bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transient Dynamic Characteristics of the Gas-Lift Unloading Process
Authors: Tang Yula , Schmidt Zelimir , Biais R. N. , Doty D. R. 
Published: December 2007

SummaryThis paper presents a new comprehensive transient model and dynamic simulator that describe the complicated characteristics of the gas-lift unloading process. The model uses conservation equations of mass, momentum and energy, for both the cocurrent and countercurrent multiphase flow, along with the necessary closure relationships. The effect of liquid flowing back into the formation is also considered. The transient temperature changes in the gaslift unloading process are studied and the transient tubing pressure and two-phase flow parameters are incorporated into the temperature calculation. Two heat transfer mechanisms within the wellbore annulus are considered in the temperature model.An explicit numerical scheme is used for the mass and momentum partial differential equations. A double iteration procedure on both the temperature and pressure numerically solves the three conservation equations simultaneously.Several example calculations are given to illustrate the characteristics of the unloading process and to underscore the unreliability of conventional design methods. Gas-lift instability is also analyzed with the dynamic simulator. In addition, field data from 25 wells support the accuracy of the transient model. Finally, the simulator can be used to perform gas-lift optimal design, stability analysis, and gas-lift operation troubleshooting.
Simplified Mechanistic Simulation of Foam Processes in Porous Media
Authors: Rossen W. R. , Zeilinger S. C. , Shi J.-X. , Lim M. T. 
Published: December 2007

SummaryThe mechanisms controlling transport and mobility of foam in porous media are complex, but in some cases the mechanisms that dominate foam properties can be represented in simple models. For instance, fractional-flow methods can reproduce the predictions of more-complex foam simulators while highlighting the mechanisms controlling foam behavior. Fractional-flow methods indicate that the effectiveness of foam processes that alternate injection of liquid and gas ("SAG" processes) depends on foam strength at extremely high foam quality, conditions difficult to control in the laboratory.A numerical simulator that incorporates the relation between capillary pressure and foam stability extends simplified foam modeling to cases where fractional-flow methods do not apply. Applications of this simulator to one-dimensional (1D) foam displacements match predictions of analytical models based on laboratory data and illustrate the numerical artifacts that challenge foam simulation. Applications to 2D flow through layers in capillary contact show that the interplay between capillary crossflow and foam collapse depends on both the dimensions of the layers and the relative magnitudes of the capillary and viscous pressure differences.
Influence of Pressure Drop Along the Wellbore on Horizontal-Well Productivity
Authors: Ozkan Erdal , Sarica Cem , Haci Marc 
Published: December 2007

Summary
This study investigates the effect of wellbore pressure drop on horizontal-well productivity and presents guidelines to design horizontal-well completions. The central new result of this study is a general semianalytical model that couples wellbore and reservoir hydraulics. The model enables the rigorous evaluation of horizontal-well productivity and can be used to determine optimum well length, wellbore diameter, and production rate. Field examples are presented to emphasize the consequences of the infinite-conductivity well assumption. The extension of the model to the flow of real gases is also discussed. It is shown that the pressure losses due to acceleration may play an important role in the wellbore hydraulics of horizontal gas wells and should not be ignored.
Characterizing Curing-Cement Slurries by Permeability, Tensile Strength, and Shrinkage
Authors: Backe K. R. , Lile O. B. , Lyomov S. K. , Elvebakk Harald , Skalle Pål 
Published: December 2007

Summary
This work was carried out to obtain more knowledge about the transition period of curing oilwell cements. The results show that the curing characteristics are a function of temperature and that there is a correlation between shrinkage and cement content. The paper also introduces a new mechanism for gas migration and discusses how the studied parameters can be used to predict gas migration.
The Use of Slimhole Drilling and Monobore Completions To Reduce Development Costs at the Kuparuk River Field
Authors: Pearson C. M. , Petrash D. K. , Zernell J. T. , Zanghi Michael 
Published: December 2007

Summary
In 1994, a low-cost development and operating plan for future wells at the Kuparuk River Field was proposed with the goal of reducing well costs 30% by the end of 1996. This paper presents this plan of a slimhole drilling and monobore completion program, a discussion of the critical issues addressed to successfully make the change, and field results from the first 16 wells drilled in 1994 and 1995.
A review of historical cost information is included which covers drilling and completing wells using the conventional well designs that had become standard in the field for the previous 10 years. A variety of new slimhole well plans are presented for both production and injection wells together with a discussion of their potential application and cost savings. The paper concludes with a look at future work plans and opportunities for additional cost savings through the use of slimhole wells.
Enhancement of Liquid Flow Through a Porous Medium by Ultrasonic Radiation
Authors: Aarts A. C. T. , Ooms Gijs , Bil K. J. , Bot E. T. G. 
Published: December 2007

