bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selecting Economic Refracturing Candidates
Authors: Reese J. L. , Britt L. K. , Jones J. R. 
Published: December 2007

Abstract
Since the first fracture treatment was performed in 1947, hydraulic fracturing has been used to accelerate production and improve ultimate recovery in many reservoirs. However, many of the early fracture treatments resulted in wells which underper-formed expectations. Naturally, refracturing has been proposed as a means of improving performance in these wells. Even with improved operational practices, fracturing techniques, and understanding, refracturing has been applied with mixed success.
Our literature survey shows that refracture stimulation treatments in tight formations require increased fracture length and that refracture stimulation treatments conducted in wells in permeable reservoirs require increased fracture conductivity to be commercially successful. Further, refracturing in depleted reservoirs, though responding similarly, may not be commercially viable. We present simulation results and interpret field data which support these conclusions. Our contribution is to evaluate refracturing and provide guidelines to the working engineer with respect to refracture stimulation design and commercial viability.
The paper is broken into three sections. These include a review of previous work, a simulation study of the refracturing process, and a section on the interpretation of field data where refracturing has been applied.
A 100-MMSCFD Portable Gas Lift Compressor
Authors: Thompson V. W. , Palfreyman D. G. , Duhon R. D. 
Published: December 2007

Abstract
This paper discusses the design and installation of two DR-61 Dresser-Rand Gas Turbines powered by LM 2500 gas generators driving tandem centrifugal gas lift compressors on converted jackup rigs. The units are currently in use in Lake Maracaibo, and they are the largest installations of their kind in the world. This discussion emphasizes the engineering and project leadership strategies that allowed the project to be completed within restrictive schedule and budget requirements.
The Effects of Light Ends and High Pressure on Paraffin Formation
Authors: Brown T. S. , Niesen V. G. , Erickson D. D. 
Published: December 2007

ABSTRACT
A thermodynamic model for paraffin formation is presented which accurately accounts for the effects of light ends, such as methane, ethane, and propane, and high pressures. The model uses the Simplified, Perturbed Hard Chain equation of state for all fluid phase fugacities and contains no adjustable parameters for the solid-liquid equilibria. Model predictions are compared to binary solid-liquid, solid-vapor, and solid-liquid-vapor equilibria data with good results. Also, a high-pressure, cold-stage microscope technique was developed to measure cloud points of live oils with which to test the model. Comparisons between the predicted and measured cloud points for live oils are presented.
Study of Perforation Friction Pressure Employing a Large-Scale Fracturing Flow Simulator
Authors: Lord D. L. , Shah S. N. , Rein R. G. , Lawson J. T. 
Published: December 2007

Abstract
Accurately estimating perforation friction pressure is important to the design and analysis of fracturing treatments. Currently, in the absence of a better approach, the industry is using sharp-edged orifice correlations developed with Newtonian fluids such as water. These correlations, however, are probably inaccurate when applied to the rheologically complex fracturing fluids being used today.
A detailed investigation of the effects of fluid type, fluid viscosity, perforation size, and perforation flow rate is conducted with a unique large-scale, high-pressure simulator (HPS). Construction of this simulator was a joint effort involving the Gas Research Institute (GRI), the Department of Energy (DOE), and the University of Oklahoma (OU). Test fluids include water, linear polymer solutions, and crosslinked polymer gels. After fluids are prepared under simulated field mixing conditions, they are pumped into a simulated wellbore through a set of four perforations on a 1-ft spacing into a simulated fracture having variable crack width. Differential pressure transducers are used to monitor pressure drop across the perforations and pressure recovery downstream in various crack widths.
Correlations are developed to describe the perforation pressure-loss behavior. Predictions of these correlations are shown to differ significantly from those made by conventional orifice-type equations. In the new correlations, pressure drop is shown to be dependent on fluid type, viscosity, and perforation size in addition to the conventional dependence on fluid density. These new correlations should significantly improve real-time and post-treatment pressure data analysis.
Film Thickness Distribution for Annular Flow in Directional Wells: Horizontal to Vertical
Authors: Paz R. J. , Shoham Ovadia 
Published: December 2007

