bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thixotropic, Crosslinking Polymer/Borate/Salt Plug: Development and Application
Authors: Powell J. W. , Stagg T. O. , Reiley R. H. , Dobson J. 
Published: December 2007

ABSTRACT
Off-bottom liner cementing operations in horizontal wells on Alaska's North Slope led to the development of a unique and patented crosslinked polymer/borate/salt (PBS) plug material. Functioning to temporarily plug back the horizontal wellbore while the gas isolation liner is reciprocated and rotated during cementing, the PBS plug protects the production zone from surge and swab pressures and minimizes the risk of sidetracking during cement cleanouts.
Fluid properties and the functional physical and chemical properties of the plug include: viscoelasticity and elevated low shear rate viscosity for plug-flow displacements, and thixotropy to aid plug placement; workable set time; no syneresis; combination of low fluid loss and water/acid solubility to minimize formation damage; a final plug shear strength high enough for functionality and low enough to ensure removal by washing or jetting.
This paper describes the use and field performance of the plug in the off-bottom cementing procedure, and reports pre-set fluid properties, chemical and physical properties, and mixing and spotting procedures. Information is also presented on how the plug has been used to combat difficult lost circulation problems encountered during drilling, workover, and coiled tubing operations.
Effect of Ultrasonic Radiation on Contaminants Adsorbed on Activated Carbon
Authors: Tumeo M. A. , Wheat P. E. 
Published: December 2007

ABSTRACT
A common practice used in water, wastewater and hazardous waste site remediation involves the use of granulated activated carbon to treat effluent waters. When the adsorption cycle is complete the contaminant saturated activated carbon is often regenerated. Regeneration commonly involves the use of high temperature steam (~800-900°C) or solvents to extract adsorbed contaminants. This process may be performed onsite or the contaminated carbon can be shipped off-site for treatment, however, both options present difficulties. Stringent emission requirements and large capital equipment investment often make on-site regeneration economically infeasible. Offsite regeneration poses the added risk of contaminant release during transport and is strongly discouraged under EPA regulations. For these reasons there is great interest in obtaining an activated carbon regeneration methodology which can be economically performed on-site while minimizing potential hazards.
The ability of ultrasound to enhance extraction of organic contaminants adsorbed on activated carbon in the presence of organic solvents has been demonstrated. The use of ultrasonic radiation to facilitate the extraction of adsorbed organic contaminants from the surface of soil and sediments into organic solvents has also been investigated and is recognized by EPA as an approved extraction technique (method #3550).. However, there is no evidence in the literature that any work has been done on using ultrasonics to induce de-adsorption in aqueous environments.
This paper presents the preliminary data from an ongoing study into the use of an ultrasonic field of varying pressure amplitude to induce physical and thermodynamic changes in contaminants adsorbed onto the surface of activated carbon. Increasing radiation intensities up to and including the cavitation point of each heterogeneous activated carbon/aqueous solution system are being investigated and physical changes in the activated carbon as well as contaminant transformation due to cavitation induced modifications examined. The aim of the research is to develop a cost-effective methodology to regenerate contaminated activated carbon, perhaps chemo-selectively.
Pressure-Transient Behavior of Horizontal Wells with Finite-Conductivity Vertical Fractures
Authors: Larsen L. , Hegre T. M. 
Published: December 2007

SUMMARY
Methods are introduced to generate synthetic pressure-transient data for horizontal wells with finite-conductivity vertical fractures. For the main results flow from the reservoir is only assumed to take place through the fractures, but methods to include flow directly to the wellbore are also outlined. Although the paper is aimed mainly at transverse circular fractures, mathematical derivations for flow to rectangular fractures have also been included. Boundaries and multiple fractures can be treated with considerable flexibility, but examples discussed in the paper are restricted to individual or pairs of circular fractures in unbounded reservoirs, and hence also to single circular fractures in the presence of a sealing fault.
The approach taken follows classical studies of vertical wells with finite-conductivity vertical fractures. Basic solutions are developed in terms of Laplace transforms, with numerical inversion used to obtain end results. The main objective of the paper is to introduce methods to generate synthetic data for fractured horizontal wells. Application of the methods to investigate productivity of various well and fracture configurations has not been considered. Only cases to illustrate the methods are included.
The results of the paper are verified in part by ccmparisans with models developed far vertical wells producing layered and double-porosity reservoirs and with results from a 3D, finite-difference, numerical reservoir simulator.
Model Pile Tests in Saline Soils
Authors: Christopherson A. , Nelson W. , Nottingham D. , Somerville D. 
Published: December 2007

