bluuebunny/crossref_metadata_2025 huggingface dataset:
Benefits and Problems of Minifrac Applications in Coalbed Methane Wells
Authors: McDaniel B. W.
Published: December 2007

In conventional oil and gas reservoirs, the use of prefrac pump-in tests, in conjunction with analysis of the shut-in pressure response, has been a tremendous asset in Improving fracture stimulation designs. Since its introduction in 1979, many modifications and improved analysis techniques have evolved to increase the value of "minifrac" tests. In recent years, the popularity of completing wells in coal formations has led to the use of minifrac applications in these wells as operators attempt to better understand how coals respond to hydraulic fracturing. Although some operators have enjoyed success with minifracs, the usefulness of these types of prefrac tests has been limited as compared to applications in conventional gas reservoirs.

In fracture stimulation of coalbed methane wells, the use of minifrac tests and other pump-in tests has sometimes resulted in abnormally high injection pressures during the subsequent fracturing treatment. Many times the result has been an early screenout during the proppant placement. Some operators have abandoned the use of minifrac type pump-in tests for fear of creating pressure problems that would jeopardize the stimulation treatment.

In this paper, problems attributed to minifrac tests are described, along with explanations for many of these occurrences. Also included are successful applications of pump-in tests and a modification to improve fluid loss calculations. Recommended procedures to minimize the possibility of creating high Injection pressures are given. Field examples from the San Juan Basin, Piceance Basin, Black Warrior Basin and the Central Appalachian Basin are used to illustrate problems and support the recommended procedures presented.
Design Rules and Associated Spacer Properties for Optimal Mud Removal in Eccentric Annuli
Authors: Couturier M. , Guillot D. , Hendriks H. , Callet F.
Published: December 2007

Effective mud removal of drilling fluids from the wellbore is still a major problem in cementing. Although good pipe centralization has been known for years to be one of the keys to the success of the operation, most current design procedures do not allow pipe standoff to be taken into account.

When attempting to displace a mud in an eccentric annulus with a fluid thought to be in turbulent flow, it is shown that the displacing fluid can channel through the mud. An explanation for this phenomenon is given and a solution is proposed. When turbulent flow displacement cannot be achieved, displacement at lower rates has then to be considered and associated criteria leading then to improved mud removal efficiency are also discussed.

These displacement guidelines, as well as other more general considerations, show the need for spacers having well controlled engineering properties: compatibility, rheology, ability to suspend weighting agent, fluid loss. Examples of such spacers are presented and the properties of laboratory and field prepared samples are compared.1
Environmentally Safe Temporary Clay Stabilizer for Use in Well Service Fluids
Authors: Himes Ronald E. , Parker Mark A. , Schmeizl Eric G.
Published: December 2007

The use of salts, such as potassium chloride (KCl) and sodium chloride (NaCl), as temporary clay stabilizers during oil well drilling, completions and servicing has been in practice for many years. Their effectiveness in this practice has been well established throughout the industry. However, because of the bulk and potential environmental hazards associated with the salts, many operators have begun to search out alternatives to their use.

Recent research has developed a relationship between physical properties of various cations (K+, Na+, etc.) and their efficiency as temporary clay stabilizers. These physical properties were then utilized to synthesize an organic cation with a higher efficiency as a clay stabilizer than the typical salts now used in the oil industry. This allows much lower salt concentrations to be used to obtain the same clay stabilizing effectiveness. The liquid product has proven to be much easier to handle and transport. It has been shown to be environmentally compatible and is biodegradable in its diluted form. Its effectiveness in fracturing operations has been extensively proven in numerous treatments in various formations throughout the U.S. and Canada.
Application of Rock Stress in Hydraulic Stimulation
Authors: Brevetti J. C. , Donaldson E. C.
Published: December 2007

Using a computer solution of the equilibrium fracture height model, fracture height growth out of the treated zone is simulated by comparison of the closure stress of the upper and lower boundaries with the closure stress of the pay zone.

Results from this model are compared to actual achieved fracture height measured from after-frac surveys on a diverse group of oil and gas wells. Pressure data are analyzed on a selected number of wells to demonstrate the effect of varying pore pressure on the model.

Utilizing this data, correlations between log-derived rock stress and fracture height growth are developed which will allow accurate prediction of total fracture height and containment pressures.
Economic Optimization of Fracture Stimulations Using Mixed Integer-Linear Programming
Authors: Thompson R. R. , Blumer D. J.
Published: December 2007

Determining an optimal fracture design can be a complex process, involving large amounts of computer and engineering time. This paper describes a method that utilizes mixed integer-linear programming to adjust a treatment's fluid selection, pump rate, proppant volume, and frac dimensions to arrive at an optimal design. This method can be readily adapted to most any fracture design model.

