scholarly journals UPPER EARTH CRUST’S REFRACTION HORIZONS ON TRAVERSE 1-SB (TRANSBAIKALIAN PART)

2019 ◽  
Vol 2 (2) ◽  
pp. 11-18
Author(s):  
Pavel Polyansky ◽  
Alexander Emanov ◽  
Alexandr Salnikov
Keyword(s):  
Seismic Data ◽  
Digital Processing ◽  
Crystalline Basement ◽  
Depth Interval ◽  
Upper Crust ◽  
Intrusive Body ◽  
Fold Belt ◽  
Head Waves ◽  
Seismic Sections

Digital processing of seismic data, which are registered on Transbaikalian part of reference geophysical profile 1-SB, is executed. These data are registered on CDP source-receiver configuration. Time sections images and wavefields of P- and S- head waves are result from technique of head waves dynamic conversion. These time sections are image a structure of refraction boundaries on the upper Earth crust on some areas of Argunskaya fold area, Mongol-Okhotsky fold belt, West-Stanovaya and Selengino-Yablonevaya fold areas. Seismic sections of depth interval of 0-2 km are constructed. Boundaries of intrusive body are detected on upper crust of Argunskaya fold area. This body is underlying lens shaped sedimentary layers on depth interval of 0.5÷1.0 km. Top of crystalline basement is established on the depth interval of 1.6-2.0 km on the northern part of Mongol-Okhotsky fold belt.

scholarly journals SEISMIC MODEL OF THE UPPER EARTH`s CRUST ON NORTH-EAST PART OF TRAVERSE 3-DV BASED ON RESULTS OF HEAD WAVES DIGITAL PROCESSING

2021 ◽  
Vol 2 (2) ◽  
pp. 225-233
Author(s):  
Pavel O. Polyansky ◽  
Alexander F. Emanov ◽  
Alexandr S. Salnikov
Keyword(s):  
Sedimentary Cover ◽  
Mineral Resources ◽  
Digital Processing ◽  
Velocity Model ◽  
Depth Interval ◽  
Tectonic Block ◽  
East Part ◽  
North East ◽  
Head Waves ◽  
Refracted Waves

Digital processing of refracted waves data, which are registered on North-East part of profile3-DV, is done. Time sections and velocity model are formed. It is proved, that refraction horizons on depth interval of 0-1.5 km are geologic boundaries in sedimentary cover on Ayan-Yuryakh tectonic block. Refraction boundary on depth of ~1.0 km is not lithologic border on Inyaly-Debin block. Layers, which are potentially productive for ore mineral resources, are substracted by low values of V/V (1.66-1.70) on depth below 1.0 km, on Inyaly-Debin block and Orotukan-Balygychan elevation.

Upper earth crust’s seismic structure on conjuction zone of Eurasian and Okhotomorskaya plates (according to head waves data)

2020 ◽  
Author(s):  
Pavel O. Polyansky ◽  
◽  
Alexander F. Emanov ◽  
Alexandr S. Salnikov ◽  
◽  
...  
Keyword(s):  
Digital Processing ◽  
Earth’S Crust ◽  
Depth Interval ◽  
Seismic Structure ◽  
Seismic Model ◽  
East Part ◽  
North East ◽  
Head Waves ◽  
Earth's Crust

Digital processing of CDP–data, which are registered on North–East part of profile 3–DV, is done. Time sections which are result from method of head waves dynamic conversion were achieved for tectonic blocks are located at conjuction zone of Eurasian and Okhotomorskaya plates. Coefficients of refraction on the upper Earth’s crust were calculated based on frequencies difference between initial seismic traces and traces–results of processing. Seismic model of 0–2 km depth interval was constructed.

scholarly journals Pitfalls and limitations in seismic attribute interpretation of tectonic features

2015 ◽  
Vol 3 (1) ◽  
pp. SB5-SB15 ◽  
Author(s):  
Kurt J. Marfurt ◽  
Tiago M. Alves
Keyword(s):  
Seismic Data ◽  
Seismic Attributes ◽  
Seismic Attribute ◽  
3D Data ◽  
Amplitude Data ◽  
Seismic Sections ◽  
Push Down ◽  
Data Coherence ◽  
Level Of Experience ◽  
Tectonic Features

Seismic attributes are routinely used to accelerate and quantify the interpretation of tectonic features in 3D seismic data. Coherence (or variance) cubes delineate the edges of megablocks and faulted strata, curvature delineates folds and flexures, while spectral components delineate lateral changes in thickness and lithology. Seismic attributes are at their best in extracting subtle and easy to overlook features on high-quality seismic data. However, seismic attributes can also exacerbate otherwise subtle effects such as acquisition footprint and velocity pull-up/push-down, as well as small processing and velocity errors in seismic imaging. As a result, the chance that an interpreter will suffer a pitfall is inversely proportional to his or her experience. Interpreters with a history of making conventional maps from vertical seismic sections will have previously encountered problems associated with acquisition, processing, and imaging. Because they know that attributes are a direct measure of the seismic amplitude data, they are not surprised that such attributes “accurately” represent these familiar errors. Less experienced interpreters may encounter these errors for the first time. Regardless of their level of experience, all interpreters are faced with increasingly larger seismic data volumes in which seismic attributes become valuable tools that aid in mapping and communicating geologic features of interest to their colleagues. In terms of attributes, structural pitfalls fall into two general categories: false structures due to seismic noise and processing errors including velocity pull-up/push-down due to lateral variations in the overburden and errors made in attribute computation by not accounting for structural dip. We evaluate these errors using 3D data volumes and find areas where present-day attributes do not provide the images we want.

