bluuebunny/crossref_metadata_2025 huggingface dataset:
Pseudolimited Entry: A Sand Fracturing Technique for Simultaneous Treatment of Multiple Pays
Authors: Stipp Louis C.
Published: December 2007

Tenneco Oil Co. has used the pseudolimited entry technique to simultaneously and effectively sand-water fracture the multiple, hard, tight Dakota gas pays in the San Juan basin. Application of this technique involves

the use of ball sealers to insure that a satisfactory number of perforations are open prior to fracturing, employment of a low (approximately 300 psi) perforation differential to insure simultaneous, effective stimulation of all perforated pays of approximately equal fracturing pressure and the use of bridge plugs when necessary to insure stimulation of zones having significantly different fracturing pressures.

The use of the pseudolimited entry technique essentially has eliminated sand-outs, poor treatment coverage and other problems associated with other fracturing techniques. As of March, 1966, the absolute open flow potentials (AOFP) of the nine wells completed by this method averaged over 4,000 Mcf/D or 78 percent above those AOFP's of conventionally treated offset wells. Constantrate pressure drawdown testing' also has supported the results attained.

The results and continued use of this technique have proved it to be an effective method for stimulating the Dakota pays of Northwest New Mexico.

Introduction

Fracturing multiple pays with conventional techniques (densely perforated zones, treatment control through the use of bridge plugs or ball sealers) can result in expensive or marginal completions. Fracturing the Dakota formation in the San Juan basin with conventional methods offers few exceptions to this.

The Dakota formation in the San Juan basin is approximately 200 to 300 ft thick. As shown by Fig. 1, it often is composed of multiple, hard, low-porosity, gas- bearing sands separated by shale. At a given location, the lower Dakota usually is composed of a series of sands of approximately equal fracturing pressures. These pressures often vary markedly between locations. The middle and upper Dakota sands are less numerous. They have approximately equal fracturing pressures significantly different from those of the lower sands; those of the middle and upper sands also can vary over a short distance. Fracturing pressures of all the Dakota sands are difficult to predict quantitatively.

The Dakota frequently is sand-water fractured with conventional multistage treatments, employing bridge plugs or ball sealers for treatment control and diversion. Normally, the amount of propping agent used is between 50,000 and 100,000 lb of sand. Treating rates usually are between 35 and 50 bbl/minute. In many cases individual sands will be perforated with so many holes that the treatment will be accepted into the sand that has the lowest fracturing pressure.

JPT

P. 457ˆ
Infill Drilling in the Rotherwood Field, Harris County, Texas
Authors: Hurst William
Published: December 2007

More than 600 billion bbl of oil are estimated to be left behind in abandoned and producing fields. The average field produces only one-third of the oil originally in place. This paper describes a method to determine where this oil exists in odd-shaped fields like the Rotherwood field in Harris County, TX. Conformai mapping is used. The field's configuration is changed to a conformai rectangle where Basset's formula for fluid flow between parallel planes applies. By this means, streamlines are developed showing the directions of oil movement to the producing wells in the reservoir. Where large gaps appear between streamlines, or where any abnormalities are evidenced, an area of unproduced oil exists.
Gas-Lift Allocation From Workstation Data Base
Authors: Woodyard A. H.
Published: December 2007

Since installation of Conoco’s artificial-lift allocation program (COALA) in mid-1988, engineer productivity has increased significantly over traditional gas-lift techniques. COALA is a series of gas-lift engineering programs integrated on a PC. The programs use a companion relational data base for troubleshooting, production maintenance (through review of flowing survey analysis), and performing system analysis. Optimum gas-lift allocation rates are identified by well and field. Reports on well data can be generated as the engineer sees fit.
Cyclic Steam Injection Project Performance Analysis and Some Results of a Continuous Steam Displacement Pilot
Authors: Adams R.H. , Khan A.M.
Published: December 2007

Introduction

The Huntington Beach oil field is on the Pacific Coast, southeast of the City of Los Angeles (Fig. 1). It lies both onshore and offshore. Most of the onshore section is operated by Standard Oil Co. of California, WOI. The Tar reservoir is of upper Pliocene age, about 200 ft thick, and consists principally of fine-grained, unconsolidated, somewhat shaly sand, with thin interbedded shale stringers throughout (Fig. 2). The reservoir is a broad, highly faulted, elongated anticline, with an areal extent of about 370 acres. Most of the faults bisecting the structure are normal, trend north-south, and are the main cause of reservoir discontinuity (Figs. 3 and 4). From 1964 to Dec., 1967, 259 steam stimulations were performed on a total of 125 Tar sand wells. Eighty-six new wells were drilled and steam stimulated. Of the total, 96 have been stimulated twice, 34 three times and 3 four times. During this same period, a two-injector steam drive pilot has been in progress. The response obtained from this project has been compared with the response to cyclic stimulation. This paper presents an analysis of the field observations for the two methods of thermal recovery.

