bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multipoint Interference Test in a Single Horizontal Well
Authors: Zhu Tao , Tiab Djebbar 
Published: December 2007

SummaryA new horizontal well testing technique, the multipoint interference (MPI) technique, is developed in a single horizontal well. This method is more sensitive than conventional buildup or drawdown tests to reservoir heterogeneities along the horizontal segment of the well. In MPI tests, the fluid is produced at a section or perforations at one end of the horizontal portion of the well and the pressure is recorded at one or more observation points (gauges) at the other end. Solutions of the pressure-transient behavior for spherical fluid flow near a linear discontinuity in a vertically confined formation are developed by using unconventional image theory. The pressure derivative was found to provide distinguishing features for analyzing pressure behavior of MPI tests in a heterogeneous reservoir. The straight-line plot of p vs. 1t provides a simple method for analyzing MPI tests. Type curves based on the model developed in this study can be used to determine reservoir properties, such as permeability and porosity, and to detect and locate the reservoir boundaries. The practical utility of MPI tests is demonstrated by several theoretical examples. The solutions developed in this study provide new insight into the pressure behavior of various flow regimes observable in MPI tests. The resulting equations are relatively simple and easy to apply.
Characterization of Devonian Shales With X-Ray Computed Tomography
Authors: Watson A. T. , Mudra Jim 
Published: December 2007

Summary
The paper investigates use of X-ray computed tomography (CT) for determining properties of Devonian shales. A dual-scan method is used to determine storage distribution quantitatively. Fractures considerably smaller than the resolution of the instrument were detected. Features observed in the CT images were validated by thin-section analysis.
Influence of an Invaded Zone on a Multiprobe Formation Tester
Authors: Goode Peter A. , Thambynayagam R. K. Michael 
Published: December 2007

Summary
When an oil or gas well is being drilled, some of the borehole fluid (mud filtrate) leaks into the formation, displacing the native reservoir fluid. This creates an invaded zone around the wellbore. The invading fluid will generally have a mobility and compressibility that differ from the formation fluid. The presence of the invaded zone will affect the pressure transients measured by a formation tester.
In this paper, a model that includes an invaded zone is presented together with an analysis of its effect at each of the probes of a multiple probe formation tester. The results show that the properties of the invaded zone dominate the pressure transient measured at the sink probe, strongly influence the transient at the horizontal probe, and only modestly affect the vertical probe transient. A suggested modification to the current interpretation procedure (which does not consider the invaded zone) for determining the horizontal and vertical mobility is also presented. The application of this modified procedure is discussed using a model example.
Pseudofunctions and Extended Dietz Theory for Gravity-Segregated Displacement in Stratified Reservoirs
Authors: Ingsøy Pål , Gauchet Renaud , Lake Larry W. 
Published: December 2007

Summary
This paper develops a new vertical equilibrium (VE) theory that accounts for gravity-segregated displacement in stratified reservoirs and is expressed either in terms of pseudofunctions or as an extended Dietz model. The theory includes reservoir stratification and capillary effects. An example calculation based on field data compares favorably with the more general numerical simulation.
Injecting Polyacrylamide Into Gulf Coast Sands: The White Castle Q Sand Polymer-Injectivity Test
Authors: Shahin G. T. , Thigpen D. R. 
Published: December 2007

Summary
A polymer-injectivity test designed to control mobility in cosurfactant-enhanced alkaline flooding was performed in the Q sand of the White Castle field, LA. Analysis of test data indicates that a polymer bank with an average viscosity of 4 cp was propagated as far as 90 ft into the reservoir with no measurable sign of degradation. It is estimated from pilot and laboratory data that injection of 500 ppm polyacrylamide through perforations at a rate of at least 32 B-D/in.2 of perforation into gulf coast sands is feasible. Monitoring of backproduced reservoir samples indicates that, to date, no detectable change in viscosity has occurred over a 2-year period.
A Type-Curve Approach to Analyzing Two-Well Tracer Tests
Authors: Datta-Gupta Akhil , Lake L. W. , Pope G. A. , King M. J. 
Published: December 2007

