Evaluation of mineral composition and petrophysical parameters by the integration of core analysis data and wireline well log data: the Carpathian Foredeep case study

Clay Minerals ◽  
2011 ◽  
Vol 46 (1) ◽  
pp. 25-45 ◽  
Author(s):  
T. Zorski ◽  
A. Ossowski ◽  
J. Środoń ◽  
T. Kawiak
Keyword(s):  
Mineral Composition ◽  
Water Saturation ◽  
Data Interpretation ◽  
Analysis Data ◽  
Exchange Capacity ◽  
Well Log ◽  
Log Data ◽  
The Matrix ◽  
Set Up ◽  
Log Interpretation

AbstractKnowledge of mineral composition is helpful in the interpretation of well-logging data, where the hydrocarbon saturation is expected as the final result.It is calculated from the electric resistivity, cation exchange capacity (CEC) and porosity.Porosity is calculated from the bulk density, which is measured directly in the well, and the matrix (mineralogical, grain) density, which can be calculated precisely only when the mineral composition is known.In the shale-sand formations, which are the subject of this study, the rock matrix can conduct electric current.The Waxman–Smits formula is applied to calculate the water saturation of such rocks.This formula combines rock porosity, water saturation, water resistivity and the CEC with the total rock resistivity measured in the well.CEC is introduced to this formula as the parameter determining the shale ability to conduct electricity.Typically, CEC is controlled by the smectite content of the rock.In order to evaluate the input data needed in the log interpretation the extended mineralogical (quantitative mineral composition, CEC) and chemical (major, trace and REE) analyses were made for over 200 core samples obtained from four gas fields in the Miocene formation of the Carpathian Foredeep.The most important clay component: the sum of mixed-layer illite-smectite and discrete illite has been quantified.The detailed recognition of clay minerals allowed for constraining the density-neutron cross-plot, which is a well log data interpretation technique for the determination of both porosity and shale content in shale-sand formations.The statistical multivariate analysis of all data helped to set up a comprehensive petrophysical model.A reliable correlation (r2 = 0.96) of the thermal neutron absorption cross-section (Σama) and the total natural radioactivity (GR) with CEC was established.Such good correlation allows for a continuous on-line CEC determination and therefore a reliable application of the Waxman-Smits water saturation model.Experimental equations with similar level of correlation were established for quartz, clay and carbonate contents, allowing the calculation of matrix density, required in the porosity calculation.The high correlation of Σama with CEC reflects the presence of boron in the illite-smectite clays.

Well logging data interpretation for appraising the performance of Alam El-Bueib reservoir in Safir Oil Field, Shushan Basin, Egypt

2021 ◽  
Vol 11 (5) ◽  
pp. 2075-2089
Author(s):  
Mohamed Mahmoud Elhossainy ◽  
Ahmed Kamal Basal ◽  
Hussein Tawfik ElBadrawy ◽  
Sobhy Abdel Salam ◽  
Mohammad Abdelfattah Sarhan
Keyword(s):  
Water Saturation ◽  
Data Interpretation ◽  
Effective Porosity ◽  
Oil Field ◽  
Reservoir Quality ◽  
Well Log ◽  
Relative Permeabilities ◽  
Log Data ◽  
Bulk Volume ◽  
Water Cut

AbstractThis paper presents different well log data interpretation techniques for evaluating the reservoir quality for the sandstone reservoir of the Alam El-Bueib-3A Member in Safir-03 well, Shushan Basin, Egypt. The evaluation of the available well log data for the Alam El-Bueib-3A Member in this well indicated high quality as oil-producing reservoir between depths 8108–8133 ft (25 ft thick). The calculated reservoir parameters possess shale volume less than or equal to 9% indicating the clean nature of this sandstone interval, water saturation values range from 10 to 23%, and effective porosity varies between 19 and 23%. Bulk volume of water is less than 0.04, non-producing water (SWirr) saturation varies between 10 and 12%, and permeability ranges from 393 to 1339 MD reflecting excellent reservoir quality. The calculated BVW values are less than the minimum (BVWmin = 0.05) reflecting clean (no water) oil production, which was confirmed through the drill stem test (DST). The relative permeabilities to both water and oil are located between 0.01–0 and 1.0–0.5, respectively. The water cut is fairly low where it ranges between 0 and 20%. Additionally, the water saturation values are less than the critical water saturation (Scw = 29.5%) which reflects that the whole net pay will flow hydrocarbon, whereas the water phase will remain immobile. This was confirmed with reservoir engineering through the DST.

