scholarly journals Application of 3-D FKK Filtering in 3-D High-density Onshore Seismic Field Data

2018 ◽  
Vol 23 (3) ◽  
pp. 369-376
Author(s):  
Jianping Liao ◽  
Songyuan Fu ◽  
Yungui Xu ◽  
Weibo Li ◽  
Jianxiong Chen ◽  
...  
Keyword(s):  
Field Data ◽  
High Density ◽  
Western China ◽  
Seismic Exploration ◽  
Single Shot ◽  
Ground Roll ◽  
Minimum Dataset ◽  
Synthetic Models ◽  
Better Than

For linear noise such as seismic ground roll, 3-D frequency-wavenumber-wavenumber (3-D FKK) domain filtering suppression is better than 2-D frequency-wavenumber (F-K) domain filtering. In recent years, with the continuous development of computer processing speed and memory capacity, high-density data acquisition in seismic exploration has been widely applied in the hydrocarbon industry, opening up the application of 3-D FKK filtering methods. We applied the 3-D FKK filtering software to a 3-D high-density onshore seismic field dataset from a coal mine in western China. The case study demonstrates that the linearity of the noise in the field data is better represented by constructing the single shot records as a minimum dataset. Both theoretical synthetic models and the 3-D high-density onshore seismic field data numerical filtering experiments demonstrate that the feasibility of 3-D FKK filtering.

Applying integrated seismic technology to complex foothill areas of foreland basins in China

2019 ◽  
Vol 38 (8) ◽  
pp. 597-603
Author(s):  
Yong Fang ◽  
Wenshan Luo ◽  
Xiaoxia Luo ◽  
Xukui Feng ◽  
Bo Zhao ◽  
...  
Keyword(s):  
Seismic Data ◽  
Model Building ◽  
New Technologies ◽  
High Density ◽  
Hydrocarbon Exploration ◽  
Western China ◽  
Seismic Exploration ◽  
Foreland Basins ◽  
Near Surface ◽  
True Surface

Due to complicated near-surface conditions, including large elevation changes and complex geologic structures, accurate imaging of subsurface structures for hydrocarbon exploration in the foreland basins of western China has been challenging for many years. After decades of research and fieldwork, we developed an effective seismic exploration workflow that uses the latest technologies from acquisition to imaging. They include 3D high-density and wide-azimuth (WAZ) acquisition, 3D true-surface tilted transverse isotropy (TTI) anisotropic prestack depth migration, and dual-detachment structural modeling and interpretation. To further reduce uncertainty in velocity model building and improve imaging quality, our geologists, geophysicists, and reservoir engineers worked closely through the exploration cycle (seismic acquisition, processing, and interpretation). This exploration model has been used successfully in hydrocarbon exploration of many complex foothill areas in western China. Three-dimensional WAZ high-density seismic surveys have been conducted over 40,000 km2 of the foreland basins, greatly improving the field seismic data quality. After application of 3D true-surface TTI anisotropic depth model building and imaging with integrated structural interpretation, new discoveries of hydrocarbon reservoirs have increased. The application of new technologies not only increased drilling success but also reduced depth well-tie errors between seismic data and wells.

scholarly journals 3-D Butterworth Filtering for 3-D High-density Onshore Seismic Field Data

2018 ◽  
Vol 23 (2) ◽  
pp. 223-233
Author(s):  
Jianping Liao ◽  
Hexiu Liu ◽  
Weibo Li ◽  
Zhenwei Guo ◽  
Lixin Wang ◽  
...  
Keyword(s):  
Field Data ◽  
Synthetic Data ◽  
High Density ◽  
Western China ◽  
Seismic Survey ◽  
Apparent Velocity ◽  
Coherent Noise ◽  
Space Domain ◽  
Filtering Method ◽  
Time Space

Three-dimensional seismic survey is widely applied, but 3-D filtering technology has yet to be fully utilized for the analysis of seismic field data. The common approach is to first filter inline and then crossline. However, an effective 3-D filtering method is expected to eliminate coherent noise, such as the ground roll. We propose a 3-D Butterworth filtering method in the time-space domain. Firstly, a Butterworth-type filter in the frequency-wavenumber-domain is designed to suppress the linear noise with a specific apparent velocity. Secondly, transforming this filter to the time and space domain yields 3-D partial differential equations (PDEs), which are applied to suppress the linear noise. Factorizing the finite-difference equations in a different direction other than decreasing the 3-D PDEs to 2-D PDEs produces a highly accurate and efficient algorithm. Designing the 3-D Butterworth filter, selecting the filtering parameters, and showing its application to synthetic data and a 3-D high-density onshore seismic field data from a region in western China are discussed in detail. Numerical experiments with 3-D high-density onshore seismic field data demonstrate that it is more effective than the 3-D frequency-wavenumber-wavenumber (FKK) filtering method.