Summary
The traditional approach to analyzing field tracer data generally involves a history-matching procedure that is time-consuming and frequently results in a nonunique solution. In this paper, we use theoretical frequency response functions to build type curves of "transfer function" and "phase spectrum" that have a dimensionless heterogeneity index as a parameter to characterize a stochastic permeability field. The transfer function contains information regarding the amplitude-attenuating characteristics of the heterogeneous medium, and the phase spectrum provides information about the spacing between the frequency components of the input and output tracer pulses. In a manner analogous to type-curve matching for well testing, we can analyze field tracer history by comparing the theoretical and field-observed transfer function and phase spectrum. This analysis leads to an estimate of the heterogeneity index and PV. We demonstrate the technique by analyzing field tracer data from the Big Muddy field, WY, and compare the use of parameters obtained in scaling up. Results show very good agreement with the field data.
Scale Consistency From Cores to Geologic Description
Authors: Damsleth Eivind , Tjølsen C. B. 
Published: December 2007

Summary
This paper describes a technique for conditioning stochastic simulation of permeability on a geologic description grid to the observed core-plug measurements. The technique handles the transition from core-plug to reservoir-description scale correctly and consistently, provided that some model assumptions are fulfilled. A North Sea case study is included for illustration.
Critical Evaluation and Processing of Data Before Pressure-Transient Analysis
Authors: Mattar Louis 
Published: December 2007

Summary
With the common use of highly sensitive electronic pressure recorders and the widespread use of reservoir characterization by type-curve pressure-derivative techniques, preprocessing data has now become an important prerequisite to pressure-transient analysis. In almost all cases during a well test, the electronic pressure recorders measure a multitude of effects other than the intended reservoir pressure transients. For example, multiphase, geotidal, microseismic, changing liquid levels, recorder drift, recorder plugging, etc. can mask the reservoir transient. If not properly identified, these effects could easily be misinterpreted as reservoir characteristics, such as pressure depletion, boundaries, or dual porosity. The preprocessing of the digital data, starting with the comparison of pressures from multiple recorders and ending with data filtration to remove the noise associated with the signal, is a significant component of well-test interpretation and is a prerequisite to pressure-transient analysis.
From experience with thousands of well tests, we have chosen several examples to illustrate the need for preprocessing the data. The observed pressures must be corrected to remove the nonreservoir effects before pressure-transient analysis is attempted. Often, diagnosis of the observed data can only be done with the help of information other than the pressure trace.
A New, Fast, Accurate Pressure-Decay Probe Permeameter
Authors: Jones Stanley C. 
Published: December 2007

Summary
The theory, design, and operation of a new probe permeameter based on a pressure-decay technique are discussed. Its useful range is from 0.001 to 30,000 md. Measurement time varies from ≈2 to 35 seconds. Slip-corrected (Klinkenberg) and conventional gas permeabilities, both of which are free from inertial flow-resistance effects, and measurement-position coordinates are obtained automatically. Computer-stored data facilitate generation of permeability "profiles" (permeability/depth logs), permeability contour plots, or "calibration" of wireline logs that imply permeability.
Fundamentals of Shale Stabilization: Water Transport Through Shales
Authors: Ballard Tracey J. , Beare Steve P. , Lawless Tom A. 
Published: December 2007

Summary
One area where water-based muds need improved performance is in shale inhibition. However, before existing mud systems can be improved, the mechanisms by which water invades shales and how present-day inhibitive additives operate must be fully understood. An experimental technique has been developed that uses radioactive tracers to monitor the progress of water and selected dissolved ions through a shale core plug. By varying experimental parameters, such as water composition and applied pressure drop, the dominant mechanisms by which water is transported through shales have been identified. Under conditions of zero applied pressure, diffusion processes control water and ion movement through shales. Concentration gradients are the driving force for mass transfer of ionic species through shales. We observed no evidence to indicate that osmosis caused mass transfer of water. Applied pressure caused an increase in water and ion transport rates. Above a threshold pressure, water and dissolved ions travel at the same rate irrespective of the ion concentration.
Scale Control in the South Brae Field
Authors: Hardy J. A. , Barthorpe R. T. , Plummer M. A. , Rhudy J. S. 
Published: December 2007

