bluuebunny/crossref_metadata_2025 huggingface dataset:
Discounted Profit per Barrel: A Comprehensive Valuation Criterion for Everyone
Authors: Randall B. L.
Published: December 2007

Economic evaluators of petroleum industry projects have long sought after a single, comprehensive valuation criterion by which investment opportunities could be properly screened and ranked. Recently, Seba has advocated, as captioned in his paper's title, that the present value ratio (or discounted profit to investment ratio, DPR) is " The Only Investment Selection Criteria You Will Ever Need". Many would agree that because DPR is a measure of both the magnitude and the time-distribution of the return, and because DPR can be computed using a discount rate reflecting the appropriate cost of funds or average opportunity rate, it is singularly the most comprehensive valuation criterion available.

However, the screening and ranking of competing investment projects on the basis of DPR is, in fact, a comparison that utilizes a per-dollar-of-investment-capital basis. Though this is certainly not incorrect, it is not always preferred. Often, it is desired instead to compare investment opportunities on a per-unit-of-product basis. Industry managers, particularly, seem to invariably pose questions regarding acquisition cost per barrel or finding cost per barrel.

This paper defines a new valuation criteria, Discounted Profit Per Barrel (DPB), that is shown to be as comprehensive as DPR, while maintaining a per-unit-of-product basis. It is demonstrated that DPB will always be directly proportional to DPR, yet will always have a ranking behavior that is unique. In addition, it will be shown that utilizing DPB instead of DPR at lower discounting rates can prevent duplicity in the economic analysis.
A Geologic and Coalbed Methane Resource Analysis of the Menefee Formation in the San Juan Basin, Southwestern Colorado and Northwestern New Mexico
Authors: Crist T. E. , Boyer C. M. , Kelso B. S.
Published: December 2007

The Menefee Formation of the Upper Cretaceous Mesaverde Group in the San Juan Basin of Colorado and New Mexico contains abundant coal beds with a substantial coalbed methane resource. Stratigraphically lower than the actively targeted coal beds of the Fruitland Formation, the Menefee Formation coal beds have until recently been overlooked as a potential gas production zone. The total coal resource of the Menefee Formation, including determination of coal rank and coal bed thickness variability, was estimated using extensive subsurface geologic data. Estimates of coal gas content were extrapolated for the Menefee Formation coal beds from a previous study of the overlying Fruitland Formation coal beds. The combination of coal resource and gas content information resulted in a preliminary in-place coalbed methane resource estimate of 38 trillion cubic feet of gas contained in 145 billion tons of coal. As part of the development of the gas in-place estimates, regional cross-sections and isopach, structure and coal quality (rank) maps were produced which illustrate the regional nature and variability of the Menefee Formation coal beds in the San Juan Basin. Because of the variable thickness of the Menefee Formation and the lenticular nature of the contained coal beds, this study delineated regional areas where the potential for the development of the coalbed methane resource is more favorable. Having identified a potential area, an in-depth geologic and reservoir evaluation on a much smaller scale would be required prior to production drilling.
Coalbed Methane Resource Evaluation From Wireline Logs in the Northeastern San Juan Basin: A Case Study
Authors: Mullen M. J.
Published: December 2007

Methane produced from coalbeds is a developing reservoir in the San Juan basin of Colorado and New Mexico. Most of the evaluation of this resource is being done by coring and testing. A cost-effective method to evaluate untested coalbeds would include using wireline logs already run through the coalbeds to assist in the evaluation process. Core analysis and production tests are essential information to use with log analysis to make meaningful evaluations from wireline logs.

This study examines 17 wells drilled in the northeastern part of the San Juan basin. These wells were drilled to produce gas from the Pictured Cliff sandstone, with the Fruitland Coal as a secondary pay zone. The objective of this study was to determine the resource potential of the Fruitland coalbeds using the available log, core and production data. The proximate analysis data from a well in which a coal core was cut was used to calibrate the log analysis in the study area. Measured gas content data was used to calibrate the algorithm which calculated gas content from wireline data. Net coal thickness, igneous intrusive thickness, productivity potential, coal tonage per acre, average gas content and gas content per acre are the results of this study. They are contoured to highlight the most probable area in the township to pursue coalbed methane development.
Understanding the Effect of Natural Fractures on the Hydrofracture Stimulation of Gas Reservoirs
Authors: Heuze F. E. , Shaffer R. J. , Blair S. C. , Thorpe R. K.
Published: December 2007

