bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of Drilling Fluid Properties to Maximize Cement Displacement Efficiency
Authors: Smith T. R. , Ravi K. M. 
Published: December 2007

AbstractThis paper describes techniques for improving the percentage of wellbore volume that is circulated before cementing. The effects of drilling fluid filtercake deposits, aging of filtercake, mechanical scraping of the filtercake, and annular velocity on the displacement efficiency are discussed. Four different water-based drilling fluids (potassium acetate, potassium chloride, gypsum, and fresh water bentonite) used by Shell Canada in their day-to-day operations were investigated in this study.A large-scale test apparatus was used for this study. The test apparatus consisted of a steel casing run inside a permeable core to realistically simulate a wellbore. The test procedure simulated conditions such as circulation, drill string tripping, drilling fluid conditioning, and cementing. A computerized tracer technique was developed to continually monitor the percentage of wellbore volume that was circulated. A continuous history of the wellbore was recorded when parameters such as annular velocity, drilling fluid rheology, and fluid loss of the drilling fluid were varied. Drilling fluid filtercake buildup and erosion were monitored throughout the test. After cementing, the test model was removed from the test well and cut into sections, and displacement efficiency was measured. The agreement between the measured displacement efficiency and calculated percentage circulatable hole volume verified the test method. The effects of modifying parameters such as drilling fluid properties, annular velocity, and mechanical scraping of filtercake on cement displacement efficiency are presented. Recommendations on which drilling fluids are most desirable for cement displacement efficiency are included.
Asphaltene Deposition: Development and Application of Polymeric Asphaltene Dispersants
Authors: Schantz S. S. , Stephenson W. K. 
Published: December 2007

ABSTRACT
Asphaltene deposition has a significant detrimental effect on oilfield production. The key to effective treatment of asphaltene deposition is recognition of the problem. Asphaltenes can be identified and quantified using laboratory methods. In the past physical, mechanical and chemical treatments have been used to control asphaltene deposition in the oilfield. Chemical treatments have included aromatic solvents and low molecular weight dispersants. However, many of these treatments are ineffective.
Recently, technically and economically effective methods to control asphaltene-created production problems have been developed. These applications make use of a new polymeric dispersant/inhibitor at clean-up dosages of 1,000 to 10,000 ppm and continuous dosages of 50 to 400 ppm.
As a result of downhole clean-outs and chemical squeezes using the new dispersant/inhibitor, production increases have been achieved and maintained. Tank bottom and interface control has been achieved through continuous feed applications. In one case, an additional benefit of the treatment was increased effectiveness in demulsifying oil/water emulsions and maintaining cleaner discharge water.
New Simultaneous Operations Guidelines Enhance Safety of Offshore Operations
Authors: Gilbert D. L. 
Published: December 2007

Abstract
Exxon Company, U.S.A. has had a Simultaneous Operations Plan for offshore operations since 1978. The plan has provided valuable guidance in conducting safe and environmentally sound operations. However, new learnings identified opportunities to make the existing plan better. A task force formed to review Exxon’s Gulf of Mexico operations with regard to overall safety and emergency response capabilities concluded that an enhanced plan would assist in describing the procedures appropriate for conducting operations (production, drilling, construction, etc.) concurrently on offshore platforms. Exxon’s Offshore Division revised Simultaneous Operations Manual was subsequently published in November 1990. The new document, developed with input from field operations personnel, describes a series of minimum requirements for each simultaneous operations scenario. A definitions section provides an understanding of various equipment, conditions, activities, etc. which are addressed in the manual.
Provisions for deviating from the Manual’s requirements with management approval are included, provided special precautions and/or unique circumstances are involved. The process utilizes office automation (computer mail) which provides for timely responses to deviation requests. This system will also be used to track the types and frequency of deviations. This tracking capability will also provide input regarding future Manual revisions and ensuring that the Manual remains "evergreen."
Actions Needed To Comply With API RP 750 Management of Process Hazards for Offshore Facilities
Authors: Arnold K. E. , Roobaert N. C. 
Published: December 2007

Abstract
API RP 750, Management of Process Hazards, which does not include offshore facilities in its scope specifies the elements required of a safety management system. It is possible to comply with RP 750 by revising an existing API Recommended Practice and making minor revisions to existing safety systems already in use by most offshore operators. This paper describes how this can be accomplished in such a manner as to derive the benefits of having a safety management system, without subjecting the industry to an unnecessary and counterproductive burden of documentation.
Snubbing Unit Applications in Potentially High-Rate Gas Wells: A Case Study of the Anschutz Ranch East Unit, Summit County, Utah
Authors: Leggett R. B. , Griffith C. A. , Wesson H. R. 
Published: December 2007

