25 Matching Results

Results open in a new window/tab. Unexpected Results? Search the Catalog Instead.

Intervals in evolutionary algorithms for global optimization (open access)

Intervals in evolutionary algorithms for global optimization

Optimization is of central concern to a number of disciplines. Interval Arithmetic methods for global optimization provide us with (guaranteed) verified results. These methods are mainly restricted to the classes of objective functions that are twice differentiable and use a simple strategy of eliminating a splitting larger regions of search space in the global optimization process. An efficient approach that combines the efficient strategy from Interval Global Optimization Methods and robustness of the Evolutionary Algorithms is proposed. In the proposed approach, search begins with randomly created interval vectors with interval widths equal to the whole domain. Before the beginning of the evolutionary process, fitness of these interval parameter vectors is defined by evaluating the objective function at the center of the initial interval vectors. In the subsequent evolutionary process the local optimization process returns an estimate of the bounds of the objective function over the interval vectors. Though these bounds may not be correct at the beginning due to large interval widths and complicated function properties, the process of reducing interval widths over time and a selection approach similar to simulated annealing helps in estimating reasonably correct bounds as the population evolves. The interval parameter vectors at these estimated bounds …
Date: May 1, 1995
Creator: Patil, R. B.
Object Type: Article
System: The UNT Digital Library
A generalized stationary point convergence theory for evolutionary algorithms (open access)

A generalized stationary point convergence theory for evolutionary algorithms

This paper presents a convergence theory for evolutionary pattern search algorithms (EPSAs). EPSAs are self-adapting evolutionary algorithms that modify the step size of the mutation operator in response to the success of previous optimization steps. Previously, the authors have proven a stationary point convergence theory for EPSAs for which the step size is not allowed to increase. The present analysis generalizes this analysis to prove a convergence theory for EPSAs that are allowed to both increase and decrease the step size. This convergence theory is based on an extension of the convergence theory for generalized pattern search methods.
Date: February 1, 1997
Creator: Hart, W.E.
Object Type: Article
System: The UNT Digital Library
Neutrino-electron scattering and the search for new physics (open access)

Neutrino-electron scattering and the search for new physics

I want to discuss the role of neutrino-electron scattering in the search for physics beyond the standard model. The standard model makes specific predictions about the nature of the neutrinos which participate in such processes and about the interactions responsible for them. The process upon which I shall concentrate is elastic scattering, but I shall pay some attention to inelastic processes in which the target electron is itself transformed into a heavier charged lepton, in other words the inverse of the decay of the heavier lepton. In the case of elastic scattering we are mainly looking at neutral-currents and we can ask a series of simple questions: Does the interaction conserve lepton flavor. Does it fit the prescriptions of the standard model. Are the neutrinos Majorana or Dirac particles. In the case of inverse muon and tau decays we are looking at charge-currents, and we want to pin down the identity of the neutrinos emitted in the decay of these charged leptons as well as to set bounds on non-(V-A) components of the interaction. In order to discuss these topics, it is useful to review the general properties of the scattering process, especially the kinematics and the general form of …
Date: January 1, 1988
Creator: Rosen, S. P.
Object Type: Article
System: The UNT Digital Library
Geothermal Reservoir Well Stimulation Program: technology transfer (open access)

Geothermal Reservoir Well Stimulation Program: technology transfer

To assess the stimulation technology developed in the oil and gas industry as to its applicability to the problems of geothermal well stimulation, a literature search was performed through on-line computer systems. Also, field records of well stimulation programs that have worked successfully were obtained from oil and gas operators and service companies. The results of these surveys are presented. (MHR)
Date: May 1, 1980
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Ground state searches in fcc intermetallics (open access)