A finite element model for propagation of discrete fractures has been coupled to an implicit time-dependent fluid flow capability to be used as a predictive tool for hydraulic fracturing through sandstone lenses, as found in the Western Tight Gas Sands. Validation of the model is obtained by simulating controlled physical experiments. Our numerical model, FEFFLAP, was used to replicate the extension of a single-wing crack, driven through gypsum cement into a sandstone lens. Pressure-time records from the model and the experiments compare favorably.
Modeling of Fracture Propagation in Layered Reservoirs
Authors: Settari A. , Wong S. K.
Published: December 2007

The paper describes a new practical method of calculating dynamic fracture growth in multilayered reservoirs. The method predicts growth rate with time for a situation with two shale layers on each side of the centre (reservoir) layer. The static (equilibrium height) results are obtained as a limiting case at large times. Based on the numerical solutions, a correlation was developed which is computationally very efficient and can be implemented in any pseudo-3-D fracture simulator.

The examples of simulated fracture growth show the importance of even small barriers for temporary containment of fractures and the importance of the dynamic pressure effects as opposed to an equilibrium height model.
Technology Advances Unlock the Potential of the Tight Frontier Formation in the Moxa Arch
Authors: Haas M. R. , McFall K. S. , Coates J-M. P.
Published: December 2007

Despite difficult reservoir settings, low wellhead prices, and limited markets for currently undedicated gas in the Rocky Mountains, the Frontier formation in the Greater Green River Basin has the potential to contribute significant new low cost gas reserves.

The Upper Cretaceous Frontier is predominantly tight and contains substantial volumes of gas. The Federal Energy Regulatory Commission (FERC) has designated over 2,700 square miles of the Frontier formation in the Greater Green River basin as tight and eligible for economic incentives.1 The United States Geological Survey (USGS) estimates that the Green River Frontier/Dakota Formations contain between 220 and 490 Tcf of tight gas in place.2 Recent improvements in formation evaluation and stimulation designs, and its location in the Moxa Arch at the gateway of a pending pipeline, make the low permeability Frontier formation a desirable near term source of gas for the growing cogeneration and thermal EOR markets in California.

Despite similar technical challenges faced in many other tight settings (e.g. inadequate formation evaluation techniques, inaccurate fracture diagnostics, and the difficulty in reliably designing and delivering effective fractures), over 175 tight Frontier wells were drilled between 1981 and 1987. While Frontier development activity has declined with the market generally in the past few years, the continued availability of economic incentives, improved stimulation techniques and the opening of new markets have further renewed operator interest in development. Finally, the Gas Research Institute (GRI) has selected the Frontier as a possible site for field-based, cooperative R&D to improve tight gas formation and stimulation technologies.

This paper characterizes the formation and describes the technical challenges and development strategies needed to add reserves. First, the paper describes the geologic setting and reservoir characteristics that control potential. Second, it outlines the evolution of stimulation and production practices in tight Frontier wells. Finally, it compares the potential of the Frontier under current technical and market conditions with estimates of future potential based on recent advances in formation evaluation and fracturing techniques.
The Role of Geology in Characterizing Low-Permeability Sandstones, North Appleby Field, East Texas Basin
Authors: Tye R. S. , Laubach S. E. , Dutton S. P. , Herrington K. L.
Published: December 2007

Geological knowledge of low-permeability (permeability <0.1 md) hydrocarbon-bearing sandstone reservoirs enhances exploration and exploitation strategies. Structural, stratigraphic, and petrographic analyses are required to interpret trap style, reservoir quality, and porosity and permeability distribution. Information compiled in such studies facilitates (1) the estimation of reservoir volume and drainage area, (2) the design of drilling and completion programs, (3) the location of development wells, and (4) the calibration of logs.

At North Appleby field, data from cored wells in the lower Travis Peak Formation have established a foundation for predictions about reservoir geometry, occurrence of natural fractures, and the degree and type of diagenesis that the reservoir has undergone. Only after integrating structural, stratigraphic, and petrographic data on the evolution of these low-permeability sandstones can relationships among sand-body geometry and orientation, diagenesis, and natural fractures be discerned. Broad, tabular reservoirs were deposited by braided- to meandering-fluvial systems. Reservoir seals and internal fluid-flow barriers consist of mudstones and porosity-occluding quartz cement. Pore types range from micropores to primary and secondary macropores. Vertical natural fractures are macropores that are oriented at approximately right angles to sandstone trends. Natural fractures are abundant in sandstone with very extensive quartz cement (>17%); in these rocks natural fractures should be considered in reservoir evaluations and hydraulic-fracture treatment design.

