Curve matching Research Papers - Academia.edu (original) (raw)

2025, Journal of Alloys and Compounds

The flow curve is constructed by flow stress data obtained from compression test conducted at different temperature and strain rate. Accurate flow stress model is crucial for investigating magnesium alloys deformation behaviour at the elevated temperatures. An analytical method, which reflects temperature, strain and strain rate effect by introducing temperature-compensated strain rate (Zener-Hollomon Parameter), is proposed in this study. This model has been applied on the experimental data and predicted flow stress curve match well with those measurements.

2025, Journal of Petroleum Science and Engineering

A significant number of well pressure tests are conducted in long, narrow reservoirs with close and open extreme boundaries. It is desirable not only to appropriately identify these types of systems but also to develop an adequate and practical interpretation technique to determine their parameters and size, when possible. An accurate understanding of how the reservoir produces and the magnitude of producible reserves can lead to competent decisions and adequate reservoir management. So far, studies found for identification and determination of parameters for such systems are conducted by conventional techniques (semilog analysis) and semilog and log-log type-curve matching of pressure versus time. Type-curve matching is basically a trial-and-error procedure which may provide inaccurate results. Besides, a limitation in the number of type curves plays a negative role. In this paper, a detailed analysis of pressure derivative behavior for a vertical well in linear reservoirs with open and closed extreme boundaries is presented for the case of constant rate production. We studied independently each flow regime, especially the linear flow regime since it is the most characteristic "fingerprint" of these systems. We found that when the well is located at one of the extremes of the reservoir, a single linear flow regime develops once radial flow and/or wellbore storage effects have ended. When the well is located at a given distance from both extreme boundaries, the pressure derivative permits the identification of two linear flows toward the well and it has been called that "dual-linear flow regime". This is characterized by an increment of the intercept of the 1/2-slope line from π 0.5 to π with a consequent transition between these two straight lines. The identification of intersection points, lines, and characteristic slopes allows us to develop an interpretation technique without employing type-curve matching. This technique uses analytical equations to determine such reservoir parameters as permeability, skin, well location and reservoir limits for both gas and oil linear reservoirs. The proposed technique was successfully verified by interpreting both field and synthetic pressure tests for gas and oil reservoirs.

2025, ISPRS Journal of Photogrammetry and Remote Sensing

The automatic co-registration of point clouds, representing 3D surfaces, is a relevant problem in 3D modeling. This multiple registration problem can be defined as a surface matching task. We treat it as least squares matching of overlapping surfaces. The surface may have been digitized/sampled point by point using a laser scanner device, a photogrammetric method or other surface measurement techniques. Our proposed method estimates the transformation parameters of one or more 3D search surfaces with respect to a 3D template surface, using the Generalized Gauss-Markoff model, minimizing the sum of squares of the Euclidean distances between the surfaces. This formulation gives the opportunity of matching arbitrarily oriented 3D surface patches. It fully considers 3D geometry. Besides the mathematical model and execution aspects we address the further extensions of the basic model. We also show how this method can be used for curve matching in 3D space and matching of curves to surfaces. Some practical examples based on the registration of close-range laser scanner and photogrammetric point clouds are presented for the demonstration of the method. This surface matching technique is a generalization of the least squares image matching concept and offers high flexibility for any kind of 3D surface correspondence problem, as well as statistical tools for the analysis of the quality of final matching results.

2024, IEEE Vehicular Technology Conference

An Irregular Bit-Interleaved Coded Modulation based Iterative Decoding (Ir-BICM-ID) aided scheme is proposed. The irregularity of the scheme pervades the three basic components of BICM-ID, namely the encoder, the unity-rate precoder and the bit-to-symbol mapper. As a result, adaptive BICM-ID schemes constituted by irregular components are created, which are capable of approaching the capacity of coded modulation. This is achieved by creating a narrow EXtrinsic Information Transfer (EXIT) chart, using a novel EXIT curve matching algorithm. The proposed Ir-BICM-ID scheme employs Irregular Convolutional Codes (IrCC), Irregular Unity-Rate Codes (IrURC) and Irregular Mappers (IrMapper).

2024, Geology

Carbonate ooze in Bahamian troughs displays cyclic variation in the content of aragonite. A 10 m core devoid of turbidites shows 3.5 cycles, each defined by a sharp increase, followed by a gradual decrease of aragonite. The aragonite curve matches closely the oxygen-isotope curve of planktic foraminifera from the same core. Aragonite highs correspond to light oxygen-isotope values and thus to interglacial stages. Content of terrigenous material is low during interglacials and higher during glacial periods. Intermittent flooding and exposure of the Bahama Banks is most probably not the cause of the cycles, because the latest increase in aragonite precedes bank flooding by 8,000 yr and because the cycles are distinctly asymmetric, with rapid increase and gradual decrease of aragonitic content. Carbonate dissolution cycles tied to the glacial rhythm of Earth's climate are a more likely explanation of the variations in aragonite content.

