bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Travis Peak (Hosston) Formation of East Texas and North Louisiana
Authors: Saucier A. E. , Finley R. J. , Dutton S. P. 
Published: December 2007

ABSTRACT
The Travis Peak Formation (Hosston Formation in Louisiana) is a basinward-thickening wedge of terrigenous clastics that extends in an arc from eastern Texas across southern Arkansas and northern Louisiana into southern Mississippi. This formation is a large reservoir of natural gas that is contained in sandstones of low permeability that are generally classified as tight gas sands. Because of the stratigraphic complexity and past limited economic interest in this Lower Cretaceous formation, little is known about the distribution or depositional environments of potentially productive sandstones within it. This subsurface study of the Travis Peak (Hosston) and Sligo Formations utilized 1,300 electric logs distributed across an area of approximately 35,000 mi2 covering the east half of the East Texas Basin, the North Louisiana Basin, and part of southern Arkansas.
In addition to the standard isopach and structure maps, several lithofacies maps and six semi-regional stratigraphic cross sections made it possible to recognize the following five depositional systems in the Travis Peak (Hosston) Formation: fluvial-deltaic, delta fringe, restricted marine shelf, shelf margin, and open marine. The most sand-rich systems are the fluvial-deltaic and the shelf-margin systems.
Two major high-constructive delta complexes have been identified in the study area. These deltas were located over the present sites of the Sabine and Monroe Uplifts. The North Louisiana Salt Basin, a marine embayment in Travis Peak (Hosston) time, accumulated a thick section of interbedded shales and limestones in a restricted back-reef or back-bar shelf area. A carbonate or sandstone barrier appears to extend across the central Louisiana Early Cretaceous shelf margin.
The delta-fringe system, although containing less sand, consists of a variety of lithofacies deposited in a transition zone ranging from delta-plain to shallow-marine-shelf environments, and it appears to correlate with the most hydrocarbon-productive part of the Travis Peak (Hosston) Formation. Oil and gas accumulations in the Travis. Peak (Hosston) are closely associated with salt-cored structures in East Texas and North Louisiana. This study should aid in the projection of prospective tight gas trends.
Models of Heat Transfer in Hydraulic Fracturing
Authors: Ben-Naceur K. , Stephenson P. 
Published: December 2007

ABSTRACT
The influence of heat-transfer mechanisms during fracture propagation is determined using a general model combining convection along the fracture with conduction and convection in the reservoir. A series of simplified models is also given, together with their ranges of applicability. The thermal simulator is coupled with a fracture propagation model, the rheology of the fracturing fluid being assumed to be time- and temperature-dependent. Implications of the heat-exchange processes on the proppant transport in the fracture and on the post-stimulation well performance are given.
In-Situ Stress Determination From Wellbore Elongation Measurements
Authors: Blanton T. L. , Teufel L. W. 
Published: December 2007

ABSTRACT
This paper explores the feasibility of making in situ stress measurements at depth from caliper measurements of deformed wellbores. The work has been carried out in three steps: (1) theoretical development of viscoelastic constitutive equations necessary for calculation of stress directions and magnitudes, (2) application of the equations to field data, and (3) comparison of results to stress measurements made by hydraulic fracturing and overcoring methods. The results of the theoretical analysis are equations that relate the minimum and maximum radii of a deformed wellbore to the maximum and minimum stresses perpendicular to the axis of the wellbore. Calculation of absolute magnitudes of stresses requires the viscoelastic compliance and Poisson's ratio of the rock, but even when this information is not available relative magnitudes of stresses can be determined. The constitutive equations were applied to caliper measurements of a horizontal borehole in unwelded ash-fall tuff near an underground tunnel complex in Rainer Mesa on the Nevada Test Site. The horizontal borehole was aligned in the direction of the maximum horizontal stress. Over a 37 day period the wellbore showed time-dependent deformation, with maximum closure in the maximum stress direction (overburden). The ratio of principal stress calculated from caliper measurements of the deformed wellbore varied from 1.73 to 2.06, depending on the time interval used. The ratios obtained from overcoring and hydraulic fracturing were 1.79 ± .22 and 2.12 ± .12. Limitations of this approach to stress measurement are discussed, but results of the present study suggest that with further development of the viscoelastic consitutive model, stress variations along the length of the wellbore might be readily examined as part of the well logging process.
Capillary Pressure and Permeability Relationships in Tight Gas Sands
Authors: Wells J. D. , Amaefule J. O. 
Published: December 2007