History of Development

Drilling to the Tar pool commenced in 1924 with an initial well production of 40 to 50 B/D of 12 degrees API gravity oil. Complete primary development of the pool has been spread over several years. Approximately 40 wells were drilled during the first phase of development, which was completed in 1945. The subsequent primary development started in 1960 with initial well productions of 30 to 40 B/D oil. Thirtyseven wells were completed in the Tar pool during this phase. For the most part, slotted, gavel flow packed liners have been used in the wells in this pool. A cyclic steam stimulation pilot was initiated in March, 1964. Based on the very successful stimulation in the pilot area, the cyclic stimulation project was expanded to include all of the Tar pool wells producing at the end of 1965 (Fig. 5). Also, a development drilling program was begun at this time. To date, 86 new wells have been drilled under this program. The number of wells drilled each year in this secondary phase of development is also shown in Fig. 5.

New Well Completion Practices

Most of the new wells have been completed to produce from both the Upper and Lower Tar zones. Generally, a casing stub is cemented from the top of Lower Tar to the base of clean Upper Tar sands to exclude intermediate water-bearing sands. The water string is then cemented from the top of Upper Tar to about 1,500 ft with neat cement and 30 percent silica flour. The annulus from 1,500 ft to surface is then filled with a petroleum-based gel through a hightemperature port collar. Once again, a history of sand-free production dictated the use of 60-mesh gravel flow packed liners.

JPT

P. 95ˆ
Accuracy of Offshore Subsidence Measurements With Seabed Pressure Gauges
Authors: Mes M. J.
Published: December 2007

Phillips Petroleum Co. Norway pioneered the application of pressure gauges to measure offshore platform subsidence histories. Four pressure-gauge systems were installed in the Greater Ekofisk area. Prototype data prove that the progression of subsi dence can be measured with pressure gauges with a relative uncertainty of ±9 mm.
A Philosophy for the Integrity Assessment of Jackup Units
Authors: Leijten S. F. , Efthymlou Michael
Published: December 2007

Survey results show that current methods to assess the structural integrity of jackups require revision. This paper presents improvement guidelines and proposes a common industry practice. It also stresses the need for site-specific location assessments and describes Shell's efforts to find a workable solution.
A Lease Consolidation, Telemetering and Supervisory Control Project
Authors: Abel W.L. , Pace F.A.
Published: December 2007

Pan American Petroleum Corp. has applied the latest techniques of tank battery consolidation and automation to control oil production from the East Texas field. A major part of this project was the consolidation of 93 leases comprising 913 wells under a central automatic custody transfer (ACT) system. This consolidation makes maximum use of the pipeline company's crude-gathering system that also handles and commingles the production from 45 outside-operated leases run by conventional tank-gauging methods. The second part of the project is a data acquisition, telemetering and computer-interfaced supervisory control system. The central control for this system is located in Tyler about 40 miles west of the East Texas field. Lease production is scheduled, controlled, accumulated and formally reported from the central control, which also monitors equipment operations and relays malfunctions to pumper patrols.

Introduction

The East Texas automation project includes 974 wells on 101 leases covering a 55 sq mile area in the north half of the East Texas field. About 95 percent of the wells are flowing and produce pipeline oil. The remainder are produced by electrically operated pumping units. Oil production in the field is obtained from the Woodbine sand at a depth of approximately 3,300 ft. It has been producing for 30 to 35 years and has a remaining estimated life of 70 years. Average well density is less than 5 acres/well. Because of this density and because of the depth of the sand, the top allowable is 20 B/D, subject to market demand factors. The average well produces its allowable when flowing on a schedule of approximately 30 minutes/ day, 3 days a week.
Development and Application of a Microcomputer Monte Carlo Simulation Model With Lotus 1-2-3
Authors: Yu John P. , Zhuang Ziqing , Watts Royal J.
Published: December 2007

A microcomputer Monte Carlo simulation model to perform economic evaluation of CO2 miscible flooding projects has been developed with Lotus 1-2-3. This study includes risk simulation using the Latin hypercube sampling technique. The risk-simulation model is completed on the spreadsheet, with keyboard macro enhancing the feasibility and application of this model. A risk-weighted discount cash flow (DCF) rate of return, profit/investment ratio, net present value, and payback periods were obtained.