Geometry and quality of Travis Peak reservoirs vary with depositional environment and degree of diagenesis. Reservoirs at the top of the formation are thin and separated by mudstones; few natural fractures occur in these sandstones. Productive sandstones at the base of the formation, however, are thicker and more sand rich; these contain a greater percentage of quartz cement and are naturally fractured.
Viscosity Measurement Throughout Frac Job Gives Increased Gel Control During Continuous Mining
Authors: Harms W. M. , Curtice R.
Published: December 2007

Economic feasibility studies have shown the need for a low cost, efficient treatment design to make stimulation of the Mancos B formation near Rangely, Colorado practical and attractive. Design simulation indicated that tight control of base gel viscosity combined with a high, but achievable, rate of displacement was necessary. This would place a 40 lb linear gel system containing 73,000 lb proppant in the formation at a rate of 50 bbl/min.

Operational efficiency from the personnel and equipment involved could best be attained through use of a continuous-mix approach since job time was short and rig-up time and expense would be greater in a batch mix scheme.

When treating wells with low viscosity linear frac gels, real-time information about frac fluid viscosity is critical, especially when using continuous mix fluid systems to stimulate shallow formations. Pipe transit time is on the order of 30-45 seconds; therefore it was essential that the fluid had developed significant viscosity to effectively create a fracture of sufficient height and width to place proppant throughout the net pay zone.

A monitoring system consisting of a rheology skid, two viscometers, and data acquisition hardware has been combined with a stabilized polymer system (SPS) to deliver a controlled, continuously-mixed linear fluid system. Viscosity was measured at three critical points in the flow stream.

From this work it has been observed that laboratory measurements are comparable to those obtained using field equipment to mix job-sized volumes of fluid. This paper presents a comparison of the laboratory findings and field results. Also presented are design details of the setup, job designs, and a discussion of the continuous mix system.
The Effect of Guar and HPG Crosslinked Fracturing Fluids on Well Performance: A Case Study
Authors: Wine J. D. , DeBonis M. P. , Thomas R. L.
Published: December 2007

A case study comparing the performance of wells fractured with crosslinked guar and hydroxypropyl guar (HPG) is presented. Data indicates that for a given crosslinked system, guar and HPG polymers yield comparable proppant pack impairment and fracture conductivity. Detailed laboratory conductivity and well performance data are presented for both low and high temperature conditions.

Laboratory conductivity data is reported for proppant placed with guar and HPG crosslinked fracturing fluids under in-situ conditions. The effects of proppant embedment, the gel filter cake, and long-term exposure to reservoir temperature and closure stress were determined in this study. Additionally, the effect of crosslinker, breaker system, and polymer load on fracture conductivity is discussed in detail.

Subsequent to laboratory testing, numerous fracture design and production simulations were performed to determine the effect of guar and HPG crosslinked fluids on well performance. The data indicates the forecasted cumulative production of wells fractured with guar and HPG are similar. However, due to the relatively lower cost of guar, the Net Present Value (NPV) of wells fractured using guar is greater due to lower treatment costs.

A case study of sixteen high-temperature wells located in Weld County, Colorado was performed to determine the "actual" effect of the fracturing fluid on well performance. A comparison of post-frac well production data indicates guar and HPG crosslinked fluid yield comparable proppant pack impairment, and thus similar well performance. A detailed discussion is presented.
Rheologic Measurements of a Crosslinked Fracture Fluid Under Conditions Expected During a Fracture Treatment
Authors: Worlow D. W. , Holditch S. A.
Published: December 2007

This paper details the development of a laboratory testing procedure that simulates the shear and temperature environment that a fracturing fluid is subjected to throughout a fracturing treatment, including the low shear rates (30-100 sec−1) experienced in the fracture. Building on previous parametric studies of fluid responses to differing test procedures, this new procedure appears to give results that are representative of the viscous properties of the fluid rather than the procedure used to run the test.

The validity of our proposed procedure has been verified by testing gels from four suppliers with gel loadings of 40 and 60 lb/1000 gal at temperatures of 200 and 250° F. Acceptance of a procedure such as the one presented in this paper would allow for more accurate control in the design and execution of fracture treatments, and serve as a basis for meaningful, quantitative comparisons between available gel systems.
J-Sand Polymer Flood Performance Review
Authors: Weiss W. W. , Chain J. M.
Published: December 2007

In this paper.the design methodology for the Warner Ranch Unit polymerflood is reviewed. The design included field tests which are believed to have underestimated polymer retention. This result in turn adversely affected project performance. The propagation of the polyacrylamide through the rock was much less than anticipated.

Performance of a polymer injection well is compared to several J-Sand water injection wells. It is evident that injectivity is greatly reduced with polymer injection; the loss in injectivity approximates that which is expected when the mobility ratio is reduced to less than one.

