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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Permeability Estimation from Fracture Calibration Test Analysis in Shale and Tight Gas

Xue, Han 1988- 14 March 2013 (has links)
Permeability estimation in tight and shale reservoirs is challenging because little or no flow will occur without hydraulic fracture stimulation. In the pressure falloff following a fracture calibration test (FCT), radial flow after the fracture closure can be used to estimate the reservoir permeability. However, for very low permeability, the time to reach radial flow can exceed any practical duration. This study shows how to use the reservoir pressure to estimate the maximum reservoir permeability when radial flow is missing in the after-closure response. The approach is straightforward and can also be used for buildup tests. It applies whenever the well completion geometry permits radial flow before the pressure response encounters a real well drainage limits. Recent developments have blurred the boundary between fracture calibration test analysis and classic pressure transient analysis. Adapting the log-log diagnostic plot representation to the FCT analysis has made it possible to perform before and after closure analysis on the same diagnostic plot. This paper also proposes a method for diagnosing abnormal leakoff behavior using the log-log diagnostic plot as an alternative method for the traditional G-function plot. The results show the relationship between reservoir permeability and pressure can be used effectively for both estimation of the permeability upper bound when there is no apparent radial flow and for confirming the permeability estimated from apparent late time radial flow. Numerous field examples illustrate this simple and powerful insight.
2

FX+ Storage and Exchange Structure of Multiplexed Data for Off-line Operations

Becue, Alain 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / With the technological evolution of flying equipment, computing and store capacity we need to have a new view of the methods of acquisition, storage and archiving data.
3

REAL-TIME TELEMETRY DATA FORMATTING FOR FLIGHT TEST ANALYSIS

O'Brien, R. Michael 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / With today's telemetry systems, an hour-long analog test tape can be digitized in one hour or less. However, the digitized data produced by today's telemetry systems is usually not in a format that can be directly analyzed by the test engineer's analysis tools. The digitized data must be formatted before analysis can begin. The data formatting process can take from one to eight hours depending on the amount of data, the power of the system's host computer, and the complexity of the analysis software's data format. If more than one analysis package is used by the test engineer, the data has to be formatted separately for each package. Using today's high-speed RISC processors and large memory technology, a real-time Flexible Data Formatter can be added to the Telemetry Front End to perform this formatting function. The Flexible Data Formatter (FDF) allows the telemetry user to program the front-end hardware to output the telemetry test data in a format compatible with the user's analysis software. The FDF can also output multiple data files, each in a different format for supporting multiple analysis packages. This eliminates the file formatting step, thus reducing the time to process the data from each test by a factor of two to nine.
4

Automated Analysis of Load Testing Results

Jiang, Zhen Ming 29 January 2013 (has links)
Many software systems must be load tested to ensure that they can scale up under high load while maintaining functional and non-functional requirements. Studies show that field problems are often related to systems not scaling to field workloads instead of feature bugs. To assure the quality of these systems, load testing is a required testing procedure in addition to conventional functional testing procedures, such as unit and integration testing. Current industrial practices for checking the results of a load test remain ad-hoc, involving high-level manual checks. Few research efforts are devoted to the automated analysis of load testing results, mainly due to the limited access to large scale systems for use as case studies. Approaches for the automated and systematic analysis of load tests are needed, as many services are being offered online to an increasing number of users. This dissertation proposes automated approaches to assess the quality of a system under load by mining some of the recorded load testing data (execution logs). Execution logs, which are readily available yet rarely used, are generated by output statements which developers insert into the source code. Execution logs are hard to parse and analyze automatically due to their free-form structure. We first propose a log abstraction approach that uncovers the internal structure of each log line. Then we propose automated approaches to assess the quality of a system under load by deriving various models (functional, performance and reliability models) from the large set of execution logs. Case studies show that our approaches scale well to large enterprise and open source systems and output high precision results that help load testing practitioners effectively analyze the quality of the system under load. / Thesis (Ph.D, Computing) -- Queen's University, 2013-01-26 22:58:29.881
5

