POROSITY AND PERMEABILITY OF RESERVOIRS AND CAPROCKS IN THE EROMANGA BASIN, SOUTH AUSTRALIA

1986 ◽  
Vol 26 (1) ◽  
pp. 202
Author(s):  
D.I. Gravestock ◽  
E.M. Alexander
Keyword(s):  
Grain Size ◽  
Gamma Ray ◽  
Size Variation ◽  
South Australia ◽  
Clay Content ◽  
Effective Porosity ◽  
Overburden Pressure ◽  
Porosity Reduction ◽  
Porosity And Permeability ◽  
Eromanga Basin

When effective porosity and permeability are measured at simulated overburden pressure, and grain size variation is taken into account, two distinct relationships are evident for Eromanga Basin reservoirs. Reservoirs in the Hutton Sandstone and Namur Sandstone Member behave such that significant porosity reduction can be sustained with retention of high permeability, whereas permeability of reservoirs in the Birkhead Formation and Murta Member is critically dependent on slight porosity variations. Logging tool responses are compared with core-derived data to show in particular the effects of grain size and clay content on the gamma ray, sonic, and density tools, where clay content is assessed from cation exchange capacity measurements. Sonic and density crossplots, constructed to provide comparison with a water-saturated 'reference' reservoir, are advantageous in comparing measured effective porosity from core plugs at overburden pressure with porosity calculated from logs. Gamma ray and sonic log responses of the Murta Member in the Murteree Horst area are clearly distinct from those of all other reservoirs, perhaps partly due to differences in mineralogy and shallower depth of burial compared with other formations.

Tight Jurassic Carbonate Reservoir Characterization and Fluid Typing Identification by Integrating Magnetic Resonance, Elemental Spectroscopy and Micro-Resistivity Image Data in Umm Ross Field, West Kuwait, Case Study

2021 ◽  
Author(s):  
Said Beshry Mohamed ◽  
Sherif Ali ◽  
Mahmoud Fawzy Fahmy ◽  
Fawaz Al-Saqran
Keyword(s):  
Magnetic Resonance ◽  
Reservoir Characterization ◽  
Clay Content ◽  
Effective Porosity ◽  
Carbonate Reservoir ◽  
High Resistivity ◽  
Permeability Index ◽  
Rock Quality ◽  
Porosity And Permeability ◽  
Bulk Volume

Abstract The Middle Marrat reservoir of Jurassic age is a tight carbonate reservoir with vertical and horizontal heterogeneous properties. The variation in lithology, vertical and horizontal facies distribution lead to complicated reservoir characterization which lead to unexpected production behavior between wells in the same reservoir. Marrat reservoir characterization by conventional logging tools is a challenging task because of its low clay content and high-resistivity responses. The low clay content in Marrat reservoirs gives low gamma ray counts, which makes reservoir layer identification difficult. Additionally, high resistivity responses in the pay zones, coupled with the tight layering make production sweet spot identification challenging. To overcome these challenges, integration of data from advanced logging tools like Sidewall Magnetic Resonance (SMR), Geochemical Spectroscopy Tool (GST) and Electrical Borehole Image (EBI) supplied a definitive reservoir characterization and fluid typing of this Tight Jurassic Carbonate (Marrat formation). The Sidewall Magnetic resonance (SMR) tool multi wait time enabled T2 polarization to differentiate between moveable water and hydrocarbons. After acquisition, the standard deliverables were porosity, the effective porosity ratio, and the permeability index to evaluate the rock qualities. Porosity was divided into clay-bound water (CBW), bulk-volume irreducible (BVI) and bulk-volume moveable (BVM). Rock quality was interpreted and classified based on effective porosity and permeability index ratios. The ratio where a steeper gradient was interpreted as high flow zones, a gentle gradient as low flow zones, and a flat gradient was considered as tight baffle zones. SMR logging proved to be essential for the proper reservoir characterization and to support critical decisions on well completion design. Fundamental rock quality and permeability profile were supplied by SMR. Oil saturation was identified by applying 2D-NMR methods, T1/T2 vs. T2 and Diffusion vs. T2 maps in a challenging oil-based mud environment. The Electrical Borehole imaging (EBI) was used to identify fracture types and establish fracture density. Additionally, the impact of fractures to enhance porosity and permeability was possible. The Geochemical Spectroscopy Tool (GST) for the precise determination of formation chemistry, mineralogy, and lithology, as well as the identification of total organic carbon (TOC). The integration of the EBI, GST and SMR datasets provided sweet spots identification and perforation interval selection candidates, which the producer used to bring wells onto production.

