scholarly journals Use of spectral decomposition technique for mapping geologic features of ‘Reigh’ field, Onshore Niger Delta

2021 ◽  
Vol 10 (1) ◽  
pp. 1-7
Author(s):  
O.K. Olaleye ◽  
P.A. Enikanselu ◽  
M.A. Ayuk
Keyword(s):  
Seismic Data ◽  
Spectral Decomposition ◽  
Niger Delta ◽  
Thickness Variation ◽  
Decomposition Technique ◽  
Meandering Channel ◽  
Seismic Resolution ◽  
Geological Features ◽  
Bed Thickness ◽  
3D Seismic Data

Spectral Decomposition Technique based on Short-Window Discrete Fourier Transform (SWDFT) was applied to threedimensional (3D) seismic data obtained from ‘Reigh’ field, onshore Niger Delta with a view to enhancing stratigraphic interpretation for geological features which are beyond seismic resolution. Two sands units from the study area were studied to produce spectrally decomposedsurfaces. The result of the study revealed thin bed layer at the centre of the field on sand unit ‘A’. Sand-filled meandering channel wasdetected and highlighted in the northern part of sand unit ‘B’ based on Red-Green-Blue frequency modulation of spectral  decomposition. The study has enhanced geologic understanding of the field by improving thin bed resolution, highlighting geologic features and displaying bed thickness variation of studied sand units in the study area. Keywords: geologic features, Niger Delta, seismic data, spectral decomposition

scholarly journals Evaluation of seismic attributes for reservoir characterization over Edi field, Niger delta, Nigeria using 3d seismic data

2020 ◽  
Vol 8 (2) ◽  
pp. 168
Author(s):  
Nyeneime O. Etuk ◽  
Mfoniso U. Aka ◽  
Okechukwu A. Agbasi ◽  
Johnson C. Ibuot
Keyword(s):  
Seismic Data ◽  
Niger Delta ◽  
Reservoir Characterization ◽  
Seismic Attributes ◽  
3D Seismic ◽  
Root Mean Square Amplitude ◽  
Phase Gradient ◽  
Major Fault ◽  
Seismic Sections ◽  
3D Seismic Data

Seismic attributes were evaluated over Edi field, offshore Western Niger Delta, Nigeria, via 3D seismic data. Manual mappings of the horizons and faults on the in-lines and cross-lines of the seismic sections were done. Various attributes were calculated and out put on four horizons corresponding to the well markers at different formations within the well were identified. The four horizons identified, which includes: H1, H2, H3 and H4 were mapped and interpreted across the field. The operational agenda was thru picking given faults segments on the in–line of seismic volume. A total of five faults coded as F1, F2, F3, F4 and F5, F1 and F5 were the major fault and were observed as extending through the field. Structural and horizon mappings were used to generate time structure maps. The maps showed the various positions and orientations of the faults. Different attributes which include: root mean square amplitude, instantaneous phase, gradient magnitude and chaos were run on the 3D seismic data. The amplitude and incline magnitude maps indicate direct hydrocarbon on the horizon maps; this is very important in the drilling of wells because it shows areas where hydrocarbons are present in the subsurface. The seismic attributes revealed information, which was not readily apparent in the raw seismic data.   

Structure of the footwall of a listric fault system revealed by 3D seismic data from the Niger Delta

2011 ◽  
Vol 24 (1) ◽  
pp. 107-123 ◽  
Author(s):  
Dominic Maloney ◽  
Richard Davies ◽  
Jonathan Imber ◽  
Stephen King
Keyword(s):  
Seismic Data ◽  
Niger Delta ◽  
Fault System ◽  
3D Seismic ◽  
Listric Fault ◽  
3D Seismic Data

scholarly journals Transition zones analysis using empirical capillary pressure model from well logs and 3D seismic data on ‘Stephs’ field, onshore, Niger Delta, Nigeria

