bluuebunny/crossref_metadata_2025_split huggingface dataset:
Friction Pressures of Proppant-Laden Hydraulic Fracturing Fluids
Authors: Shah Subhash N. , Lee Yung N. 
Published: December 2007

Summary
Friction-pressure calculations of proppant-laden fluids are very important not only in the design of any hydraulic fracturing treatment but also in real-time monitoring of fracturing treatments. Recent advances in real-time fracture analysis have necessitated an accurate knowledge of bottomhole treating pressure (BHTP). To estimate BHTP, an accurate prediction of friction pressures of fluids in the flow conduit is required.
This paper presents a new approach for predicting friction pressures of proppant-laden fracturing fluids that is based on an analytical method and uses nondimensional quantities in the analysis of flow data. From the flow data with various proppant-laden gels in multiple pipes, generalized correlations are developed and presented that incorporate such variables as proppant size, proppant density, proppant concentration, fluid density, flow rate, polymer gel concentration, and pipe size. These correlations are valid for a wide range of terminal Froude number, NFr​​​  *(8.4×10−3  to  1.3×10−4), and particle Froude number, NFrp (20 to 200). These ranges include the calculated values of NFr​​​  * and NFrp for the majority of hydraulic fracturing treatments conducted today.
The correlations are verified by comparison of the estimations with data gathered in field-size tubing and field-gathered data. Our predictions agree more closely with field data than previously published methods. Unlike previous studies, this investigation indicates that besides other factors, proppant size, pump rate, flow geometry, and polymer gel concentration play a significant role in the friction-pressure predictions of proppant-laden fluids.
Geology and Clay Mineralogy of the Morrow Formation, Southeastern New Mexico
Authors: Mazzullo L. J. , Mazzullo J. M. 
Published: December 2007

SummaryDrilling and completion procedures for Morrow sandstone reservoirs in southeastern New Mexico must be designed to anticipate vertical variations in clay mineralogy in the wellbore, because different reservoir sandstones can have different authigenic clay compositions. In southeastern New Mexico, well control and sample control are more than adequate to facilitate such predictions.
Deconvolution of Wellbore Pressure and Flow Rate
Authors: Kuchuk Fikri J. , Carter Richard G. , Ayestaran Luis 
Published: December 2007

Summary
Determination of the influence function of a well/reservoir system from the deconvolution of wellbore flow rate and pressure is presented. Deconvolution is fundamental and is particularly applicable to system identification. A variety of different deconvolution algorithms are presented. The simplest algorithm is a direct method that works well for data without measurement noise but that fails in the presence of even small amounts of noise. We show, however, that a modified algorithm that imposes constraints on the solution set works very well, even with significant measurement errors.
Description of an Improved Compositional Micellar/Polymer Simulator
Authors: Camilleri D. , Engelsen S. , Lake L. W. , Lin E. C. , Ohno T. , Pope G. , Sepehrnoori K. 
Published: December 2007

Summary
This is one of three companion papers describing a micellar/polymer or chemical flood simulator and comparing it to experimental data. A three-dimensional version of this simulator has been developed, but in this paper we describe only the one-dimensional (1D) flow equations because we focus on comparisons with linear coreflood data and related physical properties. All physical property models are the same in both versions, however. The property models described in this paper are (1) inaccessible PV, (2) permeability reduction, (3) polymer-phase viscosity, (4) adsorption, (5) residual phase saturations as a function of capillary number, and (6) relative permeabilities.
Experimental Investigation of the Interaction of Phase Behavior With Microscopic Heterogeneity in a CO2 Flood
Authors: Bahralolom I. , Bretz R. E. , Orr F. M. 
Published: December 2007

