bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compaction Behavior of Ekofisk Chalk as a Function of Stress
Authors: Johnson J. P. , Rhett D. W. 
Published: December 2007

ABSTRACT
Reservoir management of the Ekofisk field requires accurate predictions of reservoir compaction that will occur during the production lifetime of the field. Laboratory measurements must provide realistic values of strain as a function of effective stress or predictive models will not give reliable estimates of compaction and surface subsidence.
The compaction behavior of Ekofisk chalk as a function of effective applied stress has been studied in the laboratory. The objective of this study was to obtain data which can be used to predict reservoir resulting from increased stress on the chalk due to reduction in reservoir pressure with production of the field. Compaction data for uniaxial strain conditions and for ultimate strain at a given applied stress are required as input for the predictive model. It was found that results obtained under hydrostatic test conditions are very similar to those obtained in uniaxial tests when the hydrostatic test results are converted by a standard formula to uniaxial conditions in the elastic region of the compaction curve and applied directly in the plastic (pore collapse) region. This observation for this particular material is valuable in providing a means of utilizing more easily obtainable hydrostatic data for many studies, and also is interesting with regard to understanding what is happening to the chalk in the pore collapse region.
Laboratory studies clearly show that strain in chalk is time-dependent. Ideally, compressibility tests should be of sufficient duration to observe all potential strain that would occur during the life of the field. This is clearly not feasible, however, and the analyst must obtain data from tests conducted on a time frame of days or weeks. To deal with this dilemma, a numerical technique was developed that predicts the ultimate compaction chalk will undergo when subjected to a given stress for infinite time. The technique has been applied to a large number of chalk compressibility tests. Correlation coefficients indicate the numerical technique does very well predicting chalk compaction in extended laboratory tests. The numerical technique allows real-time evaluation of strain equilibration during compressibility tests, it allows shorter tests, and it provides predictions of ultimate compaction of the reservoir.
Subsea Well Servicing: A New and Economical System—The SWIMS
Authors: Le Bouteiller D. , Berthler O. 
Published: December 2007

Abstract
Presently, most of the subsea wells wire line interventions are performed from a drilling semi-submersible using a completion/work over riser, a heavy equipment for a relatively simple operation.
The paper presents a new concept of riser, specifically designed for that purpose. It permits a very significant cost reduction, it is diver less, guideline less and can be operated from a medium sized DP monomull.
Its design includes many original technical solutions in matters such as riser re-entry, safety and riser handling.
Drilling Safely Offshore in Shallow Gas Areas
Authors: Sandlin C. W. 
Published: December 2007

ABSTRACT
Procedures for top-hole drilling should emphasize the maintenance of hydrostatic control of the well. Crew and rig safety, together with environmental protection, are the most important factors used both in the design of drilling procedures and in choosing among alternative drilling methods. This paper discusses the detailed engineering design of operating procedures, seismic interpretation, selection and maintenance of equipment, contingency planning, and crew training that are key elements to successfully drilling offshore in areas prone to have shallow gas.
Drilling Environmentally Sensitive Wells in Southern England
Authors: Redman P. J. 
Published: December 2007

ABSTRACT
Recent experience at Humbly Grove and at various Southern England environmentally sensitive locations has demonstrated that wells can be drilled without unacceptable intrusion and at reasonable costs. While Southern England is an area that is particularly sensitive to any industrial encroachment a drilling programme conducted during 1985 and 1986 has helped to prove that exploration, appraisal and development wells can be drilled in an environmentally acceptable manner. Particular attention was paid by the Operator to a close working relationship with the planning and environmental officers, and the use of innovative methods of noise suppression and operational efficiency. It follows that other sensitive areas of outstanding natural beauty onshore Britain can be drilled if sufficient planning is carried out and the oil company takes a responsible and ethical approach, giving due regard to the protection of the environment in the operational methods used.
Exploration for Oil and Gas in the Michigan Basin: A Historical Review
Authors: Aminian K. , Ameri S. , Bomar R. M. 
Published: December 2007