PETROPHYSICS OF THE COOPER BASIN, SOUTH AUSTRALIA

1972 ◽  
Vol 12 (1) ◽  
pp. 23
Author(s):  
Chris R. Porter ◽  
Hugh Crocker
Keyword(s):  
Water Saturation ◽  
South Australia ◽  
Clay Content ◽  
Computer Applications ◽  
Test Results ◽  
Upper Limits ◽  
Porosity And Permeability ◽  
Log Interpretation ◽  
Logging Tool ◽  
Cooper Basin

In the Cooper Basin lithologic types can be recognised and related to logging tool response. Empirical relationships between log readings and porosity and permeability can be developed locally by comparing log readings with core data. Water saturation/porosity relationships are found to be convergently hyperbolic. The effects of clay minerals upon water saturation determination show that only in the low porosity range is correction for clay necessary.A plot of Sw versus Sxo allows prediction of probable test results and has been confirmed by actual Cooper Basin well tests.An attempt to relate clay content to permeability has been successful in estimating tentative upper limits of permeability. Computer applications to log interpretation are utilized in achieving petrophysical parameters.

The insensitivity of thermal diffusivity of natural sediments to saturation

2018 ◽  
Vol 58 (2) ◽  
pp. 705
Author(s):  
Ayman Ezdini ◽  
James Griffith ◽  
Nick Lange ◽  
Soroush Tehrani ◽  
Hamad Roshan ◽  
...  
Keyword(s):  
Grain Size ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Clay Content ◽  
Heat Diffusion ◽  
Reservoir Properties ◽  
Needle Probe ◽  
Close Relationship ◽  
Porosity And Permeability

This extended abstract presents a ground-breaking study of thermal properties of soils and their dependency on saturation. The paper tries to prove that thermal diffusivity is not significantly dependent on saturation due to its close relationship with saturation-independent parameters such as thermal conductivity and volumetric heat capacity. The investigation is divided into two main scopes of work: the first is to build statistical analysis using the Monte Carlo technique by means of random sampling certain soil thermal properties; and the second is to experimentally validate the statistical models. The experimental framework of the study encompasses the measurement of thermal properties of different soil samples. These samples varied in terms of grain size, percentage clay content, and level of saturation. The experiments were carried out using a KD2-Pro Dual Needle Probe Thermal Properties Analyser. The results demonstrate that saturation has a negligible effect on thermal diffusivity of soils but an inverse relationship exists between diffusivity and clay content. Furthermore, the variation in grain size effect on diffusivity is within 5%. The study shows a correlation between lithology, porosity, and thermal properties. The implications are numerous: from the determination of unwanted heat diffusion of pipelines to the estimation of reservoir properties such as porosity and permeability.

Controls on the reservoir quality of Late Cretaceous Springar Formation deep-water fan systems in the Vøring Basin

2017 ◽  
Vol 8 (1) ◽  
pp. 247-257 ◽  
Author(s):  
Alana Finlayson ◽  
Angela Melvin ◽  
Alex Guise ◽  
James Churchill
Keyword(s):  
Grain Size ◽  
Late Cretaceous ◽  
Clay Content ◽  
Coarse Grained ◽  
Reservoir Quality ◽  
Low Permeability ◽  
Quality Model ◽  
Depositional Facies ◽  
Porosity And Permeability ◽  
Vøring Basin

