scholarly journals Application of Seismuc Attribute Analysis to Reserch the Distribution of Middle Miocene Coral Reef Carbonate in Block 04-3, Nam Con Son Basin

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Pham Bao Ngoc ◽  
Tran Trung Dong ◽  
Tran Nghi ◽  
Nguyen Thi Phuong Thao ◽  
Tran Thi Oanh ◽  
...  
Keyword(s):  
Middle Miocene ◽  
Maximum Amplitude ◽  
Well Log ◽  
Carbonate Sediments ◽  
High Concentration ◽  
Root Mean Square Amplitude ◽  
Seismic Properties ◽  
Amplitude Maximum ◽  
Attribute Analysis ◽  
Carbonate Formations

The seismic properties of Root Mean Square Amplitude, Maximum Amplitude, and Sum of Positive Amplitude most clearly reflect the distribution characteristics of middle Miocene carbonate sediments in ​​block 04-3, Nam Con Son basin. Middle Miocene carbonate is commonly distributed on both reflection surfaces of  P1 and P2. Within each reflective surface, carbonate sediments are concentrated around the uplifting zones, such as structures of Thien Ung - Mang Cau, Dai Hung and Bo Cau. These are completely consistent with the results of the interpretation of well-log data of Vietsovpetro, VSP [1]. The wells C-2X and C-4X  located at the edge of the uplifting zone should have the thickest carbonates. According to the results of amplitude attribute analysis, these wells are distributed in the high concentration area of carbonate formations. Meanwhile well C-1X  and well C-3X, which are near the top of the uplifting zone and further away from the uplifting structure have thin carbonate set and belongs to a low carbonate density area.

The Characteristic of Algal Reef Carbonate Sedimentary and Pore Structure in the Xisha Islands: Evidence from Halimeda

2014 ◽  
Vol 1065-1069 ◽  
pp. 3291-3294
Author(s):  
Xin Wei Zhao ◽  
Hui Zhi Hao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Spectrum ◽  
Middle Miocene ◽  
Carbonate Sediments ◽  
Network Systems ◽  
Xisha Islands ◽  
Intercrystalline Pores ◽  
Algal Reef ◽  
Scanning Electron

Halimeda is an important reef-building green alga. Scanning electron microscopy (SEM) and energy spectrum tests on green and white Halimeda collected from Shidao Island in the Xisha Islands show that carbonate is predominantly deposited in the cortexes and medullas, especially in the aragonite raphides of them, as the case of calcium carbonate. These modern carbonate sediments are then compared with their ancient counterparts that are collected from Xichen-1 well in the Yongle Atoll, where a large number of Halimeda segments have been recognized in about 100-m-long late Miocene-middle Miocene whole-coring succession. In addition, there are developed great numbers of algal-frame holes, including secondary dissolved pores and intercrystalline pores in the medullas and in aragonites between cysts, which have formed particular network systems and pore throats.

Predict Channel Sand Body Distribution Characteristics of South Eighth District Based on RMS Amplitude Attributes & Frequency Division

2013 ◽  
Vol 734-737 ◽  
pp. 404-407 ◽  
Author(s):  
Yu Shuang Hu ◽  
Si Miao Zhu
Keyword(s):  
Seismic Data ◽  
Physical Property ◽  
Sedimentary Facies ◽  
Distribution Area ◽  
Frequency Division ◽  
Root Mean Square Amplitude ◽  
Seismic Attribute ◽  
Body Distribution ◽  
Attribute Analysis ◽  
Sand Body

A big tendency in oil industry is underestimating the heterogeneity of the reservoir and overestimating the connectivity, which results in overly optimistic estimates of the capacity. With the development of seismic attributes, we could pick up hidden reservoir lithology and physical property information from the actual seismic data, strengthen seismic data application in actual work, to ensure the objectivity of the results. In this paper, the channel sand body distribution in south eighth district of oilfield Saertu is predicted through seismic data root-mean-square amplitude and frequency division to identify sand body boundaries, predict the distribution area channel sand body characteristics successfully, which consistent with the sedimentary facies distribution. The result proves that seismic attribute analysis has good practicability in channel sand body prediction and sedimentary facies description.

scholarly journals Quantitative seismic interpretation of the Lower Cretaceous reservoirs in the Valdemar Field, Danish North Sea

2021 ◽  
pp. petgeo2021-016
Author(s):  
K. Bredesen ◽  
M. Lorentzen ◽  
L. Nielsen ◽  
K. Mosegaard
Keyword(s):  
Lower Cretaceous ◽  
Water Saturation ◽  
Rock Physics ◽  
Seismic Signal ◽  
Seismic Interpretation ◽  
Reservoir Quality ◽  
Well Log ◽  
Field Development ◽  
Attribute Analysis ◽  
Complex Geology