The risk-simulation model is very user-friendly. It can perform statistical analysis and generate tables and graphs for result presentations with Lotus 1-2-3 macro enhancements. In addition, the model can be modified to suit any other specific field case applications—e.g., exploration and drilling.
A Microcomputer-Based Log-Analysis Program in a Windows Environment
Authors: Rubenstein Jeff D. , Harder Steven M. , Barba Robert E.
Published: December 2007

In the past few years a number of software programs have been developed to process openhole wireline data on PC’s, but most require extensive computer experience or training to operate. At the same time, PC operating systems have evolved to incorporate graphical user interfaces. The QLA* program integrates a loganalysis package with one of these new operating systems using the Microsoft Windows™ operating environment for IBM- compatible computers. Programs run under Windows use a "visual interface" and can be executed with a minimum of keystrokes by use of a mouse and pull-down menus. All options are readily displayed to the user, and a minimum of program knowledge is required to integrate log graphics, crossplots, reports, and text into a single document.
Quantitative Use of Calibration Data to Correct Miscalibrated Well Logs
Authors: Maciula E.A. , Cochrane J.E.
Published: December 2007

A method of mathematically correcting miscalibrated well logs on the basis of calibration data is presented. The model is a logging system with a linear-response function calibrated to two standards. The model assumes that interaction between calibration error functions is negligible, and that these error functions remain essentially constant during the log recording.

The general model and the resulting correction equation were adapted to induction logging systems, and field Trials were performed to test the validity of the model. A computer program permitted induction log data to be generated continuously through the correction equation. Results indicate the assumptions are reasonable, and that adequate correction is accomplished for the range of conductivity values investigated.

The correction technique was applied to induction logs run by four service companies in the same wellbore in the Wilmington field, Calif. The corrected logs essentially are identical.

Introduction

Well logs formerly were used primarily for qualitative formation evaluation and correlation. Log accuracy has become of prime importance as logging has begun to provide quantitative parameters for the determination of formation characteristics. Measurement accuracy is dependent upon precise logging-system calibration. However, little attention has been paid by oil companies to these calibration data, and use of these data has been confined to intercompany accuracy control by the logging companies. Recently oil companies have come to realize the dependence of competent formation evaluation on accurate logging system calibration. With the nascence of this interest in highly accurate logs, we foresee advantages to be gained from a method through which a miscalibrated log can be corrected adequately on the basis of calibration information. Such a method would enable the company witness to accept such a log if he were provided with a complete calibration record. This latitude would prove especially profitable where hole conditions are severe or when rig time is a critical consideration.

A mathematical technique is proposed for correcting erroneous logs that are produced by logging systems having a linear response characteristic and calibrated to two standards. To simplify the model, assumptions were made concerning interaction of high- and low-error components. The ideal model has been adapted to fit the induction logging system. Field tests, utilizing purposely miscalibrated induction logs, were conducted to test the validity of the revised model. Results of these tests indicate the equation is correct for usual conductivity ranges observed in California formations. A computer program has been written to generate a corrected induction log using error inputs calculated from the calibration records.
Determination of Steam Quality Using an Orifice Meter
Authors: Palm J.W. , Kirkpatrick J.W. , Anderson W.H.
Published: December 2007

Steam generators used to inject steam into petroleum reservoirs are designed to produce wet steam, usually about 80 percent quality. For economical operation the steam quality should be continuously monitored, which can be done using an orifice meter. In addition to using data for flow of the generator effluent through an orifice, the method uses the flow rate of water to the generator as measured independently, such as by a positive displacement meter.

An improved calculation method has been demonstrated at pressures of 129 psig and 300 psig with qualities, of 32 to 100 percent. The calculation method is based on a literature correlation that includes data at pressure up to 929 psia. The method is expected to be useful at higher pressures as long as the volumetric gas-liquid flow ratio and the ratio of mass flow rate to pressure are above specified minimum values.

Introduction

Many references have mentioned or discussed the problem of two-phase flow through an orifice. However, most of the literature has been inaccurate or has not considered all of the important variables in this operation. Calculation methods for wet steam shown in two well known orifice meter handbooks are not accurate. For example, Diehl and Beck use the steam coefficient factor F. and state that the orifice differential is approximately linear with quality at a given pressure and constant total mass flow rate of wet steam. This is incorrect. The square root of the differential is approximately linear with quality.

An accurate and detailed treatment of measuring two-phase flow with an orifice was made by Murdock. He published experimental data that both he and W. H. Osborne had obtained, as well as a correlation of the data, which has a standard deviation of only 0.75 percent. The data included two-phase systems of steam-water, air-water. natural gas-water, natural gas-salt water and natural gas-distillate at pressures of 15 to 929 psia.

Two other recent references give data that are reasonably consistent with Murdock's correlation. However, the data in these references are not complete enough to permit exact comparisons.