Most field projects have demonstrated that the absolute benefits of polymerflooding are difficult to quantify, and the Warner Ranch Unit is not an exception. Two producing wells produced 18,000 bbl of incremental oil attributed to polymer injection.
Limited Communication Between Hydraulic Fracture and (Deviated) Wellbore
Authors: Veeken C. A. M. , Davies D. R. , Walters J. V.
Published: December 2007

When wellbores are deviated or are located in tectonically active areas it is unlikely that the plane of the wellbore and an artificial hydraulic fracture will be co-incident. This could result in limited entry effects due to poor communication between the wellbore and the hydraulic fracture or the presence of multiple fractures, and hence in a reduced well productivity.

A combined experimental and theoretical study has been carried out to investigate the influence of key parameters on the fracture-wellbore communication, aiming to identify the potential problem wells and to aid in optimising completion procedures for a North-Sea gas field.

The hydraulic fracture treatments were successfully placed, though the fluid friction experienced over the perforations during the treatments did show a dependence on well orientation (indicative that a minor form of limited entry was occurring).
Application of Foam Cement in the Williston Basin
Authors: Bour D. L. , Vennes M. R.
Published: December 2007

The properties of low density foamed cement slurries have been advantageously employed to overcome cementing problems in North and South Dakota, Wyoming, and Montana. For over 30 years, operators in the Williston Basin have encountered completion problems associated with several salt and lost circulation zones.

Poor mud displacement in washed out salt sections left long string production casing vulnerable to casing collapse. Weak zones prone to lost circulation necessitated use of multiple stage cementing techniques to perform long string casing cementing jobs.

To solve these problems, foam cement has been used with exceptional success. The use of this lightweight cementing system has helped eliminate the problem of collapsed pipe, as well as allowing for the circulation of long intervals of cement, even back to surface, in a single stage.
A Systematic Approach To Design Of Rod Pumps In Coal Degasification Wells: San Juan Basin, New Mexico
Authors: Hebert Doug W.
Published: December 2007

Pumping coal degasification wells with conventional rod pumping methods can be a virtual nightmare without a systematic approach to the wells inherent problems.

When confronted with this task there are two main problems to address, particulate matter and gas interference. Both problems must be addressed simultaneously. Because of the nature of these problems, conventional attempts to alleviate one can lead to intensification of the other.

Pump design and configuration is very important but no more important than the well bore configuration. Over the years new products and new methods have been developed to make pumping these wells feasible.
Storage Data Collection, Representation, and Analysis and How They Can Interface With Planning, Remedial Work, and Operations
Authors: Syvertson D. I.
Published: December 2007

With recent changes within the gas transmission business both internal (personnel, etc.) and external (open access, markets, etc.), companies are faced with how best to utilize their storage capabilities in this new environment. Natural, faced with this situation, had severed, options available. Initially, some discussion was given to purchasing a commercial simulator program. However, with 13 reservoirs and the time and investment involved along with the uncertainty of the final product, Natural took a different approach. Mainly, organizing data so that both trend and analytical analysis can be performed quickly and easily. With past problems of rigid data bases where data was too structured and inflexible for review, the decision was made to put as much data into spreadsheet programs as possible. From here data can be reviewed or extracted into another spreadsheet for analysis.

This paper will track data from the wellhead (type and frequency) to planning models (the final product). Intermediate steps show how the data is stored and analyzed to determine how each reservoir is behaving. From these intermediate analysis individual reservoirs are then combined into a big picture for all reservoirs, which is combined into the overall system plan.

Examples, analysis, and conclusions are drawn from various P/z vs Inventory graphs, fields data plots, and historical trends are shown and described.
The Antrim Shale of the Michigan Basin: An Active Devonian Shale Gas Play
Authors: Oliver S. J. P. , Kuuskraa V. A. , Brandenburg C. F. , Coates J-M. P. , Kelafant J. R.
Published: December 2007

The Antrim Shale, first drilled in the 1940’s, is estimated to contain significant quantities of gas, up to 76 Tcf in place. However, relatively low gas production rates, coupled with an inadequate understanding of its key reservoir properties, have limited its active pursuit. Recently, a better appreciation of the merit of the Antrim Shale as a gas resource has raised operator interest. From a base of 32 Antrim Shale wells in 1986, drilling increased to 91 wells in 1987 and to over 300 wells in 1988.

While the pace of Antrim Shale drilling has clearly increased, gas production rates are still relatively low (at about 100 Mcf/day), suggesting that innovative completion and stimulation techniques are needed to increase production and, ultimately, gas reserves. This paper examines in detail two such development strategies aimed at improving Antrim Shale productivity - large volume sand fracs and improved geologic understanding.

