scholarly journals Density-thermal dependence of sedimentary associations calls to reinterpreting detailed gravity surveys

2015 ◽  
Vol 58 ◽  
Author(s):  
Vagif G. Gadirov ◽  
Lev V. Eppelbaum
Keyword(s):  
Gravity Field ◽  
Underground Water ◽  
Temperature Data ◽  
Field Analysis ◽  
Thermal Dependence ◽  
Temperature Changes ◽  
Buried Objects ◽  
Gravity Effects ◽  
Hydrocarbon Deposits ◽  
Hydrocarbon Deposit

<p>The modern gravimetric equipment allows to register very small effects of gravity field changes and can be applied solving different geological, geophysical and environmental problems. However, sometimes insufficient calculation of various kinds of geological noise complicates effective application of detailed gravity field analysis. One of such factors is the temperature regime over and outside different buried objects of investigation. In this paper temperature changes in a subvertical zone over a hydrocarbon deposit and outside its contour are analyzed. The integrated density change and corresponding gravity effects are calculated for the Muradkhanly oil deposit situated within the south-east part of the Middle Kura Depression (central Azerbaijan). Calculation of these effects on the basis of density- temperature data correlation analysis could significantly improve the microgravity field examination over the hydrocarbon deposits. The similar correction procedure may be applied also over underground water horizons and some environmental targets.</p>

scholarly journals The deep structure of the Carmel fault zone, northern Israel, from gravity field analysis

Tectonics ◽  
1997 ◽  
Vol 16 (3) ◽  
pp. 563-569 ◽  
Author(s):  
Moshe Achmon ◽  
Zvi Ben-Avraham
Keyword(s):  
Gravity Field ◽  
Fault Zone ◽  
Deep Structure ◽  
Field Analysis

Impact of Numerical Weather Models on Gravity Field Analysis

2015 ◽  
pp. 355-365
Author(s):  
Maria Karbon ◽  
Johannes Böhm ◽  
Elisa Fagiolini ◽  
Frank Flechtner ◽  
Harald Schuh
Keyword(s):  
Gravity Field ◽  
Field Analysis ◽  
Numerical Weather ◽  
Numerical Weather Models ◽  
Weather Models

scholarly journals Temperature Measurement Reliability and Validity With Thermocouple Extension Leads or Changing Lead Temperature

2010 ◽  
Vol 45 (6) ◽  
pp. 642-644 ◽  
Author(s):  
Lisa S. Jutte ◽  
Blaine C. Long ◽  
Kenneth L. Knight
Keyword(s):  
Measurement Error ◽  
Temperature Measurement ◽  
Laboratory Study ◽  
Reliability And Validity ◽  
Temperature Data ◽  
Water Bath ◽  
Measurement Reliability ◽  
Temperature Changes ◽  
Ice Pack

Abstract Context: Thermocouples' leads are often too short, necessitating the use of an extension lead. Objective: To determine if temperature measures were influenced by extension-lead use or lead temperature changes. Design: Descriptive laboratory study. Setting: Laboratory. Other Participants: Experiment 1: 10 IT-21 thermocouples and 5 extension leads. Experiment 2: 5 IT-21 and PT-6 thermocouples. Methods: In experiment 1, temperature data were collected on 10 IT-21 thermocouples in a stable water bath with and without extension leads. In experiment 2, temperature data were collected on 5 IT-21 and PT-6 thermocouples in a stable water bath before, during, and after ice-pack application to extension leads. Results: In experiment 1, extension leads did not influence IT-21 validity (P  =  .45) or reliability (P  =  .10). In experiment 2, postapplication IT-21 temperatures were greater than preapplication and application measures (P &lt; .05). Conclusions: Extension leads had no influence on temperature measures. Ice application to leads may increase measurement error.

scholarly journals SIMULATION OF INTERACTION OF ELECTROMAGNETIC WAVES WITH ANISOTROPIC MEDIA UNDER HYDROCARBON DEPOSITS IN THE MODE OF VIDEO-PULSE SIGNALS

