bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development Of New-Generation, High-Pressure Marine Wellheads
Authors: Kempston R , Hart B 
Published: December 2007

ABSTRACT

DESIGN CRITERIA, DEVELOPMENT & FIELD HISTORY

Design Criteria of the 21.1/4"-5000 × 13.5/8"-15000 Two-Stack Wellhead

Development of the 21.1/4"-5000 × 13.5/8"-15000 Two-Stack Wellhead
The initial step in the design of this system was to develop the new 21.1/4"-5000 and 13.5/8"-15000 subsea wellhead hub configurations. The 21.1/4"-5000 hub was obtained by boring out the 18.3/4"-10000 hub to 21.1/4" and designing a new AX gasket. This was feasible as the pressure end load of the 21.1/4"-5000 was much less than that of the 18.3/4"-10000 hub. Also, with the lower working pressure, there was sufficient wall thickness to permit boring out the ID of the 18.3/4"-10000 hub.
For the 13.5/8"-15000 housing a double hub profile was proposed. This hub profile would give the needed bearing area required for the pressure end load plus bending moment and still allow the housing to be run through the 21.1/4"-5000 BOP stack. A finite-element analysis was then done to determine if the stresses were in an acceptable range. In order to reduce the high radial loads which are caused by casing load plus test pressure acting on the 45° landing shoulder in the 13.5/8"-15000 housing, hardened teeth were included on the casing hangers.
Prototype parts were then made and assembled as shown in Fig. 4. The highly-stressed areas were then analysed using strain gauges whilst an internal pressure of 22500-psi was applied to the 13.5/8"-15000 housing. (Note: The load due to 22500-psi test pressure is approximately equivalent to 16400 ft. of 7"-381b/ft and 15900 ft of 9.5/8"-53.5 lb/ft of casing in 121b/gal. mud plus 15000 psi-test pressure).
On The Fatigue Analysis of a Differential Thread Connector
Authors: Chen L Y , Williams M R 
Published: December 2007

ABSTRACT
This paper presents a fatigue analysis of a differential thread connector for a special high strength 9 5/8", 471b/ft offshore production riser. The connector was designed to be manufactured from a commercially available upset casing thereby eliminating the need for welding and enhancing the riser's fatigue life expectancy. The method of finite element analysis was used to determine the peak static and alternating stresses in the connector. Conditions considered in the analysis include assembly pre-load, dead weight and static/dynamic bending movements due to waves. Typical North Sea wave data were selected for this analysis. Miner's rule was employed to estimate the fatigue life of the connector in conjunction with the ASME section VII, Division 2 S-N curve.
Evaluation of Splashzone Maintenance Coating Systems by Accelerated Laboratory Testing and Field Trials
Authors: Tischuk J L , Brebner G 
Published: December 2007

ABSTRACT
Maintenance painting of platform splashzones is one of the most difficult offshore coating problems. There is a limited and frequently interrupted weather window for working, the temperature is generally low, the relative humidity is usually high and surfaces may be subjected to salt spray or complete immersion within a few hours of coating application.
Once a coating is on the steel, it is continually wet and must resist abrasion and impact from the sea and from debris which is in the sea. In order to stand up to these conditions, splashzone coatings must adhere tightly to the steel, they must be tough and resilient and they must be resistant to the spread of local damage.
Occidental's Piper and Claymore Platforms were installed in the North Sea in 1976 and 1977 respectively. The original splashzone coatings applied during fabrication were high-build vinyl systems over zinc silicate primers. The same coating systems were used on the platform topsides. By 1978 there was a need for coating repairs because the vinyls had poor abrasion resistance. It has proved impossible to use the original coating system for the repairs because it is intolerant of ambient conditions.
The Demand for Petroleum Engineers
Authors: Calhoun John C. 
Published: December 2007