Summary
This paper reports results of an experimental investigation of the effects of microscopic heterogeneity on local displacement efficiency in a CO2 flood. Flow-visualization experiments for first-contact miscible displacements are described and compared with effluent composition measurement for the same models. High-pressure flow-visualization experiments for multicontact miscible CO2 floods are also described. The displacements were performed in two-dimensional (2D) etched glass models made from thin-sections of San Andres carbonate core from the Maljamar field. Techniques used in preparation of the models are described briefly.
Observations of first-contact miscible displacements in heterogeneous models indicate that early breakthrough and a long transition zone occur when preferential flow paths exist in the pore structure. This behavior corresponds to a flowing fraction less than 1 in the Coats-Smith model. Because the 2D models contained no dead-end PV, the results presented indicate that a low flowing fraction can occur if flow velocities in different portions of the pore space differ significantly. Coats-Smith parameters obtained for models were comparable with values obtained in floods performed in reservoir samples.
Visual observations of the CO2/crude-oil displacements indicate that there is an interaction between phase behavior and microscopic heterogeneity. Mixing of nearly pure CO2 in the preferential flow path with oil in adjacent regions leads to a residual oil saturation (ROS) that forms in the preferential path after oil initially present has been displaced.
Thermal Alteration of Viscous Crude Oils
Authors: Fassihl Mohammed R. , Meyers Kevin O. , Weisbrod Kirk R. 
Published: December 2007

Summary
At temperatures encountered during thermal recovery, crude oil may undergo compositional changes that permanently reduce viscosity. An increase in the crude's API gravity and the formation of solids and gas accompany these viscosity reductions. This paper presents results of a laboratory study on thermal alteration of two biodegraded crudes and one immature heavy oil over a temperature range from 77 to 780°F [25 to 416°C] at reaction times up to 350 hours. Experimental results indicate that up to a 1, 000-fold reduction in viscosity can occur. Compositional changes accompanying thermal alteration are discussed and correlated to changes in the physical properties. We show that the viscosity and density of the reacted oil can be predicted from the net change in the carbon number distribution determined by simulated distillation. A kinetic model was developed and compared with laboratory results and published data.
Experiments on Mixing During Miscible Displacement in Porous Media
Authors: Brigham William E. , Reed Philip W. , Dew John N. 
Published: December 2007

Abstract
The paper describes experiments on miscible displacement in various porous media and the results of these experiments. Both glass bead packs and natural cores were used. Bead diameters varied from 0.044 to 0.47 mm, and pack lengths varied from 83 to 678 cm. Natural cores used were Berea and Torpedo sandstone.
By taking samples as small as 0.5 cc and using refractive index for analysis, the data on break through curves could be plotted to within ± 0.5 per cent. To plot the data correctly on error function paper, a parameter (Vp - v)/vV was used which allowed for the predicted growth of the front as it moved past the observer.
The change in the amount of mixing (length of mixed zone) was studied by varying velocity, length of travel, bead size, viscosity ratio and pack diameter. When the displaced material was less viscous than the displacing material (favorable viscosity ratio), these changes were adequately predicted by theory. When natural cores were used, rather than glass beads, the amount of mixing was greatly increased - also qualitatively predicted by theory.
In experiments with favorable viscosity ratios in which the ratio was varied from 0. 175 to 0. 998, it was found that the rate of mixing was changed by a factor of 5. 7. Thus, the rate of mixing is strongly affected by viscosity ratio, even when the theoretical error function relationship for mixing is valid.
Experiments using fluids with viscosity ratios near 1.0 showed that the instability effects of even a slightly unfavorable viscosity ratio (1.002) caused disproportionately more elongated breakthrough curves than found with a favorable viscosity ratio (.998). When the viscosity ratio was as high as 5.71 these instability effects were much more pronounced, as evidenced by the shape of the breakthrough curve. The displacements at viscosity ratios above 1.0 no longer followed the theoretical error function curve.
Predicting Pressure Distribution in Irregularly Shaped Bounded Reservoirs
Authors: Kuo M. C. T. 
Published: December 2007