The optimization method presented in this paper has shown to be able to design less expensive fractures for a given stimulation ratio in less time than a trial and error approach. In the examples presented, variable stimulation costs (proppant, fluid, and hydraulic horsepower charges) were reduced by 50% compared to trial-and-error-derived designs.
An Analysis of Gravity-Dominated, Immiscible Flows in Dipping Reservoirs
Authors: Walsh M. P. , Moon G. M.
Published: December 2007

This work presents a fractional flow theory analysis of gravity-dominated, immiscible displacement in porous media. This effort represents the first to extend Buckley-Leverett theory to account for the effects of countercurrent flow while fluid injection and production is ongoing. The driving force for countercurrent flow is gravity, phase density differences, and a non-horizontal flow dimension. Our analysis is limited by the usual fractional flow theory assumptions, most importantly one-dimensional flow. Countercurrent flows are possible if the ratio of gravity to viscous forces forces is sufficiently large. Our analysis characterizes the gravity to viscous force ratio by a dimensionless Gravity Number. Our effort yields a more general and unified theory of immiscible displacement. We present new graphical solution methods to predict displacement performance for arbitrary initial and injected conditions.
Field Applications of Interwell Tracers for Reservoir Characterization of Enhanced Oil Recovery Pilot Areas
Authors: Lichtenberger G. J.
Published: December 2007

This paper presents the results of interwell tracer field work carried out in the McClesky sandstone in conjunction with a surfactant polymer flood pilot, a Dundee limestone pilot designated for an in-depth permeability modification treatment, and a Potter sand steam drive pilot. The objectives were to delineate fluid migration in the reservoirs and to compare tracer performance by co-injection. SCN was the best tracer in the sandstone with recoveries above 90%. In both the McCleskey and the Dundee, tritiated water recoveries were above 75%, with evidence of tritium – hydrogen exchange. Co57 and Co60 recoveries ranged from 35 to 55%. Tertiary butanol recoveries were near 75%, while about 50% of the injected isopropanol was recovered. The performance of ethanol, methanol and methyl ethyl ketone in the Dundee was similar to that of isopropanol. Residual oil saturations in the waterflood areas were measured using interwell tracers. The above alcohols and ionic salt tracers were used in the steam flood as vapor and water tracers, respectively. Strong signatures were observed for the alcohols, but the ionic tracer signatures were erratic.
Fitting Type Curves to Austin Chalk Wells
Authors: Poston S. W. , Chen H. Y.
Published: December 2007

A geological model of a typical Austin Chalk fracture system has been constructed. The geological model is composed of a major and at least one minor fracture system dividing the rock matrix into small sized blocks. Type curves representing the expected producing characteristics for a reservoir possessing at least two different permeability fracture systems and a matrix block system have been developed. These curves represent a combination of flow through a major fracture system with infinite conductivity, linear flow through a set of lesser, subsidiary micro-fractures, and flow from the matrix block system. The mathematical model replicating these expected conditions and providing the foundation for the type curves is discussed.

A field case study of an Austin Chalk lease shows the utility of the new, dual fracture-matrix concept to determine the variation of productive capacity and the degree of connectivity of offsetting wells. The six wells penetrating the 640 acre lease appear to have encountered four different producing systems.
Oilwell Coning Control Using Dual Completion With Tailpipe Water Sink
Authors: Wojtanowicz A. K. , Xu Hui , Bassiouni Z.
Published: December 2007

The paper describes the results of a simulation study of a novel method to control water coning in an oil producing well. This method uses a dual completion configuration: above and below OWC. In this configuration, the well section above OWC is completed in the oil zone and produces oil, while the well section completed below OWC in the water-saturated zone serves as a drain to control the rise of the water cone (tailpipe water sink).

The physical principle of coning control in this method results from the effect of the water sink upon flow potential between the sink and oil-production perforations. The effect depends upon the water sink flowrate, and it results in suppression of water coning.

The objective of this study was to investigate production performance of the well with and without the water sink tailpipe. At first, the water sink's position and flowrate were investigated as they affected the critical production rate of oil, i.e. maximum production rate without the water breakthrough. Next, a comparison was made between the amounts of water produced for greater than critical oil production rates in these two systems.

The comparison tests were designed as a series of simulated oil production cycles in a well/reservoir system of known geometry and reservoir properties. The coning behavior of the production system with the tailpipe water sink was mathematically modelled using the flow potential distribution generated by two constant-terminal-rate sinks located between the two linear boundaries and the constant-pressure outer radial boundary. This new model was verified by using the existing and simulated data of water coning in conventional wells and by setting the water sink flowrate at zero, with oil being the only produced fluid. Verification tests were used to select the type of oil reservoir with the thick oil zone and the small dip angle for further comparison studies.

In these studies, the amount of produced water with and without the tail water sink was calculated for production rates exceeding the water breakthrough levels in conventional wells. Field data was compared to the results obtained from the water sink model.