This paper illustrates the application of Murdock's correlation to measuring steam quality in thermal recovery operations, and further defines the limitations of the method.
Calculation of Parachors for Compositional Simulation: An Update
Authors: Fanchi John R.
Published: December 2007

Published parachor-correlation predictions diverge for high-molecular-weight (MW) components. This divergence stems from a lack of data. This paper incorporates parachor measurements for high-MW mixtures that have not been used in the preparation of previously published parachor correlations into new parachor correlations.
1D Simulation of Polymer Flooding Including the Viscoelastic Effect of Polymer Solution
Authors: Masuda Yoshihiro , Tang Ke-Chin , Miyazawa Masashi , Tanaka Shoichi
Published: December 2007

Simple simulation models are constructed to predict the performance of 1D polymer flooding. In the models, two phases of oil and polymer solution were assumed to be immiscible with each other. Because the displacing fluid was non-Newtonian, the BucldeyLeverett equation could be modified and a new approach developed to calculate fractional-flow curves. The rheological behavior of polymer solution was modeled with an Ellis type model and a viscoelastic model. To verify the models, two 1D flooding experiments were carried out on 2.8-cm-diameter, 47-cm-long, unconsolidated cores packed with glass beads (70/100 mesh). Porosities of the cores are about 37% and permeabilities are around 26 μm2. Two white mineral oils of viscosities 25 and 60 mPa·s and a 200-ppm polyacrylamide solution were used. In each experiment, polymer flooding was done after waterflooding. Initial water saturation was controlled to be almost the same at the start of each flood. The calculated polymer-flooding performances were compared with experimental data. The Ellis model predicted earlier breakthrough of polymer solution and lower oil recoveries than the experimental data. On the other hand, the viscoelastic model predicted fractional-flow curves, oil recovery performances, and breakthrough times of the experiments very well. The viscoelastic effect of polymer solution is thought to play an important role in the improvement of oil recovery.
The Steam-Foam Process
Authors: Hirasaki George J.
Published: December 2007

The steam-foam process was developed to improve the sweep efficiency of the steamdrive and steam-soak processes. Steamdrives that are not stabilized by gravity can have a poor vertical sweep efficiency as a result of (1) gravity overlay in a thick sand with vertical communication and/or (2) channeling in a layered formation with poor vertical communication between sand members. The reduced mobility of steam foam increases the pressure, and gradient in the steam-swept region to displace the heated oil better and to divert steam to the unheated interval. Surfactants reduce the steam mobility by stabilizing the liquid lamellae that cause some or all of the steam to exist as a discontinuous phase. The propagation of surfactant is retarded by ad sorption. In the phase. The propagation of surfactant is retarded by ad sorption. In the case of ion exchange of divalent ions from the clays, the surfactant is also retarded by precipitation and/or partitioning into the oil. The rate of propagation of foam is also determined by the mechanisms that generate and destroy foam. The generation mechanisms include leave-behind, snap-off, and division. The destruction mechanisms include condensation and evaporation, coalescence by a limiting capillary pressure, and coalescence resulting from the presence ofoil. The foam texture can be predicted from a population balance that includes these mechanisms. predicted from a population balance that includes these mechanisms.

Introduction

Scope. This paper reviews the steam-foam process. It is not an exhaustive survey of the literature, and I apologize to the many contributions that had to be omitted because of length limitations.

The types of field application of steam foam are discussed first. Examples are taken from reported pilot results. The remainder of the paper focuses on process mechanisms. Understanding of the mechanisms for foam flow in porous media is still in the formative stage, and many advances can be expected. It is hoped that this paper will help the practicing engineer apply the process more efficiently and will challenge the researcher to advance the knowledge of the process and to develop more efficient formulations.
A Software Technique for Flow-Rate Measurement in Horizontal Two-Phase Flow
Authors: Darwich T. D. , Toral Haluk , Archer J. S.
Published: December 2007

This paper presents a software technique for measuring individual phase flow rates in two-phase flow. The technique is based on the extraction, classification, and identification of stochastic features from turbulent pressure and void-fraction waveforms. Experiments in a horizontal air/water loop showed that a set of stochastic features is uniquely related to the individual phase flow rates. The software flowmeter is calibrated in situ by compilation of feature sets related to individual phase flow rates in a data base. On-line flow-rate measurement is made by a pattern recognition technique that identifies the best match to the measured feature vector from the calibration data base.
Application of a Lime-Based Drilling Fluid in a High-Temperature/High-Pressure Environment
Authors: Elsen J. M. , Mixon A. M. , Broussard M. D. , LaHue D. R.
Published: December 2007

Lime-based drilling fluids are commonly used in applications that require solids tolerance, low and stable rheological properties, resistance to contaminants, and inhibition to shales. The use of lime-based systems previously was restricted to environments in which temperatures were lower than 300°F because of excessive gelation of the mud at higher temperatures. Recent developments in drilling-fluid additives and solids-control equipment now permit the use of lime-based drilling fluids in high-temperature/high-pressure (HTHP) environments.