ABSTRACT
An improved technique for determination of the Swanson Petrophysical parameter, (Sb/Pc)A for correlating permeability with capillary pressure data has been developed. (Pc/Sb)1/2 as a function of Sb, yields a well defined minimum which corresponds to the values of Pc and Sb from the Swanson graphical method. The improved technique leads to ease of computer determination of the parameter. The relationships developed by Swanson for correlating permeability with capillary pressure work well for samples with permeabilities greater than 10 microdarcies. A new relationship between the Swanson parameter and permeability has been developed for tight gas sands which leads to a more accurate permeability prediction below 10 microdarcies.
Mercury capillary pressure data at wetting phase saturations higher than 50% are approximately a factor of 10 greater than centrifuge air-brine capillary pressure for tight gas sands. This contrasts with the more commonly assumed value of 5. Consequently gas-water relative permeabilities computed from mercury injection capillary pressure data will result in predictions of higher water-gas ratios than the air-brine data. Optimistic cleanup times for tight gas wells completed in water-base fluids would, therefore, be deduced from the mercury injection data.
A Stimulation Method for the Codell Sandstone, Denver-Julesburg Basin of Colorado, Using Low pH Methanol
Authors: McLane J. E. , Edgington L. 
Published: December 2007

ABSTRACT
The clay filled low permeability sandstone of the Codell formation of Colorado has historically been a difficult formation to stimulate. In the past, conventional methods of stimulation have been used in the Codell sandstone with results below expectations.
Codell sandstone core samples were taken from several wells in the Denver-Julesberg Basin of Colorado, over a three county area, and were from various depths of approximately 1554.50m (5100 ft.) to 2438.40m (8000 ft.)
The object of this paper is to characterize the Codell sandstone cores by use of Scanning Electron Microscopy and Energy Dispersive Spectrometry (SEM/EDS) to evaluate the mineralogy and lithology of the formation. The samples were then subjected to experimental and conventional treatment fluids by use of a Gas/Liquid Reference Core Flow Apparatus to determine the least damaging stimulation treatment.
Treatment fluids evaluated in this study were: 100% methanol, low pH methanol with specific additives, KCl water/methanol blends, KCl water and various weak acid blends. One of the low pH methanol systems described in this paper has shown positive gains in permeability during core flow testing and can be an effective enhancement of conventional water based systems used for stimulating other low permeability reservoirs. The most effective method of application of such a system has been as a prepad ahead of conventional water base treatments.
The concept of low pH (4.0) methanol combined with a special silt suspension and clay control chemical additives is suspected to partially dissolve and/or reduce the size of the various clay components in the immediate wellbore vicinity where maximum leak-off/spurt-loss damage usually occurs.
Case histories from treatments done in the DJ Basin will be discussed and evaluated.
Integration of Laboratory and Field Data for Insight on the Multiwell Experiment Paludal Stimulation
Authors: Sattler A. R. , Raible C. J. , Gall B. R. 
Published: December 2007

ABSTRACT
Two stimulation operations have been conducted to date in the paludal zone of the Mesaverde formation in one well, MWX-1, at the DOE's Multiwell Experiment test site in the Piceance Basin near Rifle, Colorado. Problems were encountered in the second stimulation: MWX-1 would not sustain production for several months and post-frac production was less than pre-frac rates. The laboratory program was expanded to examine these problems and these laboratory studies were integrated with well testing and other data to help explain MWX-1 production behavior. A unique explanation cannot be found for the failure of MWX-1 to produce; a combination of factors was responsible. Water probably inhibited matrix rock production. A system of naturally occurring microfractures is important in production from the paludal zone and it probably sustained damage by water and fracture fluids. The basic gel degraded slowly because only a small amount of breaker was used. The fracture closure (viscosity break) observed from the Nolte analysis of the stimulation was not the same as the breakdown of the basic gel. The remedial treatment conducted after the second stimulation was probably too reactive. A list of items has been developed from experience gained both inside and outside the laboratory that shows what work and which procedures should be emphasized or avoided in tight sand stimulations.
Impedance of Hydraulic Fractures: Its Measurement and Use for Estimating Fracture Closure Pressure and Dimensions
Authors: Holzhausen G. R. , Gooch R. P. 
Published: December 2007

ABSTRACT
The growth of a hydraulic fracture increases the period of free oscillations in a well. Simultaneously, the decay rate of free oscillations decreases. The properties of forced oscillations in a well also change during fracture growth. All of these effects result from the changing impedance of the hydraulic fracture that intersects the well. Fracture impedance can be determined directly by measuring the ratio of downhole pressure and flow oscillations, or determined indirectly from wellhead measurements using impedance transfer functions. Because impedance is a function of fracture dimensions and the elasticity of the surrounding rock, impedance analysis offers a promising new approach for evaluating fracture geometry. Because oscillatory flow conditions occur continuously a hydraulic-fracturing treatment, data collection is simple and economical, adding to the attractiveness of this technique.
Laboratory Formation Damage Studies of Western Tight Gas Sands
Authors: Raible C. J. , Gall B. L. 
Published: December 2007

