Overpressure Identification Using The Eaton Method on The Gumai Formation of Geragai Graben, Jambi Sub Basin

2020 ◽  
Author(s):  
A. O. Marnila
Keyword(s):  
Pressure Data ◽  
Stratigraphic Sequence ◽  
Fine Grained ◽  
Marine Sedimentation ◽  
Plot Analysis ◽  
Significant Reversal ◽  
Porosity And Permeability ◽  
Upper Level ◽  
Type Data ◽  
Fine Grained Sand

Geragai graben is located in the South Sumatera Basin. It was formed by mega sequence tectonic process with various stratigraphic sequence from land and marine sedimentation. One of the overpressure indication zones in the Geragai graben is in the Gumai Formation, where the sedimentation is dominated by fine grained sand and shale with low porosity and permeability. The aim of the study is to localize the overpressure zone and to analyze the overpressure mechanism on the Gumai Formation. The Eaton method was used to determine pore pressure value using wireline log data, pressure data (RFT/FIT), and well report. The significant reversal of sonic and porosity log is indicating an overpressure presence. The cross-plot analysis of velocity vs density and fluid type data from well reports were used to analyze the causes of overpressure in the Gumai Formation. The overpressure in Gumai Formation of Geragai graben is divided into two zones, they are in the upper level and lower level of the Gumai Formation. Low overpressure have occurred in the Upper Gumai Formation and mild overpressure on the Lower Gumai Formation. Based on the analyzed data, it could be predicted, that the overpressure mechanism in the Upper Gumai Formation might have been caused by a hydrocarbon buoyancy, whereas in the Lower Gumai Formation, might have been caused by disequilibrium compaction as a result of massive shale sequence.

scholarly journals Aplicações de técnicas geofísicas na parte emersa da Baía de Guanabara: uma revisão bibliográfica

2003 ◽  
Vol 26 ◽  
pp. 117-126
Author(s):  
Paula Lucia Ferrucio da Rocha
Keyword(s):  
Salt Water ◽  
Original Data ◽  
Clay Material ◽  
Signal Attenuation ◽  
Marine Clay ◽  
Stratigraphic Sequence ◽  
Fine Grained ◽  
Deep Layers ◽  
Ground Penetrating ◽  
Fine Grained Sand

This paper presents the application of the geophysical techniques on two investigations around of Baía de Guanabara, Rio de Janeiro. The first one was carried out in the area of the Petroflex, a petrochemical industry, located at Campos Elíseos area in the bank of the bay and the second one at Ilha do Fundão, one of the island slocated in Guanabara bay. According to Anjos et al.. (2001) the research at Petroflex area was part of the company Social Project: "Conheça seu Manguezal" (Knowing your mangrove). For this research the geophysical survey was applied within the industrial park in order to identify solid waste contamination (rubber, plastic and metal barrels). The Ground Penetrating Radar (GPR) technique was used with the RAMAC/MALA equipment. The study area consists of clay and sands deposited in marine conditions, which are frequently contaminated by salt water. In general, the GPR results obtained in both media, clay material and sediments saturated with salt water are not satisfactory. However the results obtained in the Petroflex area were good. The stratigraphic sequence in the area is the following, from top to bottom: The first bed is a clay landfill, the second bed is formed by dark marine clay, and the third bed is composed of fine-grained sand with marine shells. The surveys originated sections with average depths of 14 m and average velocity of 70 m/µs. The results showed two physical discontinuities within the second bed (marine clay), which possibly represent a Pleistocene platform exposition, described in the literature as Guanabariana Regression. It was also possible to identify anomalies within the first bed (clay landfill) represented by signal attenuation, and the others identify waste deposits, where the presence of buried drums was verified. Such work has demonstrated the success of GPR applicability even to clay soil contaminated by salt water. The Ilha do Fundão where the second investigation took place, according to Rocha et al. (1998) is the result of an artificial embankment of a former small archipelago, built in the early 1950's. The aim of this work was to identify, by means of a geoelectric survey, the cores of the original islands. Normally, structures near the seacoast cannot be detected through geoelectric measurements. This is due to the presence of salt water in sediments. However, in the Ilha do Fundão case, the high electric conductivity sediments have a lens shaped with small thickness and correspond to the embankments. This circumstance allows the detection of deep layers and resistive nuclei. Results were obtained from vertical electric soundings using Schlumberger configuration with a maximum aperture (ab/2) of 100 m. The original data was published in Rocha et al. (1998).