A quantitative seismic interpretation study is presented for the Lower Cretaceous Tuxen reservoir in the Valdemar Field, which is associated with heterogeneous and complex geology. Our objective is to better outline the reservoir quality variations of the Tuxen reservoir across the Valdemar Field. Seismic pre-stack data and well logs from two appraisal wells forms the basis of this study. The workflow used includes seismic and rock physics forward modelling, attribute analysis, a coloured inversion and a Bayesian pre-stack inversion for litho-fluid classification. Based on log data, the rock physics properties of the Tuxen interval reveals that the seismic signal is more governed by porosity than water saturation changes at near-offset (or small-angle). The coloured and Bayesian inversion results were generally consistent with well-log observations at the reservoir level and conformed to interpreted horizons. Although the available data has some limitations and the geological setting is complex, the results implied more promising reservoir quality in some areas than others. Hence, the results may offer useful information for delineating the best reservoir zones for further field development and selecting appropriate production strategies.

Multiscale characterization of pore structure in carbonate formations: Application to the Scurry Area Canyon Reef Operators Committee Unit

2016 ◽  
Vol 4 (2) ◽  
pp. SF165-SF177 ◽  
Author(s):  
Emmanuel Oyewole ◽  
Mehrnoosh Saneifar ◽  
Zoya Heidari
Keyword(s):  
Pore Structure ◽  
Pore Network ◽  
Effective Porosity ◽  
Well Log ◽  
Porosity And Permeability ◽  
Network Properties ◽  
Log Domain ◽  
Carbonate Formations ◽  
Pore Types

Carbonate formations consist of a wide range of pore types with different shapes, pore-throat sizes, and varying levels of pore-network connectivity. Such heterogeneous pore-network properties affect the fluid flow in the formation. However, characterizing pore-network properties (e.g., effective porosity and permeability) in carbonate formations is challenging due to the heterogeneity at different scales and complex pore structure of carbonate rocks. We have developed an integrated technique for multiscale characterization of carbonate pore structure based on mercury injection capillary pressure (MICP) measurements, X-ray micro-computed tomography (micro-CT) 3D rock images, and well logs. We have determined pore types based on the pore-throat radius distributions obtained from MICP measurements. We developed a new method for improved assessment of effective porosity and permeability in the well-log domain using pore-scale numerical simulations of fluid flow and electric current flow in 3D micro-CT core images obtained in each pore type. Finally, we conducted petrophysical rock classification based on the depth-by-depth estimates of effective porosity, permeability, volumetric concentrations of minerals, and pore types using an unsupervised artificial neural network. We have successfully applied the proposed technique to three wells in the Scurry Area Canyon Reef Operators Committee (SACROC ) Unit. Our results find that electrical resistivity measurements can be used for reliable characterization of pore structure and assessment of effective porosity and permeability in carbonate formations. The estimates of permeability in the well-log domain were cross-validated using the available core measurements. We have observed a 34% improvement in relative errors in well-log-based estimates of permeability, as compared with the core-based porosity-permeability models.

scholarly journals Application of 3D Seismic Attribute Analyses for Hydrocarbon Prospectivity in Uzot-Field, Onshore Niger Delta Basin, Nigeria

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
U. C. Omoja ◽  
T. N. Obiekezie
Keyword(s):  
Niger Delta ◽  
Hanging Wall ◽  
Average Energy ◽  
Maximum Amplitude ◽  
Seismic Attributes ◽  
Bright Spot ◽  
Maximum Magnitude ◽  
3D Seismic ◽  
Amplitude Maximum ◽  
Niger Delta Basin

3D seismic interpretative study was carried out across the Uzot-field in the western Coastal Swamp Depobelt of the onshore Niger Delta Basin, Nigeria, with the aim to identify possible hydrocarbon leads and prospects away from the drilled zone, utilizing seismic amplitude attributes. The method employed in this study involved systematic picking of faults and mapping of horizons/reservoir tops across seismic volume and extraction of seismic attributes. Structural analysis indicates the presence of down-to-basin footwall and hanging wall faults associated with rollover anticlines and horst-block (back-to-back fault). Generated time and depth structural maps from three reservoir intervals (D3100, D5000, and D9000) revealed the presence of fault dependent closure across the field. Analyses of relevant seismic attributes such as root-mean-square (RMS) amplitude, maximum amplitude, average energy amplitude, average magnitude amplitude, maximum magnitude attribute, and standard deviation amplitude, which were applied on reservoir tops, revealed sections with bright spot anomalies. These amplitude anomalies served as direct hydrocarbon indicators (DHIs), unravelling the presence and possible hydrocarbon prospective zones. In addition, structural top maps show that booming amplitude is seen within the vicinity of fault closures, an indication that these hydrocarbon prospects are structurally controlled. Results from this study have shown that, away from currently producing zone at the central part of the field, additional leads and prospects exist, which could be further evaluated for hydrocarbon production.

scholarly journals Organic content and maturation effects on elastic properties of source rock shales in the Central North Sea