Summary
Severe scaling conditions exist in South Brae because of the high barium content of formation water and low pH downhole. Formation water is also susceptible to calcium carbonate scaling. This paper presents experiences with scale control on topsides and down-hole during field development. Topsides control has been achieved at the expense of high dose rates and secondary effects on produced-water quality. A sulfonate-based inhibitor was developed and applied for downhole control of BaSO4. This paper presents the benefits achieved by the use of desulfated seawater to minimize the BaSO4 potential and describes the methods developed to control calcium carbonate scale.
Effect of Mixing Energy Levels During Batch Mixing of Cement Slurries
Authors: Hibbert A. P. , Kellingray D. J. , Vidick Benoit 
Published: December 2007

Summary
The properties of batch-mixed slurries prepared in a series of yard tests using full-scale equipment are compared with laboratory tests on the same materials. Dramatic differences have been observed between conventional laboratory tests and field scale properties.
By splitting the batch-mixing process into distinct steps, a laboratory method is tested against the observed differences.
It is shown that mixing energy is an important parameter in slurry design and that energy levels substantially above the conventional API laboratory mixing energy may degrade slurry properties such as pumping time.
Modeling Off-Center Wells in Reservoir Simulation
Authors: Su Ho-Jeen 
Published: December 2007

Summary
In conventional reservoir simulation, wells are assumed to be at cell centers. Thus, the fluid flow pattern around an off-center well is represented incorrectly. This is especially true for large fieldwide models, which are gridded by very coarse blocks resulting in numerous off-center wells. This paper describes a new, rigorous method to model single or multiple off-center wells in a gridblock. Fluids can be drawn directly from the four closest neighboring cells into an off-center producer. Well location is honored exactly. With the new method, the calculated wellblock pressure can be interpreted at cell center rather than away from cell center as in the conventional approach. The new method is formulated fully implicitly, and although it adds more nonzero elements to the Jacobian matrix, its dimension remains unchanged. Therefore, implementation of this method is not difficult and the increase in computing costs is minimal. This work has been validated by fine-grid simulation results. Several single- and multiple-phase test cases are presented. We show that the new method can improve the accuracy of numerical results for large fieldwide models.
Induction Log Analysis of Thinly Laminated Sand/Shale Formation
Authors: Hagiwara Teruhiko 
Published: December 2007

Summary
We examine induction log responses to a thinly laminated sand/shale sequence in a deviated borehole for arbitrary deviation (or dip) angle and sand/shale composition. We found that the induction log responses in a thinly laminated sand/shale sequence are the same as they would be if the tool is placed in a homogeneous but anisotropic formation with the horizontal and vertical conductivities given respectively by the parallel and the series conductivities of the sequence.
Conversely, a thinly laminated sand/shale sequence can be identified as an anisotropic formation by induction logs. We discuss three methods to identify an anisotropic formation using induction-type logs alone.
Forces on Curved Tubulars Caused By Fluid Flow
Authors: Mitchell R. F. 
Published: December 2007

Summary
This paper examines the effects of fluid pressures and flowing fluid momentum on curved tubing, casing, or drillpipe in a wellbore. A general expression for fluid forces on curved tubing is developed. Special cases, such as the "fictitious force" used in tubing buckling analysis, are developed and explained in terms of actual physical behavior. New problems, such as the effect of tubing eccentricity on fluid forces and the effect of external flow on tubing buckling, are identified. Lateral forces developed in curved tubulars caused by fluid pressure can be much higher than expected, with significant impact on friction drag loads and pipe sticking.
Reservoir Permeability Estimation From Time-Lapse Log Data
Authors: Yao C. Y. , Holditch S. A. 
Published: December 2007