2019 ◽  
Vol 10 (3) ◽  
pp. 1227-1242
Author(s):  
O. Abiola ◽  
F. O. Obasuyi
Keyword(s):  
Capillary Pressure ◽  
Seismic Data ◽  
Niger Delta ◽  
Time Structure ◽  
Well Logs ◽  
3D Seismic ◽  
Seismic Section ◽  
Transition Zones ◽  
Mobile Water ◽  
3D Seismic Data

AbstractCapillary pressure is an important characteristic that indicates the zones of interaction between two-phase fluids or fluid and rock occurring in the subsurface. The analysis of transition zones (TZs) using Goda (Sam) et al.’s empirical capillary pressure from well logs and 3D seismic data in ‘Stephs’ field, Niger Delta, was carried out to remove the effect of mobile water above the oil–water contact in reservoirs in the absence of core data/information. Two reservoirs (RES B and C) were utilized for this study with net thicknesses (NTG) ranging from 194.14 to 209.08 m. Petrophysical parameters computed from well logs indicate that the reservoirs’ effective porosity ranges from 10 to 30% and the permeability ranges from 100 to > 1000 mD, which are important characteristics of good hydrocarbon bearing zone. Checkshot data were used to tie the well to the seismic section. Faults and horizons were mapped on the seismic section. Time structure maps were generated, and a velocity model was used to convert the time structure maps to its depth equivalent. A total of six faults were mapped, three of which are major growth faults (F1, F4 and F5) and cut across the study area. Reservoir properties were modelled using SIS and SGS. The capillary pressure log, curves and models generated were useful in identifying the impact of mobile water in the reservoir as they show the trend of saturating and interacting fluids. The volume of oil estimated from reservoirs B and C without taking TZ into consideration was 273 × 106 and 406 × 106 mmbbls, respectively, and was found to be higher than the volume of oil estimated from the two reservoirs while taking TZ into consideration which was 242 × 106 and 256 × 106 mmbbls, respectively. The results have indicated the presence of mobile water, which have further established that conventionally recoverable hydrocarbon (RHC) is usually overestimated; hence, TZ analysis has to be performed for enhancing RHC for cost-effective extraction and profit maximization.

scholarly journals Mapping of thin sandstone reservoirs in bisol field, Niger delta, Nigeria using spectral decomposition technique

2020 ◽  
Author(s):  
Oyelowo Gabriel Bayowa ◽  
Theophilus Aanuoluwa Adagunodo ◽  
Adeola Opeyemi Oshonaiye ◽  
Bisola Stella Boluwade
Keyword(s):  
Spectral Decomposition ◽  
Niger Delta ◽  
Decomposition Technique ◽  
Sandstone Reservoirs

scholarly journals Application of Spectral Decomposition and RGB Blending for Delineation of “S” Channel At Asri Basin

2020 ◽  
Vol 35 (2) ◽  
Author(s):  
Swasty Aninda Piranti ◽  
Shaska Zulivandama ◽  
Noor Cahyo Dwi Aryanto ◽  
Andi Agus Nur ◽  
Ildrem Syafri
Keyword(s):  
Spectral Decomposition ◽  
Low Frequency ◽  
Estuarine System ◽  
Channel System ◽  
Meandering Channel ◽  
Hydrocarbon Reservoir ◽  
System A ◽  
Seismic Resolution ◽  
Braided Channel ◽  
Depositional System

Gita member is part of Talang Akar Formation is known as hydrocarbon reservoir at Asri Basin, eastern part of South Sumatra. This formation consists of several depositional systems such as braided channel, meandering channel, fluvial-deltaic, and estuarine system. A channel system was an interesting system developed in the Asri Basin, however, to get the channel distribution in Asri Basin is quite challenging because the thickness of the channels caused its appearance is generally close or under seismic resolution, the existence of coal below our target also affects the impression of “S” sand on seismic data. In this study, spectral decomposition and RGB Blending have been successful to identify “S” sand. RGB Blending map is extracted from 15 Hz as low frequency, 45 Hz as middle frequency, and 75 Hz as high frequency. Our interpretation was applied at RGB Blending map and reveal the “S” sand is classified as a meandering channel depositional system with the main direction of the channel is Northeast – Southwest. 

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