ABSTRACT
This laboratory study, using formation cores, addressed problems associated with restoration of gas permeability in core from tight gas sand formations after massive hydraulic fracturing (MHF) treatments. Parametric studies affecting the flow of both brine and gas in these formation cores included the effects of the pressure differential across the fluid invaded zone, permeability, temperature, and gel damage to the fracture surface. Formation damage after exposure to fracturing fluids is primarily a problem of fluid recovery and water-saturation reduction.
Polymer damage to the fracture or fracture surface using Western tight gas sand cores caused significant brine permeability reduction and increased the fluid recovery time of the invaded zone. Increased fluid recovery time was magnified for very low permeability formations (less than 0.03 md) and low gas pressure differentials. Capillary end effects are postulated to be responsible for these results. However, after fluid saturations were reduced by displacement and evaporation, polymer damage to gas flow was less than 20 percent.
Results of this study indicate that as reservoir quality decreased there were greater capillary effects and extended time periods were required for invasion fluid recovery to attain maximum gas flow. By using cleanup time and regained gas permeability curves of saturated cores, these capillary effects were observable in the laboratory at reservoir conditions.
The Potential Role of Offshore Standby/Rescueships
Authors: McDonald H G 
Published: December 2007

Abstract
The loss of the drilling rig "Sea Gem" in 1966, in which thirteen people died, was perhaps the first occasion when a major accident connected with offshore explorations and production in the UK Sector of the North Sea resulted in multiple deaths. Since then, loss of life among offshore workers, either through major accidents or individuals falling overboard, has continued to occur throughout the various operational areas worldwide.
One method of increasing the survival chances of maritime casualties associated with offshore installations is to ensure that a designated rescue vessel is always available to attempt a rescue. At present in the UK, Regulation 10 of the Offshore Installations (Emergency Procedures) Regulations 1976, lays down that a standby vessel should be present within five miles of every manned offshore installation, ready to give assistance in an emergency, able to accommodate the entire crew of the installation, and provide aid for them all.
The requirement for a designated rescue vessel for every offshore installation has also been adopted by Norwegian legislators. In Canadian waters, there must be a vessel similarly designated; however, the specification guidelines for these craft are not nearly so detailed or rigorous. Other areas around the world where offshore exploration and development is, or will be taking place, also necessitate a degree of maritime rescue back-up. It is now generally accepted after incidents like the "Ocean Ranger" disaster, that, if it is agreed that a means of rescue from the sea has to be accounted for, then it must be of a specialist nature rather than a compromised attempt.
Safety and Environmental Auditing for Existing Offshore Facilities
Authors: Luck C J , Sellers J G 
Published: December 2007

ABSTRACT
This paper describes a cost-effective approach developed by Arthur D Little to enable companies to identify the potential safety and environmental hazards of existing facilities, quantify the risks and develop risk mitigating measures. The paper highlights the differences in the approach needed for existing facilities compared with that normally used for safety assessment at the design stage. It shows how an effective audit can indicate very rapidly whether the situation is fundamentally safe or whether there are serious deficiences which will require a high level of effort to correct.
Techniques for Quantifying Formation Stress and Fracture Fluid Response for Optimum Hydraulic Fracture Design
Authors: Frisinger M. , Cooper R. E. 
Published: December 2007

ABSTRACT
Improved fracturing treatment design has been achieved by computerised interpretation of the mechanical properties logs, laboratory rock properties measurements and production logging during minifrac tests. By combining these data acquisition techniques in a single well, optimum hydraulic fracturing design input information is obtained.
These techniques have been successfully used in a Southern Sector North Sea well. Subsequently, real-time and post-treatment evaluations have indicated the reliability of the technique.
Actual field data are presented showing use of these data. Also presented is a computer generated fracture geometry processed from mechanical properties log data. Due to the importance of accurate fracture geometry prediction in current North Sea gas field development, the techniques have proven to be a valuable aid.
An Engineering Critical Assessment – A Case History
Authors: Wheeler Dr M. F. , Baker N. J. , Shipley T. D. , Nelson S. G. 
Published: December 2007

Abstract
In order to allow for the development of the North East Frigg and Odin Gas Fields, an uprating of the Frigg Field Transportation and Treatment system was required. This uprating involved work on the Frigg Field, the North Sea Platform, Manifold Compression Platform Ol (MCP01) and the shore terminal at St Fergus in Scotland. The subject matter of this paper relates to the work carried out on MCP 01.
MCP 01, 110 miles offshore, is the centre of a gas collection system receiving gas from the Frigg, Piper and Tartan fields, and transporting this gas to the Total Oil Marine shore terminal at St Fergus. The Frigg gas comes to the MCP 01 by means of twin 32" diameter pipelines of API 5LX-65 material and that from the Piper/Tartan fields via an 18" diameter API 5LX-60 line. The gas is transported onshore via twin 32" diameter sub sea lines of API 5LX-65 material (Figure 1).
The maximum throughput of gas to St Fergus was in the region of 64 MCM/day and in order to carry the extra gas from the Norwegian sector it was required to install, on MCP 01, 2 × 28,000 MW compression sets. The installation of these compressors involved an upgrading of existing utilities and processing facilities, living accommodation and extra life saving appliances.
Computer Modeling for Strategic Planning of Petroleum Exploration and Production
Authors: Katz M. L. , Campbell W. M. , Blackburn C. R. 
Published: December 2007