Abstract
An experimental and theoretical investigation has been carried out on two-phase annular flow in inclined pipes. The study focused on the effect of the inclination angle on the liquid film thickness distribution. A conductance multi-probe instrument was utilized to measure the local liquid film thickness around half of the pipe periphery for inclination angles of 90°, 75°, 60°, and 45° from the horizontal. A simple analytical model has been developed for the prediction of the liquid film thickness at the top and bottom of the pipe. The model is applicable for the entire range of inclination angles, from horizontal to vertical. Good agreement is observed between the prediction of the model and the experimental data collected in this study and from the literature.
Oriented Perforations - A Rock Mechanics View
Authors: Abass Hazim H. , Meadows David L. , Brumley John L. , Hedayati Saeed , Venditto James J. 
Published: December 2007

Abstract
Hydraulic fracture initiation dictates the communication path between the wellbore and fracture plane. Nonplanar fracture geometries such as multiple, T-Shaped, and reoriented fractures are not advantageous and they adversely affect the potential to achieve a desired stimulation treatment. Oriented perforation can be the solution to initiate a single wide fracture in vertical and deviated wells. Also oriented perforations may be used to create stable tunnels in poorly consolidated formations thus avoiding sand failure and consequently preventing sand production.
This paper presents laboratory experimental results related to oriented perforations for hydraulic fracturing. It also discusses the use of oriented perforation for sand control. Experiments were designed to investigate the effect of perforation orientation in vertical and horizontal wells on hydraulic fracturing treatment.
Overview of Water Saturation Determination For the Ivishak (Sadlerochit) Reservoir, Prudhoe Bay Field
Authors: Holstein E. D. , Warner H. R. 
Published: December 2007

Abstract
This paper is an overview of the water saturation determination processes applied to the Ivishak, sometimes referred to as the Sadlerochit Reservoir, the major producing horizon in the Prudhoe Bay Field. Oil-base-core water saturation (Swobc) values were used to calibrate resistivity-log-derived Sw values. These log Sw values were used, in turn, to tune coefficients for a six-term algorithm (Sw= f(porosity, height)) for use in volumetric calculations of HPV. This overview discusses 1) the technologies used to validate the Swobc values, 2) the areal variations in saturation functions arising from geologic factors, 3) the observed variations in connate water salinity both areally and vertically and 4) the methods used to determine Archie ‘n’ and six-term algorithm coefficients. Other, referenced papers address each these subjects in greater detail.
Delaware Basin Sulfur Development
Authors: Barry Charles B. , Davis Glen R. 
Published: December 2007

Abstract
The Frasch sulfur industry has taken on a new dimension with the development of mineable deposits in West Texas. The sulfur bearing formations in West Texas are generally limestone and similar to those on the Gulf Coast. The West Texas sulfur search is complicated by lost circulation zones and new drilling methods have been developed to cope with these zones. This paper describes the Frasch process and discusses the variables which affect costs and efficiencies. ARCO's Fort Stockton sulfur plant is described and its flow process plant is described and its flow process diagram is presented. The unusual viscosity-temperature relationship of sulfur and its significance in sulfur mining and storage is emphasized.
Introduction
Production of commercial sulfur from gypsum beds such as occur in the Delaware and other West Texas basins will have a significant impact on the sulfur industry. The occurrence of brimstone in gypsum beds throughout the world has been known for years. But it took the recent drilling and development in West Texas to indicate how important such reserves may be. A recent article, by these same authors, presented in the British publication, presented in the British publication, "The Journal of World Sulphur," relates to the Delaware Basin sulfur activity. Gypsum and anhydrite sequences here as well as in other parts of the world contain isolated areas in which elemental sulfur occurs in concentrations up to 50 weight percent. Economic recovery of the percent. Economic recovery of the elemental sulfur from gypsum and anhydrite members is the goal of Frasch mining operations in West Texas. The feasibility of mining these deposits could not be determined until it was shown that mine water could be contained in the ore body, that water supplies were adequate, and that the water could be treated and subsequently heated to the required temperatures economically.
That these requirements could be met was demonstrated by separate pilot operations initiated by Duval and Sinclair early in 1967 near Fort Stockton in Pecos County, Texas. Both operations were later expanded to commercial levels and Duval now also operates a large mine in Culberson County, Texas.
Commercial Polymer Injection in the Courtenay Field, 1994 Update
Authors: Putz A. G. , Bazin Brigitte , Pedron B. M. 
Published: December 2007

