bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Low-Permeability Media Using Outcrop Measurements
Authors: Knutson C. F. , Cox D. O. , Dooley K. J. , Sisson J. B. 
Published: December 2007

Abstract
A complex fracture system in a formation with low matrix permeability was evaluated to provide data that could be used in fluid flow and contamination migration modeling. Outcrop and well measurements and observations were used as the basis for this study. To determine fracture permeability, fractures were chosen and their apertures measured with a feeler gauge. A flange and nipple were cemented in the middle of the fracture. Cement was injected at least 25 mm (1 in.) into the outcrop edge of the fracture, for a distance of about 0.5 m (18 in.) on both sides of the flange. A fiberglass seal was epoxied over the area to provide additional support for the equipment and cement seal. Fracture permeability was calculated from the pressure needed to inject air into the fracture at a known rate. Flow capacities ranged from 13 to 6717 md-ft on five tests and averaged 1646 md-ft. Outcrop face fracture apertures varied from 0.5 to 2.5 mm (0.02 to 0.1 in.).
Matrix permeability was determined by cementing 6 mm (0.25 in.) washers to a flat outcrop surface area and drilling a shallow hole through the center of the washer to provide a clean injection surface. Matrix permeability was determined by injecting air into the center of the washers while monitoring rate and pressure. Matrix permeabilities ranged from 0.08 to 2.2 md with an average of 0.28 md.
A well was drilled 4.5 m (15 ft) back from the outcrop through an overlying basalt flow into the measured basalt flow. A borehole TV log of the well indicated only one fracture in the measured flow and a continuation of the two foot flow top rubble zone noted in the outcrop. Water was injected into this well at a rate of 23 m^/h (100 gpm) with a 6 m (20 ft) head. This water formed a pancake in the rubble zone and flowed downward into the measured flow’s fractures system and ultimately out of fractures in the outcrop face. The heterogeneity of the system was indicated by the effectiveness of less than 10% of the fractures in distributing the flow to the outcrop.
A thermal image of the outcrop during hot air injection into the well displayed a major anomaly at the rubble zone contact.
Quantitative Description of Muddy Sandstone: Geostatistical Parameters, Automated Facies Generations, and Measurement Methodologies
Authors: Kara Bayram , Kasap Ekrem , Tillman R. W. 
Published: December 2007

Abstract
Our objectives are to study analogous outcrops and subsurface cores to test the aptness of outcrop characteristics to subsurface reservoirs and to determine whether sedimentologically defined geologic units are useful in modeling flow units. The approach involves characterization of the Muddy Sandstone of Wyoming by using geostatistical analysis methods. Incised valley-fill muddy sandstone outcrops and reservoirs near Newcastle and Casper, Wyoming are used.
First, a mechanistic model to calculate statistical error as a function of the number of measurements is derived. The proposed error model indicate a linear relationship between statistical error and the square root of the number of measurements. The slope in the linear relationship is related to a constant and the coefficient of variation. However, the model indicates a quadratic relationship for possible maximum error.
A field permeameter is used to measure permeability on both outcrop and subsurface formations (core slabs). An algorithm and a computer program were developed to generate flow units of measured sections based on permeability derivatives. Sedimentologic descriptions of those measured sections are also produced. Comparison of computer generated and geologically described facies (units) boundaries show an excellent agreement..
Variograms of both subsurface and outcrop show the same degree of oscillatory behavior (hole effect) indicating strong similarity. Various geostatistical parameters for all measured sections of both outcrop and subsurface were calculated. In all cases, Dykstra-Parsons coefficients are in the neighborhood of 0.35 for the single-unit and of 0.65 for the multi-unit data. This is true for both the outcrop and subsurface formations. We concluded that the geostatistical characteristics of valley-fill outcrops are very similar to valley-fill subsurface reservoirs for the Muddy Sandstone studied.
Lithology Determination Using Downhole Bit Mechanics Data
Authors: Wolcott D. S. , Bordelon D. R. 
Published: December 2007