Ground state searches in fcc intermetallics

A cluster expansion is used to predict the fcc ground states, i.e., the stable phases at zero Kelvin as a function of composition, for alloy systems. The intermetallic structures are not assumed, but derived regorously by minimizing the configurational energy subject to linear constraints. This ground state search includes pair and multiplet interactions which spatially extend to fourth nearest neighbor. A large number of these concentration-independent interactions are computed by the method of direct configurational averaging using a linearized-muffin-tin orbital Hamiltonian cast into tight binding form (TB-LMTO). The interactions, derived without the use of any adjustable or experimentally obtained parameters, are compared to those calculated via the generalized perturbation method extention of the coherent potential approximation within the context of a KKR Hamiltonian (KKR-CPA-GPM). Agreement with the KKR-CPA-GPM results is quite excellent, as is the comparison of the ground state results with the fcc-based portions of the experimentally-determined phase diagrams under consideration.
Date: December 1, 1991
Creator: Wolverton, C.; de Fontaine, D. (Lawrence Berkeley Lab., CA (United States)); Ceder, G. (Massachusetts Inst. of Tech., Cambridge, MA (United States)) & Dreysse, H. (Nancy-1 Univ., 54 (France). Lab. de Physique du Solide)
Object Type: Article
System: The UNT Digital Library
Reliable motion detection of small targets in video with low signal-to-clutter ratios (open access)

Reliable motion detection of small targets in video with low signal-to-clutter ratios

Studies show that vigilance decreases rapidly after several minutes when human operators are required to search live video for infrequent intrusion detections. Therefore, there is a need for systems which can automatically detect targets in live video and reserve the operator`s attention for assessment only. Thus far, automated systems have not simultaneously provided adequate detection sensitivity, false alarm suppression, and ease of setup when used in external, unconstrained environments. This unsatisfactory performance can be exacerbated by poor video imagery with low contrast, high noise, dynamic clutter, image misregistration, and/or the presence of small, slow, or erratically moving targets. This paper describes a highly adaptive video motion detection and tracking algorithm which has been developed as part of Sandia`s Advanced Exterior Sensor (AES) program. The AES is a wide-area detection and assessment system for use in unconstrained exterior security applications. The AES detection and tracking algorithm provides good performance under stressing data and environmental conditions. Features of the algorithm include: reliable detection with negligible false alarm rate of variable velocity targets having low signal-to-clutter ratios; reliable tracking of targets that exhibit motion that is non-inertial, i.e., varies in direction and velocity; automatic adaptation to both infrared and visible imagery with variable …
Date: July 1, 1995
Creator: Nichols, S. A. & Naylor, R. B.
Object Type: Article
System: The UNT Digital Library
Demonstration of safeguards technology at the Russian Institute of Experimental Physics (VNIIEF), Arzamas-16 (open access)

Demonstration of safeguards technology at the Russian Institute of Experimental Physics (VNIIEF), Arzamas-16

As part of the US-Russian Lab-to-Lab program for strengthening nuclear material protection, control, and accounting (MPC&A), a testbed facility has been established in a laboratory of the VNIIEF to demonstrate safeguards technology to nuclear facility operators. The design of the testbed MPC&A system provides the functions of nondestructive measurements for plutonium and highly enriched uranium, item control, personnel access control, radiation portal monitoring, search equipment, and computerized on-line accounting. The system controls, monitors, and accounts for nuclear material and people as the material moves through three MBAs. It also assists with physical inventory taking. A total of 39 instruments and control systems are being demonstrated in the present version of the testbed. Of these, about half are of Russian design and fabrication, including the software for the item monitoring and the accounting systems. These two computer systems are on an ethernet network and connected in a client-server local area architecture. The item monitoring system is integrated with the accounting system, providing alarm and status information to a central dispatcher terminal. The operation of the MPC&A testbed has been demonstrated under routine and alarm conditions in collaboration with safeguards staff from the six participating US national labs. Workshops and training for …
Date: September 1, 1995
Creator: Yuferev, V.; Skripka, G. & Augustson, R.H.
Object Type: Article
System: The UNT Digital Library
Feasibility of a continuous surface mining machine using impact breakers. First quarterly report, October 1-December 31, 1979 (open access)

Feasibility of a continuous surface mining machine using impact breakers. First quarterly report, October 1-December 31, 1979