ABSTRACT
Snubbing has recently been implemented as a method of routine well-control during workovers and completions at the Anschutz Ranch East (ARE) field in Summit County, Utah. This action was taken in response to poor post-workover performance caused by a water retention problem in the Nugget sandstone formation with the use of water-base well-control fluids. The incremental expense of snubbing at ARE averaged 25–40% of the cost of a standard workover and was considered reasonable in view of the alternative of poor well performance with existing well-control methods.
The concept of snubbing as a "commonplace" well-control method at ARE represents a major departure from historical control methods employed there. The new experience gained with surface control of potentially high-rate, medium-pressure, retrograde gas wells may benefit other operators in planning and executing safe, efficient snubbing operations in wells with similar conditions.
A review of the decision logic which chose snubbing versus other alternative well-control methods is presented. In addition, an overview of job pre-planning activities is provided. Finally, a detailed discussion of actual implementation problems and solutions is given with particular emphasis on underbalanced drilling of plugs and fill.
Determining Effective Residual Oil Saturation for Mixed Wettability Reservoirs: Endicott Field, Alaska
Authors: Wood A. R. , Wilcox T. C. , MacDonald D. G. , Flynn J. J. , Angert P. F. 
Published: December 2007

ABSTRACT
Waterflood residual oil saturation, in mixed wettability reservoirs, is often a strong function of pore volumes (PV) injected. The Endicott Field, Alaska displays typical mixed wettability behavior with coreflood remaining oil saturation varying from 40% at 1 PV to 12% at infinite PVs. Although only about 1 PV will be injected in the reservoir, surface film drainage may act to reduce oil saturation making determination of the correct effective residual oil saturation difficult.
Accurate determination of waterflood residual oil saturation is essential for assessment of waterflood performance and evaluation of enhanced recovery processes. To minimize uncertainty in predicting effective residual oil saturation in mixed wettability reservoirs it is necessary to consider the competing effects of relative permeability, gravity forces, and imbibition capillary pressure. A mechanistic simulation approach is presented for scaling up laboratory results, that considers all active forces.
An Integrated Approach EOR Evaluation of Production Scenarios in the Field Delineation Phase
Authors: Lemouzy P. M. , Eschard R. , Beucher H. 
Published: December 2007

ABSTRACT
A method for evaluating the production scenarios in the delineation phase of an oil field is described, and illustrated with a synthetic example build from a Mesa Verde (Colorado) area outcrop. At delineation time, only a few wells and some geophysical surveys are available for reservoir characterization. The geologist analyses these data, and determines some major characteristics of the deposition system as its type, its direction, etc.
This interpretation is then quantified so as to be used as the input of a geostatistical simulation model, in terms of lithofacies proportion curves, and variogram function parameters. This quantification is not unique, and the geologist provides ranges for each parameter.
The geostatistical simulator gives several images, with different parameters varying in the selected ranges. A first investigation among these images is performed by looking at the volume of reservoir connected to the producing or injecting wells, for various wells spacing.
Then, these images are translated into petrophysical description, allowing to perform oil recovery calculations, for the selected images. Finally, an estimation of the oil production for different development scenarios, taking into account uncertainties is performed.
This methodology is possible thanks to a geostatistical simulation model enabling integration of geology and reservoir engineering.
The geostatistical simulation model is a tool for translating geological knowledge into parameters manageable for reservoir engineers. The proposed methodology allows to make better decisions in the delineation phase, as impact of uncertainty can be more easily computed.
The availability of an integrated model, avoiding painful data handling (petrophysical data attribution, upscaling), is an important point.
A Numerical-Dispersion-Free Method for Modeling the Gas Cycling Process
Authors: Chang E. Y. , Lo T. S. 
Published: December 2007

ABSTRACT
This paper describes an effective methodology for accurate evaluation of liquid recovery during the gas cycling of condensate reservoirs. First, the fluid flow problem is solved by potential flow, which is shown to be applicable to compressible gas flows also. The mass transfer and phase behavior within the potential flow streamtubes can then be calculated using one dimensional reservoir simulators, which can efficiently control the numerical dispersion errors to any desired level. An example illustrates this method’s efficiency and accuracy advantages over conventional finite difference methods.
Analysis of the Waterflood Response of a Naturally Fractured Reservoir
Authors: Beliveau D. , Payne D. A. , Mundry M. 
Published: December 2007

