (3) ◽  
pp. T143-T153 ◽  
Author(s):  
Tatiane M. Nascimento ◽  
Paulo T. L. Menezes ◽  
Igor L. Braga
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
Acoustic Impedance ◽  
Structural Information ◽  
Low Frequency ◽  
Seismic Inversion ◽  
Background Model ◽  
Rock Properties ◽  
High Porosity ◽  
Campos Basin

Seismic inversion is routinely used to determine rock properties, such as acoustic impedance and porosity, from seismic data. Nonuniqueness of the solutions is a major issue. A good strategy to reduce this inherent ambiguity of the inversion procedure is to introduce stratigraphic and structural information a priori to better construct the low-frequency background model. This is particularly relevant when studying heterogeneous deepwater turbidite reservoirs that form prolific, but complex, hydrocarbon plays in the Brazilian offshore basins. We evaluated a high-resolution inversion workflow applied to 3D seismic data at Marlim Field, Campos Basin, to recover acoustic impedance and porosity of the turbidites reservoirs. The Marlim sandstones consist of an Oligocene/Miocene deepwater turbidite system forming a series of amalgamated bodies. The main advantage of our workflow is to incorporate the interpreter’s knowledge about the local stratigraphy to construct an enhanced background model, and then extract a higher resolution image from the seismic data. High-porosity zones were associated to the reservoirs facies; meanwhile, the nonreservoir facies were identified as low-porosity zones.

scholarly journals Assessment of updated low frequency model in delineating bypassed hydrocarbon reservoir: A 4D seismic study of ’X’ - field, offshore, Niger Delta, Nigeria

2020 ◽  
Vol 13 (36) ◽  
pp. 3738-3753 ◽  
Author(s):  
Aniefiok Sylvester Akpan ◽  
Keyword(s):  
Acoustic Impedance ◽  
Deterministic Model ◽  
Low Frequency ◽  
Seismic Inversion ◽  
Fluid Replacement ◽  
Inversion Method ◽  
Frequency Model ◽  
Hydrocarbon Reservoir ◽  
Model Based ◽  
4D Seismic

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

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
Keyword(s):  
Acoustic Impedance ◽  
Seismic Inversion ◽  
Effective Porosity ◽  
P Wave ◽  
Hydrocarbon Accumulation ◽  
Map Algebra ◽  
Petrophysical Analysis ◽  
Main Layer ◽  
Hydrocarbon Reservoir ◽  
Porous Zone

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.

scholarly journals Linking Geostatistical Methods: Co-Kriging – Principal Component Analysis (PCA); with Integrated Well Data and Seismic Cross Sections for Improved Hydrocarbon Prospecting (Case Study: Field X)

2018 ◽  
Vol 17 (1) ◽  
Author(s):  
Ryan Bobby Andika ◽  
Haritsari Dewi
Keyword(s):  
Principal Component Analysis ◽  
Acoustic Impedance ◽  
Principal Component ◽  
Component Analysis ◽  
Seismic Inversion ◽  
Gas Production ◽  
Depth Range ◽  
Kriging Method ◽  
Well Data

In this era of globalization, the demand for energy is rising in tandem with social and economic development throughout the world. Current hydrocarbon demand is much greater than domestic crude oil and natural gas production. In order to bridge the gap between energy supply and demand, it is imperative to accelerate exploration activities and develop new effective and efficient techniques for discovering hydrocarbons. Therefore, this study presents a new method for integrating seismic inversion data and well data using geostatistical principles that allow for the high level of processing and interpretation expected nowadays. The main part of this paper will concern the preparation and processing of the input data, with the aim of constructing a map of hydrocarbon-potency distribution in a certain horizon. It will make use of principal component analysis (PCA) and the co-kriging method. In the case study of Field X, we analyze a single new dataset by applying PCA to every existing well that contains multivariate rock-physics data. The interpretation that can be extracted from the output gives us information about the hydrocarbon presence in a particular depth range. We use that output as our primary dataset from which our research map is constructed by applying the co-kriging method. We also rely on an acoustic impedance dataset that is available for a certain horizon to fulfill the co-kriging interpolation requirement. All of the acoustic impedance data and output data that result from the application of PCA in a particular horizon give strong correlation factors. Our resulting final map is also validated with information from proven hydrocarbon discoveries. It is demonstrated that the map gives accurate information suggesting the location of hydrocarbon potency, which will need some detailed follow-up work to enhance the distribution probabilities. This method can be considered for hydrocarbon prediction in any area of sparse well control.

scholarly journals Hydrocarbon Reservoir Characterization of ‘UDI’ Field, Western Niger Delta