ABSTRACT
A computer model has been constructed and usedfor strategic planning in an integrated oil and gas company. The model contains representations ofopportunities in exploration, drilling, producingplant, and other types of exploration and production investments. The user specifies alternative strategies and alternative economic scenarios, anduses the model to examine the consequences of these strategies.
Examples are shown of the use of the model to calculate present worth, profit effects, and cashflows for two different economic environments, with a strategy designed to maximize present worth. The consequences of misunderstanding the future economic environment are examined. Other types of model uses which have proven useful are reviewed and summarized.
The Development of the Dubai Condensate Recovery Facilities in the United Arab Emirates
Authors: Bick H. A. , Caceydo L. 
Published: December 2007

ABSTRACT
The description of the development and facilities of the Margham field in Dubai, United Arab Emirates, is the subject of this paper. In February, 1980, ARCO International Oil and Gas Co., adivision of Atlantic Richfield, signed a concession agreement with the Government of Dubai, in the United Arab Emirates. In March, 1982, with Britoil as a partner, a discovery well was completed that confirmed a thick accumulation of gas condensate.
The principals agreed to immediate development, and construction of the production facilitieswas completed in late 1984.
This gas-condensate field is currently producing 24,000 barrels per day (3815 m3/day) of condensate and reinjecting 300 MMSCFD (8.5 × 106 standard m3/day) of the produced gas. As of October 1, 1985 it hadproduced eight million barrels (1.27 × 106m3).
The Role of Bit Type and Drilling Fluid Type in Drilling Performance
Authors: Morton E. K. , Clements W. R. 
Published: December 2007

ABSTRACT
The drilling efficiency of any operation is directly related to borehole stability and optimized drilling parameters. Borehole stability is directly related to reactions with the drilling fluid being used. Penetration rate, although directly related to the strength of the formation, can also be affected by the drilling fluid.
Many active drilling areas around the world have seen the advent of new drilling fluid systems along with new types of drilling bits. A study was initiated to correlate the similarities of these two aspects into the improved penetration rates being realized. Primary interest has been with the use of the PCD (polycrystalline) bits and the use of oil muds, especially the low toxicity oil muds for offshore use. The oil mud drilling fluid has prevented many of the wellbore instability problems that can occur with the use of water base muds. With the use of oil muds and the PCD bits, considerable savings in drilling costs have been realized.
Hydraulic Fracturing of Jointed Formations
Authors: Murphy H. D. , Fehler M. C. 
Published: December 2007

ABSTRACT
Measured by volume, North America's largest hydraulic fracturing operations have been conducted at Fenton Hill, New Mexico to create geothermal energy reservoirs. In the largest operation 21,000 m of water were injected into jointed granitic rock at a depth of 3.5 km. Microearthquakes induced by this injection were measured with geophones placed in five wells drilled into, or very close, to the reservoir, as well as 11 surface seismometers. The large volume of rock over which the microearthquakes were distributed indicates a mechanism of hydraulic stimulation which is at odds with conventional fracturing theory, which predicts failure along a plane which is perpendicular to the least compressive earth stress. A coupled rock mechanics/fluid flow model provides much of the explanation. Shear slippage along pre-existing joints in the rock is more easily induced then conventional tensile failure, particularly when the difference between minimum and maximum earth stresses is large and the joints are oriented at angles between 30 and 60 degrees to the principal earth stresses, and a low viscosity fluid like water is injected. Shear slippage results in local redistribution of stresses, which allows a branching, or dendritic, stimulation pattern to evolve, in agreement with the patterns of microearthquake locations. These results are qualitatively similar to the controversial process known as "Kiel" fracturing, in which sequential injections and shut-ins are repeated to create dendritic fractures for enhanced oil and gas recovery. However, we believe that the explanation is shear slippage of pre-existing joints and stress redistribution, not proppant bridging and fluid blocking as suggested by Kiel.
Stimulation Studies of Chinese Formations
Authors: Parker M. A. , Adams R. W. , Liankui L. 
Published: December 2007

ABSTRACT
Tests to determine mineralogy and formation characteristics were conducted to collect data on formations from the Sichuan Basin, the Zhong Yuan area, the Su Field and the Renbei Field.
This paper will outline the test results and treatment recommendations for stimulation of the various formatioils. A brief review of completion techniques is included. The completion technique can have a direct effect on the type of treatment procedure that is employed.