2018 ◽  
Vol 63 (2) ◽  
pp. 250-256
Author(s):  
V. F. Yanushkevich ◽  
K. I. Ivanova ◽  
M. M. Ivanov
Keyword(s):  
Electromagnetic Waves ◽  
Resolving Power ◽  
Radio Waves ◽  
Video Pulse ◽  
Electromagnetic Methods ◽  
Wide Range ◽  
High Level ◽  
Hydrocarbon Deposits ◽  
Hydrocarbon Deposit

The article presents the simulation of the interaction of electromagnetic waves in the mode of video pulse signals with the medium over hydrocarbon deposits. The analysis of the spectra of reflected video pulse signals from the medium over hydrocarbons is carried out. A study of the propagation of radio waves over hydrocarbons is carried out within the framework of a quasihydrodynamic approximation. The choice of the frequencies of video pulse signals is due to the determination of media characteristics over deposits at great depths compared to the surface of the earth. The spectrum of reflected signals from an anisotropic medium above a hydrocarbon deposit in the mode of video pulse signals can be used to determine the electrodynamic characteristics of the medium over the deposit over a wide range of frequencies of probed signals, dielectric permittivities and conductivity of media. The ability to reconfigure a geo-prospecting device from one mode to another (pulse width adjustment) in the presence of a deposit complements the functionality to search for hydrocarbon deposits. Electromagnetic methods for the search for and identification of hydrocarbons can be improved by obtaining information about objects through several information channels, which allows them to be identified with a sufficiently high level of reliability on the background of the underlying environment. The depths of occurrence, the resolving power in the investigated frequency range are determined. The results of the research can be used to develop new electromagnetic methods for the search for hydrocarbon deposits.

scholarly journals Time-variable gravity fields and ocean mass change from 37 months of kinematic Swarm orbits

2017 ◽  
Author(s):  
Christina Lück ◽  
Jürgen Kusche ◽  
Roelof Rietbroek ◽  
Anno Löcher
Keyword(s):  
Time Series ◽  
Gravity Field ◽  
Sea Level ◽  
Time Variable ◽  
Field Analysis ◽  
Time Variable Gravity ◽  
Ocean Mass ◽  
Grace Data ◽  
Swarm Satellites ◽  
Variable Gravity

Abstract. Measuring the spatiotemporal variation of ocean mass allows one to partition volumetric sea level change, sampled by radar altimeters, into a mass-driven and a steric part, the latter being related to ocean heat change and the current Earth’s energy imbalance. Since 2002, the Gravity Recovery and Climate Experiment (GRACE) mission provides estimates of the Earth’s time-variable gravity field, from which one can derive ocean mass variability. However, GRACE has reached the end of its lifetime with data degradation and several gaps during the last years, and there will be a prolonged gap until the launch of the follow-on mission GRACE-FO. Therefore, efforts focus on generating a long and consistent ocean mass time series by analyzing kinematic orbits from other low-flying satellites; i.e. extending the GRACE time series. Here we utilize data from the European Space Agency’s (ESA) Swarm Earth Explorer satellites to derive and investigate ocean mass variations. We investigate the potential to bridge the gap between the GRACE missions and to substitute missing monthly solutions. Our monthly Swarm solutions have a root mean square error (RMSE) of 4.0 mm with respect to GRACE, whereas directly estimating trend, annual and semiannual signal terms leads to an RMSE of only 1.7 mm. Concerning monthly gaps, our Swarm solution appears better than interpolating existing GRACE data in 13.5 % of all cases, for 80.0 % of all investigated cases of an 18-months-gap, Swarm ocean mass was found closer to the observed GRACE data compared to interpolated GRACE data. Furthermore, we show that precise modelling of non-gravitational forces acting on the Swarm satellites is the key for reaching these accuracies. Our results have implications for sea level budget studies, but they may also guide further research in gravity field analysis schemes, including non-dedicated satellites.