Experimental Evaluation of a Trailing-Arm Suspension for Heavy Trucks

Glass, Jeffrey Lewis 22 May 2001 (has links)
This study includes an experimental evaluation of a prototype trailing-arm suspension for heavy trucks. The primary goal of this new suspension is to match or improve the kinematics and dynamic performance of an existing "Z-bar" suspension. Significant reductions in cost, weight, and number of parts are the main reasons for this redesign. A permanent facility is constructed to support the testing of different heavy truck suspensions. For actuation of the vehicle suspension, hydraulic actuators are used in the kinematics tests in a quasi-dynamic manner. For the dynamic tests, the vehicle is excited using two hydrodynamic actuators. A collection of forces, displacements, velocities, and accelerations are measured during the tests using transducers that were installed on the suspension and test vehicle. The test measurements are analyzed in both time and frequency domains and then the results of the two suspensions were compared to establish the dynamic merits of the prototype suspension. The kinematics tests include vertical stiffness, roll stiffness, and roll steer measurements for each suspension. The results from the kinematics tests show that the trailing-arm suspension exhibits kinematics traits that are quite similar to the "Z-bar" suspension, within the context of the tests conducted in the study. The dynamic testing consists of three input signals commonly used for such tests, namely: a chirp signal input, a step signal input, and a range of pure tone inputs. The test results show that the resonant frequencies of the two primary suspensions differ by an amount that is most likely too small to affect ride dynamics. The two suspensions, however, exhibit significantly different damping characteristics. The new suspension has much less frictional damping than the existing suspension. This is expected to provide better ride characteristics, assuming that the primary dampers (shock absorbers) are properly tuned for the vehicle that the new suspension was designed for. / Master of Science
6

SAINT-EX Système d'Analyse INteractif de Tracé et d'EXploitation A Test Data Analysis Tool Based on FX+

Pureur, Michel 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / A sophisticated human interface can be developed for Post flight analysis with the technology of UNIX-MOTIF. Tests and measurements demand performance and reliability. SAINT-EX can meet these requirements. This paper describes the results of an appraoch in the development of DASSAULT AVIATION’s SAINT-EX software.
7

Well Test Analysis In The Presence Of Carbon Dioxide In Fractured Reservoirs

Bayram, Tugce 01 May 2011 (has links) (PDF)
The application of carbon-dioxide injection for enhanced oil recovery and/or sequestration purposes has gained impetus in the last decade. It is known that well test analysis plays a crucial role on getting information about reservoir properties, boundary conditions, etc. Although there are some studies related to the well test analysis in the fractured reservoirs, most of them are not focused on the carbon dioxide injection into the reservoir. Naturally fractured reservoirs (NFR) represent an important percentage of the worldwide hydrocarbon reserves and current production. Reservoir simulation is a fundamental technique in characterizing this type of reservoirs. Fracture properties are often not clear due to difficulty to characterize the fracture systems. On the other hand, well test analysis is a well known and widely applied reservoir characterization technique. Well testing in NFR provides two significant characteristic parameters, storativity ratio (&omega / ) and interporosity flow coefficient (&lambda / ). The storativity ratio is related to fracture porosity. The interporosity flow coefficient can be linked to the shape factor which is a function of fracture spacing. In this study, the effects of fracture and fluid flow factors (geometry, orientation and flow properties) on pressure and pressure derivative behavior are studied by applying a reservoir simulation model. Model is utilized mainly for the observation of multiphase flow effects in CO2 flooded fractured reservoirs. Several runs are conducted for various ranges of the aforementioned properties in the CO2 flooded reservoir. Results of well test analysis are compared to the input data of simulation models on a parameter basis.
8

Pressure transient testing and productivity analysis for horizontal wells

Cheng, Yueming 15 November 2004 (has links)
This work studied the productivity evaluation and well test analysis of horizontal wells. The major components of this work consist of a 3D coupled reservoir/wellbore model, a productivity evaluation, a deconvolution technique, and a nonlinear regression technique improving horizontal well test interpretation. A 3D coupled reservoir/wellbore model was developed using the boundary element method for realistic description of the performance behavior of horizontal wells. The model is able to flexibly handle multiple types of inner and outer boundary conditions, and can accurately simulate transient tests and long-term production of horizontal wells. Thus, it can serve as a powerful tool in productivity evaluation and analysis of well tests for horizontal wells. Uncertainty of productivity prediction was preliminarily explored. It was demonstrated that the productivity estimates can be distributed in a broad range because of the uncertainties of reservoir/well parameters. A new deconvolution method based on a fast-Fourier-transform algorithm is presented. This new technique can denoise "noisy" pressure and rate data, and can deconvolve pressure drawdown and buildup test data distorted by wellbore storage. For cases with no rate measurements, a "blind" deconvolution method was developed to restore the pressure response free of wellbore storage distortion, and to detect the afterflow/unloading rate function using Fourier analysis of the observed pressure data. This new deconvolution method can unveil the early time behavior of a reservoir system masked by variable-wellbore-storage distortion, and thus provides a powerful tool to improve pressure transient test interpretation. The applicability of the method is demonstrated with a variety of synthetic and actual field cases for both oil and gas wells. A practical nonlinear regression technique for analysis of horizontal well testing is presented. This technique can provide accurate and reliable estimation of well-reservoir parameters if the downhole flow rate data are available. In the situation without flow rate measurement, reasonably reliable parameter estimation can be achieved by using the detected flow rate from blind deconvolution. It has the advantages of eliminating the need for estimation of the wellbore storage coefficient and providing reasonable estimates of effective wellbore length. This technique provides a practical tool for enhancement of horizontal well test interpretation, and its practical significance is illustrated by synthetic and actual field cases.
9