Abstract
A technique has been developed which uses downhole weight on bit (DWOB) and downhole torque (DTOR) measurements to determine the occurrence and thickness of cemented zones in the pay sands of the Kuparuk River oil field. The DWOB/DTOR measurements are made by the MWD tool which is located above the bit and is normally not affected by frictional losses along the drill string. The cemented zones, containing siderite in the upper sand and ankerite in the lower, are high density streaks that reduce production or in the case of Ankerite are non productive.
Using these measurements the cemented zones can be detected, in real time, when the bit first contacts the zone. Because the downhole sensors respond immediately to the changes in lithology the vertical resolution is one ft. which is better than the open hole logs commonly obtained in the field.
From comparisons with density-neutron log data it was demonstrated that the new technique reliably discriminated between cemented and non cemented zones while drilling. Because of the reliability and the high vertical resolution of the technique, the mapping of the cemented zones and the resulting oil in place estimates have improved.
The lithology information obtained from the DWOB/DTOR measurements compliment the triple combo data. By comparing the drilling mechanics data with the density and neutron logs suspect data can be highlighted. In areas where washouts have occurred the wireline data may be adversely affected but the drilling mechanics arc not. The acquisition of downhole bit mechanics data is a useful addition to the logging program and can be effectively utilized in combination with a full log suite or as a replacement for the density-neutron tools as an ankerite or siderite locator.
A Combined Phase and Amplitude Technique for Controlling the Investigation Depth of Propagating Electromagnetic Wave Resistivity Sensors
Authors: Rodney P. F. , Bittar M. S. 
Published: December 2007

Abstract
The general question of combining electromagnetic wave phase differences and amplitude ratios to produce apparent resistivities is explored in this paper. When dealing with a step invasion model, it is possible to combine these measurements in different ways to produce readings which cover a range of investigation depths. Most significantly, the investigation depths corresponding to some of these combinations exceed those obtained using either the amplitude ratio or the phase difference alone. Tradeoffs in terms of bed resolution, effects due to instrument accuracy and uncertainties in the dielectric constant also are discussed. The paper concludes with some field examples showing the benefits and limitations of the method.
The Miniporopermeameter for Simultaneous Measurement of Permeability and Porosity
Authors: Chen Zhongming , McLemore Jim , Heller J. P. 
Published: December 2007

Abstract
Porosity, as well as permeability, of small regions at and just below the surface of a larger, slabbed sample of porous rock can be measured by using the device discussed in this paper. Measurement of permeability is accomplished as in the well-known "Minipermeameter" by forcing a steady flow of air or other gas into the face of the rock through the central passageway of a deformable rubber probe or tip that could consist of the end of a soft rubber tube. The permeability of a region of the rock directly under the probe tip is computed from the ratio of flow rate into the rock to the pressure drop between the air in the probe-tip and the atmosphere. As shown in this paper, the capability of the minipermeameter can be expanded, so that it can be used to measure porosity as well. Immediately after calculation of the permeability, and under defined conditions, a precise value of the porosity (of the same portion of the rock) may be computed from the transient pressure change that is observed at the probe-tip after cutting off air flow into the rock from the probe. This paper describes both the mathematical/numerical analysis that stands behind the measurement and computation, and the experimental apparatus and procedures required for operation of the instrument. The key device needed is a pressure transducer with very fast response, high mechanical impedance and low dead volume.
Intelligent Diagnosis of Rod Pumping Problems
Authors: Alegre Lideniro , Morooka C. K. , da Rocha A. F. 
Published: December 2007

