scholarly journals Petrophysical Reservoir Characterization of Habiganj Gas Field, Surma Basin, Bangladesh

2021 ◽  
Vol 10 (1) ◽  
pp. 1-10
Author(s):  
Shamiha Shafinaz Shreya ◽  
Md Anwar Hossain Bhuiyan ◽  
Shakhawat Hossain ◽  
Tania Sultana
Keyword(s):  
Reservoir Characterization ◽  
Water Saturation ◽  
Volumetric Analysis ◽  
Reservoir Quality ◽  
Gas Field ◽  
Hydrocarbon Production ◽  
Petrophysical Parameters ◽  
Shale Volume ◽  
Lower Reservoir ◽  
Surma Basin

The previous studies on the petrophysical and volumetric analysis of Habiganj gas field were based on limited well data. As the accuracy of volumetric analysis relies greatly on petrophysical parameters, it is important to estimate them accurately. In this study we analyzed all eleven wells drilled in the Habiganj field to determine the petrophysical parameters. Analysis of the well logs revealed two distinct reservoir zones in this field termed as upper reservoir zone and lower reservoir zone. Stratigraphically, these two reservoir zones are in the Bokabil and Bhuban Formation of Surma Group. Petrophysical analysis shows significant differences between the two zones in terms of petrophysical parameters. Porosity in the upper reservoir zone ranges from 12% to 36%, with an average of 28%. This zone is highly permeable, as indicated by the average permeability of 500 mili Darcy (mD). The average water saturation in this zone is around 18% suggesting high gas saturation. The lower reservoir zone has an average porosity, permeability, and water saturation of 12%, 60mD, and 43%, respectively, indicating poor reservoir quality. An analysis of log motifs indicates that the upper reservoir zone is composed of stacked sands of blocky pattern. The sands in this interval are clean, as indicated by the lower shale volume of 12-15%. The average thickness of this zone is 230m, and the presence of this zone in all the drilled wells suggests high lateral continuity. The lower reservoir zone consists of sand bodies of serrated pattern. The sands have high shale volume and are laterally discontinuous. Overall, the upper reservoir zone has superior petrophysical properties to the lower reservoir zone. Although the reservoir quality of the lower reservoir zone is poorer than that of the upper zone, this zone can be considered as the secondary target for hydrocarbon production. Petrophysical parameters of this study were estimated from all the eleven wells drilled in this field; hence the values are more accurate. The reported values of the petrophysical parameters in this study are recommended to use to re-estimate the reserves in Habiganj field. The Dhaka University Journal of Earth and Environmental Sciences, Vol. 10(1), 2021, P 1-10

scholarly journals Petrophysics Analysis for Reservoir Characterization of Cretaceous Clastic Rocks: A Case Study of the Arafura Basin

2020 ◽  
Vol 21 (3) ◽  
pp. 129
Author(s):  
Ade Yogi
Keyword(s):  
Reservoir Characterization ◽  
Petrophysical Properties ◽  
Stratigraphic Sequence ◽  
Petrophysical Parameters ◽  
Clastic Rocks ◽  
Shale Volume ◽  
Core Descriptions ◽  
Stratigraphic Sequences

This study presents petrophysics analysis results from two wells located in the Arafura Basin. The analysis carried out to evaluate the reservoir characterization and its relationship to the stratigraphic sequence based on log data from the Koba-1 and Barakan-1 Wells. The stratigraphy correlation section of two wells depicts that in the Cretaceous series a transgression-regression cycle. The petrophysical parameters to be calculated are the shale volume and porosity. The analysis shows that there is a relationship between stratigraphic sequences and petrophysical properties. In the study area, shale volumes used to make complete rock profiles in wells assisted by biostratigraphic data, cutting descriptions, and core descriptions. At the same time, porosity shows a conformity pattern with the transgression-regression cycle.Keywords: petrophysics, reservoir characterization, Cretaceous, transgressive-regressive cycle

scholarly journals Formation evaluation and reservoir characteristics of the Messinian Abu Madi sandstones in Faraskour Gas Field, onshore Nile Delta, Egypt