Pumping test inference of saturated/unsaturated aquifer properties

Mishra, Phoolendra Kumar January 2010 (has links)
Analytical solutions for aquifer response to pumping are commonly used to infer the hydraulic properties of aquifers. This dissertation develops new analytical solutions for the analysis of pumping test data from confined and unconfined aquifer.An analytical solution for flow to a partially penetrating well of infinitesimally small radius in a compressible unconfined aquifer is developed that allows inferring its saturated and unsaturated hydraulic properties from drawdowns recorded in the saturated and/or the unsaturated zone. The effects of unsaturated zoneconstitutive parameters and thickness on drawdowns in the saturated and unsaturated zones as functions of position and time is investigated; the solution is validated against numerical simulations of drawdown in a synthetic aquifer having unsaturated properties described by the van Genuchten (1980) - Mualem (1976)constitutive model; used to analyze drawdown data from a pumping test conducted by the US Geological Survey at Cape Cod,Massachusetts; and corresponding estimates of van Genuchten - Mualem parameters are compared with laboratoryvalues obtained for similar materials in the area.Drawdowns generated by extracting water from a large diameter (e.g. water supply) well are affected by wellbore storage. An analytical solution in Laplace transformed space for drawdown in a uniformanisotropic confined aquifer caused by withdrawing water at a constant rate from a partially penetrating well with storage is developed. When the pumping well is fully penetrating the solution reduces to that of Papadopulos and Cooper (1967); to that of Hantush (1964) when the pumping well has no wellbore storage; to the solution of Theis (1935) when both conditions are fulfilled; and to that of Yang et al. (2006) when the pumping well is partially penetrating, having finite radius but lacking storage. The solutionis validated against synthetic pumping test data and used to explore graphically the effects of partial penetration, wellbore storage and anisotropy on time evolutions of drawdown in the pumping well and in observation wells.The analytical solution for unconfined aquifers is extended to the case of a finite diameter pumping well with storage. The extended analytical solution is used to investigate the effects of storage in the pumping well and delayed piezometer response on drawdowns in the saturated and unsaturated zones as functions of position and time. The solution is validated against numerical simulations of drawdown in a synthetic aquifer having unsaturated properties described by the van Genuchten (1980) - Mualem (1976) model. It is then used to analyze a seven-day pumping test conducted by University of Waterloo researchers at the Canadian Forces Base Borden in Ontario, Canada; and to compare our results with those ofMoench (2008).
10

Modeling of the viscoelastic honeycomb panel equipped with piezoelectric patches in view of vibroacoustic active control design

Florens, Corine 22 January 2010 (has links) (PDF)
Active control has often been considered for low frequency control of noise radiated by trim panels inside aircraft or helicopter cabins. Trim panels are usually made of honeycomb core sandwich because of their high strength to mass ratio. Active control techniques applied to honeycomb panel have not always given results as good as expected and this thesis aims to understand these limitations based on validated mechanical models of the active panels. For the modeling of honeycomb panels, the main difficulty is to estimate equivalent properties for the core. A numerical homogenization procedure is introduced to estimate effective parameters of a shell/volume/shell model based on the correlation with periodic modes of a detailed 3D model. The use of periodic modes allows a detailed analysis of the influence of constituent properties, especially glue and skin. Tests show that the considered Nomex based honeycomb has significantly viscoelastic behavior. In the model, the viscoelastic behavior of the core is taken into account by a frequency dependence of material parameters. Piezoelectric actuators and sensors are included in the validated honeycomb model. Strategies for integration in a numerical design process are discussed. Finally, the static response to an applied voltage is shown to correspond to a blister shape with local bending of the skin rather than global bending of the panel. This behavior results in poor actuator performance, which is also found in a realistic panel configuration studied at ONERA.

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