This is the first quarterly report on the efforts to evaluate the feasibility of excavating coal and overburden from surface mines using impact breakers. The initial stages of the project are devoted to a literature search, equipment selection, test site selection, and conceptual test system design. Hence, this report details the progress made in these areas; the next quarter will see the finalization of Phase I. Included as appendices to this report are FMA internal reports on the individual mines visited. These reports are the basis of the test site selection, and have been censored here to remove data the mine operators deemed as confidential.
Date: January 1, 1980
Creator: Fisk, A. T.
Object Type: Report
System: The UNT Digital Library
Treating paraffin deposits in producing oil wells (open access)

Treating paraffin deposits in producing oil wells

Paraffin deposition has been a problem for operators in many areas since the beginning of petroleum production from wells. An extensive literature search on paraffin problems and methods of control has been carried out, and contact was made with companies which provide chemicals to aid in the treatment of paraffin problems. A discussion of the nature of paraffins and the mechanisms of this deposition is presented. The methods of prevention and treatment of paraffin problems are summarized. Suggested procedures for handling paraffin problems are provided. Suggestions for areas of further research testing are given.
Date: January 1, 1992
Creator: Noll, L.
Object Type: Report
System: The UNT Digital Library
A nuclear structure study of the proposed gamma-ray laser candidate nucleus /sup 186/Re (open access)

A nuclear structure study of the proposed gamma-ray laser candidate nucleus /sup 186/Re

We present results of theoretical nuclear structure model calculations for the gamma-ray laser candidate nucleus /sup 186/Re proposed by Collins. Our calculations of this odd-odd transitional nucleus are based on an axially-asymmetric (particle plus triaxial rotor) model for constructing the orbitals of the odd nucleons that couple under the influence of the residual neutron-proton interaction. We include pairing correlations in the determination of these orbitals by using the BCS approximation with newly determined pairing strengths. The matrix elements of the residual neutron-proton interaction are obtained using phenomenological spin-dependent delta function potentials of both surface and volume forms. We examine the sensitivity of the calculated low-excitation level structure of /sup 186/Re to the strength of these potentials. Calculated energy levels of /sup 186/Re will be presented and compared with experiment. The impact of our results on the proposed use of /sup 186/Re as a gamma-ray laser will be discussed. In addition, based upon these and other model calculations to be described, we assess the level of effort necessary in a full-scale theoretical search for a viable candidate nucleus for a gamma-ray laser. 17 refs., 1 fig., 3 tabs.
Date: January 1, 1988
Creator: Madland, D.G. & Strottman, D.D.
Object Type: Article
System: The UNT Digital Library
Treating paraffin deposits in producing oil wells (open access)

Treating paraffin deposits in producing oil wells

Paraffin deposition has been a problem for operators in many areas since the beginning of petroleum production from wells. An extensive literature search on paraffin problems and methods of control has been carried out, and contact was made with companies which provide chemicals to aid in the treatment of paraffin problems. A discussion of the nature of paraffins and the mechanisms of this deposition is presented. The methods of prevention and treatment of paraffin problems are summarized. Suggested procedures for handling paraffin problems are provided. Suggestions for areas of further research testing are given.
Date: January 1, 1992
Creator: Noll, L.
Object Type: Report
System: The UNT Digital Library
Search for Delta S = 2 nonleptonic hyperon decays (open access)

Search for Delta S = 2 nonleptonic hyperon decays

A sensitive search for the rare decays {Omega}{sup -} {yields} {Lambda}{pi}{sup -} and {Xi}{sup 0} {yields} p{pi}{sup -} has been performed using data from the 1997 run of the HyperCP (Fermilab E871) experiment. Limits on other such processes do not exclude the possibility of observable rates for |{Delta}S| = 2 nonleptonic hyperon decays, provided the decays occur through parity-odd operators. They obtain the branching-fraction limits {Beta}({Omega}{sup -} {yields} {Lambda}{pi}{sup -}) < 2.9 x 10{sup -6} and {Beta}({Xi}{sup 0} {yields} p{pi}{sup -}) < 8.2 x 10{sup -6}, both at 90% confidence level.
Date: March 1, 2005
Creator: White, C. G.; /IIT, Chicago; Burnstein, R. A.; Chakravorty, A.; Chan, A.; Chen, Y. C. et al.
Object Type: Article
System: The UNT Digital Library
Testing geopressured geothermal reservoirs in existing wells. Wells of Opportunity Program final contract report, 1980-1981 (open access)

