VELOCITY STRATIFICATION AS AN AID TO CORRELATION

Geophysics ◽  
1940 ◽  
Vol 5 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Roland F. Beers
Keyword(s):  
Experimental Data ◽  
Historical Development ◽  
Field Data ◽  
Reflection Coefficients ◽  
Stratigraphic Correlation ◽  
Seismic Reflections

This paper outlines the historical development of the concept “velocity stratification” from the field data of refraction and reflection seismographs. The concept is shown to form the basis of the phenomenon known as “seismic reflections.” Experimental data are interpreted to show approximately the magnitude of reflection coefficients. Employment of velocity stratification as a means of stratigraphic correlation is suggested. Means whereby data for these correlations may be collected are discussed. Finally the use of the method for attack on stratigraphic problems is outlined.

scholarly journals New correlations for predicting two-phase electrical submersible pump performance under downhole conditions using field data

2021 ◽  
Author(s):  
Thuy Chu ◽  
Tan C. Nguyen ◽  
Jihoon Wang ◽  
Duc Vuong
Keyword(s):  
Experimental Data ◽  
Field Data ◽  
Laboratory Data ◽  
Performance Curve ◽  
Submersible Pump ◽  
Two Phase ◽  
Experimental Conditions ◽  
Pump Performance ◽  
Free Gas ◽  
Electrical Submersible Pump

AbstractElectrical Submersible Pump (ESP) is one of the major Artificial Lift methods that is reliable and effective for pumping high volume of fluids from wellbores. However, ESP is not recommended for applications with high gas liquid ratio. The presence of free gas inside the pump causes pump performance degradation which may lead to problems or even failure during operations. Thus, it is important to investigate effect of free gas on ESP performance under downhole conditions. At present, existing models or correlations are based on/verified with experimental data. This study is one of the first attempts to develop correlations for predicting two-phase gas–liquid pump performance under downhole conditions by using field data and laboratory data. Field data from three oil producing wells provided by Strata Production Company and Perdure Petroleum LLC. as well as experimental data obtained from experimental facility at Production and Drilling Research Project—New Mexico Tech were used in this study. Actual two-phase pump differential pressure per stage is obtained from experiments or estimated from field data and was normalized using pump performance curve. The values are compared to pump performance curve to study the relationships between pump performance and free gas percentage at pump intake. Correlations to predict ESP performance in two-phase flow under downhole and experimental conditions was derived from the results using regression technique. The correlation developed from field data presented in this study can be used to predict two-phase ESP performance under downhole conditions and under high gas fraction. The results from the experimental data confirm the reliability of the developed correlation using field data to predict two-phase ESP performance under downhole conditions. The developed correlation using the laboratory data predicts quite well the two-phase pump performance at the gas fraction of less than 15% while it is no longer reliable when free gas fraction is more than 15%. The findings from this study will help operating companies as well as ESP manufacturers to operate ESPs within the recommended range under downhole conditions. However, it is recommended to use the proposed correlation on reservoirs with conditions similar to those of the three presented wells.

scholarly journals New capabilities of Chetaev´s model

2016 ◽  
Vol 2 (2) ◽  
pp. 104-114
Author(s):  
Михаил Савин ◽  
Mihail Savin ◽  
Юрий Израильский ◽  
Yuriy Izrailsky
Keyword(s):  
Experimental Data ◽  
Plane Waves ◽  
Reflection Coefficients ◽  
Geomagnetic Pulsations ◽  
Energy Fluxes ◽  
Field Recordings ◽  
Inhomogeneous Plane ◽  
Inhomogeneous Plane Wave ◽  
S Model ◽  
Inhomogeneous Plane Waves

This paper considers anomalies in the magnetotelluric field in the Pc3 range of geomagnetic pulsations. We report experimental data on Pc3 field recordings which show negative (from Earth’s surface to air) energy fluxes Sz<0 and reflection coefficients |Q|>1. Using the model of inhomogeneous plane wave (Chetaev’s model), we try to analytically interpret anomalies of energy fluxes. We present two three-layer models with both electric and magnetic modes satisfying the condition |Qh|>1. Here we discuss a possibility of explaining observable effects by the resonance interaction between inhomogeneous plane waves and layered media.

Real-Time Prediction Method for Performance Degradation Trend Based on Reliability Experimental Data

2013 ◽  
Vol 321-324 ◽  
pp. 757-761 ◽  
Author(s):  
Chen Liang Song ◽  
Zhen Liu ◽  
Bin Long ◽  
Cheng Lin Yang
Keyword(s):  
Experimental Data ◽  
Real Time ◽  
Field Data ◽  
Prediction Method ◽  
Field Method ◽  
Performance Degradation ◽  
New Method ◽  
Time Prediction ◽  
Prediction Result ◽  
The Relationship

According to the real-time prediction for performance degradation trend, the commonly used method is just based on field data. But this methods prediction result will not be so much ideal when the fitting of degradation trend of field data is not good. To solve the problem, the paper introduces a new method which is not only based on field method but also based on reliability experimental data coming from the history experiment. We use the relationship between the field data and reliability experimental data to get the result of the two kinds of data respectively and then get the weights according to the two prediction results. Finally, the final real-time prediction result for performance degradation tendency can obtain by allocating the weights to the two prediction results.