Amoco Production Co. recently used a lime-based mud to drill a well offshore Texas in an HTHP environment. Predetermination of the drilling-fluid objectives contributed to the success of the operation. First, the drilling fluid had to satisfy U.S. Environmental Protection Agency (EPA) environmental discharge requirements. Second, stuck pipe and lost circulation, prevalent problems in offset wells, had to be nunimized. Third, the fluid had to be stable to temperatures of 350°F and densities to 18.5 lbm/gal and to be resistant to CO2 and to saltwater flows. A high-temperature, lime-based system was developed and maintained to meet these drilling-fluid objectives.

This paper describes the planning used to select the mud system, development of the formulation in the laboratory, laboratory testing to determine treatments during the course of the well, and the performance of the drilling fluid. This experience provided a unique approach to both the formulation and maintenance of a lime-based fluid used in hostile environments.
Development of a Whirl-Resistant Bit
Authors: Warren Thomas M. , Brett J. Ford , Sinor L. Allen
Published: December 2007

Bit whirl is a major cause of early failure and reduced performance of polycrystalline-diamond-compact (PDC) bits. Attempts to control bit whirl by stabilizing the drillstring have been unsuccessful, but a "low-friction" bit design has been discovered that substantially eliminates whirl. The low-friction design is based on placing the cutters so that the net imbalance force from the cutters is directed toward a smooth pad that slides along the wellbore wall.
Analysis of Pressure-Transient Tests for Composite Naturally Fractured Reservoirs
Authors: Kikani Jitendra , Walkup Gardner W.
Published: December 2007

Naturally fractured reservoirs that undergo waterflooding or steam injection or that are acid-stimulated frequently can be modeled as a composite naturally fractured reservoir with matrix skin. A new analytical solution is presented in Laplace space for such a model that includes wellbore storage and skin. Design and analysis methods for pressure-transient tests based on the pressure derivative are also presented. Correlating parameters have been found that ease test design and analysis. Practical methods to determine the size of the inner zone are given. These methods are based on a scaled deviation time from the semilog straight line. A field example for an acidized well is presented.
Characterizing Average Permeability in Oil and Gas Formations
Authors: Rollins J. B. , Holditch S. A. , Lee W. J.
Published: December 2007

Permeability in a formation frequently follows a unimodal probability distribution. In many formations, particularly sedimentary ones, the permeability distribution is similar to the log-normal distribution. Theoretical considerations, field cases, and a reservoir simulation example show that the median, rather than the arithmetic mean, is the appropriate measure of central tendency or average value of the permeability distribution in a formation. Use of the correct estimate of average permeability is of particular importance in the classification of tight gas formations under statutes in the 1978 Natural Gas Policy Act (NGPA).
Evaluation of Flood Water Quality in the West Montalvo Field
Authors: Farley J.T. , Redline D.G.
Published: December 2007

One of the most important factors affecting success of waterflood performance is maintenance of water quality. Determining minimum water quality is difficult because water quality requirements are as varied as the formations to be flooded. Previously, attempts have been made to set quantitative standards based on simple tests for water quality. However, injection water quality is best measured by formation core flooding at conditions that model fullscale injection operations.

While acceptability of source water can be determined in the laboratory by flooding formation core material, it is difficult to acquire representative water samples because of water instability. On-site core flooding at sand face injection temperature with water from a pilot treating plant minimizes water quality uncertainty and permits continuous, on-line screening for development of treating and filtering requirements. Water injection acceptability and pilot plant evaluation provide determination of corrosivity, filtration efficiency, treatment additive compatibility and treatment economics. This source water evaluation method improves waterflooding economics in two important ways:

- minimum treatment cost to maintain continuous injection without permeability decline is established; and

- the possibility of injection well damage is reduced.

Introduction

An evaluation study of an injection water source is described. In addition to the usual determinations of bacterial activity and corrosivity, this on-site pilot plant study evaluated particle plugging tendency, scaling tendency, treating chemical compatibility and potential clay problems by formation core flooding at sand face injection temperature. The purpose was to provide an economic means of maintaining injectivity in West Montalvo field, Oxnard, Calif., by developing a chemical treatment and filtration system from core flood tests.
Stochastic Imaging of the Wilmington Clastic Sequence
Authors: Journel André G. , Gómez-Hernández J. Jaime
Published: December 2007