2024

d uring the process of reservoir characterization using well test analysis, before defining the reservoir model, it is convenient to properly identify flow regimes, which appear as characteristic patterns or "fingerprints" exhibited by the pressure derivative curve, because they provide the geometry of the streamlines of the tested formation. A set of reservoir properties can be estimated using only a portion of the pressure transient data of the flow regime. However, there are few cases with unidentified behaviors that deserve our attention. The ten flow regime patterns commonly recognized in the pressure or pressure derivative curves of vertical or horizontal wells are: radial, spherical, hemispherical, linear, bilinear, elliptical, pseudosteady, steady, double porosity or permeability and doubled slope. A ½ slope of the derivative trend is an indication of linear flow. If this shows up early, a hydraulic fractured well is dealt with, but if this shows up immediately after the radial flow regime an indication of a channel comes to our mind. A-½-slope line at early times of the derivative plot indicates either spherical or hemispherical flow. However, if this line is observed once linear flow vanishes we are facing an unidentified flow regime. We present the case of a channel reservoir with a well off-centered with respect to the extreme boundaries and close to a constant pressure boundary. At early times, the radial flow regime is observed and is followed by the linear flow regime. Once the open boundary is reached by the pressure disturbance, a-½ slope is observed on the pressure derivative plot and it lasts until the far extreme is felt. We simulated this behavior and plotted the isobaric lines and found out that a parabolic behavior shows up during this period of time. A typical behavior was found in Colombia in a reservoir of the Eastern Planes basin.

2024, BMC Systems Biology

Background: The zinc homeostasis system in Escherichia coli is one of the most intensively studied prokaryotic zinc homeostasis systems. Its underlying regulatory machine consists of repression on zinc influx through ZnuABC by Zur (Zn 2+ uptake regulator) and activation on zinc efflux via ZntA by ZntR (a zinc-responsive regulator). Although these transcriptional regulations seem to be well characterized, and there is an abundance of detailed in vitro experimental data available, as yet there is no mathematical model to help interpret these data. To our knowledge, the work described here is the first attempt to use a mathematical model to simulate these regulatory relations and to help explain the in vitro experimental data. Results: We develop a unified mathematical model consisting of 14 reactions to simulate the in vitro transcriptional response of the zinc homeostasis system in E. coli. Firstly, we simulate the in vitro Zur-DNA interaction by using two of these reactions, which are expressed as 4 ordinary differential equations (ODEs). By imposing the conservation restraints and solving the relevant steady state equations, we find that the simulated sigmoidal curve matches the corresponding experimental data. Secondly, by numerically solving the ODEs for simulating the Zur and ZntR runoff transcription experiments, and depicting the simulated concentrations of zntA and znuC transcripts as a function of free zinc concentration, we find that the simulated curves fit the corresponding in vitro experimental data. Moreover, we also perform simulations, after taking into consideration the competitive effects of ZntR with the zinc buffer, and depict the simulated concentration of zntA transcripts as a function of the total ZntR concentration, both in the presence and absence of Zn(II). The obtained simulation results are in general agreement with the corresponding experimental data. Conclusion: Simulation results show that our model can quantitatively reproduce the results of several of the in vitro experiments conducted by Outten CE and her colleagues. Our model provides a detailed insight into the dynamics of the regulatory system and also provides a general framework for simulating in vitro metal-binding and transcription experiments and interpreting the relevant experimental data.

2024, Journal of Petroleum Technology

Summary Geothermal well testing, a discipline that evolved from conventional oil and gas well testing, often requires special considerations. The geometry of the reservoir and those characteristics frequently found in geothermal systems engendered the idea of a parallelepiped model with interpenetrating fractures. Such geometry can be described mathematically using Green's and source functions. Equations of reservoir pressure behavior then can be developed for both drawdown and buildup tests. Graphs describing dimensionless pressure as a function of time and various reservoir parameters are provided in this paper. The general method used is type-curve matching. Introduction There are three major types of geothermal resources:(vapor-dominated (dry-steam) such as in The Geysers (CA) or in Tuscany of central Italy,two-phase such as in New Zealand, andhot-water, found in several locations. The most useful, in terms of power production, are the vapor-dominated reservoirs. They are al...