ABSTRACT
Since 1978 the Society of Petroleum Engineers has conducted an annual survey of companies and universities in order to obtain data on the supply and demand for petroleum engineers. The purpose of this presentation is to report on the results of trie 1983 survey with respect to demand and to compare these results with indications of demand from other sources.
The SPE survey information includes a five-year history of the numoers of engineers employed at year end, a five-year history of hirings, and a five-year projection of expected hirings. In 1982 the author presented a summary of the general conclusions that could be drawn from the series of surveys up to and including the 1982 survey1. Reference will be made to those results throughout this presentation. It is not possible to compare absolute results of these surveys from year-to-year because the companies that report are not the same ones each year.
In 1983 only 16 organizations responded to the questionnaire in a sufficiently uniform manner to construct the sample. This is the smallest number of respondents since the surveys were initiated (1979-62; 1980-35; 1981-35; 1982-27). The total population of engineers represented by the respondents also is the smallest of any of the surveys. Table 1 gives the 1983 survey data for engineers and petroleum engineers; employed at years end and the expected total work force of engineers for the future five years. The latter shows both a high and low estimate. The data are also shown in Figures 1 and 2, with earlier survey data for comparison. The future work force of petroleum engineers is not a pari: of the survey.
A Graphical Method for Estimation of Production Response From Cyclic Steam Stimulation Using Past Performance Data
Authors: Ershaghi Iraj , Al-Adawiya M. S. , Kagawan V. D. 
Published: December 2007

ABSTRACT
A graphical solution method is presented whereby the production and injection data from a number of steam stimulation cycles for a given well are used to estimate recoveries from future cycles.
The proposed method was established based on the experimentation with the analytical model originally proposed by Boberg and Lantz1. It requires a log-log plot of cumulative oil production vs. cumulative steam injection. The technique allows the computation of a response factor for individual wells undergoing cyclic stimulation in a given reservoir.
Comparison and Analysis of Reservoir Rocks and Related Clays
Authors: Crocker M. E. , Donaldson E. C. , Marchin L. M. 
Published: December 2007

ABSTRACT
A series of instrumental and chemical analyses was made to determine the surface chemical properties of sedimentary rocks and the physical characteristics of the pores. A scanning electron microscope (SEM) with energy dispersive X-ray analytic capability was used to study the morphology of the samples, surface mineral composition and type and location of clays. A centrifuge was used to determine the pore size distributions which are correlated with the SEM observations. An inductively coupled plasma (ICP) was used to obtain complete analyses of the rocks and effluents from ion exchange tests. The ion-exchange capacity and surface area in the Berea and Cottage Grove sandstones were found to be related to the distribution of the clays in the rock matrix. Upon comparison to conventinal methods the SEM was found to give quick positive results with regards to pore size, pore geometry and pore size distribution.
Conservative and Nonconservative Buckling of Drillpipe
Authors: Dunayevsky V. A. , Judzis Amis 
Published: December 2007

ABSTRACT
This paper considers three-dimensional and planar buckling of drill pipe under different boundary conditions. 3-D forms of instability and threshold criteria are presented. Post-buckling behavior of suspended drill pipe is studied for one special case of free-end boundary conditions.
Formation Blocking Agents: Applicability in Water - and Steamflood i ng
Authors: Navratil Martin , Sovak Mojmir , Mitchell M. S. 
Published: December 2007

ABSTRACT
New types of high temperature resistant formation blocking agents were studied. Laboratory techniques are described and results shown which should provide a basis for selection of blocking agents for field applications.
Permeability reductions in tar sands as a function of solution concentration and slug size are shown together with the effects of temperature. Blocking capability of these products in brine and steam floods was demonstrated in simulated heterogeneous models with various permeability contrasts.
Prior to their in-situ gelation, these products were shown to have viscosity close to that of water, have controlled rate of gelation and appear to be capable of permanently reducing the water and steam permeability of highly permeable zones in a controlled manner.
Elevated Temperature Testing of Mobility Control Reagents
Authors: Ryles R. G. 
Published: December 2007