Abstract
The Michigan Basin, which is centered in Michigan's southern pennisula, has been an oil and gas producing province for decades. The first substantial oil production in Michigan was obtained in 1925. Various structural and stratigraphic traps of different geological age have since been discovered and have produced oil and gas.
All Paleozoic systems in Michigan, except the Cambrian, have produced oil and gas. The Mississippian rocks were the major target of explorations during the 1930's and 40's while Devonian rocks became the major producers during the 1950's. The Ordovician reservoirs contributed most of the oil produced in the state during the 1960's. The discovery of the Niagaran reefs in southeastern Michigan during the late 1950's, which was followed by extensive exploration of the northern reef trend during the 1970's, resulted in the development of the Niagaran Reef Belt which has been the most prolific producing formation in Michigan.
The Niagaran Reef Belt still has good potential for future development especially in the southern and western parts of the state. In recent years, however, attention has been focused on a new deep target zone of Early Ordovician age in the central part of the basin termed Prairie du Chien. The first discovery well was drilled in 1980 with additional discoveries during the past two years. The recent discoveries suggest that the wells, which are drilled in the existing Devonian fields, are most favorable to encounter Prairie du Chien structures.
This paper reviews the exploration and developmental activities in Michigan and provides geological background as well as reserves estimates and reservoir characteristics for the selected producing formations. The emphasis is placed on those formations which have the most potential for future exploration and/or development.
Developing Gas Resources in Appalachian Basin Through Recompletion: An Economic Feasibility Study
Authors: Ameri S. , Aminian K. , Kutska H. M. , Waldrop L. A. , Yost A. B. , Komar C. A. 
Published: December 2007

Abstract
The Appalachian Basin is one of the oldest gas producing provinces in the United States. Over the years, many low permeability reservoirs of different geological ages have produced gas in this area. In recent years, the gas produced in this region has encountered difficulties in remaining competitive due to the decline in gas demand and supply surplus. In order for this gas to remain competitive and regain markets, it is necessary to reduce the cost of drilling and/or completion. One economic means of developing gas resources is through deepening/recompleting the existing gas wells to new horizons. This is particularly applicable to the Appalachian Basin where there exists many old and marginal gas producing wells.
This paper provides a general methodology to evaluate the economic feasibility for deepening/recompleting existing shallow gas wells to new horizons through slim-hole drilling. In this study, several geological units in Appalachia have been selected to demonstrate the feasibility of slim-hole drilling/recompletion as well as their relative economic incentive. Various data on these geologic units have been collected and compiled. The collected data were analyzed to delineate the production history as well as the characteristics of the formations under study. The results were later utilized in conjunction with the discounted cash flow model for determination of the rate of return and the payout time for different horizons (which are most suitable for deepening marginal wells through slim-hole drilling). In addition, the areas which are potential candidates for recompletion have been identified. These areas have further been ranked based upon the economic indicators such as the rate of return, payout time, etc. The results clearly indicate that gas can be produced at substantially lower prices in comparison to drilling new wells to the same target intervals. Thus, recompletion through slim-hole drilling provides a significant incentive for development of gas resources in this region.
An Improved Microcomputer Approach to Well Test Interpretation
Authors: Chang J. , Ershaghi I. 
Published: December 2007

Abstract
A direct search method called "DFS", Derivative Free Search is proposed for estimation of an initial guess of parameters in non-linear regression technique used in well test interpretations. The procedure consists of locating the neighborhood of a point where the objective function is minimum among qq points which are most uniformly distributed in a kk dimensional space. For certain cases, repetition of the procedure alone may result in a convergence of the solution. In general, however, the coordinates of the neighborhood minimum can be used as a starting point for any gradient type algorithm.
Production Data Analysis Type Curves for the Devonian Shales
Authors: Hazlett W. G. , Lee W. J. , Narahara G. M. , Gatens J. M. 
Published: December 2007

ABSTRACT
Analysis of production data from the Eastern Devonian Gas Shales has shown that certain reservoir characteristics correlate with observed well performance. This result led to an investigation to determine whether some combination of these characteristics in dimensionless form could be used to construct a general set of Devonian Shale production data analysis type curves. This paper presents the results of this Investigation.
A set of dimensionless production performance graphs, or type curves, has been constructed using an analytical dual-porosity reservoir model. Although developed specifically for Devonian Shale gas wells, these curves apply generally to longterm production data from dual-porosity reservoirs. These type curves can be used to analyze long-term production data. From results of this analysis, it is possible to determine certain reservoir characteristics and to predict future performance. Example applications of the type curves to typical Devonian Shale wells are presented in this paper.
Analysis of Air Drilling Circulating Systems with Application to Air Volume Requirement Estimation
Authors: Wolcott D. S. , Sharma M. P. 
Published: December 2007

ABSTRACT
Air drilling uses air or gas as the circulating medium. Because there are so many variables involved in air or gas drilling no one general method has been developed to predict the appropriate volumetric requirements for field use. In an attempt to alleviate this problem a computational model has been designed and developed which can analyze the pressure drop contributions for the complete air drilling system. This will facilitate the optimization of the air or gas pressure and volume requirements. The model is capable of analyzing the effects of variations in flow rate, sandpipe pressure, cutting size distribution, and loading.
Studies conducted using the computational model includes an analysis of several methods for determining pressure drop due to the solids phase. The results from these studies were compared with Industry Field Experience Data. Two of the methods indicated good agreement with the data.
Continuous Mixture Computational Algorithm of Reservoir Fluid Phase Behavior Applicable for Compositional Reservoir Simulation
Authors: Du P. C. , Mansoori G. A. 
Published: December 2007