SummaryA new method to enhance the oil production rate is irradiation of the near-wellbore region by an ultrasonic source. The limited success for the application of ultrasound in well stimulation to date, however, is due to the lack of understanding of the physical mechanisms between an acoustic wave field and a porous medium. In this paper the mechanism in which ultrasonic radiation deforms the walls of the pores in the shape of traveling transversal waves is studied. A quantitative description of the mechanism indicates that these waves induce a net flow of the liquid inside the pores, identical to peristaltic transport. Numerical calculations show a damping effect of liquid compressibility and a strong influence of pore wall hardness and power output on the net flow rate induced.The occurrence of a flow induced by ultrasound has been confirmed by laboratory experiments. In these experiments a water velocity of almost 1 cm/s through a rubber capillary of 0.15 mm radius could be induced by an ultrasonic source of frequency of 20 kHz. By a comparison between the trends observed in the experiments and the theoretically predicted trends, the role of the peristaltic transport mechanism in acoustic well stimulation is discussed.
Screening Criteria to Evaluate the Development Potential of Remaining Oil in Mature Fields
Authors: Weber K. J. , Dronkert Hans 
Published: December 2007

Summary
Continuing reservoir management at mature stages often concentrates on delineating pockets of remaining mobile oil. This is becoming a major task for reservoir geologists and petrophysicists. Many old fields are coming up for reactivation as investment opportunities and there is an overall expectation that modern techniques can lead to additional recovery of between 10 and 20%. In this article we will discuss the screening criteria related to reservoir architecture, accumulation condition and production history.
The mobile oil remaining can be found in a number of predictable locations in reservoirs depending on their structural style and facies.
Attic oil along faults is perhaps the most simple configuration but sizeable volumes of remaining oil can also occur as a function of reservoir stratification and lateral discontinuity. A systematic overview of the different play types has been compiled based on structural or stratigraphic lateral continuity and vertical reservoir connectivity. Screening criteria have been derived on the basis of field examples and models for four play types.
The screening criteria specify minimum conditions which may lead to economic re-development with horizontal sidetracks from existing wells. In addition recommendations are given with respect to data gathering to confirm the presence of economically viable targets.
Wettability Effects in Thermal Recovery Operations
Authors: Rao Dandina N. 
Published: December 2007

Summary
Do the three-phase oil-water-rock systems remain unaltered in wettability or do they become more strongly water- or oil-wet when the reservoir temperature is increased during thermal recovery operations? The published literature provides an affirmative support to each of the three possible answers to this question. Should we let this controversy continue or is it time to put together different pieces of the puzzle to reach at least a semblance of a solution? The latter is the purpose of this paper.
This paper aims to shed more light on the controversy surrounding the effect of temperature on wettability by bringing together the various schools of thought on this subject under a simple mechanistic explanation involving an interrelationship between the spreading behavior in solid-liquid-liquid (SLL) systems and the liquid-liquid interfacial tension, and thin wetting film stability considerations. This paper extends the Zisman-type correlation between contact angles and surface tension in solid-liquid-vapor (SLV) systems to the SLL systems. The success achieved in establishing such a correlation in this study is of practical significance in that it shows a way of identifying crucial wettability changes that may occur in secondary and tertiary recovery processes through simple laboratory experiments involving interfacial tension and contact-angle measurements. This would help in recovery process selection and optimization.
The paper also describes a technique, which was discovered during the course of this experimental study, to prevent adverse wettability shifts in thermal operations. The technique involves in-situ deposition of small quantities of calcium carbonate (scale) particles near the wellbore region to maintain a strongly water-wet region of high relative permeability to crude oil. Encouraging results from an Alberta field test of this technology are also presented.
The Vertical Multiphase Flow of Oil and Gas At High Rates
Authors: Cornish R.E. 
Published: December 2007

A method is presented for calculating the pressure drop in a vertical well flowing oil and gas. It is designed primarily for flow rates in excess of 5,000 BID in large-diameter tubing, casing, or casing annuli, and relies heavily on the use of PVT data.