Testing geopressured geothermal reservoirs in existing wells. Wells of Opportunity Program final contract report, 1980-1981

The geopressured-geothermal candidates for the Wells of Opportunity program were located by the screening of published information on oil industry activity and through direct contact with the oil and gas operators. This process resulted in the recommendation to the DOE of 33 candidate wells for the program. Seven of the 33 recommended wells were accepted for testing. Of these seven wells, six were actually tested. The first well, the No. 1 Kennedy, was acquired but not tested. The seventh well, the No. 1 Godchaux, was abandoned due to mechanical problems during re-entry. The well search activities, which culminated in the acceptance by the DOE of 7 recommended wells, were substantial. A total of 90,270 well reports were reviewed, leading to 1990 wells selected for thorough geological analysis. All of the reservoirs tested in this program have been restricted by one or more faults or permeability barriers. A comprehensive discussion of test results is presented.
Date: January 1, 1982
Creator: unknown
Object Type: Report
System: The UNT Digital Library
EVALUATING ROBOT TECHNOLOGIES AS TOOLS TO EXPLORE RADIOLOGICAL AND OTHER HAZARDOUS ENVIRONMENTS (open access)

EVALUATING ROBOT TECHNOLOGIES AS TOOLS TO EXPLORE RADIOLOGICAL AND OTHER HAZARDOUS ENVIRONMENTS

There is a general consensus that robots could be beneficial in performing tasks within hazardous radiological environments. Most control of robots in hazardous environments involves master-slave or teleoperation relationships between the human and the robot. While teleoperation-based solutions keep humans out of harms way, they also change the training requirements to accomplish a task. In this paper we present a research methodology that allowed scientists at Idaho National Laboratory to identify, develop, and prove a semi-autonomous robot solution for search and characterization tasks within a hazardous environment. Two experiments are summarized that validated the use of semi-autonomy and show that robot autonomy can help mitigate some of the performance differences between operators who have different levels of robot experience, and can improve performance over teleoperated systems.
Date: March 1, 2008
Creator: Nielsen, Curtis W.; Gertman, David I.; Bruemmer, David J.; Hartley, R. Scott & Walton, Miles C.
Object Type: Article
System: The UNT Digital Library
Deceptiveness and genetic algorithm dynamics (open access)

Deceptiveness and genetic algorithm dynamics

We address deceptiveness, one of at least four reasons genetic algorithms can fail to converge to function optima. We construct fully deceptive functions and other functions of intermediate deceptiveness. For the fully deceptive functions of our construction, we generate linear transformations that induce changes of representation to render the functions fully easy. We further model genetic algorithm selection recombination as the interleaving of linear and quadratic operators. Spectral analysis of the underlying matrices allows us to draw preliminary conclusions about fixed points and their stability. We also obtain an explicit formula relating the nonuniform Walsh transform to the dynamics of genetic search. 21 refs.
Date: January 1, 1990
Creator: Liepins, G. E. & Vose, M. D.
Object Type: Article
System: The UNT Digital Library
Natural ventilation: it's as easy as opening the windows, or is it (open access)

Natural ventilation: it's as easy as opening the windows, or is it

The research consisted of an evaluation of the existing technologies available for passive cooling with an emphasis on strategies related to the use of natural ventilation. A preliminary data base for the study was established by three major efforts: 1. An extensive literature search of the architectural press was undertaken to ascertain the degree to which passive cooling strategies in general and natural ventilation in particular are designed into buildings at the present time. 2. An investigation of existing building stock profiles was undertaken to identify the existing and potential obstacles or advantages to the implementation of natural ventilation as a passive cooling strategy. The EIA Nonresidential Buildings Energy Consumption Survey and two previous PNL studies were reviewed. 3. Components 1 and 2 were followed up with telephone interviews and site visits with the architects, building owners and operators of selected buildings from 1 and 2 above to gain more specific insights into the problems and pleasures typically associated with natural ventilation.
Date: October 1, 1984
Creator: Siebein, G.W.
Object Type: Report
System: The UNT Digital Library
Evaluation of Computer-Based Procedure System Prototype (open access)