ABSTRACT
Rod-pumping is the most common artificial lift method used to move oil to the surface in low pressure resevoirs. A variety of mechanical problems can occur with this system. The adjustment of the pumping capacity to the reservoir production rate is another source of error compromising pumping efficiency. The need to identify these problems quickly and accurately is essential in attempts to minimize operating costs and maximize production. A dynamometer is attached in general to the polished rod of the pumping unit, and a plot of load vs. position, known as (downhole) dynamometer card (DC), is obtained for the purpose of rod load monitoring. Altough DC is a very important piece of information, other data may be required to support complex decision making about the actual rod-pumping condition. For this purpose, the engineer uses also information about the characteristics of the well, the type of oil being pumped, etc., besides taking into consideration the DC shape, maximum and minimum load values, etc. A new type of neuron is used to built neural nets having powerful numeric and symbolic processing capabilities, besides permiting knowledge to be encoded not only on the wiring of the net, but also on the selection of the types of neurons and synapsis composing the net. This new type of neural nets was used to develop SICAD, a hierarchical neural system whose purpose is the intelligent control of rod-pumping. SICAD is composed by two famillies of neural nets specialized, respectively, in pattern recognition (PRN) and expert reasoning (ERN). Different modes of interactions between ERN and PRN define different pumping control strategies.
Quantitative Three-Phase Profiling and Flow Regime Characterization in a Horizontal Well
Authors: Chauvel Yves , Clayton Francis 
Published: December 2007

Abstract
Production logs have been used for flow profiling in horizontal wells for a number of years, thanks mainly to the advent of the CTL* Coiled Tubing Logging, a technique which allows strings of electrical tools to be lowered into the well and pushed along the horizontal section. Production logs are typically run for reservoir monitoring purposes or for diagnosis of problem wells. However, flow profiling in horizontal wells is usually restricted to single phase analysis owing to lack of enough applicable measurements and due to inadequate understanding of the physics of three-phase horizontal flow.
In this example a complete data set was acquired, including measurements such as the Nuclear Fluid Densimeter and the WFL* Water Flow Log. These additional, independent measurements provide data of outstanding quality and allow individual and independent quantification of the flow rates of oil, water and gas at any location in the well. Moreover, the acquired data set allows the validity and consistency of the measurements to be crosschecked. Finally, strong anomalies in the sensor readings, caused by the in-situ conditions of the flow, allow the identification and description of two highly contrasted, alternating flow regimes, and the correlation of their occurrence with changes in elevation of the well path.
Thus, besides solving a complex production identification problem, this unique data set and its interpretation shed additional light on the dynamics of multiphase flow in horizontal wells.
Friction Factor of Perforation Roughness in Pipes
Authors: Su Ze , Gudmundsson J. S. 
Published: December 2007

ABSTRACT
The friction factor of perforation roughness was measured in pipes geometrically similar to casing used in horizontal wells. There was no fluid flow through the perforations in the work reported. The experimental data were analyzed using the universal velocity distribution law and the concept of roughness function. It was found that the roughness function increased linearly with the perforation/casing diameter ratio. An empirical relationship was obtained to estimate the friction factor in pipes with perforation roughness.
Formation and Fracture Characterization by Inversion of Fracture Treatment Records
Authors: Bhalla Kenneth , Brady B. H. 
Published: December 2007

ABSTRACT
The design of hydraulic fracture treatments requires reliable determination of in-situ parameters. The algorithm presented in this paper is a method of formation and fracture characterization based on the application of a formal inversion procedure to fracture treatment data records, collected during calibration treatments before the main treatment or in the full scale treatment of offset wells.
During a fracture treatment, the bottomhole pressures are related to a set of treatment and formation parameters. The treatment parameters may be determined explicitly through measurement but the formation parameters contain considerable uncertainty.
The inversion algorithm implements pseudo-three dimensional and multi-layer fracture simulators. Results are presented for the inversion of synthetic data records generated by the fracture simulators and for field data, where independent formation characterization has been performed.
In the case studies, it is observed that the parameters which are determined by inversion, e.g., leakoff coefficient, formation Young's modulus and fracture closure pressure, are in excellent agreement together with the corresponding pressure history match.
This work suggests that useful formation characterization parameters can be extracted from a pressure history record. Furthermore, the geometry of the fracture can be determined from the defined formation parameters and the pump schedule.
"Pipelining": Viscous Fingering Prop Fracture Technique Finds Wide Success in Permian and Delaware Basins
Authors: Ely J. W. , Hargrove J. S. , Wolters B. C. , Kromer J. C. 
Published: December 2007