ABSTRACT
The 500 million barrel Midale oilfield is part of a trend of large Mississippian oil accumulations located in southeastern Saskatchewan, along the northern margin of the Williston Basin. The field was discovered in 1953 and developed on 80-acre spacing. In 1962 Midale was unitized for waterflooding, with 83 320-acre inverted ninespot patterns (Figure 1).
Waterflood performance in Midale is dominated by a system of oriented natural vertical fractures typically spaced 1–4 feet apart. Production wells located "ontrend" from injectors (aligned with the fractures) showed sharp early response to waterflood. In contrast, response of "offtrend" producers was smooth and delayed. Oil produced to-date represents recovery of 20% of the original oil in place (OOLP); ultimate waterflood recovery is predicted to be only 24% OOLP. Current watercut in the mature operation is about 80% (Figure 2). Even with the natural fractures, the Midale Unit is a low-productivity reservoir, with average production rates of 75–100 STB/D/well.
A major reservoir and process mechanism characterization effort began in the mid-1980s to guide ongoing Midale field development opportunities. A detailed study team consisting of a geologist, a petrophysicist, and production, reservoir, and research engineers spent three years analyzing waterflood performance. The large-scale effort was dictated by the complexity of predicting performance in a heavily fractured reservoir. Obviously, good communication and cross-discipline integration of expertise was a key to the project’s success. The resulting reservoir and process model honors all available data and can match performance of the field-scale waterflood as well as a tertiary CO2 flood pilot.
Floating Production Storage and Offloading: Disconnectable or Not?
Authors: d’Hautefeuille B. B. 
Published: December 2007

Abstract
Single Point Mooring Systems are commonly used to moor Floating Production tankers or barges at exposed offshore locations. The first mooring systems were designed for permanent applications. In the last five years, disconnectable systems have been developed mainly for South East Asia.
These disconnectable systems have been designed around the turret mooring concept, due to their mechanical simplicity and cost attractiveness.
The turret systems have been developed for a wide range of criteria such as environmental conditions, water depth and operating constraints.
After a brief review of different turret mooring systems, this paper discusses the concept of disconnectability. Some mooring systems have been designed to be disconnected in an event where the design weather conditions are reached or in case of typhoon or cyclone warnings.
A comparison of disconnectable versus permanent mooring systems is presented with regards to mooring feasibility, safety of personnel, equipment availability, operating philosophy, downtime, investment cost as well as operating costs.
The Uses of Buoyancy in Completing High-Drag Horizontal Wellbores
Authors: Hood J. L. , Mueller M. D. , Mims M. G. 
Published: December 2007

ABSTRACT
Unocal has been actively developing horizontal well drilling and completion technology. This technology has been used to drill and complete wells with horizontal displacement to true vertical depth ratios (HD/TVD) of up to 2.92. This technology has also has been used to drill and install casing in the world's two longest horizontal wells, each containing approximately 1.1 miles of producing formation. This paper presents the techniques used to analyze torque and drag forces, and the buoyancy assistance technology used to overcome those forces.
Dewatering Technology A Current Overview and SE Asia Applications
Authors: Tapin T. P. , Blake L. D. 
Published: December 2007

ABSTRACT
This paper discusses the operational aspects and advantages of dewatering drilling fluids at the rigsite. It covers the use of dewatering for waste control and minimization, as a recycling process for water conservation, and for total solids control. Detailed descriptions of the process and the parameters involved in setting-up and operating dewatering units are presented. A general description of the flocculation process using chemical flocculants and coagulants are also discussed.
Production and Pressure Decline Curves for Wet Gas Sands With Closed Outer Boundaries
Authors: Mohaghegh S. , Ertekin T. 
Published: December 2007

ABSTRACT
A family of pressure and production decline curves are generated for wet-gas sands with closed outer boundaries. Wet-gas sands are characterized as gas reservoirs which produce substantial amounts of water together with gas. Production of water introduces complications when practicing engineers use decline curves designed for gas reservoirs in which gas is the only flowing phase. This usually translates to over estimation of the production performance of the reservoir.
In this paper a series of pressure and production decline curves which accounts for the water production in wet-gas sands is presented. These decline curves provide a simple way of extracting valuable information from available data, using graphical methods and simple calculations. The proposed decline curves are generated for a radial system with closed outer boundary with one centrally located well which fully penetrates the formation. The application of the proposed decline curves is illustrated through a series of examples.
In the case of constant pressure inner boundary, production decline curves are generated for different ratios of sandface pressure and initial formation pressure, and in the case of constant flow rate inner boundary, pressure decline curves are generated for different initial formation pressures. The proposed decline curves covers a broad spectrum of reservoir extents and have proven to be unique for a wide range of fluid and formation parameters.
Pre- and Post-Stimulation Well Test Data Analysis from Horizontal Wells in the Devonian Shale
Authors: Salamy S. P. , Aminian K. , Koperna G. J. , Locke C. D. 
Published: December 2007