ABSTRACT
The purpose of this project was to measure the secondary creep rate of 4.5 inch (114 mm) diameter steel piles that were forced into frozen saline silt. The silt contained 30% water with a salt content of 33.4 ppt. The piles, embedded in 19°F (-7°C) silt, were loaded to produce shear stresses of 0.5, 1.0, 1.5, and 2.0 psi (3.4, 6.9, 10.3 and 13.8 kPa). Results are compared to published data related to frozen soils containing fresh water.
Evaluation of Vacuum-Insulated Tubing for Paraffin Control at Norman Wells
Authors: Purdy I. L. , Cheyne A. J. 
Published: December 2007

ABSTRACT
Paraffin deposition in the production tubing of wells in the Norman Wells field has been an ongoing operational problem. Although many solutions are possible a passive thermal solution is most desirable. Using a wellbore thermal simulator, it was predicted that vacuum insulated tubing could raise the flowing tubing temperature at the wellhead above the cloud point of the crude oil. A string of vacuum insulated tubing was installed and has performed as predicted by the thermal simulation model.
Wellbore Multiphase-Flow Correlation for the Eastern Operating Area of Prudhoe Bay
Authors: Bradley D. A. 
Published: December 2007

ABSTRACT
This paper describes the development of a pressure-calculation computer program for producing wells. The program is currently in use for the Eastern Operating Area of Prudhoe Bay. An accuracy analysis and some of the results of the use of the program are presented, as well.
The program was developed primarily to provide precise bottomhole flowing-pressure calculations for the entire range of well geometries and flowing conditions existing in the area at the time. Although the friction component of the pressure-drop of a producing well is calculated by using standard correlations, the elevation component is calculated by using an empirical fit of field data. This empirical fit involved the creation and use of a database of well tests and survey pressures for many wells. Ultimately the database was streamlined into two number groups representing the elevation and friction losses for all wells. This causes the program to run as quickly as possible, while providing accurate and smooth results.
Modeling of In-Situ Stress Change Due to Cold Fluid Injection
Authors: Clifton R. J. , Brown U. , Wang J- J. 
Published: December 2007

ABSTRACT
In hydraulic fracturing, the temperature for the treating fluid usually differs from the initial temperature reservoir. Because of fluid migration and heat transfer in the reservoir, such differential temperature induces thermal stresses. This paper presents a computational model, adaptive to hydraulic fracturing simulators, for calculating these thermoelastic changes in the in-situ stress distribution.
Evaluation of Reservoir Fluids Using Formation Tester Tool Samples
Authors: Morris C. W. , Sonnier B. 
Published: December 2007