Summary
This paper presents a method to estimate permeability using time-lapse log data. The reservoir permeability values are also obtained by history matching production data and analyzing core data. These permeability values are in agreement with the estimates derived from logs.
When a well is drilled, mud filtrate invades the formation around the borehole. The volume of mud-filtrate invasion is related to time, formation permeability, and other wellbore and formation parameters. As mud-filtrate invasion progresses, unique saturation profiles and, thus, unique profiles of resistivity and water saturation, are created in the formation surrounding the borehole. Therefore, the data from well logs change with time. By observing and analyzing the changes in log data vs. time, one can estimate formation permeability.
Slimhole Early Kick Detection by Real-Time Drilling Analysis
Authors: Swanson B. W. , Gardner A. G. , Brown N. P. , Murray P. J. 
Published: December 2007

SummaryEarly kick detection has been identified as being of primary importance in slimhole wellbores. Small annular volumes mean that, to maintain the integrity of the well, allowable kick volumes must be small. Gas influxes must therefore be detected and shut in rapidly. This paper describes an early kick-detection system developed for slimholes to detect and confirm the presence of an influx rapidly. This system has been run successfully on a number of slimhole operations.The early kick-detection (EKD) system is based on real-time analysis of drilling data obtained directly from a comprehensive mud-logging system on the rig. The analysis technique compares predictions of mud flow out and standpipe pressure from a dynamic wellbore model with corresponding values from the rig. The predicted values are derived from a model driven in real time by rig data such as pump rate and pipe rotation rate. Kick detection is based on deviations between measured data and idealized model predictions.The EKD system has been incorporated into an operational engineer-oriented graphical interface, which has provided easy access to the model for both input and output of data, and for the interpretation of results. This paper describes the design considerations and technology behind the EKD system and the engineering interface. The paper also presents examples of the system running in real time at a slimhole rig site.
Effects of Steam Quality and Injection Rate on Steamflood Performance
Authors: Hong K. C. 
Published: December 2007

Summary
A comprehensive numerical simulation study showed that for a typical heavy-oil reservoir, steamflood performance improves monotonically with increases in steam quality and injection rate. Hence, for this reservoir, the optimum quality and injection rate are the highest values that were investigated. In general, however, optimum steam conditions depend on reservoir type and operating mode (e.g., line drive or pattern flood). For most situations, published "rule-of-thumb" steam conditions are not optimum. Therefore, we recommend that optimum steam conditions for a specific reservoir be determined through economic comparison of predicted oil recoveries for ranges of steam conditions, as demonstrated in this study.
Development of a New Cuttings-Transport Model for High-Angle Wellbores Including Horizontal Wells
Authors: Larsen T. I. , Pilehvari A. A. , Azar J. J. 
Published: December 2007

Summary
This paper presents a new design model that will enable the drilling engineer to select the proper hydraulics for problem-free drilling in high-angle holes (from 55 to 90° from vertical). Empirical correlations have been developed after carrying out an extensive experimental study of cuttings transport in a 5-in. full-scale flowloop. The model predicts the required critical transport fluid velocity (CTFV), the average cuttings travel velocity (CTV), and the annular cuttings concentration under most given sets of drilling operating conditions.
A New MTV Computer Package for Hole-Cleaning Design and Analysis
Authors: Ford J. T. , Gao Erhu , Oyeneyin M. B. , Peden J. M. , Larrucia M. B. , Parker David 
Published: December 2007