AbstractA new reservoir quality model is proposed for the Late Cretaceous Springar Formation sandstones of the Vøring Basin. Instead of a depth-related compactional control on reservoir quality, distinct high- and low-permeability trends are observed. Fan sequences which sit on the high-permeability trend are characterized by coarse-grained facies with a low matrix clay content. These facies represent the highest energy sandy turbidite facies within the depositional system, and were deposited in channelized or proximal lobe settings. Fan sequences on the low-permeability trend are characterized by their finer grain size and the presence of detrital clay, which has been diagenetically altered to a highly microporous, illitic, pore-filling clay. These fan sequences are interpreted to have been deposited in proximal–distal lobe environments. Original depositional facies determines the sorting, grain size and detrital clay content, and is the fundamental control on reservoir quality, as the illitization of detrital clay is the main mechanism for reductions in permeability. Core-scale depositional facies were linked to seismic-scale fan elements in order to better predict porosity and permeability within each fan system, allowing calibrated risking and ranking of prospects within the Springar Formation play.

Effect of Fluid Invasion to Formation Resistivity

2015 ◽  
Vol 1113 ◽  
pp. 285-295
Author(s):  
Wan Zairani Wan Bakar ◽  
Arina Sauki ◽  
Mohd Haziafiz Abd Halim ◽  
Norrulhuda Mohd Taib
Keyword(s):  
Grain Size ◽  
Clay Content ◽  
Exchangeable Cation ◽  
Petrophysical Properties ◽  
Fine Grain ◽  
Porosity And Permeability ◽  
Good Conductor ◽  
Formation Resistivity ◽  
Reaction With Water ◽  
Different Grain Size

Clay is the primary cause for resistivity reduction in most of the low resistivity pay cases. While dry clay acts as insulator, reaction with water made wet clay a good conductor. Clay conductivity is contributed by the exchangeable cation properties of the mineral. This reduces the actual resistivity of the formation, especially in the invaded zone. The effect is more severe if clay existed as dispersed type in the formation; which will also reduce other important petrophysical properties such as porosity and permeability. The study was conducted to observe the mechanism and reduction of formation resistivity due to mud invasion and find the relationship between resistivity reduction and petrophysical properties of the formation. The resistivity was measured on four types of samples with different grain size and sorting; well sorted fine grain size, well sorted medium grain size, well sorted coarse grain size and not well sorted sand. Three types of fluids were flushed into sand pack those are brine, crude oil and water based mud to simulate the invasion process. Sand pack with not well sorted sand and fine grain size had the most resistivity reduction, which possibly due to the high clay content that interacted with water.

The pelagic archive of short-term sea-level change in the Cretaceous: a review of proxies linked to orbital forcing

2019 ◽  
Vol 498 (1) ◽  
pp. 39-56 ◽  
Author(s):  
Michael Wagreich ◽  
Veronika Koukal
Keyword(s):  
Grain Size ◽  
Sea Level ◽  
Gamma Ray ◽  
Clay Content ◽  
Sea Level Change ◽  
Point Of View ◽  
Heavy Minerals ◽  
Deep Time ◽  
Level Change ◽  
Sea Level Oscillations

AbstractDeep-time sea-level oscillations in the Milankovitch-band of orbital cyclicities govern deposition in the pelagic realm mainly by varying siliciclastic input. Pelagic sediments from the Cretaceous greenhouse climate phase provide a valuable archive for sea-level change. Although sea-level variations are of negligible amplitude compared with depositional water-depths, direct physical proxy data are based on higher and coarser siliciclastic input during sea-level lowstand and regressions, and include coarser grain size and grain-size parameters as well as the heavy mineral and clay content. Chemical proxies that relate to siliciclastics are manganese, titanium and zirconium, often normalized v. aluminium. Further proxies provide the ratios of strontium v. calcium, controlled by shelf carbonate erosion, and partly redox-sensitive elements like uranium and thorium. From a mineralogical point of view, the total amount of siliciclastics and their diversity relating to heavy minerals provides sea-level information in hemipelagites, as well as the phyllosilicate content v. biogenic pelagic background deposition of carbonate and siliceous microfossils in pelagites. In addition, measurements of gamma ray emission, linked to U, Th, K content and magnetic susceptibility may relate to sea-level cycles and various other more climate-dependent proxies like oxygen isotopes of fossil calcite and compositional maturity of hemipelagic sediments.

scholarly journals NMR AND WELL LOGS PETROPHYSICAL CHARACTERIZATION OF SANDSTONE FROM THE MARACANGALHA FORMATION, BAHIA, BRAZIL