On the Processing of Non-Rectangularly Sampled Multi-Dimensional Geophysical Data

1991 ◽  
Vol 02 (01) ◽  
pp. 223-226
Author(s):  
VIRGIL BARDAN
Keyword(s):  
Seismic Data ◽  
Geophysical Data ◽  
Seismic Sections

In this paper the processing of triangularly sampled 2-D seismic data is illustrated by examples of synthetic and field seismic sections.

Using Logging and Seismic Data to Identify Boundaries Between Different OWC Units in a Deepwater Carbonate Reservoirs

2021 ◽  
Author(s):  
Kangxu Ren ◽  
Junfeng Zhao ◽  
Jian Zhao ◽  
Xilong Sun
Keyword(s):  
Seismic Data ◽  
Carbonate Rocks ◽  
Carbonate Reservoir ◽  
Carbonate Reservoirs ◽  
Sedimentary Process ◽  
Core Samples ◽  
Tight Carbonate ◽  
Porosity And Permeability ◽  
Seismic Sections ◽  
Parameters Inversion

Abstract At least three very different oil-water contacts (OWC) encountered in the deepwater, huge anticline, pre-salt carbonate reservoirs of X oilfield, Santos Basin, Brazil. The boundaries identification between different OWC units was very important to help calculating the reserves in place, which was the core factor for the development campaign. Based on analysis of wells pressure interference testing data, and interpretation of tight intervals in boreholes, predicating the pre-salt distribution of igneous rocks, intrusion baked aureoles, the silicification and the high GR carbonate rocks, the viewpoint of boundaries developed between different OWC sub-units in the lower parts of this complex carbonate reservoirs had been better understood. Core samples, logging curves, including conventional logging and other special types such as NMR, UBI and ECS, as well as the multi-parameters inversion seismic data, were adopted to confirm the tight intervals in boreholes and to predicate the possible divided boundaries between wells. In the X oilfield, hundreds of meters pre-salt carbonate reservoir had been confirmed to be laterally connected, i.e., the connected intervals including almost the whole Barra Velha Formation and/or the main parts of the Itapema Formation. However, in the middle and/or the lower sections of pre-salt target layers, the situation changed because there developed many complicated tight bodies, which were formed by intrusive diabase dykes and/or sills and the tight carbonate rocks. Many pre-salt inner-layers diabases in X oilfield had very low porosity and permeability. The tight carbonate rocks mostly developed either during early sedimentary process or by latter intrusion metamorphism and/or silicification. Tight bodies were firstly identified in drilled wells with the help of core samples and logging curves. Then, the continuous boundary were discerned on inversion seismic sections marked by wells. This paper showed the idea of coupling the different OWC units in a deepwater pre-salt carbonate play with complicated tight bodies. With the marking of wells, spatial distributions of tight layers were successfully discerned and predicated on inversion seismic sections.

scholarly journals Seismic Data Interpretation and Identification of Hydrocarbon-Bearing Zones of Rajian Area, Pakistan

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 891
Author(s):  
Naveed Ahmad ◽  
Sikandar Khan ◽  
Eisha Fatima Noor ◽  
Zhihui Zou ◽  
Abdullatif Al-Shuhail
Keyword(s):  
Seismic Data ◽  
Foreland Basin ◽  
Data Interpretation ◽  
Indus Basin ◽  
Subsurface Structure ◽  
Vertical Wells ◽  
Salt Range ◽  
Seismic Sections ◽  
The Given ◽  
Triangular Zone

The present study interprets the subsurface structure of the Rajian area using seismic sections and the identification of hydrocarbon-bearing zones using petrophysical analysis. The Rajian area lies within the Upper Indus Basin in the southeast (SE) of the Salt Range Potwar Foreland Basin. The marked horizons are identified using formation tops from two vertical wells. Seismic interpretation of the given 2D seismic data reveals that the study area has undergone severe distortion illustrated by thrusts and back thrusts, forming a triangular zone within the subsurface. The final trend of those structures is northwest–southeast (NW–SE), indicating that the area is part of the compressional regime. The zones interpreted by the study of hydrocarbon potential include Sakessar limestone and Khewra sandstone. Due to the unavailability of a petrophysics log within the desired investigation depths, lithology cross-plots were used for the identification of two potential hydrocarbon-bearing zones in one well at depths of 3740–3835 m (zone 1) and 4015–4100 m (zone 2). The results show that zone 2 is almost devoid of hydrocarbons, while zone 1 has an average hydrocarbon saturation of about 11%.