scholarly journals Reservoir quality and its controlling diagenetic factors in the Bentiu Formation, Northeastern Muglad Basin, Sudan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yousif M. Makeen ◽  
Xuanlong Shan ◽  
Mutari Lawal ◽  
Habeeb A. Ayinla ◽  
Siyuan Su ◽  
...  
Keyword(s):  
Clay Content ◽  
Petroleum Exploration ◽  
Reservoir Quality ◽  
Burial Depth ◽  
Petroleum Reservoir ◽  
Fine Grained ◽  
Porosity And Permeability ◽  
Negative Role ◽  
Crevasse Splay ◽  
Channel Deposits

AbstractThe Abu Gabra and Bentiu formations are widely distributed within the interior Muglad Basin. Recently, much attention has been paid to study, evaluate and characterize the Abu Gabra Formation as a proven reservoir in Muglad Basin. However, few studies have been documented on the Bentiu Formation which is the main oil/gas reservoir within the basin. Therefore, 33 core samples of the Great Moga and Keyi oilfields (NE Muglad Basin) were selected to characterize the Bentiu Formation reservoir using sedimentological and petrophysical analyses. The aim of the study is to de-risk exploration activities and improve success rate. Compositional and textural analyses revealed two main facies groups: coarse to-medium grained sandstone (braided channel deposits) and fine grained sandstone (floodplain and crevasse splay channel deposits). The coarse to-medium grained sandstone has porosity and permeability values within the range of 19.6% to 32.0% and 1825.6 mD to 8358.0 mD respectively. On the other hand, the fine grained clay-rich facies displays poor reservoir quality as indicated by porosity and permeability ranging from 1.0 to 6.0% and 2.5 to 10.0 mD respectively. A number of varied processes were identified controlling the reservoir quality of the studies samples. Porosity and permeability were enhanced by the dissolution of feldspars and micas, while presence of detrital clays, kaolinite precipitation, iron oxides precipitation, siderite, quartz overgrowths and pyrite cement played negative role on the reservoir quality. Intensity of the observed quartz overgrowth increases with burial depth. At great depths, a variability in grain contact types are recorded suggesting conditions of moderate to-high compactions. Furthermore, scanning electron microscopy revealed presence of micropores which have the tendency of affecting the fluid flow properties in the Bentiu Formation sandstone. These evidences indicate that the Bentiu Formation petroleum reservoir quality is primarily inhibited by grain size, total clay content, compaction and cementation. Thus, special attention should be paid to these inhibiting factors to reduce risk in petroleum exploration within the area.

Failures of avionic generators and contactors operated under harsh ambient conditions

2012 ◽  
Vol 30 (1) ◽  
pp. 153-176
Author(s):  
Andrzej Gębura ◽  
Tomasz Radoń
Keyword(s):  
Climatic Conditions ◽  
Ambient Conditions ◽  
Power Devices ◽  
Lower Intensity ◽  
Fine Grained ◽  
Rotary Machines ◽  
Paint Coatings ◽  
Corrosion Pits ◽  
Fine Grained Sand ◽  
Final Consequence

The paper outlines failures of selected avionic electric power devices operated onboard of combat helicopters in Iraq and Afghanistan. While the authors were examining the electric power system of aircrafts in order to prolong their operation life they paid attention to numerous symptoms of wear demonstrated by some units of aircrafts. It was peculiar that such symptoms have never appeared during similar examinations of aircrafts operated in our country. By all accounts, the weird wear of components results from high intensity of flights and specific features of operating missions, but harsh climatic conditions seem to be the crucial factor. The authors believe that many of spotted failures experienced by electric power equipment may also happen to aircrafts operated in Poland but obviously, due to much lower intensity of operation and mild impact of environmental factors, such failures shall occur much later. The authors focused their attention on two groups of electric devices and associated destructive factors: 1. Air-cooled electric rotary machines. Fine-grained sand sucked together with air leads to very quick abrasion of protective paint coatings inside the machines. Not frequent but intense rainfalls are the reason for appearance of corrosion pits that lead to such effects as increase of pole shoe volumes. This, in turn, results in shearing of winding insulations with breakdowns (shorts) to ground and, as a final consequence, considerable drop of power demonstrated by an electric machine. 2. Contactors and electromagnets, which are allegedly tight. However, dust penetrates anyway via microfissures and disables operation of moving parts.

scholarly journals Granite micro-porosity changes due to fracturing and alteration: secondary mineral phases as proxies for porosity and permeability estimation