The study demonstrated the existence of an active mechanism to control water coning with the tailpipe water sink. The mechanism is particularly effective with low flowrate at the sink because it prevents the water cone from breaking through the oil zone into the producing perforations. Also evaluated were the configurations of the well/reservoir system for the tailpipe water sink process. This process yielded less produced water than the conventional method did at the same or higher oil rate.
Evaluation of Underbalanced Through-Tubing Perforating and Closed Chamber Test Interpretation Techniques
Authors: Manohar M. M. , Morris C. W. , Brunner S. R. , Hill D. D.
Published: December 2007

Underbalanced, through-tubing perforating operations represent a compromise between the pressure differential needed for effective perforation cleanup and the differential that causes sand production or tends to the the gun and cable. This paper explores the dynamic variables involved in through-tubing perforating and describes a new model developed to evaluate the underbalance perforating conditions and predict the effects on the wireline gun system. Using this model, formations can be aggressively perforated with the optimum safe underbalance pressure, and completion operations can also be combined with closed chamber test techniques to accurately evaluate the completion efficiency and initial reservoir parameters.

Utilizing new wireline technology to measure downhole pressure and temperature during perforating, operational data were obtained from numerous field tests to validate the dynamic model. The results indicate that the model reliably predicts the maximum underbalance to avoid sanding, the change in gas cushion pressure, the volume of reservoir fluid influx and the gun/cable movement Examples from Louisiana Gulf Coast wells are used to illustrate the application of the design model and the associated closed chamber test technique.

The transient pressure data from the closed chamber test are used to accurately evaluate reservoir parameters and completion efficiency. The data are analyzed by assuming the formation is subjected to an impulse rate created by briefly flowing the well. In addition, by measuring the surface and bottomhole pressure during the perforating operation, the approximate fillup rate can be determined as well as the cumulative volume of fluid entry. In the field examples presented, these data are utilized in other interpretation techniques, such as rate convolved pressure analysis, and the derived formation parameters are compared with conventional well test results.
Compensation for Borehole Effects and Porosity Determination With the Thermal Multigate Decay Log
Authors: Wyatt D. F.
Published: December 2007

The determination of reservoir porosity through casing has become a vital concern as more old fields undergo detailed re-evaluation. Many times the prevailing situation is that there is no reliable porosity data and the well has tubing in place. In such cases, pulsed neutron capture (PNC) logs are often relied on for both formation porosity and capture cross-section information.

Environmental effects on the pulsed neutron count rate ratio curve can be quite large and can have a dramatic effect on porosity calculations. This paper discusses the empirical modeling of typical downhole conditions that affect the TMD* ratio log and introduces updated corrections that can be applied to compensate for them. Included in the modeling are effects due to varying borehole fluid salinity, casing and tubing diameter, and cement. A lithology dependent ratio-to-porosity transform makes this conversion more consistent with density, neutron and acoustic techniques. When wellbore conditions are known, these computations can be applied either real-time or post-log at the wellsite to allow immediate reservoir evaluation.

Both test formation and field log data are presented to demonstrate the accuracy and utility of the environmental corrections and porosity transform.
Sucker-Rod Pump Diagnosis With Fluid Inertia Considerations
Authors: Csaszar A. B. , Laine R. E. , Keating J. F. , Jennings J. W.
Published: December 2007

Existing state-of-the-art diagnostic models neglect fluid inertia. Sometimes fluid inertia distorts the shape of the pump card. This is important because the shape of the pump card is used to diagnose the operating condition of the sucker rod pump, and to effectively monitor and maintain rod pumped wells. This paper presents guidelines for predicting when fluid inertia is likely to cause pump card distortion. This paper then discusses the equations, boundary conditions, and solution method for calculating fluid inertia forces and removing them from a calculated pump card.
Dynamic Behavior of the Sucker Rod String in the Inclined Well
Authors: Lukasiewicz S. A.
Published: December 2007

The paper presents a model for predicting and analysing the behaviour of sucker rod pumping installations in the inclined wells. This model incorporates the dynamics of the curved sucker rod string, and the friction forces resulting from the contact of the rod with the tubing through a system of two partial differential equations. This system of equations is solved by the finite difference technique. The model predicts the polished rod and pump dynamometer cards and incorporates the effects of fluid inertia and viscosity. The model is capable of simulating a wide variety of pump conditons, and geometry of the rod string. The examples and comparisons with the results obtained using a program for vertical wells to analyse the deviated well are presented. The information predicted by the model is useful in the design and operation of sucker rod pumping installations.
Application of a Pattern-Matching Expert System to Sucker-Rod, Dynamometer-Card Pattern Recognition
Authors: Keating J. F. , Laine R. E. , Jennings J. W.
Published: December 2007

