scholarly journals Reservoir characterization and volumetric estimation of reservoir fluids using simulation and analytical methods: a case study of the coastal swamp depobelt, Niger Delta Basin, Nigeria

Author(s):  
B. K. Kurah ◽  
M. S. Shariatipour ◽  
K. Itiowe

AbstractSuites of wireline well logs and three-dimensional (3D) seismic data were integrated to characterise the reservoir and estimate the hydrocarbon in Otigwe field, coastal swamp depositional belt, Niger Delta. The 3D seismic data were used to generate seismic sections through which fourteen faults and two horizons of interest were mapped across four wells. Depth structural map generated from the mapped faults and horizons of interest shows that the trapping mechanism within the field is fault-supported anticlinal structural trap. The four available wells were correlated using lithostratigraphic correlation to establish two reservoir continuities (Reservoir A and B). The estimated reservoir fluid volume at surface condition using reservoir simulation and modelling software is 59 MMstb for reservoir A and 25.70 MMstb for reservoir B. On the other hand, the estimated reservoir fluid volume at surface condition using analytical method is 52.58 MMstb for reservoir A and 18.85 MMstb for reservoir B. Using reservoir simulation and modelling software, the average net-to-gross ratio and shale volume for reservoir A range from 0.86 to 0.89 and 0.11 to 0.14, respectively, while for reservoir B the range is between 0.69 to 0.82 and 0.18 to 0.31, respectively. On the flipside using the analytical method, the average net-to-gross ratio and shale volume for reservoir A is 0.78 and 0.22, respectively. The results from the volumetric estimation of reservoir fluids showed close values using both methods and reservoir A is more prolific compare to B.

2014 ◽  
Vol 2 (2) ◽  
pp. 18-26
Author(s):  
Sonny Inichinbia ◽  
◽  
Peter O. Sule ◽  
Halidu Hamza ◽  
Aminu L. Ahmed

2020 ◽  
Vol 8 (2) ◽  
pp. 168
Author(s):  
Nyeneime O. Etuk ◽  
Mfoniso U. Aka ◽  
Okechukwu A. Agbasi ◽  
Johnson C. Ibuot

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.   


2011 ◽  
Vol 24 (1) ◽  
pp. 107-123 ◽  
Author(s):  
Dominic Maloney ◽  
Richard Davies ◽  
Jonathan Imber ◽  
Stephen King

2019 ◽  
Vol 10 (3) ◽  
pp. 1227-1242
Author(s):  
O. Abiola ◽  
F. O. Obasuyi

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.


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