ABSTRACT
Recent drilling and completion operations have demonstrated the technical and economical successes of horizontal wells over that of vertical wells. The need for horizontal wells was established as a vital production enhancement technique for wells producing from economically marginal, low permeable gas formations in the Appalachian Basin exhibiting strong permeability anisotropy.
As part of a U.S. Department of Energy (U.S.DOE) funded research project, several horizontal wells were drilled and completed to the Devonian Shale strata in the Appalachian Basin. Production from these wells exhibited high improvement ratios to that from vertical wells; however, to enhance the economics of the horizontal wells, stimulation was indicated. The success of the stimulation techniques and the measure of improvements were determined from production results and/or pressure analyses.
This paper exhibits and summarizes the results of production and pressure buildup data analyses for the different horizontal wells. Based on pre- and poststimulation production and pressure data, various well test analysis techniques such as type curves for horizontal gas wells, reservoir simulation, Horner's method, and other applicable techniques are utilized.
Finally, the correlation of production and pressure analysis results helped in the assessment and evaluation of the stimulation techniques.
Mathematical and Experimental Simulation of Hydraulic Fracturing in Shallow Coal Seams
Authors: Abass H. , Hedayati S. , Kim C. M. 
Published: December 2007

ABSTRACT
Laboratory hydraulic fracturing experiments on unconfined coal blocks were conducted to simulate fracture stimulation of shallow coal seams. Fractures were initiated by injecting a gelled water into an openhole section of a wellbore. Multiple fractures appeared at the sample periphery during injection period. This paper describes observations made during laboratory experiments, and discusses implications of the experimental results to field-scale treatments. The results have application in modifying fracture width calculations for shallow coal seams. When a shallow coal seam is hydraulically fractured, the created fracture width may be developed as a result of inflating some cleats and closure of surrounding cleats. Stress-strain curves for coal samples under uniaxial compression showed nonlinear, stress-dependent Young's modulus. The traditional approach for the fracture width calculation based on a constant Young's modulus is not valid in shallow coal seam fracturing. Therefore, an approach that accounts for nonlinear compaction using stress-dependent modulus in calculating fracture width is described.
Design and Evaluation of Stimulation and Workover Treatments in Coal Seam Reservoirs
Authors: Nimerick K. H. , Hinkel J. J. , England K. W. , Norton J. L. , Roy M. 
Published: December 2007

ABSTRACT
This paper presents the results of field trials conducted primarily to evaluate the efficacy of a new additive developed specifically for use in fracturing coal seams and shale wells. The case histories were carefully chosen so that the effects related to use of the new material could be isolated as well as possible. The data show that substantial production improvements may be achieved. This paper also presents results from laboratory tests which show that the new additive may also be useful in workover treatments.
Field Use of the Compiled Spreadsheet Analysis (CSA): Log Analysis for the Laptop
Authors: Walbe K. A. , Collart D. 
Published: December 2007

ABSTRACT
With the introduction of reasonably-priced 386-based, co-processed, multi-meg. hard drive laptops occuring at the same time ASCII formatted log data became available in the field from logging companies, the ability of the company geologist or engineer to quickly analyze this data themselves, while in the field, became possible.
Basically the CSA program takes a spreadsheet with all pertinent formulas, macros, settings (print, database and communications) and compiles these templates into runtime applications. The advantages of this system are in both the mechanical aspect (where the compiled program will run many times faster than the original; will utilize co-processor and expanded memory support; and will support virtual memory by using the system hard drive as temporary storage when all available RAM has been exhausted), and the programming aspect (where all formulae, macros and settings can be easily tailored to customer criteria and then become secure and unmodifiable).
Once the templates have been compiled into a CSA runtime application, they may be legally run without the need of the original spreadsheet software or the resulting royalties.
New System for Advanced Well Test Analysis
Authors: Da Prat G. , Pacheco E. , Sierra L. 
Published: December 2007

Abstract
In this work the fundamentals and theoretical principles are presented that describe a system used for both pressure data acquisition and analysis. The advantages of using equivalent time and pseudo equipment time in the plotting functions used for pressure transient analysis is explained. For pressure data analysis, the system automatically optimizes the reservoir parameters, resulting in a theoretical profile that matches the measured data with minimum standard deviation within the noise band of the measured data. Regarding calculation of reservoir parameters, the system calculates the value of the parameter by non linear regression using the entire test profile. The reservoir models included in the system are described and several field applications are presented. A main result derived from this work is that we can conduct an accurate test faster and reduce rig time using advanced plotting functions and regression techniques. Complex systems like layered reservoirs and horizontal wells can be handled by the system.
Solids Control and Low-Solids: Important Binary to Drill Deep Wells
Authors: Machado J. C. , Castilho P. F 
Published: December 2007

Abstract
This study describes experiments and techniques relative to the control of solids and fluids used for deep well drilling, in the Marajó Basin, in the Amazon area, in Brazil, where the well bottom temperatures reach around 148,9°C(300°F).
The solids removal system associated to a low solids fluid, non disperse, without densifier, basically composed of bentonite/polyacrylamide/potash have been considered as important factors for drilling with density inferior to 1080Kg/m3 (9.O lb/gal), during all phases of the drilling process.