Two expert systems distinguish between acceptable and abnormal operations; both utilize an established pattern recognition algorithm. Surface dynamometer cards for individual wells are used to check for normal operation. Surface cards can also provide feedback to pumpoff controllers and to variable speed drives. Calculated pump dynamometer cards are used to diagnose malfunctioning wells. These expert programs improve productivity by focusing attention on malfunctioning wells. The analysis could be part of a centralized operation with remote data acquisition and an automatic daily computer printout identifying malfunctions by well. Library maintenance involves communication between the day-to-day users, the repair shop and the expert.
A Single-Trip, Dual-Zone Gravel Pack System Successfully Gravel Packs Green Canyon Area Wells, Gulf of Mexico
Authors: Brannon D. H. , Harrison D. T. , Van Sickle E. W.
Published: December 2007

A system was designed for the Green Canyon 52 A Platform (Marquette Project) to gravel pack close proximity, dual zones in a single trip. The use of this single trip system resulted in significant time and cost savings when compared to similar conventional dual gravel packs performed on this platform.

This paper describes the equipment, the benefits and limitations of the system, a comparison of operations and associated time between a conventional dual and a single trip dual gravel pack, and the specific well parameters and field results.
A Reeled-Tubing Downhole Jet Cleaning System
Authors: Fowler S. H.
Published: December 2007

Operators having wells with increased water production, water flood projects, and geothermal wells are experiencing downhole scale buildup problems that can be quite severe. Production can become choked off, and in extreme cases, complete plugging of the tubulars can occur.

A total system approach has been developed to remove scales without removing or damaging the production tubing and casing. This method involves the use of high-pressure, polymer-enhanced, submerged fluid jets combined with reeled tubing equipment. This efficient system has proven significant cost reductions can be achieved compared to existing scale removal techniques.
Successful Cementing of the Horizontal In-Situ Combustion GRI/DOE: Rocky Mountain No. 1 Coal Seam Project
Authors: Daulton D. J. , Wiercinski G. M.
Published: December 2007

The requisite of zonal isolation in a highly deviated, ultra-high temperature wellbore placed extraordinary technical demands on slurry design and cementing operations. This paper documents: (1) the project criteria, (2) proposed ultra high temperature and conventional cement slurries, (3) testing considerations, (4) quality control steps, and (5) operational procedures taken to successfully cement six wells. These wells were a critical part of an evaluation process involving two of the foremost in-situ coal gasification techniques.

The Rocky Mountain #1 project tested the Hanna #1 Coal Seam near Hanna, Wyoming. A 100 day controlled burn took place to gather data. This information would allow comparison of two combustion techniques. A water quality control program was implemented postburn in order to ensure non-contamination of the aquifer. The efficiency and effectiveness of the Controlled Retraction Injection Point (CRIP) module was compared with the Extended Link Well (ELW) module. A program was developed to drill and cement to surface three wells in each of the burn and production patterns. The ELW process would require two shallow vertical cased and cemented injection wells. These vertical wells would intersect a medium radius to horizontal cased and cemented production well. The CRIP process required three cased and cemented wells. Two of the wells, medium radius to horizontal, were designed for injection and production purposes. The third well was used for ignition of the CRIP and initiation of the in-situ combustion process.

Hydraulic isolation of all the wells was confirmed by a lack of uncontrolled by-products at the surface, controlled accountability of tracer elements during the burn and good pressure test of the casing shoe. The results of the successful cementing of both the horizontal and the vertical wells contributed to the precise monitoring and comparison of the in-situ burn patterns. In addition, restoration and maintenance of the quality of the aquifer could be recorded for future projects.
Process Control of Slurry Density: Impact on Field Performance of Slurry Density
Authors: Hitt R. J. , Sherwood R. M. , Nelson E. B. , Poyet G.
Published: December 2007

Before a cement job, cement system compositions are carefully designed in the laboratory at a given anticipated slurry density; however, during the job, significant density errors or fluctuations can occur, and the properties of the resulting cement system may differ dramatically from those observed in the laboratory. For this reason, the accuracy and precision of cement mixing in the field have been topics of concern for many years. In this paper, the design and operation of a newly developed computerized vortex cement mixing system, which provides excellent density control, is described. In addition, case histories are presented which demonstrate the accuracy and precision of the mixing system, and the successful transfer of laboratory cement system performance to the wellsite.
The Versatility of Silica Fume as an Oilwell Cement Admixture
Authors: Mueller D. T. , Dillenbeck R. L.
Published: December 2007

Micropozzolan spheres, condensed from the vapors of a metallic silicon/ferrosilicon liquid, possess multifunctional applications in oilwell cements. Commonly available and cost-effective, this amorphous substance imparts significant improvements in the physical and mechanical properties of Portland cements. The practical utility of silica fume as an admixture is primarily attributable to its particle size, chemical composition, and reactivity. Composed largely of silicon dioxide (SiO2), silica fume has an average particle diameter of 0.1 μm (100 times finer than cement or fly ash) and yields a surface area on the order of 20 m2/g.