scholarly journals Hydrocarbon reservoir characterization of “Otan-Ile” field, Niger Delta

2021 ◽  
Vol 11 (2) ◽  
pp. 601-615
Author(s):  
Tokunbo Sanmi Fagbemigun ◽  
Michael Ayu Ayuk ◽  
Olufemi Enitan Oyanameh ◽  
Opeyemi Joshua Akinrinade ◽  
Joel Olayide Amosun ◽  
...  
Keyword(s):  
Niger Delta ◽  
Reservoir Characterization ◽  
Water Saturation ◽  
Structural Deformation ◽  
Well Log ◽  
Reservoir Properties ◽  
Good Tool ◽  
Log Data ◽  
Hydrocarbon Reservoir ◽  
Hydrocarbon Saturation

AbstractOtan-Ile field, located in the transition zone Niger Delta, is characterized by complex structural deformation and faulting which lead to high uncertainties of reservoir properties. These high uncertainties greatly affect the exploration and development of the Otan-Ile field, and thus require proper characterization. Reservoir characterization requires integration of different data such as seismic and well log data, which are used to develop proper reservoir model. Therefore, the objective of this study is to characterize the reservoir sand bodies across the Otan-Ile field and to evaluate the petrophysical parameters using 3-dimension seismic and well log data from four wells. Reservoir sands were delineated using combination of resistivity and gamma ray logs. The estimation of reservoir properties, such as gross thickness, net thickness, volume of shale, porosity, water saturation and hydrocarbon saturation, were done using standard equations. Two horizons (T and U) as well as major and minor faults were mapped across the ‘Otan-Ile’ field. The results show that the average net thickness, volume of shale, porosity, hydrocarbon saturation and permeability across the field are 28.19 m, 15%, 37%, 71% and 26,740.24 md respectively. Two major faults (F1 and F5) dipping in northeastern and northwestern direction were identified. The horizons were characterized by structural closures which can accommodate hydrocarbon were identified. Amplitude maps superimposed on depth-structure map also validate the hydrocarbon potential of the closures on it. This study shows that the integration of 3D seismic and well log data with seismic attribute is a good tool for proper hydrocarbon reservoir characterization.

scholarly journals Petrophysical Properties Estimation of Euphrates Reservoir in Qayyarah Oil Field Using Core and Well Log Data

2021 ◽  
Vol 54 (2E) ◽  
pp. 186-197
Author(s):  
Maan Al-Majid
Keyword(s):  
Water Saturation ◽  
Oil Field ◽  
Oil Reservoirs ◽  
Coefficient Of Determination ◽  
Well Log ◽  
Secondary Porosity ◽  
Log Data ◽  
The Core ◽  
Core Samples ◽  
True Resistivity

The Early Miocene Euphrates Formation is characterized by its oil importance in the Qayyarah oil field and its neighboring fields. This study relied on the core and log data analyses of two wells in the Qayyarah oil field. According to the cross-plot’s information, the Euphrates Formation is mainly composed of dolomite with varying proportions of limestone and shale. Various measurements to calculate the porosity, permeability, and water saturation on the core samples were made at different depths in the two studied wells Qy-54 and Qy-55. A relationship between water saturation and capillary pressure has been plotted for some core samples to predict sites of normal compaction in the formation. The line regression for this relationship was considered as a function of the ratio of large voids to the total volume of voids in the sample. The coefficient of determination parameter was used in estimating the amount of homogeneity in the sizes of the voids, as it was observed to increase significantly at the sites of shale. After dividing the formation into several zones, the well log data were analyzed to predict the locations of oil presence in both wells. The significance of the negative secondary porosity in detecting the hydrocarbon sites in the Euphrates Formation was deduced by its correspondence with the large increase in the true resistivity values in both wells. More than 90% of the formation parts represent reservoir rocks in both wells, but only about 75% of them are oil reservoirs in the well Qy-54 and nearly 50% of them are oil reservoirs in the well Qy-55.