A case study of high-density 3D geometry key parameters test method in western China

2018 ◽  
Author(s):  
Xiaoyang Wang ◽  
Furong Wu ◽  
Jiangli Chen ◽  
Fuguo Wang ◽  
Chengyi Li ◽  
...  
Keyword(s):  
High Density ◽  
Test Method ◽  
Western China ◽  
3D Geometry

Compressive seismic data acquisition in a desert area of western China: A case study

2020 ◽  
Vol 39 (5) ◽  
pp. 340-344
Author(s):  
Guoxu Shu ◽  
Taikun Shi ◽  
Liang Huang ◽  
Zhenghui Gao ◽  
Gonghe Lv ◽  
...  
Keyword(s):  
Seismic Data ◽  
Western China ◽  
Seismic Exploration ◽  
Data Reconstruction ◽  
Desert Area ◽  
Data Set ◽  
Imaging Quality ◽  
Seismic Data Acquisition ◽  
Legacy Data

The seismic exploration industry continuously demands better imaging quality and consequently requires denser spatial sampling, which increases acquisition cost and time. To alleviate this burden, compressive sensing (CS) theory has been introduced in the design of acquisition geometry, as it requires fewer shot and receiver locations than traditional methods. In 2017, we conducted a field experiment in a desert area in western China. This was the first such test in China to utilize CS theory in a field test. The survey had 1760 shot records with irregular shot and receiver locations designed with guidance from CS theory. By way of data reconstruction, a seismic data set with higher sampling density (7.5 × 7.5 m bin size) was acquired, and the imaging quality was improved significantly compared to existing legacy data (15 × 15 m bin size). These results indicate that a CS-designed acquisition may reduce cost while enhancing imaging quality.

High-density point-receiver seismic survey of a deep carbonate cave reservoir system: a case study from the Tarim Basin, Western China

First Break ◽  
2015 ◽  
Vol 33 (10) ◽  
Author(s):  
Xianghao Liang ◽  
Yi Zhou ◽  
Gengxin Peng ◽  
Wensheng Duan ◽  
Duoming Zheng ◽  
...  
Keyword(s):  
Tarim Basin ◽  
High Density ◽  
Western China ◽  
Seismic Survey ◽  
Density Point ◽  
Reservoir System ◽  
System A

Sediment transport under dry weather conditions in a small sewer system

1998 ◽  
Vol 37 (1) ◽  
pp. 155-162
Author(s):  
Flemming Schlütter ◽  
Kjeld Schaarup-Jensen
Keyword(s):  
Sediment Transport ◽  
Field Data ◽  
Field Measurements ◽  
Weather Conditions ◽  
Sewer System ◽  
Transport Models ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Initial Results

Increased knowledge of the processes which govern the transport of solids in sewers is necessary in order to develop more reliable and applicable sediment transport models for sewer systems. Proper validation of these are essential. For that purpose thorough field measurements are imperative. This paper renders initial results obtained in an ongoing case study of a Danish combined sewer system in Frejlev, a small town southwest of Aalborg, Denmark. Field data are presented concerning estimation of the sediment transport during dry weather. Finally, considerations on how to approach numerical modelling is made based on numerical simulations using MOUSE TRAP (DHI 1993).