When silica fume was added to cements or cement/fly ash mixtures, several beneficial effects were noted: (1) the water consumptive nature of silica fume allows it to function as an extender and a pozzolan substitute for lightweight cements; (2) high water adsorption combined with an increased pozzolanic reactivity promotes enhanced compressive strengths; (3) the purity and solubility of the material makes it suitable for combating strength retrogression in cements at temperatures above 230°F (110°C); (4) permeability and alkali content of the set product are reduced, both desirous properties in a carbon dioxide (CO2) environment.
Field Experiments With Automatic Casing Swabs
Authors: Haynes C. D. , Miller T. C.
Published: December 2007

This paper describes the development and field testing of an automatic casing swab in northeast Ohio. This swab, operating in Clinton sandstone wells to depths of 5000 feet (1523 m), demonstrated an ability to increase gas production, improve orifice meter chart configurations and reduce operating costs on existing wells. On new wells, its use in lieu of tubing plunger and beam pump-sucker rod pumping systems has resulted in lower capital cost and enhanced profitability.

Development of the swab tool is continuing, and results to date indicate this system ultimately will be used in many of the 2500 Beiden & Blake wells in the Appalachian Basin.
Reeled-Tubing Technology Accelerates Coalbed Methane Production In the Black Warrior Basin
Authors: Coats E. A. , Johnson K. J.
Published: December 2007

Reeled tubing technology has proven to be beneficial in solving both economical and production problems in the Coal Bed Methane (CBM) industry of the Black Warrior Basin near Tuscaloosa, Alabama. The primary benefit from using reeled tubing technology is one of economics. Operators can now prepare CBM wells for production quicker than was previously possible.

CBM completions must be cemented, the well bore cleaned and zones selectively stimulated. Reeled tubing technology can be used in cleaning cement residue from the casing ID and in cleaning frac sand, frac balls and perforating debris from the wellbore. Isolation bridge plugs can be retrieved and debris washed from the well. Five hundred wells have been cleaned of unwanted cement residue using high pressure submerged fluid jets and in excess of two thousand wireline-set retrievable bridge plugs have been retrieved using reeled tubing technology in the Black Warrior Basin.
Cost-Effective Completion Design for Offshore Oil Wells in Nigeria
Authors: Murphy S. S. , Nwankwo A. S.
Published: December 2007

Oil companies have been forced to become more efficient and try new ideas to remain competitive in today's economic environment. This involves re-evaluating the cost effectiveness of tubing and downhole equipment designs and trying innovative ideas that have potential for significant cost savings.

This paper tells how Mobil Producing Nigeria (MPN), operator of the Joint Venture between MPN and the Nigerian National Petroleum Corporation (NNPC), reduced completion costs as a result of efficient tubing design. Tubing and thread design are discussed in detail and statistical tubing data is presented to show the need for thread standardization. Gravel pack and other downhole equipment designs are discussed in detail with case histories presented. Emphasis is placed on elimination of unnecessary downhole equipment and considerations for future fishing operations.

This paper also discusses in detail innovative ideas that reduced workover and completion costs during the last 24 months. These include:

A plugback completion design within the same reservoir that allowed the lower part of the interval to be isolated when cased hole logs were questionable. Innovative use of a joint of tubing to retrieve lost washpipe. A gravel packed open hole completion through a milled window in an inadvertently sidetracked hole. The milled window was the original completion interval prior to the workover. Innovative use of the cementing unit to free a stuck gravel pack crossover tool.
Project Management for Small Projects: A Case Study
Authors: Will M. R. , Stewart D. C.
Published: December 2007

Those principles and techniques referred to as "Project Management" have recently been applied to small oil and gas construction projects and the results have been observed in the efficiency with which such projects are completed. This paper describes such techniques and utilizes a case study to illustrate the effectiveness of the approach.
Rate Behavior of Composite Dual-Porosity Reservoirs
Authors: Olarewaju J. S. , Lee W. J.
Published: December 2007

The main objective of this paper is to present a mathematical model of vugular or naturally fractured reservoirs with a radial discontinuity around the wellbore. This type of reservoir configuration is encountered in wells that are damaged, acidized, gravel-packed, or stimulated by cyclic steam soaking. This model is useful in predicting production performance or analyzing production data from these types of well-reservoir systems.
Small-Volume Sampling Technique Brings Economy and Efficiency to Well Testing Operations
Authors: Schultz R. L. , Breaux M. J.
Published: December 2007

A Small Volume Sampling Technique (SVST) allows operators to perforate, record temperature and pressure, and collect a formation sample prior to or in lieu of a well test efficiently and economically. Using this method, formations can be tested on a preliminary basis without the logistical burden of a comprehensive well test. Because of its economy, the SVST can also be used to test zones that were bypassed in older wells when expected production was not considered worth the expense of a comprehensive well test. The test apparatus is run in on drill pipe or tubing. Test procedure consists of perforation (usually about a 2 ft. interval)collection of a preliminary sample to allow formation cleanupcollection of a second sample (one to two barrels) in a chamber that also houses quartz-based electronic temperature and pressure recorders and small PVT samplers.