Summary
This paper describes a computer package that can be used to calculate the minimum transport velocity (MTV) required to ensure efficient hole cleaning during deviated drilling operations. The package was developed in the Dept. of Petroleum Engineering at Heriot-Watt U. It operates in a Windows environment and allows the user to do the following:
Define, from viscometer data, the rheological model (PowerLaw, Bingham Plastic, or Herschel-Bulkley) that best describes a particular drilling fluid. Model the drilling fluid velocity profile in a defined annular geometry. Predict the minimum circulation rate required to ensure efficient cuttings transport for a wide range of operational conditions.
The paper describes how the lift and drag forces on the cuttings have been determined and used in the development of the package. Case studies that demonstrate the functionality of the package are also presented.
Coiled Tubing Buckling Implication in Drilling and Completing Horizontal Wells
Authors: Wu Jiang , Juvkam-Wold Hans C. 
Published: December 2007

Abstract
This paper discusses coiled tubing buckling and load transmission when drilling and completing horizontal wells. Comprehensive analyses and new equations are presented to predict buckling of coiled tubing, "slack-off" weight transmission, actual bit weight or packer load, and maximum horizontal length. Coiled tubing "lockup" and yield due to buckling are also discussed. These equations can also be used for other coiled tubing operations, such as coiled tubing workover, coiled tubing well stimulation, and even for conventional joint-connected drill strings. Calculations based on the equations presented are also compared with the previous literature.
Adsorption Studies of Natural Gas Storage in Devonian Shales
Authors: Lu Xiao-Chun , Li Fan-Chang , Watson A. Ted 
Published: December 2007

Summary
Significant amounts of natural gas exist as an adsorbed, or condensed, phase in Devonian shale formations and other unconventional gas resources. The amount of the adsorbed phase depends on the pressure and temperature. The Langmuir isotherm has been used to describe the pressure dependence. However, temperature dependence has not been explored. This is important to evaluate thermal stimulation as a recovery method and to extrapolate laboratory measurements to reservoir conditions. We investigate adsorption as a function of both pressure and temperature. We found that the effects of temperature are significant and that the Langmuir model does not describe adsorption adequately. We reconciled the data with bi-Langmuir models.
Application of Linear Programming to Reservoir Development Evaluations
Authors: Lo K. K. , Starley G. P. , Holden C. W. 
Published: December 2007

Summary
A production forecasting model that uses linear programming concepts has been developed to generate composite forecasts from multiple streams produced through a common facility. The model treats petroleum processing as a linear optimization problem to maximize oil production under a set of independent constraints. The model represents production streams competing for limited facility capacity on a consistent basis. This approach allows resolution of production streams of varying character [GOR, gas/liquid ratio (GLR), or WOR] into a composite rate forecast while facility capacity is used optimally. In particular, the model may be used to forecast production of several unrelated fields producing through a common facility. The model was applied to forecast production for three Alaska North Slope reservoirs (Kuparuk, Lisbume, and Point McIntyre) for development and facility-expansion evaluations.
Field Trial Results of Annular Pressure Behavior in a High-Pressure/High-Temperature Well
Authors: Oudeman P. , Bacarreza L. J. 
Published: December 2007

Abstract
The problem of annular pressure buildup due to heating of the strings by the (hot) well effluent, will typically be of concern in the design of casing strings for high-pressure/high-temperature (HP/HT) sub-sea wells. In such completions bleeding off the pressure through the wellhead, as done routinely with surface wells, is not possible.
Theoretical studies indicated that, potentially, extreme pressures could develop in confined sealed annuli of subsea completions, posing a severe threat to well integrity. To investigate the effect under realistic conditions, Shell Expro (UK) ran battery operated gauges in the 9 5/8 in. × 13 5/8 in. annulus of an offshore HP/HT well, to record pressure and temperature changes during drilling, cementing and production testing.
This paper presents the results of these tests and a general model for pressure buildup in unconfined sealed annuli to correlate the field data. Since only pressure and temperature measurements were available certain assumptions had to be made with respect to, e.g., formation response to pressure buildup, in situ liquid properties, etc. Although these assumptions could be debatable, it is hoped that by publishing and sharing ideas, a better understanding of annular pressure behavior can be developed.