Abstract
The polymer injection in the Courtenay field has reached a mature stage as a large part of the polymer slug has been injected. The total production of oil confirms the original expectations and the operation is profitable.
The Courtenay field is an elongated layer at a depth of 600 m. The oil is viscous (40cp), water is fresh and the temperature is 30°C, making the conditions favorable for a polymer injection.
The area swept by polymer encompasses 640 000 m3. It consists of three contiguous zones with a total of 4 injectors and 18 producers. Injection of a 900 ppm solution of polyacrylamide diluted in field water started in July 1989 at a total rate of 380 m3/day. Up to now, 640 000 m3 (100 % pore volume) of solution have been injected, polymer injection was terminated in November 1993; since then, water is injected at a rate of 420 m3/day.
Compared to primary production, a strong increase in oil production has been observed. Definite tertiary oil banks breakthroughs have been observed at 14 producing wells.
The operation has been simulated with the Σcorepol model, a 3 dimensional 3 phases simulator with polymer and tracers option.
The total oil production is well represented on a global basis but the actual quantity of polymer produced in the effluent water is lagging behind the value expected by simulation.
A full physico-chemical characterization of the polymer in the effluents of the well CY55 has confirmed that it was not degraded by its flow through the formation and the injection/production facilities.
Reservoir Characterization and Production Forecasting for Antrim Shale Wells: An Integrated Reservoir Analysis Methodology
Authors: Zuber M. D. , Frantz J. H. , Gatens J. M. 
Published: December 2007

ABSTRACT
This paper presents an integrated reservoir simulation based approach for analyzing production data and forecasting future production for Antrim Shale wells. The practical experience that has been gained through analysis of 40+ projects is presented, including guidelines for estimation of key reservoir properties for use in analysis. Guidelines are presented for conducting Antrim Shale formation evaluation for operators wishing to facilitate accurate reservoir analysis and reserves forecasts.
Pilot Testing of a Radio Frequency Heating System for Enhanced Oil Recovery From Diatomaceous Earth
Authors: Kasevich R. S. , Price S. L. , Faust D. L. , Fontaine M. F. 
Published: December 2007

Abstract
This paper describes a high power, full scale field demonstration of a radio frequency (RF) downhole applicator system which has the objective of ultimately expanding the scope of Texaco’s thermal operations beyond conventional operations. Field testing of KAI Technologies radio frequency heating system was performed in the Texaco Denver Producing Division’s Midway area, N. Midway field, CA, in a shallow diatomite reservoir during the summer of 1992. Two tests (a low power test and a high power test), gave every indication that RF technology is a viable way of heating a formation.
A Fresh Look at Wettability Detergent Flooding an Secondary Recovery Mechanisms
Authors: Kamath Krishna I.S. 
Published: December 2007