2020 ◽  
pp. 12-21
Author(s):  
N. E. Osuya ◽  
J. O. Ayorinde
Keyword(s):  
Niger Delta ◽  
Good Control ◽  
Sequential Gaussian Simulation ◽  
Computational Techniques ◽  
High Porosity ◽  
Simulation Algorithm ◽  
Reservoir Properties ◽  
Hydrocarbon Reservoir ◽  
Potential Reservoir ◽  
Net To Gross

The increasing demand for petroleum products has posed a challenge to the search for oil and gas. This search for hydrocarbon has developed due to advances in computational techniques to evaluate the probability of hydrocarbon proneness of a basin, thereby limiting the risk factor associated with hydrocarbon. This study was therefore designed to assess the hydrocarbon potential and generate a static reservoir model of UDI Field, Onshore Niger Delta. Well, the correlation was carried out to establish stratigraphic continuity of the reservoir sand bodies. The identified potential reservoir intervals were tied to the seismic data using available check shot survey data. With a good match achieved, seismic events were interpreted through paying attention to reflection continuity, amplitude and frequency. Interpreted horizons were converted to surfaces using a convergent interpolation algorithm. Faults within the Field showed a dominant East-West trend with two (2) major faults and five (5) minor ones. A Pixel-based facies model was built based on the normal distribution of the upscaled lithofacies log using the Sequential Indicator Simulation algorithm. Petrophysical models were built by constraining the petrophysical logs to the facies models using Sequential Gaussian simulation algorithm.  Four potential reservoir intervals, A100, A125, A150 and A200 were delineated. Average petrophysical parameters were computed for all the four intervals and the results revealed the reservoir intervals to be of good quality. Sand A100 has the highest average porosity value of 29.4%, while Sand A200 has the lowest value of 25.3%. Net-to-gross ratio also follows the pattern of decreasing value with depth. Sand A150 has the highest average gross thickness value, 170.4 m, while Sand A200 has the least thickness of 80.5 m. The net-to-gross ratio preserved the pattern of gross thickness and this resulted in Sand A150 still having the highest Net thickness and Sand A200 having the least Net sand thickness. The relatively large net sand thicknesses, high net-to-gross ratio values and the high porosity values all support the reservoir intervals within UDI Field to be of good quality. Extrapolations of reservoir properties away from good control honored the geological interpretation of reservoir Sand A125 thereby reducing the subsurface reservoir uncertainties. The availability of pressure data of the reservoir will help in establishing whether the reservoir is compartmentalized and hence the model can be updated to accommodate the effect of compartmentalization.

Past Verses Present; Metamorphosis in Different Spheres of Guwahati: A Study of Srutimala Duara’s Mindprints of Guwahati

2020 ◽  
Vol 8 (2) ◽  
pp. 13
Author(s):  
Ankita Pandey
Keyword(s):  
Point Of View ◽  
Areca Nut ◽  
Medieval Period ◽  
River Bank ◽  
North East India ◽  
North East ◽  
The North ◽  
Indian State ◽  
The City ◽  
Beautiful City

Guwahati derives its name from the Assamese word “Guwa” means areca nut and “Haat” means market. However, the modern Guwahati had been known as the ancient Pragjyotishpura and was the capital of Assam under the Kamrupa kingdom. A beautiful city Guwahati is situated on the south bank of the river Bramhaputra. Moreover, It is known as the largest city in the Indian state of Assam and also the largest metropolis in North East India. It has also its importance as the gateway to the North- East India. Assamese and English are the spoken languages in Guwahati.  In 1667, the Mogul forces were defeated in the battle by the Ahom forces commanded by Lachut Barphukan. Thus, in a sense Guwahati became the bone of contention among the Ahoms, Kochas and the Moguls during the medieval period.  Guwahati the administrative headquarters of Lower Assam with a viceroy or Barbhukan was made by the Ahom king.  Since 1972 it has been the capital of Assam. The present paper will discuss the changes happened in Guwahati over the period of late 1970s till the present time. It will focus on the behavior of people, transformed temples, Panbazar of the city, river bank of Bramhaputra, old Fancy Bazaar, chaotic ways, festivals and seasons including a fifth man made season etc. It will also deal how over the years a city endowed with nature’s gifts and scenic views, has been changing as “a dirty city”. Furthermore, it will also present the insurgencies that have barged into the city. The occurrence of changes will be discussed through the perspective and point of view of Srutimala Duara as presented in her book Mindprints of Guwahati.

Sign in / Sign up

Export Citation Format

Share Document