Poststack velocity analysis by separation and imaging of seismic diffractions

Geophysics ◽  
2007 ◽  
Vol 72 (6) ◽  
pp. U89-U94 ◽  
Author(s):  
Sergey Fomel ◽  
Evgeny Landa ◽  
M. Turhan Taner
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
Field Data ◽  
Small Scale ◽  
Velocity Analysis ◽  
High Resolution Imaging ◽  
Diffracted Waves ◽  
Resolution Imaging ◽  
Seismic Reflections ◽  
Optimal Focusing

Small geologic features manifest themselves in seismic data in the form of diffracted waves, which are fundamentally different from seismic reflections. Using two field-data examples and one synthetic example, we demonstrate the possibility of separating seismic diffractions in the data and imaging them with optimally chosen migration velocities. Our criteria for separating reflection and diffraction events are the smoothness and continuity of local event slopes that correspond to reflection events. For optimal focusing, we develop the local varimax measure. The objectives of this work are velocity analysis implemented in the poststack domain and high-resolution imaging of small-scale heterogeneities. Our examples demonstrate the effectiveness of the proposed method for high-resolution imaging of such geologic features as faults, channels, and salt boundaries.

THE EFFECT OF DENSITY ON SEISMIC REFLECTIONS

Geophysics ◽  
1941 ◽  
Vol 6 (1) ◽  
pp. 45-51
Author(s):  
S. S. West
Keyword(s):  
Seismic Waves ◽  
Reflection Coefficients ◽  
Seismic Reflections ◽  
Existing Data

By means of existing data on the density of rocks, it is shown that reflection coefficients of seismic waves, calculated from velocities alone, often differ greatly from the actual values. Data on a large number of density discontinuities have been tabulated, and the true reflection coefficients calculated for six cases in which velocities are also known.

scholarly journals Influence of Wind on Suspended Matter in the Water of the Albufera of Valencia (Spain)

2021 ◽  
Author(s):  
Juan Soria ◽  
Miguel Jover-Cerdá ◽  
Jose Antonio Domínguez-Gómez
Keyword(s):  
Experimental Data ◽  
Wind Speed ◽  
Suspended Matter ◽  
Field Data ◽  
Satellite Images ◽  
Great Influence ◽  
Fine Sediment ◽  
Total Suspended Matter ◽  
Know How ◽  
Sentinel 2

Wind is one of the factors that has a great influence on suspended matter in lakes, especially in shallow lagoons. In order to know how wind affects the water in Albufera of Valencia, a shallow coastal lagoon, the measured variables of turbidity and transparency have been correlated with the estimates by processing Sentinel-2 satellite images with the Sen2Cor processor. Data from four years of study show that most of them are light to gentle easterly breezes and moderate to fresh westerly breezes. The results obtained show significant correlations between the measured variables and those obtained from the satellite images for total suspended matter and water transparency and with the average daily wind speed. There is no significant correlation between wind and chlorophyll a. Moderate to fresh breezes resuspend the fine sediment reaching concentration values from 100 to 300 mg L-1 according to satellite data. However, it is necessary to obtain field data for the values of moderate and fresh winds, as for now there are no experimental data to verify the validity of the satellite estimates.

Evolutionary attributes of headfirst prey manipulation and swallowing in piscivores

1991 ◽  
Vol 69 (11) ◽  
pp. 2912-2916 ◽  
Author(s):  
T. E. Reimchen
Keyword(s):  
Experimental Data ◽  
Field Data ◽  
Gasterosteus Aculeatus ◽  
Cutthroat Trout ◽  
Escape Rate ◽  
Oncorhynchus Clarki ◽  
Large Prey ◽  
Fish Prey ◽  
Fold Reduction ◽  
Maximum Gape

Headfirst swallowing of fish prey is a common attribute of gape-limited predators, conferring the presumed advantage of reduced esophageal abrasion. I evaluate swallowing orientation using cutthroat trout (Oncorhynchus clarki) as predator and three-spine stickleback (Gasterosteus aculeatus) as prey. Field data indicate that orientation is random when prey diameter is less than one-half the gape of the predator, but this increases to 90% headfirst orientation as prey diameter approaches and exceeds the maximum gape, consistent with the suspected reduction in abrasion. Experimental data show two additional advantages to headfirst orientation. Following capture, there is a 2- to 5-fold reduction in escape rate of the prey, and among prey that were swallowed, the manipulation period is substantially reduced (mean 29 vs. 81 s for headfirst and tailfirst orientation, respectively), the differences being most accentuated at large prey sizes.

The lattice filter in ground‐roll suppression

Geophysics ◽  
1994 ◽  
Vol 59 (4) ◽  
pp. 623-631 ◽  
Author(s):  
Ruhi Saatçilar ◽  
Nezihi Canitez
Keyword(s):  
Surface Waves ◽  
Field Data ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Filter Technique ◽  
Lattice Filter ◽  
Ground Roll ◽  
Noise Ratio ◽  
Seismic Reflections

Seismic reflections are sometimes masked by Ray‐leigh‐type surface waves that are termed ground roll in seismic literature. An adaptive lattice filter is used to recover reflected signals contaminated by ground roll. Experiments on synthetic and field data showed that the adaptive lattice filter technique is very effective in ground‐roll elimination. In addition, the filter works as a whitening operator, compresses the signal, and increases the signal‐to‐noise ratio.

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