ABSTRACT
During the past two and a half years, a new fracturing technique has been developed to selectively place proppant across a well's producing interval. The new technique, termed "pipelining," has been employed in hundreds of wells in the Permian and Delaware basins. This technique utilizes high differential viscosity to selectively place high concentrations of proppant across the well's producing zone. This technique involves specialized design and iterative modeling procedures.
In the paper, we will discuss the ongoing improvement of the "pipeline" fracture design and present numerous case histories of various sand members of the Delaware formation throughout Southeastern New Mexico as well as other producing horizons in the Permian Basin.
The authors feel that the "pipeline" fracture technique, combined with intense quality control and aggressive forced closure, greatly enhances the ability to selectively place proppant in the pay zone and allows for highly conductive propped fractures for much greater lengths than were heretofore felt possible.
Development of a Standard Coiled-Tubing Fatigue Test
Authors: Newman K. R. , Brown P. A. 
Published: December 2007

Abstract
The understanding and modelling of coiled tubing (CT) fatigue life has continued to be a major area of concern as CT diameters have increased, usage and variety of applications continue to grow, and tubing is subjected to higher pressures. This paper presents a method and testing apparatus which has been developed in an attempt to simplify and standardize CT fatigue testing. Preliminary results from this testing method are compared with full-scale tests and a fatigue life prediction model to demonstrate that this method is valid.
Measurement and Prediction of the Kinetics of Paraffin Deposition
Authors: Brown T. S. , Niesen V. G. , Erickson D. D. 
Published: December 2007

ABSTRACT
Economically and technically viable methods for controlling paraffin buildup in pipelines and wellbores are critical to the production of crude oil in deep water and cold environments. Laboratory test methods and a computational model have been developed to predict rates of paraffin deposition in pipelines and the effect of long-term deposition on the pipeline pressure drop and temperature profile. The model has been incorporated into a fully menu-driven program that runs on a personal computer. The two major portions of the program are the thermodynamic model which is used to calculate solid-liquid-vapor phase equilibria and the kinetic model which is used to predict the deposition and paraffin buildup rates. The thermodynamic portion is described in a companion paper7. The kinetic model is based on information present in the literature and on several hundred measurements of paraffin deposition rates in a laboratory-scale test loop.
Development of a Film-Persistent Water-Dispersible Corrosion Inhibitor
Authors: Cain J. J. , Rosenthal L. M. 
Published: December 2007

ABSTRACT
We have developed a new film-persistent, water-dispersible corrosion inhibitor, a quaternary ammonium salt, that was optimized for brine dispersibility and corrosion inhibition. The inhibitor was tested at several concentrations under many accepted industry methods, including kettle tests and continuous and film persistence wheel tests. Our inhibitor performance in those tests was equivalent or superior to the performance of common quaternary intermediates at only one quarter of their concentrations.
Most importantly, the inhibitor displays excellent film persistence. This can be a major advantage as most existing water soluble corrosion inhibitors have very poor film persistence, and must be administered continuously rather than batch-wise. They do not strongly adhere to metal surfaces, and are ineffective unless continually present in the surrounding fluid. The new film persistent inhibitor will allow batch treatment to be an option, which in some cases could reduce chemical cost significantly.
Optimization of Heavy Oil and Gas Pumping in Horizontal Wells
Authors: Rondy Philippe , Cholet H. J. , Federer Imre 
Published: December 2007