Initial analysis of the Antrim Shale suggests that large, water-based stimulation treatments may increase gas flow by more efficiently removing the water in the formation thus improving relative permeability to gas. In addition proper interval selection and well spacing could improve gas recovery. A tworphase, dual porosity reservoir simulator was used to examine the well performance and gas flow rates for applying improved technology to the Antrim Shale.
Field Experience with Production of Deep Sour Gas Reservoir
Authors: Morsi K. M.
Published: December 2007

The design, construction, pre-commissioning, commissioning and operating phases oE major projects involve several various personnel. Operating problems encountered subsequent to commissioning are not always communicated to designers. This can result in the repeat of the errors which will cause costly modifications.

This paper reviews ADNOC’s experience in well completion and production of deep sour gas reservoir. In addition it presents a summary of several operating problems encountered in producing these wells, actions done to reduce failure probability and the resulting recommendations which should be considered in design and operation of similar reservoirs.
Fabrication and Erection of Jack-Up Drilling Platform Legs of Heat-Treated Steels
Authors: Crawford David C. , Walker James H.
Published: December 2007

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

This paper was prepared for the 42nd Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, Tex., Oct. 1–4, 1967. 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 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.

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.

The utilization of newly developed heat treated steels in the legs of jack-up drilling platforms required the development of new welding and quality control techniques for both shop and field applications. The necessity of these techniques, their development and subsequent application is described.

Introduction

Early in 1964 it became apparent that the offshore drilling industry had entered an era in which contractors, through the stimulation and requirements of the offshore operators, would be called upon to construct several offshore rigs with an operating depth capability of 200 to 300 feet. One of the major new areas opened to exploration at this time, thus creating an immediate rig demand, was the North Sea.

The immediate initiation of new rig construction in the U.K. was the path chosen by The offshore Company as the most expeditious and economical way to meet the need for rigs in this area. The rush to the North Sea had commenced, and it was incumbent on the contractor to construct (offshore rigs as soon as possible with all the modern refinements and suitable for the intended area of operation— in an area of the world where rig construction experience was practically non-existent.

As the legs of a self-elevating drilling platform are the most important single structural component, the necessity of rigorous fabrication controls is of vital importance. utilization of newly developed heat treated steels in the legs not only increased the magnitude of fabrication controls, but created the need for development of new welding and quality control techniques for both shop fabrication and field erection applications.
Evaluation Programme for Offshore Development System
Authors: Ihara M.
Published: December 2007

The purpose of this research is to develop the prompt assisting tool programme named "EPODS" ( Evaluation Programme for Offshore Development System ) for the decision making of selecting optimum oil field development system. The programme is designed to be used at various stages such as preliminary stage when bidding for a concession, conceptual study stage after acquisition of the concession and final study stage prior to actual development design.
The Fluid Properties Measurement Expert System
Authors: Dharan M. B. , Turek E. A. , Vogel J. L.
Published: December 2007

This paper describes the development of an expert system to provide routine consulting advice to petroleum reservoir engineers in the highly specialized field of fluid properties. Obtaining reliable reservoir fluid properties is a critical first step in various reservoir engineering studies. Knowledge of the fluid properties required for various applications and the technically appropriate and cost effective methods for obtaining the data can save time and money. The likelihood of obtaining representative data is increased. In order to provide advice on the fluid property needs for various applications and to recommend appropriate ways to obtain the requisite data, the Fluid Properties Measurement Expert System was developed. The system has been developed using an EMYCIN like expert system shell. In addition to containing over 600 rules in its knowledge base, the expert system connects to several processing programs and a database of fluid property reports. An initial prototype of an important subsystem was validated against a panel of fluid property experts. The validation methodology is also detailed.
Experience with the Development of a Well Test Program in a Windows Environment
Authors: Blanc L. M. , Peters E. J.
Published: December 2007

A computer-aided pressure transient analysis program has been developed in a Microsoft Windows™ environment resulting in a highly interactive and user-friendly application. Programming in such an environment involved a completely new approach to program logic and design. In Windows, programs respond to events and process messages -mouse clicks, requests to redraw window contents, etc- rather than issue commands as in conventional software design.

Personal computer operating systems are evolving towards creating a graphical user interface. The main advantage of such a visual interface is that the user can learn how to operate a particular application quicker and more efficiently than a DOS-based application. The learning process is intuitive and all the applications consistently have the same feel and look. Users of both Macintosh™ and IBM™ family of personal computers are well aware of the difference in operating systems.