Collection of two samples also yields valuable drawdown and pressure buildup data from two flow periods and two closed-in periods. After the tool is retrieved to the surface, an approximate liquid-gas ratio and water cut can be determined while the sample is drained. PVT analysis is then performed in the lab on samples taken by the small PVT samplers.
A Management Planning Tool for Optimizing Use of Manpower and Equipment Resources
Authors: Welsch James W. , Hobbs N.M. , Alanis Rene E.
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

This paper was prepared for the 43rd Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, Tex., Sept. 29-Oct. 2, 1968. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

An application of the computer as a management tool to aid in optimizing manpower and equipment resources is presented. The computer is used in the coordination of a large number of periodically recurring job functions to assemble, process and compile the various functions on the basis of priority, timing, accounting function, manpower and skill type requirements.

In the application described the computer is used to store, and retrieve pertinent information relative to the testing needs of several thousand gas wells. A properly designed computer system provides managers with ready accessability to tailored test schedules for each well. This allows periodic review of the demands on personnel and equipment with minimum effort. The ability to retrieve current information in several ways permits flexibility in analyzing changing situations. The application of the computer to this and similar problems also aids managers to satisfy work requirements in a timely manner.

Introduction

One of a managers primary functions is to efficiently coordinate manpower and equipment resources under his supervision. The problems associated with this management responsibility are compounded when the resources are spread over large geographical areas and engaged in a multitude of different activities.

This paper presents an application of the electronic computer as a management tool. The application discussed involves the coordination of well testing activities on sever thousand gas wells annually. The large number of wells, at various sages of depletion, and the resulting variations in testing needs create a multitude of activities which must be coordinated. To efficiently coordinate such a large number of activities manually is impossible. The computer, however, affords a tool with which a manager can rapidly assemble and compile the required job functions to aid him in discharging his responsibilities in a more prudent manner.
The Use of Acrolein as a Hydrogen Sulfide Scavenger in Multiphase Production
Authors: Howell J. J. , Ward M. B.
Published: December 2007

The efficient reduction and removal of hydrogen sulfide (H2S) from produced fluids is an important technology that can have great impact on oil and gas operations. Hydrogen Sulfide is increasing in many production streams as water content rises. Not only can the export of gas be halted if H2S reaches too high a level, but employee safety and the environment are also influenced by rising H2S concentrations. In colder climates such as Alaska, facilities are predominantly enclosed which necessitates careful monitoring of H2S to maximize personnel safety. Burning of produced gas as fuel creates sulfur dioxide which is under strictly enforced limits. One of the more operationally attractive ways of minimizing H2S is via the addition of chemical scavengers directly to production containing oil, water, and gas. Acrolein (2-propenal) is evaluated in this manner on the North Slope. Although the sulfide scavenging ability of acrolein is well known to some production companies, this product has not been previously evaluated in North Slope operations. The results from a field test indicate that acrolein scavenges H2S rapidly at a low treating ratio. Approximately 65% of the total H2S was removed in less than two minutes from the production stream of one producing well making water, oil and gas, at a 1:1 molar ratio of acrolein:H2S. From the same wellhead injection point, it is further demonstrated that additional downstream production entering the pipeline system can be effectively treated. Reaction byproducts are completely soluble and stable, there are no stream upsets, and no acrolein residuals are detected downstream.
Evaluation of Paraffin Deposition Potential Using Drillstem Test Fluids
Authors: Santamaria M. M. , Roberts R. B. , Gill S. K. J.
Published: December 2007

A laboratory study was conducted to determine the potential for paraffin deposition for three oils from offshore Angola discovery fields using drill stem test fluids. Additional tests were conducted to select an effective paraffin inhibitor and determine the appropriate chemical dosage.

Using the test results, the engineering design group planned for storage and injection of the chemical and pigging for the flowlines and pipelines.

The proposed paraffin control measures were implemented as the fields were brought on production. Coordination and planning by personnel from drilling, producing, engineering and the laboratory allowed implementation of an effective paraffin control program from the start-up of production.
Increased Breaker Concentration in Fracturing Fluids Results in Improved Gas Well Performance
Authors: Elbel J. , Gulbis J. , King M. T. , Maniere J.
Published: December 2007

Conductivity damage resulting from fracturing fluids has been frequently observed in laboratory tests and is often indicated by production results. Abnormally high breaker concentrations were used in a number of fracturing treatments of gas reservoirs in attempts to minimize proppant conductivity damage and improve well performance. Concentrations of breaker of up to 10 lb/1,000 gal (three to five times the normal concentration) were added to fluids without causing premature loss of viscosity. These concentrations were made possible by encapsulating the breaker with a water-barrier coating and properly scheduling the breaker addition. The breaker addition schedule was optimized to account for the increasing polymer concentrations due to fluid loss as well as the fluid exposure time at the maximum temperature.