ABSTRACT
Horizontal and highly deviated wells have become very attractive for the production of reservoirs with gas coning problems.
The presence of free gas has been recognized as having, in general, detrimental effects on the performance of downhole pumps: production is drastically decreased, equipment is damaged, etc. This document put forward the experimental tests that have been carried out in a laboratory- scale flow loop to investigate the efficiency of gas-anchor systems under various conditions (inclined position, different GLR, …).
Using the important contrast of density and velocity of the two different phases, the tested apparatus prevents free gas from entering the pump intake, and provides a simple and reliable mean for optimizing production from inclined drainhole, capable of handling two-phases viscous mixtures with gas fractions as high as 80% without excessive downtime/production losses. The tests data show that performances measured on the lab bench could potentially reach 75-100%. The role of GOR, as well as the influence of viscosity (up to 1000cP) are specially identified and discussed.
Fluid Selection for Fracturing High-Permeability Formations
Authors: McGowen J. M. , Vitthal Sanjay , Parker M. A. , Rahimi Al , Martch W. E. 
Published: December 2007

ABSTRACT
Hydraulic fracturing is a well established technique for stimulating low permeability formations and for bypassing damage in moderate permeability formations. It is now being applied to high permeability formations (k &gt; 10 md) to increase production and control formation fines. Fluid selections for these treatments range from typical gravel pack fluids to typical hydraulic fracturing fluids. To determine guidelines for fluid selection, detailed measurements, of fluid loss, core damage, and fracture conductivity were performed under realistic fracturing conditions on cores with liquid permeabilities ranging from 10 md to 1000 md. The bulk of the data presented is on Berea Sandstone ranging from 200 md to 400 md. Results of these tests indicate the relative effectiveness of these treatment fluids for fracturing high permeability formations based on fluid loss, formation permeability damage, and fracture conductivity. Treatment and production simulations are provided stressing the difference in performance between systems.
Elastomeric Composites for Use in Well Cementing Operations
Authors: Onan D. D. , Goodwin K. J. , McPherson T. W. 
Published: December 2007

Abstract
Considerable work has been conducted in the study of cement sheath stress failure. Laboratory and field tests indicate that conventional cementing compositions are susceptible to the effects of excessive casing test pressure or temperature changes experienced during production or workover operations. More specifically, those studies show that the typical range of compressive strengths used in most cementing operations, as well as the limited tensile properties afforded by pore-filling latex cements, are not adequate to prevent failure under conditions of excessive differential temperature and pressure. A crosslinked synthetic polymer containing a quick-setting cement has been developed that provides unique resilient properties better suited for those conditions where Portland cements will not suffice. These elastomeric formulations enhance tensile and shear strength, as well as increase resistance to chemicals and heat. Thus, both pipe support and sufficient ductility to complement pipe expansion are achieved with little or no permeability. These properties can be further enhanced by the addition of reinforcing agents such a silica, ground rubber, hard hydrocarbon, natural and synthetic fiber, barite, clays, carbon black and microspheres. Data from field case histories and laboratory studies are discussed. This investigation was limited to the evaluation of a synthetic rubber, styrene-butadiene. The use of the elastomeric system in other applications is also discussed.
A Study of the Effects of Mixing Energy Imparted on Cement Slurries by Field Equipment and Coiled Tubing
Authors: Heathman J. F. , Sands F. L. , Sas-Jaworsky Alexander , Badalamenti A. M. 
Published: December 2007

Abstract
More widespread application of coiled tubing workover operations involving cement slurry placement has developed in recent years because of associated advances in coiled tubing technology.1–3 Consequently, one of the parameters of job design which has come under scrutiny for cement slurries associated with coiled tubing operations is the effect of various levels of mixing energy during batch mixing, as well as the effect of shear through a coiled tubing spool.4-7 The measurable effect on a cement slurry batch mixed for extended periods of time can be seen as being very much a factor of the slurry design (admixtures, water ratio, etc.) as well as the energy applied at the point of cement-water contact.8 The work presented in this paper examines the effects of various levels of energy (mixing power) imparted by batch-mixing equipment on various types of cement slurries. Likewise, the effects, on a slurry, of pumping it through a length of coiled tubing are also examined.