2018 ◽  
Author(s):  
Martin Staněk ◽  
Yves Géraud
Keyword(s):  
Mercury Intrusion Porosimetry ◽  
Fluorescent Light ◽  
Fracture Density ◽  
Void Space ◽  
Mercury Intrusion ◽  
Fine Grained ◽  
Mineral Phases ◽  
Space Geometry ◽  
Porosity And Permeability ◽  
The Difference

Abstract. Several alteration facies of fractured Lipnice granite are studied in detail on borehole samples by means of mercury intrusion porosimetry, polarized and fluorescent light microscopy and microprobe chemical analyses. The goal is to describe the granite void space geometry in vicinity of fractures with alteration halos and to link specific geometries with simply detectable parameters to facilitate quick estimation of porosity and permeability based on e.g. drill cuttings. The core of the study are results of porosity and throat size distribution analyses on 21 specimens representing unique combinations of fracture-related structures within 6 different alteration facies basically differing in secondary phyllosilicate chemistry and porosity structure. Based on a simple model to calculate permeability from the measured porosities and throat size distributions the difference in permeability between the fresh granite and the most fractured and altered granite is 5 orders of magnitude. Our observations suggest that the porosity, the size of connections and the proportion of crack porosity increase with fracture density, while precipitation of iron-rich infills as well as of fine grained secondary phyllosilicates acts in the opposite way. Different styles and intensities of such end-member agents shape the final void space geometry and imply various combinations of storage, transport and retardation capacity for specific structures. The study also shows the possibility to use the standard mercury intrusion porosimetry with advanced experimental setting and data treatment to distinguish important differences in void space geometry within a span of few per cent of porosity.

Durable Architectural and Decorative Powder-Activated Concrete Using Waste-Crushing Stone Rocks

2019 ◽  
Vol 802 ◽  
pp. 1-15
Author(s):  
Sergey Victorovich Daletsky ◽  
Yuri Mikhailovich Kolitievsky ◽  
Victor Vasilievich Nikonov ◽  
Nikolay Nikolaevich Sirotin ◽  
Vladimir Vladimirovich Yudaev
Keyword(s):  
High Strength ◽  
High Density ◽  
Term Operation ◽  
Fine Grained ◽  
Concrete Mixtures ◽  
Technical Properties ◽  
Fine Grained Sand

The article consists in the development of compositions of self-compacting powder-activated fine-grained (sand) concrete mixtures, including color ones, for the production of high-density, high-strength and durable architectural and decorative concretes, which do not lose their architectural appeal during long-term operation, on the basis of multi-tonnage waste of stone crushing of various rocks, without the use of expensive mineral reactive components and the study of their physical and technical properties.

Particle size distributions of radioactive pollution soils and its influence on consistence of the shelterbelt forest ranges

2015 ◽  
Vol 5 (2) ◽  
pp. 93-103
Author(s):  
Маркина ◽  
Zoya Markina ◽  
Вечеров ◽  
Vladislav Vecherov
Keyword(s):  
Size Distributions ◽  
Clay Loam ◽  
Particle Size Distributions ◽  
Glacial Deposits ◽  
Parent Materials ◽  
Fine Grained ◽  
Soil Fractions ◽  
South West ◽  
Dominant Soil ◽  
Fine Grained Sand

Presents characteristic of the soil texture that formed at mixture of moraine and fluvial-glacial deposits, moraine that overlaid clay loam mantle, clay loam mantle in shelterbelt forest ranges at south-west areas of the Bryansk region that contaminate radioactive fallouts in conse-quence of the Chernobyl accident. Dominant soil fractions determined in soil horizonts, its formed at different parent rock materials. There is a growing number of fine-grained sand and silt soil fractions in the moraine overlaid clay loam mantle compared to fluvio-glacial deposits in the relief of parent materials.

scholarly journals Post-Caledonian sediments in North-East Greenland between 76° and 78°30'N

1990 ◽  
Vol 148 ◽  
pp. 123-126
Author(s):  
L Stemmerik ◽  
S Piasecki
Keyword(s):  
Lower Cretaceous ◽  
Middle Jurassic ◽  
East Greenland ◽  
Fine Grained ◽  
North East ◽  
Fine Grained Sand

Post-Caledonian sediments in North-East Greenland between 76° and 78° 30´N are, with the exception of an outlier near Kulhøj, restricted to Store Koldewey. The sediments on Store Koldewey, believed to span the Middle Jurassic to Lower Cretaceous (Callovian to Aptian), are dominated by fine-grained sand and silt. They contain a rich macrofauna which, together with material collected for microfloral investigations, will form the basis for a detailed stratigraphy and dating of the sequence.

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