Correct modeling of the geometric architecture of the sand/shale geometry within shaly layers of the Wilmington field is critical to predict performance recovery accurately. Stochastic images of that clastic sequence are obtained with sequential indicator simulation with non-Cartesian coordinates to ensure stratigraphic conformity.
Chemical Characterization of CMC and Its Relationship to Drilling-Mud Rheology and Fluid Loss
Authors: Hughes T. L. , Jones T. G. J. , Houwen O. H.
Published: December 2007

Four carboxymethyl cellulose (CMC) polymers were characterized by molecular weight, degree of substitution, and intrinsic viscosity. These polymers were used to make simple water-based muds with various polymer and bentonite contents. API fluid loss and high shear viscosity were determined for each mud. Fluid loss is independent of polymer molecular weight at low ionic strength. The high shear viscosity of muds and polymer solutions is related to the product of the intrinsic viscosity of the polymer and its concentration.
A Cement Channel-Detection Technique Using the Pulsed-Neutron Log
Authors: Blount C. G. , Copoulos A. E. , Myers G. D.
Published: December 2007

A channel-detection technique has been developed using boron solutions and pulsed-neutron logging (PNL) tools. This technique relies on the extremely high-neutron-absorption cross section that boron exhibits relative to other common elements, including chlorine. The PNL tool is used to detect movement of a boron solution in a log-inject-log procedure.

The technique has identified channels in such difficult applications as logging through two strings of pipe and in highly deviated wellbores. Logging procedures are simple and cement channels can be readily identified. The boron solutions are relatively inexpensive, safe to handle, and nonradioactive. Additional PNL information for reservoir performance evaluation is collected simultaneously during channel-detection logging. This paper describes the theory, development, field application, and limitations of this channel-detection logging technique.
Flow and Displacement of Bingham Non-Newtonian Fluids in Porous Media
Authors: Wu Y-S. , Pruess Karsten , Witherspoon P. A.
Published: December 2007

This work presents a theoretical study of the flow and displacement of a Bingham fluid in porous media. An integral method of analyzing the single-phase flow of this type of fluid is developed. The accuracy of a newly developed approximate analytical solution for transient-flow problems is confirmed by comparison with numerical solutions. The flow behavior of a slightly compressible Bingham fluid is discussed, and a new well-test-analysis method is developed by use of the integral solution. To obtain some understanding of the physics of immiscible displacement with Bingham fluids, a Buckley-Leverett analytical solution with a practical graphic evaluation method was developed and applied to the problem of displacing a Bingham fluid with water. Results revealed that the saturation profile and displacement efficiency are controlled not only by the relative permeabilities, as in the case of Newtonian fluids, but also by the inherent complexities of Bingham non-Newtonian behavior. In particular, we found that in the displacement process with a Bingham fluid, a limiting maximum saturation exists beyond which no further displacement can be achieved.
The Ressslation Between Wellblock and Wellbore Pressures in Numerical Simulation of Horizontal Wells
Authors: Babu D. K. , Odeh A. S. , Al-Khalifa A. J. , McCann R. C.
Published: December 2007

An analytical equation for calculating the effective radius, r0, in a wellblock is derived. The radius r0 is needed to relate wellblock pressure to well pressure. The equation is general and valid for vertical and horizontal wells and for any well location, aspect ratio of the well's drainage area, and anisotropy. The equation is used to show when Peaceman's formulations are adequate and when they require modification. Generally, if the drainage area of the well is a rectangle with sides of large aspect ratio and/or the formation is highly anisotropic, Peaceman's equations need modifications. Simplified forms of the equation applicable to special cases are reported. Furthermore, an easy-to-use approximate equation for calculating r0 values for nearly centered horizontal wells is given. The formulas of this work, as well as those of Peaceman, are relevant only to simulations on uniform grids in homogeneous media.
Drilling and Completion Computerized Information System: PINFOR
Authors: Courteille J-M. , Boutrolle P.
Published: December 2007

This paper discusses PINFOR, a computerized information system whose goals are to have a modern data base to store drilling and completion information, to provide good and accurate statistics and performance indicators, and to help drilling and completion engineers prepare and overview operations by providing anywhere and at anytime accurate information in the form of pre-established reports, simple consultation, or specific requests through the data base. The system is installed on several HP-9000 workstations, from the rig site to the operational base, linked together with telecommunications. Tested on a French field in 1989, it is now in the process of being extended to all other subsidiaries of Elf Aquitaine worldwide.
Cooperative Processing: A Team Approach
Authors: Howard S. T. , Mangham H. D. , Skruch B. R.
Published: December 2007