2019 ◽  
Vol 7 (2) ◽  
pp. T477-T497 ◽  
Author(s):  
Jørgen André Hansen ◽  
Nazmul Haque Mondol ◽  
Manzar Fawad
Keyword(s):  
Elastic Properties ◽  
Source Rock ◽  
North Sea ◽  
Empirical Relation ◽  
Organic Content ◽  
Rock Properties ◽  
Geochemical Data ◽  
Well Log ◽  
Seismic Properties ◽  
Central North Sea

We have investigated the effects of organic content and maturation on the elastic properties of source rock shales, mainly through integration of a well-log database from the Central North Sea and associated geochemical data. Our aim is to improve the understanding of how seismic properties change in source rock shales due to geologic variations and how these might manifest on seismic data in deeper, undrilled parts of basins in the area. The Tau and Draupne Formations (Kimmeridge shale equivalents) in immature to early mature stages exhibit variation mainly related to compaction and total organic carbon (TOC) content. We assess the link between depth, acoustic impedance (AI), and TOC in this setting, and we express it as an empirical relation for TOC prediction. In addition, where S-wave information is available, we combine two seismic properties and infer rock-physics trends for semiquantitative prediction of TOC from [Formula: see text] and AI. Furthermore, data from one reference well penetrating mature source rock in the southern Viking Graben indicate that a notable hydrocarbon effect can be observed as an addition to the inherently low kerogen-related velocity and density. Published Kimmeridge shale ultrasonic measurements from 3.85 to 4.02 km depth closely coincide with well-log measurements in the mature shale, indicating that upscaled log data are reasonably capturing variations in the actual rock properties. Amplitude variation with offset inversion attributes should in theory be interpreted successively in terms of compaction, TOC, and maturation with associated generation of hydrocarbons. Our compaction-consistent decomposition of these effects can be of aid in such interpretations.

Frequency-dependent seismic anisotropy due to fractures: Fluid flow versus scattering

Geophysics ◽  
2013 ◽  
Vol 78 (2) ◽  
pp. WA111-WA122 ◽  
Author(s):  
Alan F. Baird ◽  
J.-Michael Kendall ◽  
Doug A. Angus
Keyword(s):  
Fluid Flow ◽  
Seismic Anisotropy ◽  
Fractured Rock ◽  
High Concentration ◽  
Frequency Dependent ◽  
Similar Frequency ◽  
Seismic Properties ◽  
Microseismic Data ◽  
Fracture Parameters ◽  
Mineral Scale

Anisotropy is a useful attribute for the detection and characterization of aligned fracture sets in petroleum reservoirs. Unfortunately, many of the traditional effective medium theories for modeling the seismic properties of fractured rock are insensitive to the size of the constituent fractures. For example, the same pattern of anisotropy may be produced by a high concentration of small, stiff cracks or by a lower concentration of large, compliant fractures. The distinction between these models is important for assessing permeability anisotropy because fluid flow is dominated by the largest fractures. One method to gain further insight is through the analysis of frequency-dependent shear-wave splitting in microseismic data because fracture compliance is frequency dependent, and microseismic data are relatively rich in frequency content. We compared two potential mechanisms causing frequency-dependent compliance of fractures: (1) squirt flow in fractured porous rock and (2) wave scattering over rough fractures. Both models showed a sensitivity to average fracture size or compliance of the constituent fractures, and thus they provide a potential means to differentiate between anisotropy produced by small cracks or large fractures. We used both mechanisms to model frequency-dependent anisotropy data obtained from a fractured gas reservoir and invert for fracture parameters. Under certain conditions, the squirt-flow mechanism can cause significant frequency dependence in the microseismic band. However, the model is highly sensitive to the empirically derived mineral-scale relaxation time, which is poorly known and requires laboratory measurements to constrain. Conversely, producing a similar frequency response using the scattering model requires implausible fracture parameters; therefore, the squirt-flow model appears to be the most likely mechanism for microseismic applications. At higher frequencies, however, scattering may become more significant. Care should be taken when upscaling ultrasonic laboratory results for field-scale problems because different mechanisms may be at play within different frequency bands.

scholarly journals On <i>Pseudotaberina malabarica</i> (Carter) <i>(Foraminiferida)</i>

1989 ◽  
Vol 8 (1) ◽  
pp. 113-129 ◽  
Author(s):  
F. T. Banner ◽  
J. Highton
Keyword(s):  
Type Species ◽  
Middle Miocene ◽  
Carbonate Sediments ◽  
Inner Shelf ◽  
History Of

Abstract. Pseudotaberina Eames, 1971, has as its (originally designated) type species Orbitolites malabarica Carter, 1853. The taxonomic and nomenclatural history of P. malabarica is given, and the diagnoses of both the genus and the species are corrected and emended, following re-examination of the type and other relevant specimens. A lectotype is selected and, with syntypes, strict topotypes and other specimens, is used for redescription of the species. P. malabarica is believed to characterise Early to Middle Miocene marine, inner shelf carbonate sediments of Tethys.

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