Abstract
On the basis of surface energetics of solid-liquid and liquid-liquid interaction, our present concepts of oil-wet reservoirs and present concepts of oil-wet reservoirs and conventional waterfloods are subject to serious limitations. The significant part played by electrolytes in wettability played by electrolytes in wettability alteration floods and by small amounts of impurities in surfactant floods are interpreted as evidence to support the view that electrokinetic and interfacial forces play an important, but not yet clear, role in oil recovery processes.
Introduction
It is well known that by present methods only a third or less of the petroleum originally present in the oil reservoir can be economically recovered. The development of new methods for producing all or part of the oil thus left behind in the ground will not only be a major contribution to conservation, but will also increase our oil reserves at a time when these are being depleted at a rapidly increasing rate. The only means by which this can be achieved is through improvements in our recovery methods with the aid of new technology. The prospects of developing such new technology are good, because much remains yet to be learned about the mechanism of oil recovery and the related area of multiphase flow through porous media. Much of our work in oil recovery porous media. Much of our work in oil recovery research has been empirical, so far, with a fundamental approach to the understanding of multiphase flow through porous media on the basis of surface chemistry principles shows promise of being far more fruitful. A promise of being far more fruitful. A beginning has already been made in this direction with initially encouraging results, but much more remains to be done. This paper proposes to point out some of the apparent inconsistencies in our thinking in some aspects of petroleum recovery research from the viewpoint of petroleum recovery research from the viewpoint of surface chemistry and the necessity of clearing them before progress can be made in this area.
DARCY'S LAW AND MULTIPHASE FLOW
The petroleum engineer is interested mainly in understanding the distribution and flow of oil, water and gas in an oil reservoir and using such knowledge to enhance oil recovery. The presence of more than one phase in a porous medium generates large areas of interfaces in addition to the enormous surface area of the porous medium itself. These solid-fluid and fluid-fluid interfaces are associated with forces which are determined by the chemical nature of the fluids and the porous medium. Though such a system teems with interfacial forces, our present description of the flow process, nearly completely ignores them. In applying Darcy's law to multiphase flow we consider only one rock property, the relative permeability, and only one fluid property, the viscosity. property, the viscosity.
An Improved Viscosity Model for Natural Gases: Application of the Free Volume Concept
Authors: Awuy A. I. , Bretz R. E. 
Published: December 2007

ABSTRACT
A model to predict viscosities of natural gases was developed using the Doolittle free volume equation as a framework. The model was tested against experimental values and in comparison to the three commonly used viscosity models used in petroleum engineering calculations. It was found superior to the other models with respect to deviation from experimental data, ranges of temperature and pressure, and ranges of compositions and components.
Reconstruction of Petrophysical Images Using Cross-Well Traveltime Tomography
Authors: Mendoza-Amuchastegui J. A. , Ramirez-Cruz L. C. 
Published: December 2007

ABSTRACT
In this paper we present the results obtained from a cross-well seismic tomography experiment carried out in an oil producing field of the West Permian Basin, Texas, U.S.A.
Three fundamental stages can be identified from the tomographic method: Field data acquisition, data conditioning, and the actual tomographic process including forward modeling and inversion. For our case, we present a synopsis of each.
The resulting Vp and Vs tomograms show a clear separation of high and low velocity zones that are in agreement with sonic logs. From the final tomograms, we computed images of Vp/Vs ratio, Poisson ratio, porosity and density using well known empirical formulas.
The results attained from the experiment provide an idea of the potential usefulness of the tomographic method as an alternative for in-field exploration and detailed characterization of hydrocarbon producing reservoirs.
On the Petrophysics of Carbonate Reservoirs through Whole Cole Analysis
Authors: Rafael Herrera G. , Fernando Samaniego V. , Francisco Hernández P. 
Published: December 2007

ABSTRACT
This paper presents results of petrophysical whole core analyses carried out in highly permeable dolomite cores, intensively vugular and fractured. The estimated parameters were: multi-directional permeability tests kHθ and kv, matrix ϕmab and fracture porosity ϕfb, the high velocity flow coefficient β, relative permeabilities to oil and water, the effective oil permeability (as a function of effective stress), capillary functions, and the variation of absolute permeability with temperature. The temperature and effective hydrostatic stress used ranged up to 150°C and 20 000 psi, respectively. Several sleeve materials were tested, finding that silicon withstood successfully the test conditions. Stainless steel was used for the flow screens needed for the horizontal permeability measurements. The fluids used in these tests were nitrogen, helium, and brine. As an example of the values estimated for some of these parameters, the ratios for horizontal to vertical permeabilities at an standard effective stress of 400 psi were kh0°/kv = 117, kh90°/kv = 17, and kh0°/kh90° = 6.87. The ratio of matrix to fracture porosities ϕmab/ϕfb = 9.15 and for the compressibilities cfb/cmab = 5.56. Finally, specific values of matrix porosity and multidirectional permeabilities for an increment of the effective stress conditions from 1000 to 8000 psi, resulted in a decrease of 23% for the total 78% for vertical permeability. A new correlation for the high-velocity coefficient is presented for conditions of these highly macrovugular formations, which approximately is parallel 1.6 log cycles above the Firoozabadi and Katz correlation.
Evaluation of Fracture Distribution and Continuity in Carbonate Reservoirs Using Wellbore Imaging Tools
Authors: Roca-Ramisa Luis , Mendoza Jesus , Sanchez-Galindo Miguel Angel 
Published: December 2007