2021 ◽  
pp. 239-252
Author(s):  
Nathália De Souza Penna ◽  
Joelson Da Conceição Batista ◽  
Suzan Sousa de Vasconcelos
Keyword(s):  
Gamma Ray ◽  
Production Capacity ◽  
Clay Content ◽  
Well Logs ◽  
Depth Interval ◽  
Porous Space ◽  
Petrophysical Parameters ◽  
Porosity And Permeability ◽  
Using Data ◽  
Geophysical Well Logs

The storage and production capacity of reservoir rocks can be estimated through some petrophysics characteristics involving the lithological identification of the constitute rocks, fluids nature in the porous space, porosity, permeability, saturation and clay content. The most popular tools for obtaining these petrophysical parameters are the conventional geophysical well logs. However, the determination of petrophysical parameters from tools based on the phenomenon of nuclear magnetic resonance (NMR) has gained prominence in recent decades. In this work, we analyzed rock samples from outcrops in Frades Island region, Bahia, Brazil, through laboratory NMR measurements, to estimate and evaluate the petrophysical properties of the Maracangalha Formation, one of the main hydrocarbons reservoirs in the Recôncavo Basin. The Sandstone samples were characterized in terms of porosity, permeability, saturation, and petrofacies. Finally, we calculated porosity, permeability, and clay content using data from gamma-ray, electrical and density logs, measured in a depth interval interpreted for Maracangalha Formation. These results corroborate with the obtained by NMR since, despite the effects of weathering and erosion on the samples used, the values of porosity and permeability obtained in NMR are in the range of values calculated from these profiles.

scholarly journals Finite element modelling of microstructural changes during equal channel angular drawing of pure aluminium

2021 ◽  
Author(s):  
Serafino Caruso ◽  
Stano Imbrogno
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Finite Element ◽  
Size Variation ◽  
Fe Model ◽  
Pure Aluminium ◽  
Continuous Dynamic Recrystallization ◽  
Research Activities ◽  
Hardness Change ◽  
Continuous Dynamic

AbstractGrain refinement by severe plastic deformation (SPD) techniques, as a mechanism to control microstructure (recrystallization, grain size changes,…) and mechanical properties (yield strength, ultimate tensile strength, strain, hardness variation…) of pure aluminium conductor wires, is a topic of great interest for both academic and industrial research activities. This paper presents an innovative finite element (FE) model able to describe the microstructural evolution and the continuous dynamic recrystallization (CDRX) that occur during equal channel angular drawing (ECAD) of commercial 1370 pure aluminium (99.7% Al). A user subroutine has been developed based on the continuum mechanical model and the Hall-Petch (H-P) equations to predict grain size variation and hardness change. The model is validated by comparison with the experimental results and a predictive analysis is conducted varying the channel die angles. The study provides an accurate prediction of both the thermo-mechanical and the microstructural phenomena that occur during the process characterized by large plastic deformation.

scholarly journals Correlation between the Porosity and Permeability of a Polymer Filter Fabricated via CO2-Assisted Polymer Compression

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 391 ◽  
Author(s):  
Takafumi Aizawa ◽  
Yoshito Wakui
Keyword(s):  
Pore Size ◽  
Gas Permeability ◽  
Physical Property ◽  
Polymer Fibers ◽  
Darcy Law ◽  
Compression Method ◽  
Porosity Reduction ◽  
Sintered Porous Material ◽  
Porosity And Permeability ◽  
Size Data

A porous filter was fabricated by plasticizing polymer fibers with CO2, followed by pressing and adhering; then, its gas permeability, a basic physical property of filters, was measured using N2. The as-obtained filter was well compressed and expected to approximate a sintered porous material. Therefore, the fabricated filter was analyzed by applying the Darcy law, and the correlation between its gas permeability and porosity was clarified. The gas permeability decreased owing to both pore size and porosity reduction upon increasing the degree of compression, which is a feature of the CO2-assisted polymer compression method. In particular, without any contradiction of pore size data previously reported, the gas permeability was clearly determined by the filter porosity and pore size. This study can serve as a guide for designing filters via CO2-assisted polymer compression.

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