2024, 2009 IEEE International Geoscience and Remote Sensing Symposium

The In-Flight Characterization (IFC) facility of the Airborne Prism Experiment (APEX) is presumably the first onboard characterization unit implemented in an airborne imaging spectrometer. This study is meant to test methodologies for the retrieval of temporal relative center wavelength drifts based on IFC data. A rare Earth material filter with a set of well-known absorption features is imaged through the IFC on APEX and recorded at several time positions. The shift of the center wavelengths covered by a spectral feature is estimated by means of curve matching algorithms. Two algorithms are evaluated: in the former the shift is determined by using the correlation coefficient as merit function to determine changes of the feature shape and position, while the latter evaluates the distance between centers of gravity. These methods have demonstrated an uncertainty in the order of 6-9 % of a pixel. A test case has been designed in which the APEX system was exposed to a temperature profile with a thermal excursion of 26°C, reproducing flight conditions. Results show the spectral stability of the APEX imaging spectrometer.

2024

In this first Chapter, the terminology used in well testing and interpretation is presented, and different testing procedures are explained. In the second part, characteristic well pressure behavior is illustrated, and the corresponding analysis methods are introduced. It is shown that well test responses follow chronological characteristic behavior at different times, depending upon the well and reservoir configuration. The interpretation techniques are presented in detail in the following Chapter 2. 1.1 Principles of transient testing When the well is shut-in, the build-up pressure change Ap is estimated from the last flowing pressure p(At=O):

2024

Calculation of reservoir properties for linear flow regime for both constant p wf production and constant q g production.

2024

SUMMARY Traditional reservoir simulation and modeling is a bottom-up approach. It starts with building a geological model of the reservoir followed by adding engineering fluid flow principles to arrive at a dynamic reservoir model. The dynamic reservoir model is calibrated using the production history of multiple wells and the history matched model is used to strategize field development in order to improve recovery. Top-Down Intelligent Reservoir Modeling approaches the reservoir simulation and modeling from an opposite angle by attempting to build a realization of the reservoir starting with well production behavior (history). The production history is augmented by core, log, well test and seismic data in order to increase the accuracy and fine tune the Top-Down model. The model is then calibrated (history matched) using the most recent wells as blind dataset. Although not intended as a substitute for the traditional reservoir simulation of large, complex fields, this novel approa...

2024, Proceedings of SPE Gas Technology Symposium

The most common data that engineers can count on, especially in mature fields, is production rate data. Practical methods for production data analysis (PDA) have come a long way since their introduction several decades ago and fall into two categories: decline curve analysis (DCA) and type curve matching (TCM). DCA is independent of any reservoir characteristics, and TCM is a subjective procedure. State of the art in PDA can provide reasonable reservoir characteristics, but it has two shortcomings: First, for reservoir characterization, the process requires bottomhole or wellhead pressure data in addition to rate data. Bottomhole or wellhead pressure data are not usually available in most of the mature fields. Second, a technique that would allow the integration of results from hundreds of individual wells into a cohesive fieldwide or reservoirwide analysis for business decision making is not part of today's PDA tool kit. To overcome these shortcomings, a new methodology is introduced in this paper that has three unique specifications: • It does not "require" pressure data, bottomhole or wellhead (but it can make use of it, if available, to enhance accuracy of results). • It integrates DCA, TCM, and numerical reservoir simulation or history matching (HM) to iteratively converge to a near unique set of reservoir characteristics for each well. • It uses fuzzy pattern recognition technology to achieve fieldwide decisions from the findings of the analysis.

2024

2024, Rahul Agarwal, Swati Gade, M. Ahfaz Khan and Nagendra Singh

Grounding is a protection method that uses a grounding electrode placed in the ground to pass leakage current from an electrical system to the earth. Rod electrodes, plate electrodes, mesh-connected electrodes, and other types of grounding electrodes can be used. To safeguard the safety of working employees and costly installed equipment in the substation, a low resistance path for the discharge of short circuit fault current is required. Furthermore, soil resistivity, mineral content, soil moisture, and temperature, particularly owing to weather fluctuations, have an impact on earth resistance value. As a result, a grounding system that can be monitored and regulated automatically is required to prevent a rise in the value of earth resistance owing to weather change. In this paper, the literature review of earthing resistance measurement and monitoring techniques, along with the designing of grounding system for the substation is presented. An electrical ground is the source point in an electrical circuit from which voltage is measured or a direct physical connection to the earth. An exhaustive literature survey has been carried out in the present study to show the present trend and the methodology used in the earthing system.