Evaluation of Computer-Based Procedure System Prototype

This research effort is a part of the Light-Water Reactor Sustainability (LWRS) Program, which is a research and development (R&D) program sponsored by Department of Energy (DOE), performed in close collaboration with industry R&D programs, to provide the technical foundations for licensing and managing the long-term, safe, and economical operation of current nuclear power plants. The LWRS program serves to help the U.S. nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. The introduction of advanced technology in existing nuclear power plants may help to manage the effects of aging systems, structures, and components. In addition, the incorporation of advanced technology in the existing LWR fleet may entice the future workforce, who will be familiar with advanced technology, to work for these utilities rather than more newly built nuclear power plants. Advantages are being sought by developing and deploying technologies that will increase safety and efficiency. One significant opportunity for existing plants to increase efficiency is to phase out the paper-based procedures (PBPs) currently used at most nuclear power plants and replace them, where feasible, with computer-based procedures (CBPs). PBPs have ensured safe operation of …
Date: September 1, 2012
Creator: Oxstrand, Johanna; Blanc, Katya Le & Hays, Seth
Object Type: Report
System: The UNT Digital Library
Genetic algorithms and their use in Geophysical Problems (open access)

Genetic algorithms and their use in Geophysical Problems

Genetic algorithms (GAs), global optimization methods that mimic Darwinian evolution are well suited to the nonlinear inverse problems of geophysics. A standard genetic algorithm selects the best or ''fittest'' models from a ''population'' and then applies operators such as crossover and mutation in order to combine the most successful characteristics of each model and produce fitter models. More sophisticated operators have been developed, but the standard GA usually provides a robust and efficient search. Although the choice of parameter settings such as crossover and mutation rate may depend largely on the type of problem being solved, numerous results show that certain parameter settings produce optimal performance for a wide range of problems and difficulties. In particular, a low (about half of the inverse of the population size) mutation rate is crucial for optimal results, but the choice of crossover method and rate do not seem to affect performance appreciably. Optimal efficiency is usually achieved with smaller (< 50) populations. Lastly, tournament selection appears to be the best choice of selection methods due to its simplicity and its autoscaling properties. However, if a proportional selection method is used such as roulette wheel selection, fitness scaling is a necessity, and a high …
Date: April 1, 1999
Creator: Parker, Paul B.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Survey of existing underground openings for in-situ experimental facilities (open access)

Survey of existing underground openings for in-situ experimental facilities

In an earlier project, a literature search identified 60 underground openings in crystalline rock capable of providing access for an in-situ experimental facility to develop geochemical and hydrological techniques for evaluating sites for radioactive waste isolation. As part of the current project, discussions with state geologists, owners, and operators narrowed the original group to 14. Three additional sites in volcanic rock and one site in granite were also identified. Site visits and application of technical criteria, including the geologic and hydrologic settings and depth, extent of the rock unit, condition, and accessibility of underground workings, determined four primary candidate sites: the Helms Pumped Storage Project in grandiodorite of the Sierra Nevada, California; the Tungsten Queen Mine in Precambrian granodiorite of the North Carolina Piedmont; the Mount Hope Mine in Precambrian granite and gneiss of northern New Jersey; and the Minnamax Project in the Duluth gabbro complex of northern Minnesota.
Date: July 1, 1981
Creator: Wollenberg, H.; Graf, A.; Strisower, B. & Korbin, G.
Object Type: Report
System: The UNT Digital Library
Sediment Decontamination With Beneficial Use for the Port of New York and New Jersey. (open access)

Sediment Decontamination With Beneficial Use for the Port of New York and New Jersey.