Summary
Many methods use radial and rectangular systems to interpret unsteady-state reservoir flow problems, but very little information is currently available for irregular drainage shapes. For many practical cases, however, the reservoir drainage shape is too complicated to be approximated by a circular or rectangular shape. This paper develops a means of predicting pressure-transient behavior in an irregularly shaped reservoir.
To generate a dimensionless-pressure-drop function, it is difficult to superpose the line-source solution of image wells in space for irregular drainage shapes. In this paper, the dimensionless-pressure-drop function is obtained by superposing the line-source solutions of image wells in time. The flow rates of image wells at each timestep are determined through solving a set of simultaneous linear algebraic equations that describe the conditions at the drainage boundary. The validity of this approach is proved by comparison of the calculated dimensionless-pressure-drop functions with literature values for various rectangular drainage shapes.
Maureen Oil Field—First Year of Production
Authors: Wootton D. 
Published: December 2007

Summary
This paper presents the first year of development of the Maureen field in the British sector of the North Sea. A steel platform gravity structure was used for development. The crude oil is tanker-loaded at an articulated loading column (ALC). Production, seawater injection, and gas lifting are discussed.
Production covers well completions, wellhead tiebacks, process-plant performance, and downtime. In particular, the performance of the ALC is detailed. At the column, successful modifications to the hawser system for tanker mooring were made, to reduce excessive hawser replacements. Seawater injection experiences are described, and details of the perforating techniques and stimulation treatments are given. Gas lifting of a well to test the surface and downhole facilities is described.
Operational Experience of Running Multicasing Gas Compression Trains on a North Sea Platform
Authors: Hancock W. P. 
Published: December 2007

Summary
This paper describes the difficulties of operating multicasing compression trains in parallel and the special problems associated with a very-high-pressure centrifugal gas-injection compressor. The Statfjord B platform features one of the most complex gas-compression systems in the world for an offshore platform and uses some of the most advanced centrifugal gas compressors and aeroderivative gas turbines currently available. Four different gases flashing from the crude in flash drums of cascading pressures are recompressed and injected into the producing reservoir at pressures as high as 45 000 MPa [450 bar gauge].
Conservation of valuable associated gas from offshore oil-production facilities demands high gas-compression efficiencies. Therefore, timely resolution of operational problems is paramount.
This paper details the operational problems and their resolutions, which helped the Statfjord B platform attain and exceed its design output.
Steamflood Strategies for a Steeply Dipping Reservoir
Authors: Hong K. C. 
Published: December 2007

Summary
A computer simulation study was conducted to determine the best steamflood strategy for a steeply dipping (20° [0.35-rad]) reservoir. A compositional steamflood simulator was used with both two-dimensional (2D cross section) and three-dimensional (3D) models of the reservoir.
The study showed that gravity drainage of the heated oil is the main production mechanism in steamflooding steeply dipping reservoirs. Consequently, oil production is strongly affected by injector and producer locations. The best steamflood strategy for this type of reservoir, therefore, involves judicious selection of injector and producer locations, reducing steam injection rate and shutting in wells selectively at appropriate times, and injecting a noncondensable gas to prevent steam cycling in the depleted updip portion of the reservoir.
This paper compares oil production performances and steamflood efficiencies for nine different operating strategies and recommends the best strategy for a steeply dipping reservoir.
Effect of WAG Injection and Rock Wettability on Oil Recovery During CO2 Flooding
Authors: Huang E. T. S. , Holm L. W. 
Published: December 2007

SummaryPrevious studies to determine the extent of oil trapping by water during CO2 water-alternating-gas (WAG) flooding have shown that rock wettability strongly affects this trapping. A significant trapping occurs in water-wet rock, and less trapping occurs in oil-wet rock. This paper presents laboratory results of Devonian crude oil displacement from watered-out Berea and reservoir cores by use of continuous CO2 injection, single-slug CO2 injection (followed by water), and CO2 WAG injection at miscible reservoir conditions of 120°F and 2,500 psig [49°C arid 17.2 MPa]. The reservoir cores used in this study were mixed- wet (Devonian and Muddy formations) and oil-wet (Tensleep formation). The Berea cores used had their wettability artificially altered to simulate these natural wettabilities. The X-ray photoelectron spectroscopic (XPS) method for measuring carbon content of rock surface was used to provide a qualitative measurement of wettability of the rock samples.The results of the study indicated that the experimental wettability-altering technique came close to duplicating reservoir rock wettability. The oil recovery data at the end of 1 PV fluid injection (continuous CO2 or WAG CO2) indicated that (1) in preferentially water-wet Berea cores, more than 45% of the waterfiood residual oil trapped by CO2 WAG; (2) in mixed-wettability Berea cores, 15 to 20% of the waterfiood residual oil was trapped; and (3) in oil-wet Berea cores, less than 5% residual oil was trapped.
Gladfelter Deconvolution
Authors: Kuchuk Flkrl J. 
Published: December 2007