Magnetotelluric signature and well log data interpretation of Santos Basin, Brazil

2009 ◽  
Author(s):  
Vinicius R. Pinto ◽  
Sérgio L. Fontes ◽  
Emin U. Ulugergerli
Keyword(s):  
Data Interpretation ◽  
Well Log ◽  
Log Data

The System of Adaptive Well Log Data Interpretation in Geological Modeling

2012 ◽  
Author(s):  
A.N. Petrov ◽  
D.A. Kozhevnikov ◽  
K.V. Kovalenko ◽  
I.S. Deshenenkov
Keyword(s):  
Data Interpretation ◽  
Well Log ◽  
Geological Modeling ◽  
Log Data

Application of Walsh Filter in Geophysical Well-Log Data Interpretation for Automated Lithological Bed Boundary Detection

2021 ◽  
Author(s):  
Gagandeep Singh ◽  
Deepan Datta ◽  
William K. Mohanty ◽  
Aurobinda Routray ◽  
Rahul Mahadik
Keyword(s):  
Data Interpretation ◽  
Boundary Detection ◽  
Well Log ◽  
Log Data

Correlation of vertical electrical sounding and borehole-log data for delineation of saltwater and freshwater aquifers

Geophysics ◽  
2006 ◽  
Vol 71 (1) ◽  
pp. G11-G20 ◽  
Author(s):  
G. K. Hodlur ◽  
Ratnakar Dhakate ◽  
Rolland Andrade
Keyword(s):  
Cost Effective ◽  
Data Interpretation ◽  
Quantitative Relation ◽  
Well Log ◽  
Log Data ◽  
Resistivity Data ◽  
Electrical Sounding ◽  
Electrical Soundings ◽  
Longitudinal Unit Conductance ◽  
Freshwater Aquifers

In a case history from the Mahanadi basin (India), we demonstrate the use of resistivity data from electric-log soundings and from borehole logs to discriminate between saltwater and freshwater aquifers. We use interpreted data from eight surface-based vertical electrical soundings (VES) and electric well logs from three boreholes in this study. We establish a quantitative relation among longitudinal unit conductance S (obtained from VES), water resistivity [Formula: see text], and layer thickness h. We show that ambiguities in resistivity data interpretation limit its ability to distinguish between freshwater and saltwater aquifers. Electric well-log data interpretation is much more accurate but requires boreholes, which are not cost effective when exploring for groundwater. Integrating well-log-based estimates of [Formula: see text] into resistivity interpretation of surface-based soundings improves its ability to discriminate freshwater aquifers while maintaining cost-effective exploration.

scholarly journals Methodology for determining the average diameter of rock pores and channels by well-log data based on lithological and petrophysical studies

2021 ◽  
pp. 47-57
Author(s):  
N.A. Skibitskaya ◽  
V.A. Kuzmin ◽  
M.N. Bolshakov ◽  
K.V. Kovalenko ◽  
E.A. Babich ◽  
...  
Keyword(s):  
Gas Permeability ◽  
Pore Space ◽  
Average Diameter ◽  
Digital Processing ◽  
Data Interpretation ◽  
Space Structure ◽  
Well Log ◽  
Electron Microscopic ◽  
Log Data ◽  
Pore Space Structure

The paper presents a method for determining the parameters characterizing the features of the pore space structure of rocks continuously along the section, based on the results of well-log data interpretation. The results of the well-log data interpretation are presented with diagrams of average values of pore and channel diameters calculated continuously along the section, which are consistent with the results of laboratory measurements on rock samples. The proposed method is based on the use of the established correlation relationships between the slope tangent of the graph of dependence of gas permeability on reciprocal of mean pressure drop and the parameters of the pore space structure, determined from the digital processing of raster electron microscopic images.

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