ABSTRACT
Development of compositional reservoir simulators is presently hampered due to the complexity of the existing computational algorithms of reservoir fluid phase behavior calculations. Through the application of the theory of polydisperse fluid mixtures we have been able to develop a number of algorithms for phase behavior calculations. In the present report we introduce one of such algorithms. In this algorithm reservoir fluid is considered to consist of a continuous mixture with a defined molecular weight/composition distribution function. Computational computer time required for the new algorithm is shown to be one order of magnitude smaller than the existing algorithms. As an example, the new algorithm is used to perform retrograde condensation calculations for two different gas-condensate reservoir fluids. Comparisons of experimental data with the calculated results indicate good agreement between the two.
Development and Application of a Limited-Compositional, Miscible Flood Reservoir Simulator
Authors: Bolling J. D. 
Published: December 2007

ABSTRACT
A simulator to model immiscible and miscible displacements was developed. The simulator uses a multi-component, limited-compositional PVT model with pressure dependent K-values. A mixing parameter formulation is included to account for displacement instabilities in miscible studies. The simulator can be used for studies involving a variety of important reservoir fluids. A finite-difference numerical formulation uses each cell's pressure and component masses as primary variables. This choice offers flexibility in coupling PVT models of varying complexity to the reservoir flow equations. The formulation solves the PVT relationships, component mass balances, and a volume constraint simultaneously using a Newton-Raphson method. Of the three nonlinear terms of the component balance equations, the accumulation and well terms are treated implicitly in all variables. In the IMPES method the flux terms are treated implicitly in pressure only. If required, a fully-implicit method evaluates the flux terms implicitly in all variables. The simulator code has been written in an efficient, structured, and modular manner with vectorization of the majority of the cell and matrix calculations. Benchmark problems and examples comparing results from this model to a fully-compositional simulator are presented.
A New Simulator for Naturally Fractured Reservoirs
Authors: Sonier F. , Eymard R. 
Published: December 2007

ABSTRACT
This paper describes a three-dimensional, three-phase, simulator designed for modelling fluid flow in a naturally fractured reservoir. A dual permeability system and/or a dual porosity system, is used to describe complex porous media including highly-fractured, micro-fractured and non-fractured regions. In addition to the viscous and capillary pressure forces, the matrix-fracture exchange terms can handle gravity effects with differing results depending on matrix block sizes or matrix block connections.
The conservation equations are expressed in compositional form and equilibrium K-values are used. The fully implicit equations are linearized by a Newton-Raphson iteration scheme. The method of checking the changes of phase allows a complete compatibility with the conservation equations. Because of the multi-purpose nature of the model, several different choices of discretized time-solution techniques are available. Various sequential solutions and the IMPES solution are obtained as simplified versions of the fully implicit technique.
This multi-purpose simulator is designed for solving full-field reservoir problems as well as laboratory experiments. Standard one porous medium black-oil problems can be solved with this simulator without any computer-time penality.
Examples are presented to illustrate the stability of the model, the differences in performance depending on the time-solution schemes used and the essential differences between the new approach and those used in earlier naturally fractured reservoir models.
Local Grid Refinement for Three-Dimensional Simulators
Authors: Wasserman M. L. 
Published: December 2007

ABSTRACT
A static local grid refinement technique has been developed and implemented in a three dimensional, three phase reservoir simulator. The technique increases simulator accuracy without a major increase in computing cost. The method performs a "domain decomposition" whereby rectangular regions (called windows) are chosen from a coarse grid and refined in all three dimensions. Areal grid lines terminate when they hit the boundary of the refined domain. They need not be extended to the boundary of the model, as is the case in our current simulators. An efficient linear equation method is used which takes full advantage of the domain decomposition. Using this technique, the time required to solve a multi-window model increases linearly with the number of windows – not exponentially, as would be the case when no advantage is taken of the matrix structure. Results for several idealized test cases are given.
A New Innovation in Directional Only MWD Systems
Authors: Wesenberg D. L. , Polito J. 
Published: December 2007

ABSTRACT
As the petroleum industry continues to feel the impact of a depressed economy and the erosion of world oil prices, some of the world's leading service and manufacturing companies have made great technical advances toward improving the drilling industry's ability to drill for oil and gas in these difficult economic times.
An example of one of the latest technical advances is a new directional only MWD system. Simplicity and flexibility provides real cost savings over many existing systems. Design simplicity has led to a helicopter supportable system which is easily delivered to both on and offshore drilling locations.
The results of a series of directional only MWD field tests and commercial jobs, run worldwide under a wide variety of drilling conditions, are presented in this paper. The results substantiate the viability of the low cost, high reliability approach to the directional-only MWD market.
Automated Pipe Handling: A Fresh Approach
Authors: Brugman J. D. 
Published: December 2007