2020 ◽  
Author(s):  
Mahmoud Leila ◽  
Ali Eslam ◽  
Asmaa Abu El-Magd ◽  
Lobna Alwaan ◽  
Ahmed Elgendy
Keyword(s):  
Water Saturation ◽  
Nile Delta ◽  
Hydrocarbon Exploration ◽  
The Other ◽  
Reservoir Rock ◽  
Reservoir Quality ◽  
Pore System ◽  
Reservoir Properties ◽  
Gas Field ◽  
Irreducible Water Saturation

Abstract The Messinian Abu Madi Formation represents the most prospective reservoir target in the Nile Delta. Hydrocarbon exploration endeavors in Nile Delta over the last few decades highlighted some uncertainties related to the predictability and distribution of the Abu Madi best reservoir quality facies. Therefore, this study aims at delineating the factors controlling the petrophysical heterogeneity of the Abu Madi reservoir facies in Faraskour Field, northeastern onshore part of the Nile Delta. This work provides the very first investigation on the reservoir properties of Abu Madi succession outside the main canyon system. In the study area, Abu Madi reservoir is subdivided into two sandstone units (lower fluvial and upper estuarine). Compositionally, quartzose sandstones (quartz > 65%) are more common in the fluvial unit, whereas the estuarine sandstones are often argillaceous (clays > 15%) and glauconitic (glauconite > 10%). The sandstones were classified into four reservoir rock types (RRTI, RRTII, RRTIII, and RRTIV) having different petrophysical characteristics and fluid flow properties. RRTI hosts the quartzose sandstones characterized by mega pore spaces (R35 > 45 µm) and a very well-connected, isotropic pore system. On the other side, RRTIV constitutes the lowest reservoir quality argillaceous sandstones containing meso- and micro-sized pores (R35 > 5 µm) and a pore system dominated by dead ends. Irreducible water saturation increases steadily from RRTI (Swir ~ 5%) to RRTIV (Swir > 20%). Additionally, the gas–water two-phase co-flowing characteristics decrease significantly from RRTI to RRTIV facies. The gaseous hydrocarbons will be able to flow in RRTI facies even at water saturation values exceeding 90%. On the other side, the gas will not be able to displace water in RRTIV sandstones even at water saturation values as low as 40%. Similarly, the influence of confining pressure on porosity and permeability destruction significantly increases from RRTI to RRTIV. Accordingly, RRTI facies are the best reservoir targets and have high potentiality for primary porosity preservation.

scholarly journals Integrated reservoir characterization and quality analysis of the carbonate rock types, case study, southern Iraq

2020 ◽  
Vol 10 (8) ◽  
pp. 3157-3177 ◽  
Author(s):  
Sameer Noori Ali Al-Jawad ◽  
Muhammad Abd Ahmed ◽  
Afrah Hassan Saleh
Keyword(s):  
Reservoir Characterization ◽  
Water Saturation ◽  
Rock Type ◽  
High Water ◽  
Quality Analysis ◽  
Reservoir Quality ◽  
High Porosity ◽  
Rock Types ◽  
Porosity And Permeability ◽  
Medium Porosity