Effective operation of the multi-state Port ofNew York/New Jersey (Port), which contributes $20 billion to the regional economy and generates nearly 250,000 jobs, is dependent on yearly navigational dredging of several million m{sup 3} of sediment for channel maintenance and deepening. Further dredging is required for remediation of environmentally sensitive areas. However, more stringent ocean placement testing regulations in the Port region have necessitated a search for other means of handling the most contaminated dredged materials. Here, we describe a dredged material decontamination program for the Port aimed at the creation of sediment decontamination facilities that produce a beneficial use product to obviate the need for ocean placement. These facilities, to be a viable component of an overall dredged material management plan, must be environmentally balanced and economically feasible with the predictable ability to process large volumes of dredged materials with rapid turn-around. Our program recognizes that the responsible management of contaminated dredged materials is a complex problem that requires the effective application and coordination of a variety of cross-cutting skills to make decontamination facilities a reality. Participants do not come from a single agency, but are ad hoc teams of scientists, engineers, regulators, port authorities and operators, technology development …
Date: May 1, 2002
Creator: Stern, E. A.; Jones, K. W.; Douglas, W. S.; Feng, H.; Clesceri, N. L. & Lodge, J. L.
Object Type: Article
System: The UNT Digital Library
Unattended mode operation of specialized NDA (nondestructive assay) systems (open access)

Unattended mode operation of specialized NDA (nondestructive assay) systems

Nondestructive assay systems have been developed to allow data acquisition equipment to operate unattended in an automated mixed oxide facility, reducing inspector time in a facility and giving them time for other activities. Fewer inspector visits mean less impact on plant operators. Neutron detectors are located at key measurement points in the facility. Near each detector is located an electronics cabinet, which contains two JSR-11 shift registers, two COMPAQ Portable III computers, and a printer. The signal from the detector is split and sent to each shift register for redundancy and reliability. The software for unattended operation consists primarily of two programs, COLLECT and REVIEW. The COLLECT program runs on the computers in unattended operation; shift-register data are acquired each 60 s. The COLLECT program distinguishes between a normal background and a disconnected signal, between material moving near the detector and material in the detector, and whether the material in the detector is a sample or a californium normalization source. Depending on the type of assay, different data are stored on the hard disk. During an inspection, the inspector stops the current measurement campaign, examines the data from both computers briefly at the electronics cabinet, copies the campaign data to …
Date: January 1, 1989
Creator: Klosterbuer, S.F.; Kern, E.A.; Painter, J.A. & Takahashi, S.
Object Type: Article
System: The UNT Digital Library
Baryon Spectroscopy and Resonances (open access)

Baryon Spectroscopy and Resonances

A short review of current efforts to determine the highly excited state spectrum of QCD, and in particular baryons, using lattice QCD techniques is presented. The determination of the highly excited spectrum of QCD is a major theoretical and experimental challenge. The experimental investigation of the excited baryon spectrum has been a long-standing element of the hadronic-physics program, an important component of which is the search for so-called 'missing resonances', baryonic states predicted by the quark model based on three constituent quarks but which have not yet been observed experimentally. Should such states not be found, it may indicate that the baryon spectrum can be modeled with fewer effective degrees of freedom, such as in quark-diquark models. In the past decade, there has been an extensive program to collect data on electromagnetic production of one and two mesons at Jefferson Lab, MIT-Bates, LEGS, MAMI, ELSA, and GRAAL. To analyze these data, and thereby refine our knowledge of the baryon spectrum, a variety of physics analysis models have been developed at Bonn, George Washington University, Jefferson Laboratory and Mainz. To provide a theoretical determination and interpretation of the spectrum, ab initio computations within lattice QCD have been used. Historically, the calculation …
Date: December 1, 2011
Creator: Edwards, Robert
Object Type: Article
System: The UNT Digital Library
SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT (open access)

SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper …
Date: March 1, 2003
Creator: Reeves, Scott
Object Type: Report
System: The UNT Digital Library
SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT (open access)

SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper …
Date: March 1, 2003
Creator: Reeves, Scott
Object Type: Report
System: The UNT Digital Library