Summary
In this paper, I present the general characteristics of the Gladfelter deconvolution method, which has been used for determining the constant-rate behavior of a system from measured flow rate and pressure. The validity of the method is established for different rate variations and flow geometries (radial, linear, and spherical). The method works well for linear and exponential flow variations and fails for the general flow case. The commonly assumed first semilog straight line resulting from the Gladfelter deconvolution is instead a tangential line parallel to the final semilog straight line owing to a constant-flow-rate period. New solutions are presented for cylindrical, linear (fractured), and spherical wellbore flow geometries with exponential-flow and constant-storage cases. In addition, useful asymptotic solutions are given for the determination of reservoir parameters from the Gladfelter method.
Correlation of Drag Reduction With Modified Deborah Number For Dilute Polymer Solutions
Authors: Rodriguez J.M. , Zakin J.L. , Patterson G.K. 
Published: December 2007

Abstract
Correlation has been obtained between drag-reducing characteristics forturbulent flow in a pipe and measurable properties of several polymersolutions. Several concentrations of high molecular weight polymethylmethacrylate in toluene, high molecular weight polyisobutylene in both tolueneand cyclohexane, medium molecular weight polyisobutylene in cyclohexane andbenzene and low molecular weight polystyrene in toluene were studied. Dataobtained in these nonpolar solvents and literature data for more polar solventswere successfully correlated as the ratio of measured friction factor to purelyviscous friction factor vs the modified Deborah numbervr1/D0.2, where r1 is the first-moderelaxation time of the solution estimated by the Zimm theory. A shift factorwhich is a function of intrinsic viscosity 1/(4[?] - 1) allowed all the dataobtained with nonpolar solvents to be correlated as a single function. Forthese systems, most of the data fit a single curve to within ±5 percent of theaverage friction factor ratio. The shift factor did not give a unique functionof the data for the more polar systems.

INTRODUCTION
The phenomenon of drag reduction in polymer solutions was first studied byToms1 in dilute solutions of polymethyl methacrylate inmonochlorobenzene. The drag ratio for flow through circular tubes has beendefined2 as the ratio of the pressure - drop of the solution to thepressure drop of the solvent at the same flow rate. The drag ratio is less than1.0 for a drag-reducing fluid. Practical use of drag reduction is being made infracturing operations in the petroleum industry.3
A more fundamental quantity is the friction factor ratio, defined as theratio of the observed pressure drop to that predicted for a solution of thesame viscosity characteristics and density at equal flow rates using theDodge-Metzner friction factor equation.4Equation 1
Viscous solutions with drag ratios greater than 1.0 can have friction factorratios less than 1.0. For practical applications, it is drag reduction which isof interest. However, for correlation the fundamental ratio is the frictionfactor ratio.
In recent years, drag reduction has been studied extensively. Recent studieshave shown that reasonable predictions of the incipience of drag reduction inpolymer solutions can be made from the properties of the solutions and the flowvariables.5 However, it has not been possible to predict accuratelythe amount of drag reduction to be expected for a given polymer solutionwithout any drag-reducing turbulent flow data on the samesolution.6
Analysis of the Pressure Response of a Single-Probe Formation Tester
Authors: Dussan V. E. B. , Sharma Yogeshwar 
Published: December 2007

SummaryThe single-probe formation tester is a logging tool used for measuring the vertical pressure profile of formation fluids and retrieving fluid samples. We propose using the pressure measurements taken during this tool's normal operation to determine local values of both the horizontal and vertical permeability (i.e., permeability parallel and perpendicular to the formation bedding planes, respectively) in an anisotropic formation.
Diamond-Bit Hydraulics Model
Authors: Warren T. M. , Behr Suzanne M. 
Published: December 2007