Improved well performance has been seen when using higher than normal breaker concentrations. The improved performance includes higher production rates. It can be shown that all of these results can be attributed to higher fracture conductivity because of the reduction of proppant conductivity damage.
Design Considerations for Fracturing Job Sizing of Low-Permeability Gas Reservoirs of the Arkoma Basin
Authors: Robbins R. E. , Chen Shixin , Lemp S. P.
Published: December 2007

Since no other single expenditure has a greater impact on a tight reservoir's profitability than a hydraulic fracture treatment, optimal job size selection is imperative. However, the actual reservoir deliverability improvement is usually quite different from the forecasted results. Poor fracturing results are primarily attributed to poor reservoir characterization and reduction of the in-situ fracture conductivity over the laboratory estimates. To estimate in-situ fracture conductivity, and subsequently enhance the fracturing job design, a historical correlation between job size and wellbore improvement was established. This correlation was based on the post-fracture evaluation of 70 wells in the Arkoma basin.

Matching our data with McGuire and Sikora's solution, the retained fracture conductivity ranged from 20% to 50% of laboratory estimates depending on the aggressiveness of proppant placement. The influence of a different thickness in propped height and net pay height was factored into the optimal job sizing process. When modified for this difference, the PKN modeled FCD was consistent with our field observation for low FCD treatments. A field estimate of the optimal job size was also developed from the historical correlation using a marginal benefit and marginal cost model. Ease of application and historical accuracy are the two major strengths of this approach.

Greater cost effectiveness was achieved when these design considerations were incorporated into the field practice in the Arkoma basin. Since this study surveyed the diverse reservoirs and depositional environments within the Pennsylvanian age, we feel the approach will be applicable in similar areas.
Ambient Air Quality Impacts of Natural Gas Compressor Stations
Authors: Ramsey S. H. , Roger P. L.
Published: December 2007

Several hypothetical situations are presented analyzing the impacts which stack design can have upon ambient air quality concentrations due to nitrogen oxides emissions from natural gas compressor stations. Results show that relatively small changes in stack height, stack location, and stack orientation (for multiple source facilities) can dramatically affect air quality impacts.
A Generic Hand-Held Terminal for Production Data Acquisition
Authors: Moore R. D. , Dennison J. A. , Greenhill K. L. , Sisk L. B.
Published: December 2007

Over the past several years, the development of hand-held data terminal systems has improved the efficiency of production data collection. However, many of the early systems were designed for specific applications or areas and were not sufficiently generic to be used in all domestic operations without additional time and expense for code changes. Also, in some cases the early systems were not capable of collecting the full range of data necessary in all locations, i.e., data from different well types, different well testing methods, various types of compressors, various chemical injection procedures, etc. A system has been developed that provides the needed flexibility to handle the majority of data types required in any location without changes in the program code.

The system is a comprehensive production data acquisition and reporting system that provides a fast, accurate, and accessible information source. The production data is collected by the lease operator using a hand-held computer terminal, which has been customized for his route from menu screens on the personal computer. The hand-held terminal displays the previous day's data as it prompts the lease operator to enter the new data. After the lease operator completes his rounds, the hand-held terminal is connected to a personal computer in the field office, and the data is moved into a database system on the PC. The data in the database can be checked and edited if necessary, and daily, weekly, and monthly field reports can be generated as needed. The data is transferred to the area office overnight for managerial reports. It is then transferred to the mainframe for use in production allocation and reporting to state agencies.

Software development cost is a significant investment in a system of this type. However, the flexibility of this system has enabled it to be deployed throughout domestic operations and has significantly reduced the cost to each location.
A Study of the Effect of Condensate Formation on Performance Predictions in a Gas Pipeline Network
Authors: Mucharam L. , Adewumi M. A.
Published: December 2007

A unified model is presented for describing both single-phase and two-phase flow in complex gas pipeline networks. The form of the model is such that it can easily admit any energy-loss model that is expressible in a particular non-linear functional form of energy loss-flow rate relationship. Four popular single-phase gas pipeline design equations, namely, Darcy-Weishbach, Panhandle-A, Panhandle-B and Weymouth equations and a two-phase flow equation (Beggs-Brill) are used to test the development. All these tests are successful. A viable algorithm for solving the resulting equations is presented. Four field cases are analyzed using this model. Results show that Weymouth equation underpredicts pressure distribution for single-phase gas flow but predicts comparable pressure distribution to Beggs-Brill's two-phase model for two-phase flow in the network. The results further demonstrate significant effect of the presence of condensate on network performance.
Multiphase Long-Distance Pipeline Transportation: An Emerging Technology for Offshore Production
Authors: Rai R. , Sharma P. K. , Mukerjie R. K.
Published: December 2007

Multiphase flow is widely encountered in the petroleum industry. It is expected that a significant part of the future production of oil and gas in Offshore will come from deeper water and in many cases from marginal fields. Rigid fixed platform system with production and processing facuity located in the same field may not be economical in such cases.