A Note on Gravity Effects in Supercavitating Flow

1965 ◽  
Vol 9 (01) ◽  
pp. 39-45
Author(s):  
R. L. Street
Keyword(s):  
Gravity Field ◽  
Quantitative Agreement ◽  
Cavitation Number ◽  
Number Range ◽  
First Order ◽  
Average Value ◽  
Flow Past ◽  
Supercavitating Flow ◽  
Gravity Effects ◽  
Linearized Theory

Two approximations to the linearized theory for supercavitating flow about slender bodiesare applied to the case of flow past a slender wedge in a transverse gravity field. The additional lift and moment forces arising as a result of the gravity field are calculated by theories that are expected to hold when the gravity effects are of first-order smallnessconsistent with the linearization appi'oximations. The lift and moment coefficients obtained from the two approximations are in general quantitative agreement over the most important cavitation-number range. The results obtained confirm the validity of the average-value approximation introduced by Parkin.

Microcrack Analysis of Composite Materials

2010 ◽  
pp. 159-175
Keyword(s):  
Composite Materials ◽  
Polarized Light ◽  
Fatigue Loading ◽  
Dark Field ◽  
Field Analysis ◽  
Thermal Cycles ◽  
Dynamic Impact ◽  
Bright Field ◽  
Temperature Changes

Abstract The formation of microcracks in composite materials may arise from static-, dynamic-, impact-, or fatigue-loading situations and also by temperature changes or thermal cycles. This chapter discusses the processes involved in the various methods for the microcrack analysis of composite materials, namely bright-field analysis, polarized-light analysis, contrast dyes analysis, and dark-field analysis. The analysis of microcracked composites using epi-fluorescence is also covered. In addition, the chapter describes the procedures for the determination and recording of microcracks in composite materials.

Numerical Study on the Temperature Behavior in Naturally Fractured Geothermal Reservoirs and Analysis Methodology for Geothermal Reservoir Characterization and Development

2021 ◽  
Author(s):  
Cao Wei ◽  
Shiqing Cheng ◽  
Bin Jiang ◽  
Ruilian Gao ◽  
Yang Wang ◽  
...  
Keyword(s):  
Pressure Field ◽  
Temperature Data ◽  
Geothermal Reservoir ◽  
Reservoir Temperature ◽  
Development Potential ◽  
Temperature Changes ◽  
Geothermal Reservoirs ◽  
Naturally Fractured ◽  
Heat Expansion ◽  
Pressure Analysis

Abstract An important way to develop geothermal energy is by producing low-medium temperature fluids from naturally fractured geothermal reservoirs. Pressure analysis is the most used to characterize such reservoirs for improving development efficiency. However, pressure inversion easily leads to non-uniqueness and cannot estimate thermal properties. Additionally, no reliable methods are proposed to evaluate the development potential of geothermal reservoirs. To narrow the gap, this study aims at studying the temperature behaviors and exploring suitable analysis method for characterizing geothermal reservoir and evaluating development potential. The numerical and analytical models are simultaneously established to analyze the temperature behaviors. Our models account for the J-T effect (μJT), adiabatic heat expansion/compression effect (η), reservoir damage, viscous dissipation, heat conduction and convection effects. The solution's development is dependent on the fact that the effects of reservoir temperature changes on transient pressure can be ignored so that the pressure and energy equations can be decoupled. We firstly compute reservoir pressure field based on Kazemi model, then use this obtained pressure field to solve the energy-balance equations. The numerical solution is verified and is found to be in good agreement with the proposed analytical solutions. This work shows that the most used constant μJT and η assumption will produce inaccurate temperature results when reservoir temperature changes significantly. Moreover, we find that temperature behaviors can exhibit three heat radial flow regimes (HRFR) and a heat inter-porosity regime with V-shape characteristic. Fracture thermal storativity ratio and matrix heat inter-porosity coefficient defined in this study can be estimated from this characteristic, which are further used to evaluate geothermal development potential. Our work also shows that temperature data can give information that would not be provided by conventional pressure analysis. The temperature derivative curve will show ‘hump’ characteristic if reservoir is damaged. The temperature data can characterize the skin-zone radius and permeability. More than that, the properties such as J-T coefficient, effective adiabatic heat expansion coefficient and porosity can be estimated. Eventually, an integrated workflow of using both temperature and pressure data analysis is presented to characterize naturally fractured geothermal reservoir for the first time. Simulated test examples were interpreted to demonstrate its applicability.

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