For the non-professional software developer, programming in Windows creates a whole new array of concepts and requires a deep understanding of computer architecture, in particular, memory management and organization. The experience obtained in developing a pressure transient analysis application has reinforced our belief that engineers need to become acquainted with such operating systems. This paper covers the most important topics on how to write Windows applications and the changes in our programming habits involved in creating them.
Business Interruption Insurance for North Sea Oil and Gas Production Fields
Authors: Canaway R. T.
Published: December 2007

The phased discovery of oil and gas reserves in isolated pockets beneath the seas has led to an interesting network of interlinked offshore developments.

Oil and gas reserves which are many miles offshore have to be extracted, separated and transported to the shore. The planned development of the North Sea has made it possible to share facilities such as oil and gas pipelines, platform processing and export equipment and tanker loading facilities. Older declining fields possess facilities which can yield spare capacity for use in the development of new marginal fields and the capital cost savings make good sense. However, associated with this comes the disadvantages of interdependency of one field on the availability of another's facilities for production continuity. Business interruption evaluations become more complicated and the placing of insurance cover must take into account all possible incidents which can yield both short and long term losses.

This paper looks at some of the incidents which might lead up to periods of long term business interruption for typical North Sea main oil and/or gas gathering stations and interconnected ‘edge’ fields.
A Remote System for Subsea Well Maintenance
Authors: Torgersen Richard C. , McGregor Ian D.
Published: December 2007

Mobil North Sea Limited and FSSL Limited have worked together for the past two plus years on the development of a deep water satellite well system. The design features an integrated production system which is remotely installed and maintained. Maintenance is performed by an ROV/cage combination which is deployed from a dynamically positioned support vessel or pipe carrier. This development work has endeavoured to achieve a reliable and cost effective system which can also be used as an alternative to diver assisted wells in shallower water areas.

This paper outlines the design work conducted to date by addressing the subsea tree and controls hardware, cage system, special tooling and the surface vessel heavy weather launch and recovery system. Selected prototype hardware has been built and tested.
A New Wellhead Design Concept
Authors: Heijnen W. H. P. M.
Published: December 2007

A conceptual wellhead design is described based on the use of 18 3/4″ BOP stacks. It can also be used with the more popular 13 5/8″ BOP. The concept is based around three main parameters:

1] Maximum BOP protection during installation. 2] Full maintainibility to the point of total replacement. 3] Flexibility in use during the total lifetime.

The conceptual design incorporates not only operational requirements but also explains and gives solutions on the level of the detailed design.
Design and Application of an Integral Jet Pump/Safety Valve in a North Sea Oilfield
Authors: Allan J. C. , Moore P. C. , Adair P.
Published: December 2007

Offtake levels, under natural flow, from Thistle and Deveron wells A46(45) and A51(03) are both constrained by relatively poor pressure support. It was decided to install jet pumps in the existing completions to test the reservoir performance under artificial lift. If enhanced offtake levels could be supported permanent gas lift completions would be installed at a later date. In addition to this interim increases in the production rates would be achieved prior to workover.

A wireline retrievable jet pump, complete with a integral sub-surface safety valve (SSSV), has been designed for installation in the (open) sliding side door (SSD) of the existing completions. Power fluid, supplied from the water injection system, is routed via the casing-tubing annulus and returns are produced up the tubing string. Downhole isolation of both the tubing and the annulus is achieved by means of the annulus pressure operated SSSV which is located immediately below the jet pump.

The design procedure for the selection of the optimum nozzle/throat combination is described. Operating procedures have been developed to ensure successful operation of the device and details are given of both the downhole and surface hardware.

Results of actual field performance are presented and comparisons made with predicted values. Finally details are given of design modifications which were implemented in response to problems which developed during field trials.
TRISS, Unmanned Deep Water Tower
Authors: Larsen Jan
Published: December 2007

This paper describes the TRILITE Super Satellite Platform (TRISS), a light 3-legged cost-effective fixed jacket substructure concept supporting a simple topside facility intended for unmanned operation. An overall objective has been to develop a realistic alternative to sub-sea concepts in water depths down to app-rox. 350 meters with the added advantage of having the wellheads located above sea level.

The jacket concept incorporates all known and proven features contributing to weight reductions. Furthermore, additional ideas conforming with this objective has been launched and studied, such as utilizing prestressed conductors and routing caissons inside the legs. Another novel feature is the installation method for cases where the installation weight exceeds the current SSCV lifting capacity, i.e. with use of a special purpose concrete barge-CONRAFT. The approach involves e.g. upending of the jacket jointly with the barge.

The topside facilities studied ranges from the simplest possible sub-sea type arrangement to a more elaborate concept including first stage separation, thereby avoiding multi-phase transportation to the processing facility. Special emphasis has been placed upon developing a layout adapted to a triangular support configuration and minimizing equipment within the frame-work of safety regulations in the Norwegian sector of the North Sea.