Abstract The reservoir characterization and rock typing is a significant tool in performance and prediction of the reservoirs and understanding reservoir architecture, the present work is reservoir characterization and quality Analysis of Carbonate Rock-Types, Yamama carbonate reservoir within southern Iraq has been chosen. Yamama Formation has been affected by different digenesis processes, which impacted on the reservoir quality, where high positively affected were: dissolution and fractures have been improving porosity and permeability, and destructive affected were cementation and compaction, destroyed the porosity and permeability. Depositional reservoir rock types characterization has been identified depended on thin section analysis, where six main types of microfacies have been recognized were: packstone-grainstone, packstone, wackestone-packstone, wackestone, mudstone-wackestone, and mudstone. By using flow zone indicator, four groups have been defined within Yamama Formation, where the first type (FZI-1) represents the bad quality of the reservoir, the second type (FZI-2) is characterized by the intermediate quality of the reservoir, third type (FZI-3) is characterized by good reservoir quality, and the fourth type (FZI-4) is characterized by good reservoir quality. Six different rock types were identified by using cluster analysis technique, Rock type-1 represents the very good type and characterized by low water Saturation and high porosity, Rock type-2 represents the good rock type and characterized by low water saturation and medium–high porosity, Rock type-3 represents intermediate to good rock type and characterized by low-medium water saturation and medium porosity, Rock type-4 represents the intermediate rock type and characterized by medium water saturation and low–medium porosity, Rock type-5 represents intermediate to bad rock type and characterized by medium–high water saturation and medium–low porosity, and Rock type-6 represents bad rock type and characterized by high water saturation and low porosity. By using Lucia Rock class typing method, three types of rock type classes have been recognized, the first group is Grain-dominated Fabrics—grainstone, which represents a very good rock quality corresponds with (FZI-4) and classified as packstone-grainstone, the second group is Grain-dominated Fabrics—packstone, which corresponds with (FZI-3) and classified as packstone microfacies, the third group is Mud-dominated Fabrics—packstone, packstone, correspond with (FZI-1 and FZI-2) and classified as wackestone, mudstone-wackestone, and mudstone microfacies.

Low Resistivity Reservoir Pay Evaluation, New Opportunity for Further Development, Case Study On Gumai Formation Of B Field, Jambi Sub Basin, South Sumatera Basin

2021 ◽  
Keyword(s):  
Oil And Gas ◽  
Water Saturation ◽  
Neutron Density ◽  
Gas Field ◽  
Data Set ◽  
Volume Calculation ◽  
Low Resistivity ◽  
Shale Volume ◽  
Fluid Saturation ◽  
Further Development

The understanding of low resistivity reservoir zone is one of the most challenging cases for further development in order to optimize the remaining oil and gas field productions. In the Intra-Gumai Formation “B” Field where marine clastic reservoirs are deposited, a low resistivity reservoir is being developed as a new perforation and workover target. This study discusses how to identify the cause of low resistivity case and evaluate the proper petrophysical parameters to unlock the potential reservoir pay zones. The data set consists of petrographic, X-Ray Diffraction (XRD), Cation Exchange Capacity (CEC), routine core, Drill Stem Test ((DST) and wireline logs data. Petrographic, XRD, CEC and routine analysis were performed to recognize the low resistivity causes characterized by the presence of framework grain (quartz, K-feldspar and glaucony, calcite and kaolinite) observed in intergranular pore and also quartz overgrowth developed prior to kaolinite precipitation. Petrophysical analysis defines the reservoir property parameters by comparing some equations also validated with routine core and DST result. Based on the quantitative analysis carried out, namely the evaluation of the distribution of shale volume, calculation of porosity, and determination of water saturation, it is recommended to use the Stieber method for the distribution of shale volume in the reservoir and its properties, the neutron density porosity method to calculate porosity model, and the Waxman Smits method to determine the final fluid saturation model. Finally, by using the hydrocarbon saturation results in the current study, this interval was improved as pay zone. This method will be applied to other wells and other structures that have a similar depositional environment to increase hydrocarbon reserves in the same field.

Time‐lapse (4-D) seismic monitoring of primary production of turbidite reservoirs at South Timbalier Block 295, offshore Louisiana, Gulf of Mexico

Geophysics ◽  
2000 ◽  
Vol 65 (2) ◽  
pp. 351-367 ◽  
Author(s):  
Tucker Burkhart ◽  
Andrew R. Hoover ◽  
Peter B. Flemings
Keyword(s):  
Reservoir Characterization ◽  
Water Saturation ◽  
Seismic Analysis ◽  
Time Lapse ◽  
Hydrocarbon Production ◽  
Seismic Surveys ◽  
Seismic Amplitude ◽  
Fluid Properties ◽  
Multiple Reservoir ◽  
Gas Drive