Summary
This paper describes an analytical technique that calculates the fluid velocities and pressures under a surface-set diamond bit. The technique is based on solving the continuity and energy equations for a series of flow cells that covers the bit face. Each cell is described with geometrical dimensions and an integrated property model to account for flow around the cutters. Experimental data from simulated diamond-bit segments provide friction-factor data and model validation. The results of analyzing a commercial diamond bit are also presented. The model is being developed to improve the hydraulic design of diamond bits.
Field Correlation Between Internal Taper Length and Tube Failures in 4.5-in., 16.60E, IEU Drillpipe
Authors: Gensmer Richard P. 
Published: December 2007

SUMMARY
Noble Drilling Corp. has become increasingly concerned with premature failures in 4.5-in. [11.4-cm], 16.60 Grade E, IEU drillpipe tubes that meet industry requirements for metal structure, hardness, strength, and chemical composition and that show no signs of physical abuse. Our study of the pipe structure showed that a high percentage of tube failures were in tubes with short internal taper lengths. We examined a string of drillpipe with 18 tube cracks in the first 2, 800 rotating hours in an area where 13, 000 to 18, 000 hours is a common life expectancy and studied drillstrings produced by three other manufacturers. We found that 80% of our failures occur within 10 to 12 in. [25 to 30 cm] of the internal taper, that the taper lengths are shorter among the failed joints than among a general population of drillpipe, and that these short taper lengths are not common to just one manufacturer or nation. We did not prove a causal relationship, but we did establish a correlation strong enough to warrant further investigation of the phenomenon and the establishment of a method that uses internal taper length as a criterion to inspect and purchase drillpipe.
Inspection Interval Guidelines To Reduce Drillstring Failures
Authors: Dale B. A. 
Published: December 2007

Summary
Inspection interval guidelines were developed to reduce the occurrence of costly drillstring fatigue failures. The guidelines are based on a state-of-the-art fracture mechanics model and incorporate reliability data of commercial inspection services using conventional nondestructive testing techniques. On the basis of extensive full-scale testing, the model was found to predict fatigue-crack-growth behavior reliably. By establishing inspection intervals on the basis of fatigue-crack growth, inspection services are systematically and cost-effectively specified to achieve acceptable reliability (or risk). Simple equations and charts are presented in terms of practical drilling parameters to reduce typical downhole fatigue failures.
Polymer/Bentonite/Soil Admixtures as Hydraulic Barriers
Authors: Liao W. A. 
Published: December 2007

Summary
Preventing waste fluids retained in on-site earthen pits from leaching into the surrounding environment has become a growing concern in the oil and gas industry. One possible solution is to incorporate a pit liner that acts as an impervious barrier between the contained fluids and adjacent soil or groundwater outside the pit. Such materials as flexible membranes, recompacted native soils, and polymeric/soil admixtures are commercially available for pit-lining applications. This paper briefly discusses the relative merits of each type of liner for oilfield waste. Among these liner materials, polymer/bentonite/soil admixtures, which consist of a blend of high-molecular-weight linear and crosslinked polymers, have many advantages, including self-sealing capability, inertness to degradation, and easy installation at low cost.
The objective of the study was to compare the permeability and the susceptibility to chemical degradation of a variety of modified clay liners designed for oilfield waste pits. The ideal liner should be resistant to brines and hydrocarbons, with permeability &lt;0.4 × l0−7 in./sec [&lt;1 × 10−7 cm/s]. A number of such admixtures were investigated to study sealing effectiveness. The results of this study indicate that certain modified clay liners are highly impermeable to brines and water-immiscible hydrocarbons and can significantly reduce hydraulic conductivity to &lt;0.4 × l0−7 in./sec [&lt; 1 × 10−7 cm/s] when incorporated into native soil. The resultant improved sealing capabilities offer a low-cost, reliable, long-term solution for impervious hydraulic barriers (pit liners). This paper also discusses applications of the selected polymer/bentonite/soil admixtures.