2024

Production data analysis is an important tool for estimating important reservoir parameters. In particular, determining the average reservoir pressure (pav) and tracking its change with time is critical to analyzing and optimizing reservoir performance. The traditional method for determining pav involves pressure buildup tests. A direct method for estimating (pav) from flowing pressures and rate data is available. However, the method is for an idealized case that assumes constant production rate during pseudo steady-state (PSS) flow, which is not generally true for real wells. This research extends that approach so that it can be used to analyze field data with variable rates/variable pressures during boundary-dominated flow (BDF). For gas reservoirs, pseudopressure and pseudotime functions are used to linearize the gas flow equation and enable the liquid diffusivity solution to satisfy gas behavior when analyzing gas test data. This project investigated when the use of pseudo time becomes necessity, and developed a technique to complete the linearization of diffusivity equation without using conventional pseudo time. A further objective of this research included extending our modified approach into a multi-well system. This modified approach is based on a combination of rate-normalized pressure and superposition-time function. The mathematical basis is presented in support of this approach, and the method is validated with synthetic examples and verified with field data. This modified approach is used to estimate average-reservoir pressure, calculate both connected oil volume and reservoir drainage area as a function of time, and provide a reasonable estimation of the reservoir's shape factor. These calculations, allowing the reservoir performance and management to be properly evaluated. v ACKNOWLEDGMENTS First and foremost, all the praise and gratitude be to Allah, the sole Creator and Sustainer of the Universe, he is the one that deserves all the praise. Peace be upon his prophet Muhammad. I would like to express my most sincere appreciation to my advisor, Dr. Flori for his invaluable guidance, encouragement, and his patience in helping bring this work to completion. Appreciation is also extended to Mr. Shah Kabir, global reservoir engineer at Hess Corporation, for his invaluable help and suggestions that played a vital role to get part from this work accepted for publishing.

2024, Proceedings of Nigeria Annual International Conference and Exhibition

N on-Newtonian fluids are often used during various drilling, workover and enhanced oil recovery processes. Most of the fracturing fluids injected into reservoir-bearing formations possess non-Newtonian nature and these fluids are often approximated by Newtonian fluid flow models. In the field of well testing, several analytical and numerical models based on Bingham, pseudoplastic and dilatant non-Newtonian behavior, have been introduced in the literature to study their transient nature in porous media for a better reservoir characterization. Most of them deal with fracture wells and homogeneous formations. Well test interpretation is conducted via the straight-line conventional analysis or type-curve matching. Only a few studies consider the pressure derivative analysis. However, there is a need for a more practical and accurate way of characterizing such systems. So far, there is no methodology to characterize heterogeneous formation bearing non-Newtonian fluids through well test analysis. In this study, an interpretation methodology using the pressure and pressure derivative log-log plot is presented for non-Newtonian fluids in naturally fractured formations. The dimensionless fracture storativity ratio, ω, and interporosity flow parameter, λ, are obtained from characteristics points found on such plot. The developed equations and correlations are successfully verified by their application only to synthetic well test data since no actual field data are available. A good match is found between the results provided by the proposed technique and the values used to generate the simulated data.

2024, 2011 6th International ICST Conference on Communications and Networking in China (CHINACOM)

concatenated source channel coding for binary Markov sources over AWGN channels. To exploit the memory structure inherent within the sequence output from the source, modifications are made on the BCJR algorithm. To decode the outer code, the modified version of the BCJR algorithm is used, while the inner code by the standard version of the algorithm. Since optimal design of serially concatenated convolutional code falls into the problem of curve matching between the extrinsic information transfer (EXIT) curves of the inner and outer codes, we first evaluate the EXIT curve of the outer code decoded by the modified BCJR algorithm. It is then shown that the EXIT curve obtained by the modified BCJR algorithm is better matched with short memory inner convolutional code, which significantly reduces coding/decoding complexity. Numerical results demonstrate significant gains over the systems in which source statistics are not exploited (i.e., the standard BCJR algorithm is used for the both codes), and thereby narrowing the performance gap to the Shannon limit. We also compare in this paper the performance of the proposed design with the algorithm presented in [1], designed also for transmission of binary Markov source using parallel concatenated convolutional code (the authors of Ref. [1] refer the technique as Joint Source Channel Turbo Code (JSCTC)). It is shown that our proposed system is superior in both system complexity and BER performance to the JSCTC technique presented in [1].

2024, Journal of Petroleum Science and Engineering

2024

Traditional reservoir simulation and modeling is a bottom-up approach. It starts with building a geological model of the reservoir followed by adding engineering fluid flow principles to arrive at a dynamic reservoir model. The dynamic reservoir model is calibrated using the production history of multiple wells and the history matched model is used to strategize field development in order to improve recovery.

2024

Data Bias in Rate Transient Analysis of Shale Gas Wells.

2024

Data Bias in Rate Transient Analysis of Shale Gas Wells.