Introduction
While many investigators have attempted to develop methods for predicting the pressure loss that occurs in a vertical wellbore in which oil and gas are flowing simultaneously, few have specifically considered casing annulus flow, and then only at relatively low rates. Most Middle East oil companies have studied the problem, but little has been published. High-rate wells, problem, but little has been published. High-rate wells, although few in number when compared with the total number of producing wells worldwide, account for a considerable proportion of the world's production; yet none of the presently published articles predicts the two-phase pressure drop with any precision. Sanchez has calculated the bottom-hole flowing pressure for many wells using the methods of Hagedorn and Brown, Duns and Ros, Orkiszewski, and Baxendell and Thomas. Included in Sanchez data are the first 10 wells listed in Table 1. Table 2 compares his results for these 10 wells with those found below.
The objective of this paper is to describe a more accurate means for calculating the two-phase pressure drop in a vertical wellbore for flow rates in excess of about 5,000 B/D, with large-diameter tubing, casing, or casing annulus "oil strings." The limitations to the range of application are discussed.
Pressure Traverse Equation Pressure Traverse Equation The pressure traverse equation, as used in this paper, is of the form (1)
This equation is similar in many ways to that of Poettmann and Carpenter and Hagedorn and Brown Poettmann and Carpenter and Hagedorn and Brown and can be derived from the general energy equation. The fundamental difference between this paper and the work of those previously mentioned is that no general correlations are made from masses of field or experimental data. The pressure traverse is evaluated using PVT data for the crude oil being considered, friction PVT data for the crude oil being considered, friction factors obtained from a standard Moody diagram or the Colebrook equation, and implicitly assumes no slippage between phases. The individual parameters and their treatment are discussed in the following sections.

Fluid Density
The fluid density is derived from PVT data for the flowing crude oil. These data are usually obtained from laboratory measurements made on a bottom-hole sample collected from the well and pressure sealed during transportation from the field.
JPT
P. 825
Analyzing Well Production Data Using Combined-Type-Curve and Decline-Curve Analysis Concepts
Authors: Agarwal Ram G. , Gardner David C. , Kleinsteiber Stanley W. , Fussell Del D. 
Published: December 2007

Summary
This paper presents new production decline curves for analyzing well production data from radial and vertically fractured oil and gas wells. These curves have been developed by combining decline-curve and type-curve analysis concepts to result in a practical tool which we feel can more easily estimate the gas (or oil) in place as well as to estimate reservoir permeability, skin effect, fracture length, conductivity, etc. Accuracy of this new method has been verified with numerical simulations and the methods have been used to perform analyses using production data from several different kinds of gas wells. Field and simulated examples are included to demonstrate the applicability and versatility of this technology.
These new production decline-type curves represent an advancement over previous work because a clearer distinction can be made between transient- and boundary-dominated flow periods. They also provide a more direct and less ambiguous means of determining reserves. The new curves also contain derivative functions, similar to those used in the pressure transient literature to aid in the matching process. These production decline curves are, to our knowledge, the first to be published in this format specifically for hydraulically fractured wells of both infinite and finite conductivity. Finally, these new curves have been extended to utilize cumulative production data in addition to commonly used rate decline data.
Applications of Wireline Stress Measurements
Authors: Desroches Jean , Kurkjian A. L. 
Published: December 2007

Summary
This paper describes applications of wireline stress measurements based on the microhydraulic fracturing and packer fracturing techniques.
New testing and interpretation procedures have been developed. These procedures make it possible to obtain reliable measurements of the minimum horizontal stress and also the maximum horizontal stress in a near-vertical openhole environment, or to conduct tests in a cased-hole environment.
Examples of stress tests carried out in a wide range of formations are presented, with applications to the design of hydraulic stimulations, the stability of deviated wells, screenless completions for sand control, and enhanced recovery programs.
Enriched-Gas Miscible Flooding: A Case History of the Levelland Unit Secondary Miscible Project
Authors: Brannan G. , Whitington H.M. 
Published: December 2007