Municipal wastewater treatment with pond–constructed wetland system: a case study

2005 ◽  
Vol 51 (12) ◽  
pp. 325-329 ◽  
Author(s):  
X. Wang ◽  
X. Bai ◽  
J. Qiu ◽  
B. Wang
Keyword(s):  
Constructed Wetland ◽  
Municipal Wastewater ◽  
Municipal Wastewater Treatment ◽  
Oxidation Pond ◽  
System A ◽  
Treated Effluent ◽  
Wetland System ◽  
Oxidation Ponds ◽  
Better Than

The performance of a pond–constructed wetland system in the treatment of municipal wastewater in Kiaochow city was studied; and comparison with oxidation ponds system was conducted. In the post-constructed wetland, the removal of COD, TN and TP is 24%, 58.5% and 24.8% respectively. The treated effluent from the constructed wetland can meet the Chinese National Agricultural and Irrigation Standard. The comparison between pond–constructed wetland system and oxidation pond system shows that total nitrogen removal in a constructed wetland is better than that in an oxidation pond and the TP removal is inferior. A possible reason is the low dissolved oxygen concentration in the wetland. Constructed wetlands can restrain the growth of algae effectively, and can produce obvious ecological and economical benefits.

scholarly journals Investigating the Potential of Network Optimization for a Constrained Object Detection Problem

2021 ◽  
Vol 7 (4) ◽  
pp. 64
Author(s):  
Tanguy Ophoff ◽  
Cédric Gullentops ◽  
Kristof Van Beeck ◽  
Toon Goedemé
Keyword(s):  
Computational Complexity ◽  
Object Detection ◽  
Network Optimization ◽  
Real Life ◽  
Optimization Techniques ◽  
Training Data ◽  
Single Shot ◽  
Standard Object ◽  
Number Of Classes

Object detection models are usually trained and evaluated on highly complicated, challenging academic datasets, which results in deep networks requiring lots of computations. However, a lot of operational use-cases consist of more constrained situations: they have a limited number of classes to be detected, less intra-class variance, less lighting and background variance, constrained or even fixed camera viewpoints, etc. In these cases, we hypothesize that smaller networks could be used without deteriorating the accuracy. However, there are multiple reasons why this does not happen in practice. Firstly, overparameterized networks tend to learn better, and secondly, transfer learning is usually used to reduce the necessary amount of training data. In this paper, we investigate how much we can reduce the computational complexity of a standard object detection network in such constrained object detection problems. As a case study, we focus on a well-known single-shot object detector, YoloV2, and combine three different techniques to reduce the computational complexity of the model without reducing its accuracy on our target dataset. To investigate the influence of the problem complexity, we compare two datasets: a prototypical academic (Pascal VOC) and a real-life operational (LWIR person detection) dataset. The three optimization steps we exploited are: swapping all the convolutions for depth-wise separable convolutions, perform pruning and use weight quantization. The results of our case study indeed substantiate our hypothesis that the more constrained a problem is, the more the network can be optimized. On the constrained operational dataset, combining these optimization techniques allowed us to reduce the computational complexity with a factor of 349, as compared to only a factor 9.8 on the academic dataset. When running a benchmark on an Nvidia Jetson AGX Xavier, our fastest model runs more than 15 times faster than the original YoloV2 model, whilst increasing the accuracy by 5% Average Precision (AP).

scholarly journals Modeling Insights into Precipitation Deuterium Excess as an Indicator of Raindrop Evaporation in Lanzhou, China

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 193
Author(s):  
Fenli Chen ◽  
Mingjun Zhang ◽  
Athanassios A. Argiriou ◽  
Shengjie Wang ◽  
Qian Ma ◽  
...  
Keyword(s):  
Arid Region ◽  
Quantitative Methods ◽  
Isotope Composition ◽  
Sampling Site ◽  
Western China ◽  
Cloud Base ◽  
Deuterium Excess ◽  
Semi Arid Region ◽  
Semi Arid

The deuterium excess in precipitation is an effective indicator to assess the existence of sub-cloud evaporation of raindrops. Based on the synchronous measurements of stable isotopes of hydrogen and oxygen (δ2H and δ18O) in precipitation for several sites in Lanzhou, western China, spanning for approximately four years, the variations of deuterium excess between the ground and the cloud base are evaluated by using a one-box Stewart model. The deuterium excess difference below the cloud base during summer (−17.82‰ in Anning, −11.76‰ in Yuzhong, −21.18‰ in Gaolan and −12.41‰ in Yongdeng) is greater than that in other seasons, and difference in winter is weak due to the low temperature. The variations of deuterium excess in precipitation due to below-cloud evaporation are examined for each sampling site and year. The results are useful to understand the modification of raindrop isotope composition below the cloud base at a city scale, and the quantitative methods provide a case study for a semi-arid region at the monsoon margin.

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