Abstract
The evaluation of petroleum resources requires a good understanding of the reservoir fluids and their behavior. Specifically, PVT (pressure-volume-temperature) data are required at the earliest possible stage to develop economic evaluations, interpret well test data, design production equipment, and predict future reservoir performance.
A fluid sample obtained with an openhole wireline formation tester tool provides the engineer with the first (and potentially the only) chance to analyze a representative reservoir fluid sample before significant decisions are made. The fluids must be characterized by direct measurement of certain properties and the quality of the PVT laboratory results depends almost entirely on the validity of the sample used for the analysis.
This paper compares the fluid PVT data obtained using samples from wireline formation tester tools and from surface production test equipment. The PVT laboratory procedures and the accuracy of the analysis methods are discussed. The compositional analyses of the hydrocarbon samples are compared, from methane to heptanes-plus chemical structure, along with the key volumetric parameters such as density, bubblepoint pressure, viscosity, formation volume factor, and gas-oil ratio. Different types of reservoirs (with fluids ranging from low gas-oil ratio oils to dry gas) were examined to determine the effects of mud filtrate invasion in the openhole environment, type of fluid, and reservoir characteristics.
In general, the results indicate that samples obtained with wireline formation tester tools can provide representative reservoir fluid parameters from compositional analyses to basic volumetric behavior as a function of pressure and temperature. Critical reservoir parameters such as the fluid density, bubblepoint pressure, formation volume factor, viscosity, and gas-oil ratio are consistent within about 15 percent for most oil reservoir fluids.
Gas condensate reservoir fluids present the most difficult sampling conditions for both the downhole and surface sampling operations. Careful sampling techniques and detailed monitoring of the downhole and surface fluid conditions are required to reconstruct useful results for the reservoir fluid properties.
Shaft and Tunnel Access (SATAC) Concepts for Developing Petroleum Reserves
Authors: Haskin C. A. , Bugno W. T. , Miller R. M. 
Published: December 2007

ABSTRACT
Shaft and tunneling technology commonly employed in the mining and construction industries has been shown to have application in the development of some petroleum deposits. The use of Shaft And Tunnel Access (SATAC) technology in the Athabasca Oil Sands in Alberta has been well documented by Hasten,1 Best,2 and others.3-8
Arctic reservoirs, because of the hostile weather, are among the potential candidates for development using SATAC methods, particularly shallow (&lt;5000’) heavy oil reservoirs. Underground space concepts offer solutions to many problems now commonly associated with developing oil reserves in these and other areas.
While not applicable to all reservoirs, SATAC is recognized technology and should be considered among the available tools to access and develop oil reservoirs. Possibilities include: (1) employing mining to develop oil reserves; (2) using for infrastructure, like access roads and pipelines; or (3) using in combination with other technologies like subsea production.
Creation of High-Productive Seeding Meadows on Disturbed Arctic Lands
Authors: Tikhmenev E. A. 
Published: December 2007

ABSTRACT
The specific features of disturbed lands-heat resource accumulation, aeration and deep seasonal surface melting (up to 1.5-2.0 m) - work to the advantage of their successful reclamation.On the basis of the field experiments an effective technology of the biological stage of reclamation with the use of perrenial grasses has been worked out. This reclamation technology helps to creat valuable communities adaquate to nature. Different species of natural flora adapted to the extreme conditions of the Arctic are being used: Elymus sibiricus, E. mutabilis, Bromopsis inermis, Arctagrostis latifolia. Positive results have been obtained by reclamation of reindeer pastures. The productivity of reclaimed plant cover being 1.5-2 times higher than that of initial native lands. Chemical analysis indicated high quality of plants quite appropriate for reindeer grazing.
Cold Region Hydraulic Oil Applications
Authors: Uhrik S. L. 
Published: December 2007

ABSTRACT
A literature search confirmed that the engineering design for machinery and systems used in cold region environments needs to include an evaluation of the hydraulic oil application. The process begins with a basic understanding of the terms absolute viscosity, kinematic viscosity, cloud point and pour point.
The most apparent effect of cold weather on hydraulic oil is the rapid viscosity increase that accompanies the lowering of ambient temperatures. Viscosity Index (VI) defines this effect. Various authors and methods have attempted to use equations, graphs, and tables to compare this response for different fluids. The theoretical work has found practical application in oil classification systems developed by API, SAE and ASTM.
Viscosity Index improvers, additives and oil blend formulations can overcome the operating problems associated with low temperature. A discussion of this knowledge is presented with applications to aviation hydraulic oils, motor vehicle oil change intervals, storing marine engines for the winter months, starting cold soaked engines and an empirical equation for refinery formulations of summer, winter and arctic product blends.
Guidelines are given to aid in the evaluation and selection of hydraulic fluids for cold region applications. Five major fluid classes are examined. Hydraulic system maintenance and troubleshooting tips complete the presentation.
A Comparison of MWD and Wireline Steering Tool Guidance Systems in Horizontal Drilling
Authors: Gaudin D. B. , Beasley J. C. 
Published: December 2007