2024, Malaysian Journal of Science and Advanced Technology

This paper presents the development of a robust CAMSHIFT model for theoretical face detection and tracking. The proposed model integrates innovative techniques such as Perceptual Grouping, three Connected Component Operators, Weighted Adaptive Colour Histogram, and Selective Adaptation. Experimental results highlight its superior performance across scenarios like occlusions, varying illumination, near/far face tracking, skin-like background tracking, and disturbance from multiple faces. The normalized log-likelihood index serves as a robust indicator for face tracking analysis. Connected Component operations provide strong markers for error detection in video sequences. The enhanced CAMSHIFT algorithm exhibits resilience and stability, even in the presence of occlusions. Comparisons with the original CAMSHIFT reveal the enhanced model's superiority, extending tracking range to 500 cm, a calculated enhancement of 42.9 percent improvement. The study consistently favours the robust and resilient CAMSHIFT model in tracking against skin-like backgrounds and disturbances. Despite webcam convenience in used for algorithm development, the benefits of high-performance camera systems are envisioned for future research. This model is a significant advancement in face detection methods, promising improved adaptability and tracking capabilities.

2024, Mechanism and Machine Theory

This paper presents a new method for the design of a slider-crank mechanism to satisfy specified behavior of the moving centrode. The method is based on the technique of curve matching using a series of design curves. The various families of centrode curves possible from the slider-crank mechanism are discussed. An example of the use of the curve matching method is presented.

2024, Canadian Conference on Computational Geometry

Given a point set S and a polygonal curve P in R d , we study the problem of finding a polygonal curve through S, which has a minimum Fréchet distance to P. We present an efficient algorithm to solve the decision version of this problem in O(nk 2) time, where n and k represent the sizes of P and S, respectively. A curve minimizing the Fréchet distance can be computed in O(nk 2 log(nk)) time. As a by-product, we improve the map matching algorithm of Alt et al. by a log k factor for the case when the map is a complete graph.

2024, Computational Geometry: Theory and Applications

In this paper, we introduce a new generalization of the well-known Fréchet distance between two polygonal curves, and provide an efficient algorithm for computing it. The classical Fréchet distance between two polygonal curves corresponds to the maximum distance between two point objects that traverse the curves with arbitrary non-negative speeds. Here, we consider a problem instance in which the speed of traversal along each segment of the curves is restricted to be within a specified range. We provide an efficient algorithm that decides in O(n 2 log n) time whether the Fréchet distance with speed limits between two polygonal curves is at most ε, where n is the number of segments in the curves, and ε 0 is an input parameter. We then use our solution to this decision problem to find the exact Fréchet distance with speed limits in O(n 2 log 2 n) time.

2024, Spe Journal

A fully implicit, 3D simulator with local refinement around the wellbore is developed to solve reservoir and horizontal well flow equations simultaneously for single-phase liquid and gas cases. The model consists of conservation of mass and Darcy's law in the reservoir, and mass and momentum conservation in the wellbore for isothermal conditions. The coupling requirements are satisfied by preserving the continuity of pressure and mass balance at the sandface. The proposed simulator is tested against and verified with the results obtained from a commercial code ECLIPSE-100, and available public domain simulators and semianalytical models. The model can be used to simulate the transient pressure and flow rate behavior of both the reservoir and the horizontal wellbore. Traditional decoupling of the wellbore transients from the reservoir transients does not capture the horizontal well pressure and flow rate transients at early times because the interaction between the reservoir and wellbore is inherently neglected. Simulation runs with the proposed model reveal the actual characteristics of horizontal wellbore storage and unloading, as well as flow pattern determination during transient well testing using pressure derivative curves. The effects of permeability, formation thickness, well length, and fluid compressibility are also studied.

2024, Estonian Journal of Earth Sciences

2024

Contents ii List of Figures vii List of Tables xii I gratefully appreciate Prof. Norimasa Yoshida for a careful reading and helpful comments on an earlier draft of this thesis. And of course, many thanks are due to my thesis committee for... more

2024, marte.dpi.inpe.br

Erosion by water removes the surface of the soils and exposes the subsurfaces layers. Soil characteristics varies in depth. Some soil characteristics that varies with depth, such as soil texture, soil organic carbon and iron oxide content have important effects on spectral characteristics of the soils. As an example, for a given soil type the increase in soil organic matter content decreases soil reflectance and, thus, soil albedo. The objective of this paper is to compare soil spectral curves from "unaltered" soil and degraded soils using small depth samples and to evaluate the depth of the layer removed by soil erosion on the base of these comparisons. Spectral curves matches between "preserved" and eroded soils was able to assess the depth of the layer removed by erosion. The next step will be to extend these results to produce maps of quantified soil losses on the base of hyperspectral images. Palavras-chave: hyperion, erosão do solo, carbono orgânico, óxidos de ferro, caatinga, soil erosion, organic carbon, iron oxides.