Many oil companies are investing heavily to develop multiphase technology, with the ultimate goal to transport unprocessed multiphase well fluid for a long distance. Initial efforts for development of multiphase pumping and metering have been successful. The R&D backup for flow modelling is being provided by the research centres.

In the present study, a review of present state of multiphase long distance transportation, multiphase pumping, metering and flow modelling have been presented. The case histories of long distance multiphase flow from Indian Onshore and Offshore fields have been presented. Pour new field developments with multiphase well fluid transportation have been presented which are currently under execution.
The Forces Created in Wellhead Equipment During Blowdown After a Nitrogen Foam Fracture Operation
Authors: Hand K. L. , Lyons W. C.
Published: December 2007

The reaction forces in wellhead equipment due to the flow-back of nitrogen foam fracture fluids are analyzed. The forces in the flow-back lines are analyzed for both unchoked and choked lines. The reaction forces are found to be excessive and uncontrollable for unchoked lines with normal field equipment and procedures. The reaction forces in choked flow-back lines are controllable and a safe choke size can be determined for the anticipated wellhead pressure. A new technique for controlling blowdown operations is discussed and preliminary designs for equipment to be used in applying such a technique are given.
A New, High-Strength and High-Corrosion-Resistant Titanium Alloy for Oilwell Use
Authors: Okada M. , Kuroda A. , Kitayama S. , Shida Y. , Ueda M. , Kudo T. , Nagashima K. , Ueda H.
Published: December 2007

A new corrosion resistant, high strength and economical titanium alloy has been developed. This alloy is based on T1-6A1-4V with small Pd and Ni additions. This new titanium alloy tubes showed higher strength and toughness balance compared with the conventional titanium alloys through the Ni addition and the fine bi-modal microstructure. Corrosion resistance of this new alloy has been significantly improved by the addition of small amount of Pd, showing a surprising superior corrosion resistance to conventional alloys in severe conditions including hostile sour environments. Pd addition of this alloy is about 0.05%, which is smaller than that of corrosion resistant Ti-0.15%Pd alloy. Thus, this new alloy may have significant merits to conventional materials as Ni base high alloys, ie. light weight, high strength and superb corrosion resistance.

In this paper, comparison of various properties between the new alloy and conventional alloys including titanium and nickel base alloys were presented. The result of pipe and tube performance of this alloy was also presented.
Performance of a Peripheral Waterflood Project in the Main Body ‘B’ Reservoirs (Stevens) at the Elk Hills Oil Field, California
Authors: Ezekwe N. , Smith S. , Wilson M. , Humphrey M. , Murphy J.
Published: December 2007

The peripheral waterflood in the Main Body ‘B’ Reservoir located in the Elk Hills Oilfield, Kern County, California, is mature with remaining reserves estimated at 122 MMBO from initial reserves of 212 MMBO.

Pressure maintenance early in the life of the reservoir improved oil recovery. Recent performance data indicate that the MBB Reservoir is layered and has potential for bypassed reserves.

Future geologic, reservoir and production activities will be dominated by defining, correlating and managing the reservoir by layers.
Design and Implementation of the First Arctic Offshore Waterflood, Endicott Field, Alaska
Authors: Adamson G. R. , Hellman H. L. , Metzger R. R.
Published: December 2007

The Endicott Field is the first Arctic offshore producing oil field. Early reservoir studies showed that optimum recovery would require start-up of waterflooding within the first two years of production. This paper describes the engineering and geological work done to implement and optimize the Endicott Field waterflood.

The reservoir at Endicott Field is contained within the Mississippian Kekiktuk Formation. These multistory fluvial sandstones are characterized by wide variations in rock properties. Thick areally extensive shales combined with sealing intra-reservoir faults, serve to subdivide the field into seven distinct reservoir management sub-zones.

The design and implementation of this waterflood project extensively used simulation studies. These studies showed that waterflooding would nearly double the recovery and there were significant benefits for returning the field to original pressure. Simulation models optimized both the number and placement of production and injection wells.

The first production facility sealift included waterflood facilities. This enabled a pilot program to be implemented within five months after production start-up to shake down facilities, determine well injectivity and obtain early waterflood performance data.