ABSTRACT
In horizontal drilling, proper equipment selection is a key factor for success. Particularly in today's horizontal drilling market, where technology is changing so rapidly, a well informed and systematic approach to well planning can help ensure selection of equipment that will result in the most efficient and cost effective drilling program. However, it is often difficult for oil company personnel to assure themselves that they are indeed selecting the best available techniques for particular applications.
One area in which this dilemma is particularly evident is wellbore guidance. Many people are of the opinion that measurement while drilling (MWD) tools are best; others prefer to use wireline steering tools. To determine which method is actually best for any given situation, factors such as economics, availability, accuracy and application should be considered.
This paper analyzes the operational details of each system as they pertain to the different intervals of horizontal wells, and offers comparative information that will help operators in selecting the most efficient surveying method for any application.
The Principle of a Critical Invasion Rate and Its Implications for Log Interpretation
Authors: Fordham E. J. , Allen D. F. , Ladva H. K. J. 
Published: December 2007

ABSTRACT
The interpretation of MWD and wireline logs of invaded formations can be enhanced by an understanding of the controls on invasion rates. Experimental investigation of dynamic filtration rates has shown that under certain conditions these are dependent only on the hydraulic shear stress at the mudcake surface for a given mud composition. They are virtually independent of differential pressure and independent of porous medium permeability (as opposed to mudcake properties) over a 1:104 range. For very low permeability media however, the clear fluid Darcy flux may already be below the dynamic filtration rate. Then no mudcake forms and filtration rates obey Darcy's law. Comparison with theory suggests that there is a critical flux (filtration rate per unit area) above which clay particles accrete irreversibly to the mudcake; below this flux they cannot stick at all.
Invasion volumes at the time of wireline logging are usually dominated by fluid loss that occurred under conditions of dynamic filtration. The conjecture of a critical dynamic filtration rate, dependent only on mud composition and shear, means that invasion volumes should be independent of mud overbalance pressure and of formation properties (permeability, saturation, far field pressure, internal mudcake)—unless formation permeability is so low that it limits the filtration flux to less than the critical flux. Then, formation properties control fluid loss. The permeability at which the behavior changes depends on both mud overbalance pressure and mud flow rate.
These results are important for the interpretation of MWD and wireline logs in the presence of invasion. Field examples of multiple pass MWD and wireline resistivity logs and invasion volume computations from a single pass of wireline resistivity and porosity logs often indicate trends in the invasion volume within a zone or between zones. These trends may be interpreted as indicating differential formation resistance to invasion at low permeabilities but must be due to factors other than the loss rate at moderate to high permeabilities. One such factor is vertical movement of the filtrate under the influence of gravity.
Current Calibration and Quality Control Practices for Selected Measurement-While-Drilling Tools
Authors: Brami J. B. 
Published: December 2007