Identification of submarine landslides in the Colombian Caribbean Margin (Southern Sinú Fold Belt) using seismic investigations

2021 ◽  
Vol 40 (12) ◽  
pp. 914-922
Author(s):  
Darwin Mateus Tarazona ◽  
Jorge Alonso Prieto ◽  
William Murphy ◽  
Julian Naranjo Vesga
Keyword(s):  
Seismic Data ◽  
Transport Processes ◽  
Submarine Landslides ◽  
Fold Belt ◽  
Study Zone ◽  
Internal Deformation ◽  
Ground Condition ◽  
Transport Complex ◽  
Continental Shelf Break ◽  
3D Seismic Data

Submarine landslides can be triggered by several processes and involve a variety of mechanisms. These phenomena are important sediment transport processes, but they also constitute a significant geohazard. Mapping of the southwestern Caribbean Sea using 3D seismic data has allowed identification of several submarine landslides in the Colombian Margin in the area dominated by the Southern Sinú Fold Belt (SSFB). A poststack depth-migrated seismic cube survey with a 12.5 by 12.5 m bin spacing was used to identify landslides in an area covering 5746 km2. Landslides were interpreted using a seafloor morphologic parameter identification process and the internal deformation of the slope-forming material, as seen from seismic data. A total of 93 landslides were identified and classified based on their movement styles as follows: 52 rotational, 29 translational, and 12 complex landslides. In addition, 12 distinct deformational zones and a zone of mass transport complex (MTC) were identified. Five different ground condition terrains were interpreted based on landslide type and distribution as well as in geologic structures and seismic reflection analysis. Two main processes seem to influence landslides in the study area. First is the folding and faulting involved in the SSFB evolution. This process results in oversteepened slopes that start as deformational zones and then fail as translational or rotational slides. Those individual landslides progressively become complex landslide zones that follow geologic structural orientation. Second is the continental shelf break erosion by debris flows, which fills in intraslope subbasins and continental rise with several MTCs. According to the results, risk of damage by landslides increases in distances shorter than 4 km along structural ridge foothills in the study zone.

Seismic detection and interpretation of porosity in Carboniferous age rocks of Kansas and Oklahoma

Geophysics ◽  
1989 ◽  
Vol 54 (11) ◽  
pp. 1371-1383 ◽  
Author(s):  
M. R. Thomasson ◽  
R. W. Kettle ◽  
R. M. Lloyd ◽  
R. K. McCormack ◽  
J. P. Lindsey
Keyword(s):  
Seismic Data ◽  
Acoustic Properties ◽  
Reservoir Quality ◽  
Seismic Modeling ◽  
Work Station ◽  
South Central ◽  
Seismic Detection ◽  
Seismic Sections

Many large Mississippian fields (5–130 MMBO) in south‐central Kansas and northern Oklahoma produce from discrete pods of porous chert and dolomite called “chat.” Chat has unusual acoustic properties that allow the porosity pods to be recognized on seismic sections. Integrated geologic and geophysical studies of two analog fields indicate that both reservoir quality and geometry can be interpreted from good quality seismic data. Seismic modeling on an interactive work station plays an important role in developing these interpretations.

Supercritical reflections observed in P- and S- wave data

Geophysics ◽  
1985 ◽  
Vol 50 (2) ◽  
pp. 185-195 ◽  
Author(s):  
D. F. Winterstein ◽  
J. B. Hanten
Keyword(s):  
Seismic Data ◽  
Critical Angle ◽  
Plane Waves ◽  
Critical Distance ◽  
P Wave ◽  
S Wave ◽  
Sh Waves ◽  
Midland Basin ◽  
Head Waves ◽  
Sonic Logs

We have observed a conspicuous example of supercritical reflection in both P- and SH- wave seismic data. Data were recorded in the Midland Basin (Texas) Project of the Conoco Shear Wave Group Shoot in 1977–1978. P- and S- wave critical angle phenomena, as observed in the data, are remarkably similar. Event amplitudes are small or undetectable at offsets out to about 2 000 ft, but at offsets from 2 500 to 3 600 ft amplitudes are higher than those of any other event. Head waves originating at the critical distance are weak but detectable. Long path multiplies of the supercritical parts of P and SH events appear at expected times and offsets. Constant velocity moveout corrections helped identify them. Sonic logs in combination with a knowledge of the lithology made it possible to model P- wave critical angle phenomena. Agreement of model results with the data was good when we assumed cylindrical wavefronts. As expected, modeling based on plane waves was unable to match observed phase and amplitude behavior. A number of potential uses for supercritical reflections in exploration and data processing readily come to mind, many of them related to the recording of relatively high amplitudes at distances where source noise is low. Observed rise in amplitude near the critical offset was very abrupt, particularly for SH-waves. This suggests that variations in the onset of high amplitudes may be useful for monitoring changes in velocity contrast at the reflecting interface.

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