PRISM (PRoducing Information System for Mobil E&P U.S.) is a production-and drilling-information collection and retrieval system with a centralized data-storage facility that uses both PC’s and mainframes. The system uses cooperative processing through PC programs that enter and extract data that reside on a mainframe. The mainframe and PC’s work together as a team, cooperatively processing the data input to and output from the system. This team concept provides the capability to maximize the best features of both types of computers, providing the user with a very powerful, yet extremely simple, system. This system has been developed on multiple platforms, including the IBM PC, IBM mainframes, and the Apple Macintosh. The PC’s are used to display the input and output screens and reports to the user. The application is written with Microsoft Windows™ on the IBM PC and the same type of graphical interface native to the Macintosh. The PC programs interactively transmit the data to and from the mainframe DB2 data base. The users interact with a program that appears to exist entirely on their own PC’s. The system was developed with the same type of cooperative philosophy exhibited in the system itself. The development team consisted of engineers, geologists, accountants, field supervisors, computer professionals, and other client representatives. This team approach included a major commitment of the client sponsors, who assigned full-time staff members to work on the project from start to finish. The project team could use the best characteristics and experience of each team member to develop a system to meet the ever-increasing informational needs of the user community.
Production Computing Management
Authors: Mason D. H. , Wiesenthal J. A.
Published: December 2007

Exxon Co. Inti. (ECI) was formed in July 1986 to handle Exxon’s oil and gas operations outside the U.S. and Canada. One part of this responsibility was coordination of the application and use of information systems technology, which required a significant amount of funds. To focus this coordination, development of an Upstream Computing Framework was initiated in 1988. This framework would serve as a management and planning guide for use in meeting the different requirements of the affiliated companies. The framework required 2 work-years of effort from a multidisciplinary team. The focus of this paper is the production portion of the framework, the implementation of which began in Jan. 1989.

This paper summarizes the Upstream Computing Framework and the results from its use to coordinate the development of production computing applications. Six key areas are addressed: (1) development of a set of core technical computing tools; (2) development of core computing and telecommunications hardware and software standards; (3) guidelines and principles for data resource management (DRM); (4) planning for the complexity that computer training places on an organization; (5) strategic application planning; and (6) assessing, capturing, and stewarding the benefits of production computing. The last two items are the most significant, and examples of their implementation and benefits are presented.
Maximizing "User Friendliness" in PC Engineering Programs
Authors: Zamora M. , Wilson D.
Published: December 2007

Few computer experiences are more frustrating than struggling with software that is not "user-friendly." This is especially true in the oil industry, where field personnel often are required to run complex engineering programs. In this paper, we discuss and demonstrate techniques that maximize user-friendliness in PC-based engineering programs. The guidelines provided are applicable to other technical and nontechnical areas.
A Hitchhiker’s Guide to Life on the Internet
Authors: Bishop K. A.
Published: December 2007

This paper provides a survey-level introduction to the Internet, the high-speed communications network that provides access to remote supercomputers, libraries, and other specialized information services. In addition to describing the physical and logical topology of the network, it describes the supercomputing and network-oriented visualization capabilities offered by one node on the Internet, the Natl. Center for Supercomputing Applications (NCSA). Engineering studies are used as vehicles throughout the paper.
Integrated Technical Computing of the 1990's
Authors: Brewer K. E. , Pritchard R. J.
Published: December 2007

The business environment of the 1990’s demands that the technical professional approach problems and opportunities in their global context. Recommendations must not only be based on technical analysis but must also consider the impact on the entire enterprise. Application of modern computing technology allows technical computing systems to facilitate and enhance this approach to problem solving. But future program development will require a different user/computer interaction architecture from today’s stand-alone application architecture. The object-driven environment, where the world is represented by objects, is a technical computing architecture that can support the technical professional in the 1990’s.
Reservoir Simulation With Simultaneous Graphic Display on the Macintosh II PC
Authors: Norris S. O. , Capps K. S.
Published: December 2007

This paper describes how a Macintosh II™ PC, which is usually thought of as a desk-top publishing system, can be used as an efficient tool for conducting reservoir simulation and evaluating the large amounts of data commonly generated by simulation runs. A unique feature is the machine’s ability to produce simultaneous graphics with minimal programming. This ability, which allows the engineer to "monitor" the simulation, is particularly useful in history matching.