Performance is reviewed of an enriched hydrocarbon-gas Performance is reviewed of an enriched hydrocarbon-gas miscible-displacement process in the Levelland Unit. Cyclic injection of enriched gas and water has been in progress for about 4 years. No significant operational problems have been encountered. The project is experiencing response, but peak response has not yet been reached. Performance indicates this project will be an economic success. Performance indicates this project will be an economic success. Introduction
The Levelland Unit secondary miscible project consists of 28 injection wells and 40 producing wells in the west central portion of the Levelland Unit, Levelland field, Hockley County, Tex. (Fig. 1). Production is from the San Andres formation at an average depth of 4,900 ft. The discovery well for this reservoir was drilled in 1946. The field was developed originally on a well spacing of 42.5 acres/well.
In 1954, the Levelland Unit was formed to conduct secondary recovery operations. A pressure maintenance program was initiated in 1955, consisting of dry gas program was initiated in 1955, consisting of dry gas injection into 18 wells scattered within the unit. Three of these former dry gas injectors are located in the secondary miscible project. All dry gas injection operations had ceased by Feb. 1971. Water injection was initiated in parts of the Levelland Unit in Oct. 1964; however, water parts of the Levelland Unit in Oct. 1964; however, water injection in the area that became the secondary miscible project did not begin until later. project did not begin until later. In April 1970, the west central portion of the Levelland Unit was evaluated for infill drilling and possible miscible flooding. Infill development would establish a well spacing of 21.25 acres/well and was justified for either the straight waterflood case or for a miscible-flood case. All the proposed infill drilling has been completed. Original plans included miscible flooding of the entire west central portion of the unit. This was to be done in two phases beginning with 28 injection wells in the Phase 1 phases beginning with 28 injection wells in the Phase 1 area, with the remaining wells to the south to be converted at a later date; however, because of supply limitations of enriched gas, the Phase 2 area has remained on waterflood.
Enhanced recovery will not take place in the Phase 2 area as a secondary operation. If enhanced recovery takes place as a tertiary-type operation, it most likely will be a place as a tertiary-type operation, it most likely will be a CO2 miscible flood rather than hydrocarbon miscible because of an insufficient additional supply of enriched gas.
P. 919
A Review of Drill-Stem Testing Techniques and Analysis
Authors: Black W. Marshall 
Published: December 2007

Abstract
The present techniques of using the drill-stem test as a formation evaluation tool are discussed. The basic drill-stem test operation is divided for discussion into three phases: planning the test, performing the test, and interpretation, both qualitative and quantitative. The use of small bottom choices and large top choices is suggested in order to permit quantitative interpretation for gas-oil ratio, productivity, and permeability. The importance of measuring chloride content on a suite of samples taken from a recovered column of salt water is illustrated.

Introduction
A drill-stem test is a temporary completion of the well. Drill-stem tests are usually made for one or both of the following reasons:to determine the producible fluid content of a formation, andto determine the ability of a formation to produce.

Drill-Stem Testing Methods
The drill-stem test, or temporary completion, can be made either in open hole or inside casing through perforations. A drill-stem testing program can be planned for a well so that the tests will be made in accordance with one of three general methods:Test possibly productive intervals in open hole as the zones are penetrated; normally, this method is used in conjunction with coring and ether cuts may be used to detect hydrocarbon shows.Test possibly productive intervals in open hole after drilling deeper or reaching total depth; normally, this method requires that a cement plug be set for each test, unless straddle packer testing is employed. Sidewall cores and logs are commonly used to detect the shows.Test possibly productive intervals through perforations after casing has been set; log and core data may be used in selecting the intervals.
Drill-stem testing is widely used to confirm or prove the presence and/or the producibility of oil and gas that is detected by the other services. The testing program in a well can follow any one of the methods of drill-stem testing outlined in the preceding section; however, the method of testing cored shows as the prospective pays are penetrated is probably most widely used at present.
Quantitative Study of the Applicability of Fiber-Optic Gyroscopes for MWD Borehole Surveying
Authors: Noureldin Aboelmagd , Tabler Herb , Irvine-Halliday Dave , Mintchev M. P. 
Published: December 2007

SummaryHorizontal drilling increases the productivity of the drilling processes, but inevitably requires a measurement-while-drilling surveying system employing three-axis accelerometers to determine the inclination and the tool face angles, and three-axis magnetometers to provide the azimuth. The magnetometer measurements are affected by drillstring magnetic interference and downhole ore deposits, which necessitates the installation of the magnetometers inside costly nonmagnetic drill collars. The aim of this article was to examine the usefulness of the fiber-optic gyroscope (FOG) to replace magnetometers for real-time monitoring of the azimuth. System analysis of the effect of the severe downhole environment on the FOG's overall performance is presented. This analysis includes modeling the effects of shock forces, vibrations due to mud pump noise, bending vibrations due to drill collar whirling and linear coupling between the axial and transverse modes of vibration. The results obtained show that the FOG has excellent immunity to shock and vibration. Moreover, since magnetic fields have only a minor effect on the FOG, it can be installed directly behind the drill bit, thus eliminating nonmagnetic drill collars. This improves the measurement accuracy and eliminates the cost associated with nonmagnetic drill collars.