ABSTRACT
Electrical wellbore images had been used extensively in Mexico in order to identify geological features including the distribution and continuity of fractures in carbonate reservoirs.
The main problem associated with the evaluation of fracture continuity has been the fact that sometimes is difficult to distinguish between natural fractures (those present in the rock before drilling) and induced fractures (produced as direct result of drilling), especially when shallow depth of investigation electrical imaging tools are used.
Drilling induced fractures observed in carbonate rocks occur as a result of reduction of stress field around the wellbore and propagate in a direction perpendicular to the unloading direction. In this study, the integration of mechanical properties derived from dipole sonic data and wellbore images has considerably improved the understanding of the induced fracture development.
The Micro TLP Production System for Deepwater Gulf of Mexico
Authors: Zimmer R. A. 
Published: December 2007

ABSTRACT
This paper will describe a production system and associated operating scenarios which allow more cost effective methods of accessing and depleting deep water reservoirs in the Gulf of Mexico. The system is named the "Micro TLP" (Tension Leg Platform) and it has been developed by a multi discipline team. It is based on Conoco's operating experience over the last five years in the deep waters, particularly that gained from the Jolliet TLWP.
The Micro TLP is a very small tension leg platform. It achieves the required performance through load management techniques and past experience from a strong multi discipline design team. Its small size makes it is easier and quicker to fabricate. The Micro TLP is also easily installed, moved and reused in different water depths which facilitates staged or phased production. Staged development with several Micro TLPs instead of a single large TLP will lead to fewer more productive wells being used to deplete the reserves.
In the Gulf of Mexico, deep water may be generally broken into areas near and far from existing infra-structure. This paper will show how a properly designed and operated Micro TLP System may greatly reduce up front capital costs and cash exposure in near infrastructure deep water development scenarios. Further, it will discuss how a Micro TLP may be used in conjunction with a second generation semi-submersible to provide greatly improved economics for a far from infrastructure scenario.
Single-Trip Subsea Completions
Authors: Johnson K. J. , Lorenzatto R. A. , Rittershaussen J. H. , Barreto J. L. , Filho Everaldo Lima 
Published: December 2007

Abstract
Reliability of completion equipment and rig time are becoming more and more critical for subsea completions because of continually increasing water depths in which operators are being required to complete wells. In addition, completion designs must reflect the more stringent economic requirements of today's oil and gas industry. This paper will describe the use of a single-trip completion system that has been successfully and economically installed in the offshore Marimba and Bonito fields of South America. This new completion system has the capability to land the tubing hanger and install it in the wellhead before setting the packer and compensating for subsequent tubing movement.1
The new system also can employ pre-job calculations — based on initial well conditions and anticipated conditions during production — that help determine appropriate completion configurations and bottomhole equipment compatibility. Many failures in offshore wells, whether platform or subsea, can be attributed to inappropriate application of downhole completion tools or methods.2 Use of pre-job calculations during the equipment design stage can facilitate proper selection of design criteria and can help ensure operational safety and cost efficiency.
The development of this new completion system will be discussed in detail. Three case histories that document successful test completions will be reviewed along with the economic gains and advantages that the reduction in rig time generated.