Technical merits have been studied and estimates of weight, cost and schedule prepared for a case in 330 m water depth.
An Application of an Artificial Intelligence Program for Bailing Operation Management in West Virginia
Authors: Yu J. P. , Mustafa A. , Yang J. R. , Zhao D. , Suhy T. E. , Hefner M. H.
Published: December 2007

The success of a bailing operation depends solely on management in order to keep the operation economical. A novel approach to solve this managment challenge is to use an artificial intelligence program. A prototype bailing evaluation package has been completed with decline curve analysis, artificial intelligence program, and data base.

A decline curve analysis program can be applied to fit the bailing cycles of each well in order to predict the future bailing schedule and bailing gain. The bailing cost and other economic parameters have been used to determine the economic limits for bailing cycle investment, These parameters are being used to set the multiwell priority list for planning one month bailing operations. The line pressure, geographic location, weather conditions, farming activities, and operational problems are optimized into a working list to establish a priority list for the bailing of each well. An artificial intelligence program is being used for selecting and evaluating the priority list of the bailed wells. In addition, a database system is also being compiled to supply pertinent data for the bailing evaluation. This paper presents the way these three programs work together as a bailing evaluation package.
Modeling the Discovery of New Natural Gas Reserves
Authors: Iledare O. O.
Published: December 2007

In this paper we have attempted to develop a microanalytical model of new natural gas supply response using a careful analysis of West Virginia geological, petroleum engineering and economic data. The model equations were estimated statistically, using covariance analysis model for pooling crosssections of time series data. The regression results support the a priori expectations that higher natural gas prices has a positive effect on drilling activities. There is also an indication that expected wellhead price has a positive effect on the finding rate of new reserves. The contentions that increasing tax rate and increasing reserves-production ratio from preferred level have negative effects on drilling activities were confirmed. The empirical results also show that the margins of substitution in these geologic environments, are not well known.
Selection of Well Completion Zones Using the Dye Leachback Technique
Authors: Bennett R. , Schettler P. D. , Parmely C. R. , Bowles G. H. , Morton B. F.
Published: December 2007

Selecting specific zones to stimulate in wells is a major problem in designing stimulation treatments for low permeability reservoirs, such as the Devonian shale. Treatments should be concentrated over small intervals of a well, so the selection of the most productive intervals is critical. The Dye Leachback technique helps to locate these zones by determining the areas of highest permeability on the borehole wall.

This patented technique involves measuring the rate of dye penetration into rock cuttings under controlled conditions. The degree of penetration is measured by allowing the dye to diffuse out of the cuttings into an initially clear solution. This process is termed leachback. Dye Leachback Coefficients are calculated from time windows associated with dye immersion, rinse, and leachback. Leachback Coefficients are plotted versus depth of the sample to obtain a permeability profile. The profile indicates zones in the well which are more conducive to gas flow. Profiles from drill cuttings we have analyzed correlate reasonably with gas production zones in the wells. Therefore, the profile information can be used to assist in the selection of intervals for stimulation treatments in a well.
Recovery of Oil from Underground Drillsites
Authors: Streeter W. S. , Hutchinson T. S. , Ameri S. , Wasson J. A. , Aminian K.
Published: December 2007

A significant quantity of oil is left in reservoirs after conventional oil recovery techniques have been applied. In West Virginia and Pennsylvania alone, this oil has been estimated at over 4.5 billion barrels (0.72 billion m3). Conventional recovery methods are already being used when applicable. But a new recovery method is needed for use in reservoirs that have been abandoned. One alternative method for recovery of the residual oil is known as "oil recovery from underground drill sites". This recovery technology is a combination of proven methods and equipment from the petroleum, mining, and civil construction industries.

Underground oil recovery can be an economically viable method of producing oil. This has been shown in producing fields, field tests, and feasibility studies. Faced with decreasing domestic oil production, the petroleum industry should give serious consideration to the use of oil recovery from underground drill sites as a safe, practical, and environmentally sensitive alternative method of producing oil from many reservoirs.
Steerable Systems Drilling: The Right Angle for Horizontal Drilling
Authors: Claytor S. B. , King R. , Speed J.
Published: December 2007

A steerable system was recently employed off the coast of Western Australia to accomplish the longest continuously drilled horizontal section in Australia to date. This paper examines the practical aspects of drilling this horizontal well. The pre-well planning process is discussed with emphasis placed on steerable system design and drill stem design. Finally, a brief chronology of the drilling operation is presented along with results of the actual well.
The Cardinal Rules of Gravel Packing To Avoid Formation Damage
Authors: Winchester P. H.
Published: December 2007

The Troll field, offshore Norway, was known to be sand prone, and one of the basic planning parameters of the field development was the deliverability of gravel packed oil and gas wells. It was considered imperative that high rate production with minimum drawdown should be demonstrated to confirm the viability of the project.