2024, 2011 6th International ICST Conference on Communications and Networking in China (CHINACOM)

2024, Computer Vision and Image Understanding

netic resonance imaging) apparata. These cross sections, In this paper we present a new technique for piecewise-linear hereafter called slices, are the basis for interpolating the surface reconstruction from a series of parallel polygonal cross boundary surface of the organ. The interpolated object sections. This is an important problem in medical imaging, can then be displayed in graphics applications, or (more surface reconstruction from topographic data, and other applirecently) even manufactured by an NC (numerically concations. We reduce the problem, as in most previous works, to trolled) or an RP (rapid prototyping) machine. Another a series of problems of piecewise-linear interpolation between motivation for this problem is the nondestructive digitizaeach pair of successive slices. Our algorithm uses a partial curve tion of objects: after an object is scanned by an echomatching technique for matching parts of the contours, an graphic or an X-ray apparatus, the obtained slices are used optimal triangulation of 3-D polygons for resolving the unfor the reconstruction of the original object. Yet another matched parts, and a minimum spanning tree heuristic for interpolating between nonsimply connected regions. Unlike motivation is the reconstruction of a three-dimensional previous attempts at solving this problem, our algorithm seems model of a terrain from topographic elevation contours. to handle successfully in practice any kind of data. It allows Many solutions were suggested for the pure raster intermultiple contours in each slice, with any hierarchy of contour polation. These usually handle two raster images, where nesting, and avoids the introduction of counterintuitive bridges each pixel is either white or black, or assigned a gray level between contours, proposed in some earlier papers to handle taken from a fixed range. The interpolation produces one interpolation between multiply connected regions. Experimenor more intermediate raster images, which smoothly and tal results on various complex examples, involving actual medilocally turn the first image into the second one. Then, the cal imaging data, are presented and show the good and robust bounding surface is detected using other methods, such as performance of our algorithm.

2024, IEEE Transactions on Pattern Analysis and Machine Intelligence

In this paper we present a new technique for partial surface and volume matching of images in three dimensions. In this problem we are given two objects in 3-space, each represented as a set of points, and the goal is to find a rigid motion of one object which makes a sufficiently large portion of its boundary lying sufficiently close to a corresponding portion of the boundary of the second object. This is an important problem in pattern recognition and in computer vision, with many industrial, medical, and chemical applications. Our method treats separately the rotation and the translation components of the Euclidean motion that we seek. The algorithm steps through a sequence of rotations, in a steepest-descent style, and uses a novel technique for scoring the match for any fixed rotation. Experimental results on various examples, involving data from industrial applications, medical imaging, and molecular biology, are presented, and show the accurate and robust performance of our algorithm.

2024, Computational Geometry: Theory and Applications

In this paper we present a new technique for partial surface and volume matching of images in three dimensions. In this problem, we are given two objects in 3-space, each represented as a set of points, scattered uniformly along its boundary or inside its volume. The goal is to find a rigid motion of one object which makes a sufficiently large portion of its boundary lying sufficiently close to a corresponding portion of the boundary of the second object. This is an important problem in pattern recognition and in computer vision, with many industrial, medical, and chemical applications. Our algorithm is based on assigning a directed footprint to every point of the two sets, and locating all the pairs of points (one of each set) whose undirected components of the footprints are sufficiently similar. The algorithm then computes for each such pair of points all the rigid transformations that map the first point to the second, while making the respective direction components of their footprints coincide. A voting scheme is employed for computing transformations which map significantly large number of points of the first set to points of the second set. Experimental results on various examples are presented and show the accurate and robust performance of our algorithm.

2024, Journal of Natural Gas Science and Engineering

Reservoir entropy generation has a significant role in production cycles of a hydrocarbon reservoir. During production, entropy generation characterizes the irreversible fluid energy losses. This paper aims to develop a new production strategy that minimizes the entropy production to improve operational efficiencies. The second law of thermodynamics is used to calculate entropy generation in a porous medium during hydrocarbon production. The model considers different sections of a production system, including the reservoir, near-wellbore, and wellbore regions. The proposed model is an extension of the Civan model. The introduced model considers the near wellbore region as a separate zone, which allows flexibility in modelling skin effects near the wellbore. In addition, a new performance criterion, called the coefficient of performance (COP). This COP integrates the recovery factor with entropy generation and provides a quantitative measure to optimize the reservoir production. The model is used to conduct a parametric sensitivity analysis including effects of fluid and rock parameters such as permeability, porosity, viscosity, skin factor, and temperature on the total entropy production. The COP is used to optimize operating conditions of the reservoir such as production rates and bottomhole pressure. It was found that permeability and the bottom hole pressure have the most impact on the total entropy production. This article will present new approaches and findings to maximize the recovery efficiency by minimizing entropy generation of fluid transport processes in a hydrocarbon reservoir.