ABSTRACT
The purpose of this paper is to compile and explain calibration and quality control practices for Measurement While Drilling (MUD) formation evaluation tools for current vendors. MWD logs are usually run in high-operating-cost, geologically complex, and hostile environments. They are commonly justified as "insurance logs" in case the operator can’t get a wireline log. On occasion, these insurance logs become "the only log". Uhen the MUD log exhibits either the desired or expected response, it is believed. Conversely, when an unexpected response is recorded, the MUD log is treated skeptically. Uhen the operator does not believe a log, the data may be suspected to be inaccurate or uncalibrated.
Regardless of the type of measuring device, wireline or MUD, calibrations must be understood before a log is trusted. Standards for reference for MUD logs are not always understood by operating oil company personnel. Over the past 50 years, log analysts have studied and become comfortable with the standards to which wireline tools are referenced. The understanding of calibration practices for MUD tools by oil company operators has proven to be a major hurdle for MUD service companies. Until MUD tool calibrations are understood and accepted by oil company petrophysicists, MUD tools will continue to be followed out of the hole by wireline tools. These redundant logs result in additional cost, risk, and delay in hydrocarbon production.
This paper is the product of several preparation steps. In the first phase of preparation, MWD service companies were asked to supply very general and simplified explanations of how they calibrated or verified their tools. In the second step, more detailed explanations were supplied. Then, several Ad Hoc MUD Calibration Committee meetings were held over the course of a year to develop concise explanations of calibration practices in the MUD industry.
Using a common format and vocabulary, this paper explains MUD calibration practices for gamma ray, resistivity, density, neutron porosity, and caliper tools that are now, or soon to be, commercially available. The data compiled in this paper identify the extent and frequency of calibrations for all major MUD tools. Several case histories are reviewed to illustrate some of the more common quality control concerns. MUD and corresponding wireline logs are shown that raise questions or concerns about invasion and washouts, depth control, and high rates of penetration.
Technical information on tool calibration/verification has been supplied by service companies and has not been independently verified by the authors.
Bending Stress Magnification in Constant Curvature Doglegs With Impact on Drillstring and Casing
Authors: Paslay P. R. , Cernocky E. P. 
Published: December 2007

ABSTRACT
When drill string in a gradual dog leg is subjected to either tensile or compressive axial loads, the maximum curvature of the drill pipe body exceeds that of the hole axis curvature. Lubinski recognized this fact and published an analysis in 1961 for the tensile case. His results are given in the API RP7G manual.
Contemporary technology uses compressive axial loads in some extended reach and horizontal drilling applications. In addition, when casing is set, it is common to have the casing in a dog leg under compression. An analysis for compressive loads, analogous to Lubinski's analysis, is required to evaluate the bending stresses in these situations accurately.
This work presents the analytical solution for maximum drill pipe curvature when an axial compressive load, in the practical range, is applied to the drill string. Similar to the tensile case, contact (point and wrap) between the drill pipe and the hole wall as well as tool joint contact load must be taken into account.
Dimensionless curves are presented for bending stress calculation for both tensile and compressive axial loads. The curves allow easy evaluation of the bending stress magnification (BSM). The results show it is important to take the bending stress and the BSM into account in practical design particularly because of coupling with axial tension and compression loads. The results given in this paper complement calculations based on torque and drag models of drill strings. The results also complement and build on the earlier work of Lubinski.
The results are extended to burst and collapse analysis in casing and to fatigue analysis in drill pipe. The important influences of BSM are made clear in design curves for these applications.
The Effects of Temperature, Pressure, and Angle of Deviation on Free Water and Cement Slurry Stability
Authors: Matson R. P. , Rogers M. J. , Go Boncan V. C. , Gandy R. G. 
Published: December 2007

ABSTRACT
The importance of free water control upon slurry design and performance in deviated and horizontal wellbores has been recognized and documented. The literature contains suggested procedural modifications to API Spec 10, Free Water Test, to better approximate bottom-hole cementing conditions. Suggestions include (1) pre-conditioning the slurry in a pressurized consistometer at bottom-hole conditions, (2) conducting the Free Water Test at various angles from a vertical position, (3) utilization of a new settling tube for evaluating the degree of segregation of the cement particles (density segregation). Little has been written on the interaction of temperature, pressure and increased slurry surface area due to deviated conditions on free water and cement slurry stability.
This paper presents laboratory results of a comparison between the current API Free Water procedure, modified API Free Water procedure and modified British Petroleum Settling Tube Test. The comparison includes differences in both free water and slurry stability at elevated temperatures and pressure at various angles. From this research, results highlight possible unsupported optimism concerning cement slurry performance in deviated and horizontal applications when based on current API Free Water Test procedure.