Two seismic surveys acquired over South Timbalier Block 295 field (offshore Louisiana) record significant differences in amplitude that are correlated to hydrocarbon production at multiple reservoir levels. The K8 sand, a solution‐gas‐drive reservoir, shows increases in seismic amplitude associated with gas exsolution. The K40 sand, a water‐drive reservoir, shows decreases in seismic amplitude associated with increases in water saturation. A methodology is presented to optimize the correlation between two seismic surveys after they have been individually processed (poststack) This methodology includes rebinning, crosscorrelation, band‐pass filtering, and cross‐equalization. A statistical approach is developed to characterize the correlation between the seismic surveys. This statistical analysis is used to discriminate seismic amplitude differences that record change in rock and fluid properties from those that could be the result of miscorrelation of the seismic data. Time‐lapse seismic analysis provides an important new approach to imaging hydrocarbon production; it may be used to improve reservoir characterization and guide production decisions.

scholarly journals Evaluation of Reservoir Quality and Forecasted Production Variability along a Multi-Fractured Horizontal Well. Part 1: Reservoir Characterization

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6154
Author(s):  
Daniela Becerra ◽  
Christopher R. Clarkson ◽  
Amin Ghanizadeh ◽  
Rafael Pires de Lima ◽  
Farshad Tabasinejad ◽  
...  
Keyword(s):  
Horizontal Well ◽  
Reservoir Characterization ◽  
Water Saturation ◽  
Geometric Approach ◽  
Horizontal Wells ◽  
Reservoir Quality ◽  
Reservoir Properties ◽  
Geomechanical Properties ◽  
Using Data ◽  
Lateral Length

Completion design for horizontal wells is typically performed using a geometric approach where the fracturing stages are evenly distributed along the lateral length of the well. However, this approach ignores the intrinsic vertical and horizontal heterogeneity of unconventional reservoirs, resulting in uneven production from hydraulic fracturing stages. An alternative approach is to selectively complete intervals with similar and superior reservoir quality (RQ) and completion quality (CQ), potentially leading to improved development efficiency. In the current study, along-well reservoir characterization is performed using data from a horizontal well completed in the Montney Formation in western Canada. Log-derived petrophysical and geomechanical properties, and laboratory analyses performed on drill cuttings, are integrated for the purpose of evaluating RQ and CQ variability along the well. For RQ, cutoffs were applied to the porosity (>4%), permeability (>0.0018 mD), and water saturation (<20%), whereas, for CQ, cutoffs were applied to rock strength (<160 Mpa), Young’s Modulus (60–65 GPa), and Poisson’s ratio (<0.26). Based on the observed heterogeneity in reservoir properties, the lateral length of the well can be subdivided into nine segments. Superior RQ and CQ intervals were found to be associated with predominantly (massive) porous siltstone facies; these intervals are regarded as the primary targets for stimulation. In contrast, relatively inferior RQ and CQ intervals were found to be associated with either dolomite-cemented facies or laminated siltstones. The methods developed and used in this study could be beneficial to Montney operators who aim to better predict and target sweet spots along horizontal wells; the approach could also be used in other unconventional plays.

scholarly journals Determination of Petrophysical Parameters of Reservoir Rock with a Special Look to Shale Effect (Case Study: One of the Gas Fields in Southern Iran)

2021 ◽  
Vol 5 (2) ◽  
pp. 1-10
Author(s):  
Taheri K
Keyword(s):  
Water Saturation ◽  
Accurate Determination ◽  
Reservoir Rock ◽  
Petrophysical Properties ◽  
Gas Reservoir ◽  
Reservoir Water ◽  
Petrophysical Parameters ◽  
Hydrocarbon Reservoir ◽  
Shale Volume

Determination of petrophysical parameters is necessary for modeling hydrocarbon reservoir rock. The petrophysical properties of rocks influenced mainly by the presence of clay in sedimentary environments. Accurate determination of reservoir quality and other petrophysical parameters such as porosity, type, and distribution of reservoir fluid, and lithology are based on evaluation and determination of shale volume. If the effect of shale volume in the formation not calculated and considered, it will have an apparent impact on the results of calculating the porosity and saturation of the reservoir water. This study performed due to the importance of shale in petrophysical calculations of this gas reservoir. The shale volume and its effect on determining the petrophysical properties and ignoring it studied in gas well P19. This evaluation was performed in Formations A and B at depths of 3363.77 to 3738.98 m with a thickness of 375 m using a probabilistic calculation method. The results of evaluations of this well without considering shale showed that the total porosity was 0.1 percent, the complete water saturation was 31 percent, and the active water saturation was 29 percent, which led to a 1 percent increase in effective porosity. The difference between water saturation values in Archie and Indonesia methods and 3.3 percent shale volume in the zones show that despite the low shale volume in Formations A and B, its effect on petrophysical parameters has been significant. The results showed that if the shale effect not seen in the evaluation of this gas reservoir, it can lead to significant errors in calculations and correct determination of petrophysical parameters.