2024

Production data analysis has extensively been applied to predicting the future production performance and field recovery. These applications are mostly on a single well basis. This paper presents a new approach to production data analysis using Artificial Intelligence (AI) techniques where production history is used to build a field-wide performance prediction models. In this work AI techniques and data driven modeling are utilized to predict future production of both synthetic (for validation purposes) and real field cases. In the approach presented in this article production history is paired with geological information from the field to build datasets containing the spatio-temporal dependencies amongst different wells. These dependencies are addressed by compiling information from Closest Offset Wells (COWs) that includes their geological and reservoir characteristics (spatial data) as well as their production history (temporal data). Once the dataset is assembled, a series of neural networks are trained using backpropagation algorithm. These networks are then fused together to form the "Intelligent Time-Successive Production Modeling"(ITSPM) system. This technique only uses the widely available measured data such as well logs and production history of existing wells to predict a) future performance of the existing wells, b) production performance of the new (infill) wells and c) the initial hydrocarbon in place using a "volumetric-geostatistical" method. To demonstrate the applicability of this method, a synthetic oil reservoir is modeled using a commercial simulator. Production and well-log data are extracted into an all-inclusive dataset. Several neural networks are trained and validated to predict different stages of the production. ITSPM method is utilized to estimate the production profile for nine new wells in the reservoir. Furthermore, ITSPM is also applied to a giant oil field in the Middle East with more than 200 wells and forty years of production history. ITSPM's production predictions of the four newest wells in this reservoir are compared their actual production.

2024, All Days

2024, Proceedings of SPE Eastern Regional Meeting

Minimize subjectivity. Address the entire field. Identify opportunities in mature fields: Sweet spots for infill drilling. Underperformer wells. Introduction Objective Methodology Results Conclusion Methodology The methodology is demonstrated through application to a mature field in the U.S. Carthage field, Cotton valley formation in Texas 349 wells were used in this analysis. Only publicly available production rate data were used.

2024, Journal of King Saud University: Engineering Sciences

The primary objective of hydraulic fracturing is to create a propped fracture with sufficient conductivity and length to amplifY or at least optimize well performance of low permeability tight gas reservoir. The oil industry has suggested that hydraulically fractured tight gas wells performance is hindered significantly by non-Darcy flow effect. This work will present an investigation of non-Darcy flow effect to hydraulically fractured gas well s performance and provide the development, validation, and application of actual well test analysis for wells with a finite conductivity vertical fracture. Also, this work presents the results obtained in the study of actual post frac modified isochronal test data of gas wells intersected by a finite conductivity vertical fracture in a tight low permeability gas reservoir. In addition, the estimation of reservoir properties and fracture properties were carried out to construct a simple analytical model, which used for rate prediction. The effect of non-Darcy flow in fractures is clearly seen in the tests data and will lead to limiting production especially on higher chokes (after one inch). Therefore, non-Darcy effects should be considered in design of hydraulic fracture treatments, otherwise the design might be far from optimal

2024, Pattern Recognition Letters

We present a curve matching framework for planar open curves under similarity transform 1 based on a new scale invariant signature. The signature is derived from the concept of integral of unsigned curvatures. If one input curve as a whole can be aligned with some part in the second curve then the algorithm will find the requisite starting and end positions and will estimate the similarity transform in OðN logðNÞÞ time. We extend our frame work to a more general case where some part of the first input curve can be aligned with some part of the second input curve. This is a more difficult problem that we solve in OðN 3 Þ time. The contributions of the paper are the new signature as well as faster algorithms for matching open 2D curves. We present examples from diverse application set to show that our algorithm can work across several domains.