ABSTRACT
The viscosity stability behavior of dilute aqueous polymer solutions was studied at temperatures up to 150°C. It was shown that performance was test-method dependent if necessary precautions were not taken. Suitable procedures are described. In the absence of significant quantities of oxygen (ca. 1 ppb residual) polyacrylamides were found to be stable for many months, with or without addition of chemical scavenging agents, and they gave an incremental viscosity response in low to medium salinity waters. The performance of biopolymers was found to be dependent upon source. All polymers studied exhibited degradation in the presence of air. The use of stabilizers greatly retarded viscosity loss under these conditions.
Computer Modeling of Katy Cockfield Sands
Authors: Dalton B. A. , Kane T. V. , Ramsower S. E. 
Published: December 2007

ABSTRACT
The Katy field is a major Gulf Coast gas accumulation with over 6 trillion cubic feet (170 Gm3) originally in place in the Cockfield (Yegua) formation. After more than 40 years of cycling and production operations, induction logs from recently drilled wells indicated uneven water advance within several sands which had, in the past, been treated as single reservoirs. A comprehensive geologic/engineering re-evaluation resulted in defining 48 sand members within an interval which had been described as 14 producing zones. Extensive computer modeling applications aided the geologists and engineers in describing the many vertical and areal reservoir heterogeneities which must be understood in order to maximize ultimate recovery.
Computer-Controlled Measurement of Laboratory Areal Flood Saturation Distributions
Authors: Davis L. A. 
Published: December 2007

ABSTRACT
A microcomputer controlled microwave absorption instrument has been developed for automated measurement of laboratory linear and areal flood oil/water saturation distributions. The instrument design and performance characteristics are given in detail, and the roles of micro, mini and mainframe computers in data collection and analysis are described. Much of the design criteria and features are applicable to other oil recovery laboratory experimentation. An applications study is presented in a companion paper, SPE 12038.
An error analysis study of experimental saturation distribution data is used to identify localized structured water present in a linear core at residual oil saturation to chemical flood. Comparison is made to the residual microemulsion phase predicted by a simulator study of the experiment.
Numerical Simulation of the Litho-Density Tool Lithology Response
Authors: Watson C. C. 
Published: December 2007

ABSTRACT
The numerical simulation of gamma ray logging in the context of the measurement of a formation's average photoelectric absorption properties by the LITHO-DENSITY Tool (LDT) is discussed. The accuracy of a model of the LDT's response, which has been developed using the MCNP transport code, is exhibited through comparison to experimental data. This model is then used to examine in detail the connection between the tool's response and formation properties by means of spectral studies of the spatial, angular and energy distribution of the photons which contribute to this response. Further model calculations of the collision density distributions of detected gamma rays are used to explore bow the LDT's measurements spatially sample the formation.
Monte Carlo Computational Model for the Gamma-Ray Spectroscopy Tool (GST)
Authors: Tsang James S. K. , Evans Michael L. 
Published: December 2007

ABSTRACT
The GST tool is a gamma-ray spectrometer designed to measure the elemental constituents of a rock formation. The carbon to oxygen ratio measured by the tool is a valuable quantity for locating oil- and/or gas-bearing formations. A Monte Carlo model has been developed that simulates the response of the GST tool. Comparisons of calculated and experimental results are shown for a variety of borehole sizes and formation lithologies, porosities, and salinities. The GST model can corroborate and extend experimentally determined responses and, hence, provide a better understanding of tool function.
Fracture Height Containment by Creating an Artificial Barrier with a New Additive
Authors: Nguyen H. X. , Larson D. B. 
Published: December 2007

ABSTRACT
This paper discusses the development of a novel fracture treatment technique which uses a nonreactive, buoyant diverter to control upward propagation of vertical fracture during the treatment. It is necessary to control such growth to prevent fracture penetration into undesirable zones, such as gas cap, water-bearing or nonproductive zones, and to promote maximum fracture extension within the producing interval.
Results of field evaluations indicate that the new treatment technique is successful. It offers a unique solution to preventing upward fracture growth that is independent of the formation properties and geologic stress environment.
An Engineering Simulator for Drilling: Part I
Authors: Millheim K. K. , Huggins R. L. 
Published: December 2007