scholarly journals Reservoir quality evaluation of the Farewell sandstone by integrating sedimentological and well log analysis in the Kupe South Field, Taranaki Basin-New Zealand

2020 ◽  
Author(s):  
S. M. Talha Qadri ◽  
Md Aminul Islam ◽  
Mohamed Ragab Shalaby ◽  
Ahmed K. Abd El-Aal
Keyword(s):  
Water Saturation ◽  
Total Porosity ◽  
Effective Porosity ◽  
Log Analysis ◽  
Reservoir Quality ◽  
Well Log ◽  
Shale Volume ◽  
Diagenetic Processes ◽  
Hydrocarbon Saturation ◽  
Well Log Analysis

AbstractThe study used the sedimentological and well log-based petrophysical analysis to evaluate the Farewell sandstone, the reservoir formation within the Kupe South Field. The sedimentological analysis was based on the data sets from Kupe South-1 to 5 wells, comprising the grain size, permeability, porosity, the total cement concentrations, and imprints of diagenetic processes on the reservoir formation. Moreover, well log analysis was carried on the four wells namely Kupe South 1, 2, 5 and 7 wells for evaluating the parameters e.g., shale volume, total and effective porosity, water wetness and hydrocarbon saturation, which influence the reservoir quality. The results from the sedimentological analysis demonstrated that the Farewell sandstone is compositionally varying from feldspathic arenite to lithic arenite. The analysis also showed the presence of significant total porosity and permeability fluctuating between 10.2 and 26.2% and 0.43–1376 mD, respectively. The diagenetic processes revealed the presence of authigenic clay and carbonate obstructing the pore spaces along with the occurrence of well-connected secondary and hybrid pores which eventually improved the reservoir quality of the Farewell sandstone. The well log analysis showed the presence of low shale volume between 10.9 and 29%, very good total and effective porosity values ranging from 19 to 32.3% as well as from 17 to 27%, respectively. The water saturation ranged from 22.3 to 44.9% and a significant hydrocarbon saturation fluctuating from 55.1 to 77.7% was also observed. The well log analysis also indicated the existence of nine hydrocarbon-bearing zones. The integrated findings from sedimentological and well log analyses verified the Farewell sandstone as a good reservoir formation.

Incorporation of Sequence Stratigraphy in Gas Reservoir Correlation: A Case Study

2019 ◽  
Vol 45 (2) ◽  
pp. 209-216
Author(s):  
Afroza Parvin ◽  
ASM Woobaidullah
Keyword(s):  
Sequence Stratigraphy ◽  
Reservoir Characterization ◽  
Gamma Ray ◽  
Stratigraphic Correlation ◽  
Gas Field ◽  
Sequence Stratigraphic ◽  
Neutron Porosity ◽  
Wireline Logs ◽  
Surma Basin

The application of sequence stratigraphy to resolve the miscorrelation between different genetic units in reservoir characterization in a gas field of Surma Basin is dealt with. Interpretation of available seismic and wireline logs (gamma ray, resistivity, density and neutron porosity) give the sequence stratigraphic correlation of reservoir sands. The reservoirs geometry, its extent, seal architecture and trapping styles have been revealed better with this correlation. There is juxtaposition of two reservoir sands, namely A1 and A2. A1 is located at older highstand sand, whereas A2 is in the younger lowstand sand. Lithostratigraphically they might be same but sequences stratigraphy reveals that they are different and deposited at different times. Moreover, the concept reveals that lowstand sand has better reservoir quality than any highstand and transgressive sand. Asiat. Soc. Bangladesh, Sci. 45(2): 209-216, December 2019

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