Postprocessing can be accomplished with public-domain software that yield excellent graphical presentations. Color contour maps are easily created and can be statistically evaluated. Special options—such as cross-section profiles, edge detection, and reverse imaging—allow comprehensive interpretation of simulation data.
Generalized Computer-Assisted Operations: A Comprehensive System for Day-to-Day Oilfield Operations
Authors: Dunham C. L. , Anderson S. R.
Published: December 2007

Shell Oil Co. and a U.S. subsidiary, Shell Western E&P Inc., developed a comprehensive, generalized, computer-assisted-operations (CAO) system for day-to-day oilfield operations. The system addresses many of the daily operating needs of data acquisition, well and facility monitoring and control, problem detection and diagnosis, design and/or redesign of artificial-lift systems, and oilfield data management. It is generalized in that one system, with common computer hardware, software, and techniques, serves several different oil fields with diverse operating requirements and conditions.
Computer Imaging for the Electromagnetic Inspection of Oil-Country Tubular Goods
Authors: Lam C. C. , Kahil J. E.
Published: December 2007

A new imaging system has been developed for the nondestructive evaluation of oil-country tubular goods (OCTG). It consists of smallarea-resolution magnetic sensors, data acquisition, digital signal processing, and a computer for image processing and pattern recognition. The main output of the system is a map of the pipe showing defects at the proper locations and orientations. Information on signal amplitude and waveform is also displayed. The system thus provides, in addition to the traditional information on signal waveform, information on contiguity and geometrical distribution of defect signals. Detection performance is enhanced by taking full advantage of digital signal processing. Depending on inspection needs and custom requirements, various signal-processing algorithms can be substituted at will by just loading new signal-processing programs. This flexibility, combined with small sensors, allows simulation and simultaneous use of many conventional detector configurations. The system described is the first step toward fully automated intelligent systems. It automatically extracts from the display image the length and orientation of suspected defects to produce a prove-up summary that includes longitudinal and circumferential position. This summary can expedite and refine the process of verifying the defects detected by the electronic inspection.
Gas-Rise Velocities During Kicks
Authors: Johnson A. B. , White D. B.
Published: December 2007

Experiments to examine gas migration rates in drilling muds were performed in a 15-m [49-ft] -long, 200-mm [7.8-in.] -ID inclinable flow loop where air injection simulates gas entry during a kick. These tests were conducted using a xanthan gum (a common polymer used in drilling fluids) solution to simulate drilling muds as the liquid phase and air as the gas phase. This work represents a significant extension of existing correlations for gas/liquid flows in large pipe diameters with non-Newtonian fluids.

Bubbles rise faster in drilling muds than in water despite in the increased viscosity. This surprising result is caused by the change in the flow regime, with large slug-type bubbles forming at lower void fractions. The gas velocity is independent of void fraction, thus simplifying flow modeling. Results show that a gas influx will rise faster in a well than previously believed. This has major implica tions for kick simulation, with gas arriving at the surface earlier than would be expected and the gas outflow rate being higher than would have been predicted.

A model of the two-phase gas flow in drilling mud, including the results of this work, has been incorporated into the joint Schlum berger Cambridge Research (SCR)/BP Intl. kick model partly funded by the U.K. Dept. of Energy.
A Review of the Acoustic Determination of Liquid Levels in Gas Wells
Authors: Thomas Kent L.
Published: December 2007

In a recent article by Andsager and Knapp, a new method was presented foracoustically determining liquid levels in natural gas wells. The methodconsists of generating a sound wave at the wellhead, and measuring the timerequired for the wave to travel to the liquid level and back to the wellhead. The depth of the liquid level then can be obtained by integrating therelationship between velocity, distance and time.

(Equation 1)

The accurate determination of liquid levels by this technique is necessarilydependent upon one's ability to predict acoustic velocities of natural gas as afunction of both temperature and pressure.

Starting from the equation of the speed of sound in a compressible fluid,

(Equation 2)

Andsager and Knapp derived the following equation for a real gas.

(Equation 3)

When Eq. 3 was tested against 42 sets of experimental data, they found thatthe predicted values were too low. The ratio of the predicted to experimentalvelocity in each case was approximately equal to the square root of the gascompressibility factor.

(Equation 4)

In evaluating Eq. 3 during the integration of Eq. 1, Andsager and Knapp usedgas compressibility factors based on AGA data and specific heats from theEngineering Data Book. In using these specific heats to calculate K, theauthors were assuming K (T, p) to be independent of pressure since thespecific heats listed in this reference were evaluated at atmospheric pressure. It appears, therefore, that for the conditions of the experiments reported intheir paper

(Equation 5).

Data from Edmister for methane bears out the validity of Eq. 5 over thepressure range shown in Table 1.

Andsager and Knapp should be commended for providing an excellent workingequation for calculating acoustic velocities for the pressure range for whichEq. 5 is valid. Eq. 4, however, should be used with caution at high pressuresor in the neighborhood of the critical point of a gas since the approximationshown as Eq. 5 becomes invalid in these regions.
Estimating Three-Phase Fluid Saturations From Well Production and Relative Permeability Data
Authors: Diver C.J. , Earlougher R.C.
Published: December 2007

Fluid saturations around a well, producing oil, water and gas can be estimated if reliable production data and relative permeability data are available. For a given set of relative permeability data a single correlation, which is entered with the production data, suffices for determining the fluid saturation, as explained below.