2024, Journal of Natural Gas Science and Engineering

The oil and gas reservoir pressure response to the changes in the fluid production rate has been traditionally used to estimate the reservoir properties. Numerous analytical and numerical models have been developed to describe the transient pressure in and around a production well so as to interpret the in-well pressure measurements. Pressure Transient Analysis (PTA) is routinely used by Production and Reservoir Engineers at various stages in a wells life; initially for reservoir characterisation and, later, for well performance monitoring and (wider) reservoir surveillance. The recent application of high precision, downhole, temperature sensors has resulted in PTA being complemented by Temperature Transient Analysis (TTA). Recent TTA research has shown that comprehensive information on the state of the near-wellbore zone and fluid flow rates and composition can potentially be derived from such measurements. However, the derivation of useable TTA solutions describing the mass and energy transfer in porous media is challenging since it is necessary to simultaneously account for both the thermodynamic and the transient transfer effects. This paper reports a step in the development of a novel Temperature Transient Analysis (TTA) workflow. This is the first publication, to our knowledge, where the gas production TTA solutions, properly accounting for the compressible gas nature, are presented and discussed. A numerical model for determining sandface tran

2024, Journal of Geophysics and Engineering

This study automates a type-curve technique for estimating the rock pore-geometric factor (λ) from capillary pressure measurements. The pore-geometric factor is determined by matching the actual rock capillary pressure versus wetting-phase saturation (P c-S w) profile with that obtained from the Brooks and Corey model (1966 J. Irrigation Drainage Proc. Am. Soc. Civ. Eng. 61-88). The pore-geometric factor values are validated by comparing the actual measured rock permeability to the permeability values estimated using the Wyllie and Gardner model (1958 World Oil (April issue) 210-28). Petrophysical data for both carbonate and sandstone rocks, along with the pore-geometric factor derived from the type-curve matching, are used in a discriminant analysis for the purpose of developing a model for rock typing. The petrophysical parameters include rock porosity (φ), irreducible water saturation (S wi), permeability (k), the threshold capillary-entry-pressure (P d), a pore-shape factor (β), and a flow-impedance parameter (n) which is a property that reflects the flow impedance caused by the irreducible wetting-phase saturation. The results of the discriminant analysis indicate that five of the parameters (φ, k, P d , λ and n) are sufficient for classifying rocks according to two broad lithology classes: sandstones and carbonates. The analysis reveals the existence of a significant discriminant function that is mostly sensitive to the pore-geometric factor values (λ). A discriminant-analysis classification model that honours both static and dynamic petrophysical rock properties is, therefore, introduced. When tested on two distinct data sets, the discriminant-analysis model was able to predict the correct lithofacies for approximately 95% of the tested samples. A comprehensive database of the experimentally collected petrophysical properties of 215 carbonate and sandstone rocks is provided with this study.

2024, IEEE Transactions on Systems, Man, and Cybernetics - Part A: Systems and Humans

In this paper, we consider the problem of matching two-dimensional (2-D) planar object curves from a database, and tracking moving object curves through an image sequence. The first part of the paper describes a curve data compression method using B-spline curve approximation. We present a new constrained active B-spline curve model based on the minimum mean square error (MMSE) criterion, and an iterative algorithm for selecting the "best" segment border points for each B-spline curve. The second part of the paper describes a method for simultaneous object tracking and affine parameter estimation using the approximate curves and profiles. We propose a novel B-spline point assignment algorithm which incorporates the significant corners for interpolating corresponding points on the two curves to be compared. A gradient-based algorithm is presented for simultaneously tracking object curves, and estimating the associated translation, rotation and scaling parameters. The performance of each proposed method is evaluated using still images and image sequences containing simple objects.

2024, Proceedings. 1998 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (Cat. No.98CB36231)

We present a method for matching curves which accommodates large and small deformation. The method preserves geometric similarities in the case of small deformation, and loosens these geometric constraints when large deformations occur. The approach is based on the computation of a set of geodesic paths connecting the curves. These two curves are defined as a source area and a destination area which can have an arbitrary number of connected components and different topologies. The applicative framework of the presented method is the study of the crustal deformation from a set of iso-elevation curves. An experiment with real curves demonstrates that the approach can be successfully applied to characterize deformation of Digital Elevation Models.

2024

MR imaging technology enables the acquisition of in vivo brain structure and has therefore found widespread application in studies of anatomic changes associated with brain disorders. However, the cytoarchitectural boundaries that define individual functional units in the brain, as for example the borders between neighboring cortical areas, cannot be captured at the resolution of MR

2024

This paper describes a simple colour-based object tracking plugin for the video annotation tool ANVIL. The tracker can be used to automatically annotate hand gestures or the movements of any object that is distinguishable from its background. The tracker records velocity duration and total travel distance of hand gestures and can be configured to display gesture direction. Results of the tracker are compared to manually created annotations for hand gestures. Data recorded by the tracker is not accurate enough to provide a complete alternative to manual annotation, but could rather be used as a basis for determining where hand gestures can be detected. Thus using the tracker in combination with a human annotator could significantly speed up the annotation process.

2024, Matematychni Studii

The aim of this note is to extend the notion of Fréchet distance over the set of weighted rooted trees. The weighted trees naturally appear as skeletons of planar domains. The defined distance allows for defining a distance between... more