Earlier attempts to achieve these objectives, especially in gas wells, were unsuccessful although methods and procedures normally acceptable to the industry were employed. Consequently a set of cardinal rules was derived for the drilling and completion phases so as to engineer the placement of a near perfect gravel pack.

This was achieved, first by more than doubling the productivity of the previous best oil test, then by achieving a 124 MMscf/D (3.55 × 106m3/d) test through an external gravel pack, followed by a 120 MMscf/D (3.44 × 106m3/d) test through an internal gravel pack.
Quantitative Interpretation of the Surface Dynamometer Card
Authors: Mantecon J. C.
Published: December 2007

The surface dynamometer card has been used routinely for many years as an aid in analyzing the performance of sucker rod pumping equipment. This is an essential step toward increasing profits by improving system design and rectification of pumping problems. The present paper compiles a series of practical tools and procedures concerning quantitative interpretation of the surface dynamometer card. Preparation and use of a data sheet and a calculation form is covered, emphasizing the amount of information made available to the foreman and members of the production team. The form is the output of a microcomputer based program, designed to quantitatively interpret surface dynamometer cards, and has been used successfully to diagnose the control pumping problems and related operating costs, and to enhance the learning process for trainee personnel as well as graduate and undergraduate students. The program is one of the tools discussed in the paper and will be available on SPE EXCHANGE DISKS for potential users.

The methodology presented results in better retention of the information, more accurate records, and more effective liaison between field production teams in areas geographically far removed from computerized offices and supervising engineers.
Multiphase Metering for Production Pipeline Flows
Authors: llic V. , Thorn R.
Published: December 2007

This paper reviews multiphase flow meter development for application in the oil industry against basic theoretical concepts involved in the flow measurements.

Several metering concepts for the mass flow rate measurement of oil/water/gas mixtures in oil pipelines have been proposed. Determination of components' volumetric fraction is an integral and essential part of such a meter and reported methods of its measurement are also reviewed here.

Although a number of multiphase flow concepts have been patented and a number of prototype models built, no extensive field trials of a multiphase flow meter have been reported.
Pilot Development of Tight Limestone Reservoir in the Khafji Field
Authors: Yokoyama Y. , Arima E.
Published: December 2007

This paper deals with a pilot project for the development of a relatively low-transmissibility, tight area of a limestone reservoir in the Khafji Field. In the project, the productivities of two wells, K-A and K-B, were enhanced by acid-fracturing and horizontal drilling. The objectives of this paper are to investigate the effectiveness of the above two methods and to seek the possibility of developing the tight zone.

In K-A, where the acid-fracturing was applied, a laboratory core test as well as intensive field tests such as a step rate injection test, pump in/flow back test and mini-fracturing test1 were performed. Bottom hole pressure measurements and production loggings during such field tests were important in detemining accurate fracturing parameters for effective acid-fracturing design. K-B was initially completed as a vertical well with the productivity enhancement by foam-acid fracturing, and was later converted to a horizontal completion well -- two horizontal holes were drilled by side-tracking from the existing casing.

This paper principally reviews the various well stimulation techniques applied in these two wells such as limited entry, mini-frac optimization, foam acid and gelled acid fracturing and a newly applied horizontal completion technique. The horizontal completion was evaluated in terms of completion technique, stimulation for the horizontal holes and well testing. The two field applications in the project indicated prospective steps for future development of the tight zone.
Advanced Technology for Laboratory Measurements of Drilling Fluid Friction Coefficient
Authors: Quigley M. C.
Published: December 2007

Proper evaluation of drilling fluid (mud) friction coefficient (CF) depends on more than good test equipment. Detailed planning, statistical test design, and proper experimental technique are crucial to advanced technology for laboratory measurements of mud CF. Numerous factors affect these measurements. Technology which can rapidly screen selected factors, anticipates natural variation in measurements, effectively minimizes bias, and insures that responses tu test parameters are precisely measured is described. Moreover, a method for statistical data analysis which clearly and concisely summarizes the important features of experimental data is presented.

Specialized test equipment for accurately measuring mud CF between simulated tool joints and wellbore materials is described. Effects of tool joint type and surface condition, wellbore sample, and operating conditions are included. Twenty-eight mud lubricants were evaluated in two mud types weighing 9–16 Ibm/gal (1078–1917 kg/m3) using this advanced technology. Results of these tests are summarized.