ABSTRACT
This paper (Part 1) reports on the development of an Engineering Simulator for Drilling (ESD), an analytical system's approach to planning and analyzing drilling systems in real or faster than real time.
It is shown that a complex drilling system can be subdivided into component parts of geology, the drilling rig, wellbore, fluid system, and the drill string. Representing each subsystem with the appropriate set of algorithms that best depict the physics of the system, and interacting the various algorithms with other systems an accurate representation of the complete drilling process is achieved.
Each subsystem is described, showing the causality of some of the major algorithms. The use of previous analytical and laboratory drilling research in the development of some of the algorithms is cited.
The Engineering Simulator system is described, including the overall top down design of the operating system, the use of interactive color graphics, and the special use of the simulator computer hardware.
How the simulator is used to initialize and operate a drilling system is explained. The Engineering Simulator for Drilling (Part 2)1 goes into the operating levels of the ESD and how a drilling person would use it. Part 2 also gives an example of how a drilling system could be evolved and operated using the interactive graphics menus and pictures.
Pressure Transient Analysis in a Reservoir with a Compressible or Impermeable Circular Subregion: Gas Cap or EOR-Induced
Authors: Sageev Abraham , Horne R. N. 
Published: December 2007

ABSTRACT
A practical pressure transient analysis method is presented for the analysis of a drawdown test in a well near a circular subregion. Such subregions may exist naturally as gas caps or may be artificially produced by EOR operations. These subregions may be treated as either constant pressure or impermeable inner boundaries. The problem is mathematically posed and solved using the Laplace Transformation. A new semilog type curve method is presented which may be used to determine the size of the circular subregion and the distance to it. The method is of particular importance in that it permits the estimation of the size of an EOR affected region without shutting in the injection well.
Chemical Stability of Biopolymer Solutions
Authors: Ash S. G. , Clarke-Sturman A. J. , Calvert R. , Nisbet T. M. 
Published: December 2007

ABSTRACT
Biopolymers such as xanthan are being used increasingly in oilfield operations where the stability of the biopolymer is a prime consideration. The stability of xanthan depends on the brine salinity. Good viscosity retention over many months is observed in sea water at 90°C. The successful application of xanthan at temperatures higher than 90°C requires an understanding of the factors that limit stability. These factors include the nature of the polymer and the mechanisms of degradation. The stability features of a novel biopolymer are also described.
Porosity From Well Logs of the Kuparuk Reservoir: Procedures for Using Core Data
Authors: O'Brien W. J. 
Published: December 2007

ABSTRACT
This paper describes a reservoir description technique for computing porosity using both core and log data from the Kuparuk formation, North Slope, Alaska. Core porosity is used as a calibration tool to define clay parameters of the gamma ray and porosity logs. The gamma ray log must be normalized to apply its corresponding clay parameters. This approach is necessary in this reservoir because of the uncertainty in estimating clay volume fractions from well logs alone. Clay parameters can be applied over a wide area to compute porosity in uncored wells.
An analysis of core samples indicates that quartz and siderite are the dominant non-clay components. Various clay minerals and minor amounts of other carbonate minerals are also present. Moreover, natural fractures and vugs have been identified in core samples from zone C of the Kuparuk. Porosity and volume fractions of quartz, siderite, and clay are calculated using the density, neutron, and gamma ray logs. Fractured intervals are identified with the sonic log.
A comparison of core versus log data is presented from three cored wells of the Kuparuk field. Siderite concentrations obtained from logs agree with foot-by-foot measurements on cores. Agreement between computed and core porosity is usually two porosity units or better.
Monitoring the Effects of Hydraulic Stimulation by Microseismic Event Location: A Case Study
Authors: Batchelor A. S. , Baria Roy , Hearn Kevin 
Published: December 2007

ABSTRACT
One of the most promising techniques for monitoring the effects of hydraulic stimulation or fracturing is the use of the induced microseismicity to define the shape and orientation of the stimulated regions. The results presented in this paper are believed to be the first of their kind with an on-line location system mapping the stimulated zone during injection. The stimulation was undertaken as part of an investigation into the generation of hot dry rock geothermal reservoirs and consisted of a 3.5 million gallon injection at flow rates as high as 40 B/min. Many thousands of microseismic events were produced, located and presented as maps to enable the interpretation to proceed during the operation.
There are very few techniques which have been applied to give an independent measurement of fracture height, length and orientation. The monitoring of microseismicity offers the prospect of an accurate definition of the geometry provided other observation wells are available. The techniques presented in the paper would be applicable in dense, brittle formations without a significant velocity anisotropy. They are of direct relevance to the stimulation of geothermal systems, tight gas sands and limestone reservoirs. The results from such case studies will enable the design of fracturing procedures to be evaluated on directly measured results.
The results presented in the paper consist of a series of microseismic images relating to different stages in the hydraulic fracturing. The fracture front can be seen to grow with time and change orientation. The initial stimulated zone produced was 1.2 km long, 1.5 km high and 100 m thick. When the pressure was maintained on the system the stimulated zone grew to 400 m thick with the principal dimensions remaining the same.
These results represent a considerable step forward in the state of the art of monitoring hydraulic stimulation and have been an essential tool in understanding the geothermal reservoir performance.
Automated Type-Curve Matching in Well Test Analysis Using Laplace Space Determination of Parameter Gradients
Authors: Rosa A. J. , Home R. N. 
Published: December 2007

ABSTRACT
This paper presents an investigation of automatic methods of type curve matching for the interpretation of drawdown tests in the presence of wellbore storage and skin. Gauss or Gauss-Marquardt nonlinear regression methods are used to estimate wellbore, reservoir and boundary parameters in single layered, unbounded reservoirs. The use of numerical Laplace Transform inversion techniques to obtain gradients of the solution with respect to the unkown reservoir parameters makes the problem particularly streamlined, and is a major improvement on existing techniques. In addition, constraining the reservoir parameters to positive values (where appropriate) is found to improve convergence of the nonlinear regression algorithms.
Nonlinear regression algorithms require analytical expressions for the reservoir pressure drop and its derivatives with respect to the unknown reservoir parameters. These are frequently not available for existing type curves, which has prevented their automated fitting so far.
This work was successful in calculating these functions by numerical inversion of the known analytical expressions in Laplace space, making the automated fitting procedure possible in a wide range of formerly inaccessible cases.
Examples given demonstrate that the regression analysis in some cases can yield better results than the conventional graphical techniques.
Optimum Production Scheduling Using Reservoir Simulators: A Comparison of Linear Programming and Dynamic Programming Techniques
Authors: Lang Z. X. , Horne R. N. 
Published: December 2007

ABSTRACT
An automatic control procedure for the determination of optimal production schedules is developed. Some production parameters such as injection rates or downhole flowing pressure are considered to be the decision variables, the values of which are to be chosen to maximize oil production. At the same time other production and economic parameters (such as water oil ratio) are to be constrained. The procedures discussed here are a way of using reservoir simulators to optimize production schedules in an automatic manner. The approximation of the non-linear processes in the models in terms of locally linear processes permits such problems to be solved iteratively using linear programming. This in turn results in a procedure which is feasible within reasonable expense. The multistep optimization procedure can be carried out in several different ways; step by step, over all time steps at once or using dynamic programming. Step by step optimization converges more quickly but does not take into account influences from one step to the next. Iterating over all time steps is the most desirable but is computationally the most expensive and converges least quickly. Dynamic programming was found to be the most efficient, requiring little additional computational effort beyond the step by step method while still allowing the solution in one time step to influence subsequent time steps.