ABSTRACT
A new generation pipe racking system has been developed which combines the functions of traditional power pipe racking systems with the functions of remote controlled floor mounted iron roughnecks into one machine for automated pipe handling. The machine enables a single operator to execute all the pipe tripping functions from the floor to the monkey board. It incorporates stand makeup and breakout within itself, which eliminates the need for other equipment and people to perform those functions. The one operator can individually control each function manually, using observed position, or he can let automatic sequences take over. Improvements over previous racking systems and iron roughnecks include:
– One-man operation versus up to five-man operation, and no derrickman; – Total pipe handling – drill pipe and drill collars without jaw changes; – Improved safety through elimination of manual floor operations.
This paper describes this system, which represents a major step toward a practical automated drilling rig, and documents its performance during actual field operations.
An Evaluation of the API Oil/Water Retort Apparatus and Procedure for Monitoring Oil in Offshore Discharges
Authors: Jones M. , Bagnall R. A. 
Published: December 2007

ABSTRACT
The API Oil/Water Retort Apparatus was evaluated for use in monitoring oil content of offshore drilling discharges. A total of 526 samples of various drilling muds were retorted with 5 different models of two basic types (heating element and heating jacket) and 3 sample sizes (10, 20, and 50 mL). The 20 mL heating element retort was determined to be the best unit for this purpose in terms of accuracy, speed, convenience, and cost. The minimum amount of oil in a mud that could accurately be measured was 1% (v/v), although &lt;1% could be detected. To achieve precision and accuracy of retort measurement required modifications of the API procedure. Retort extraction was compared to shaker and soxhlet extraction and to the proposed EPA cup sheen test.
Improving BHA Tool Reliability with Drillstring Vibration Models: Field Experience and Limitations
Authors: Burgess T. M. , McDaniel G. L. , Das P. K. 
Published: December 2007

ABSTRACT
Statistics on BHA tool components revealed significantly more failures in vertical holes than in deviated holes. The difference was attributed to damping of vibrations at stabilizers in deviated holes. Modelling of drillstring vibrations showed that high shocks associated with transverse vibrations of the BHA were the probable cause of failure.
A model of the transverse vibration response of the BHA was developed to improve the design and the location of the tools in the drillstring. The model was able to associate the failure of many MWD and other components with resonance in the drillstring. Application of the model at the BHA planning stage reduced the number of tool failure attributed to BHA design and operating conditions by about one half. As a consequence a rig site program was developed.
This paper gives examples of field case studies, describes the rig site model, and discusses the sometimes real limitations of BHA vibration models.
BHA Lateral Vibrations: Case Studies and Evaluation of Important Parameters
Authors: Allen M. B. 
Published: December 2007

Abstract
Recent efforts to compute and measure drillstring and bottom hole assembly vibrations have shown that vibrations occur in the BHA which do not coincide with computed natural frequencies for axial and torsional vibrations. Analysis of BHA failures has indicated that lateral vibrations in the BHA was the probable cause of some failures.
This paper presents a collection of bottom hole assembly failures. The possibility of lateral vibrations being the cause of a failure has been evaluated by considering circumstances surrounding the failure and making comparisons to a lateral vibration computer model. Similarities between lateral vibration failures are analyzed to determine what parameters are important in identifying the susceptibility of a bottom hole assembly to large lateral vibrations. The parameters include depth, hole size, ratio of hole size to drill collar diameter, and stabilizer placement.
The results of this paper allow the drilling engineer to avoid BHA designs which have been shown to be susceptible to lateral vibration failures and identify designs which should be evaluated in more detail such as with a lateral vibration analysis.
Preliminary Field Test Results of Diamond-Enhanced Inserts for Three-Cone Rock Bits
Authors: Salesky W. J. , Payne B. R. 
Published: December 2007

ABSTRACT
Increased penetration rate accompanied with longer life have always been primary objectives of both rock bit manufacturers and drilling contractors. Tungsten carbide inserts have been used in rock bits for over 30 years and are a mature technology. Synthetic diamond insert technology may prove to be the next step in three-cone rock bit performance.
For the past 24 months a development program has been conducted focusing on the application of high pressure diamond technology to three-cone rotary rock bit drilling. A diamond coated insert has been developed that shows little wear even when run in the gage row, after drilling over 200 hours and 6000 feet of formation.
This paper reviews the design and laboratory testing of diamond enhanced gage Inserts with an emphasis on field performance. The impact of this technology on bit life, penetration rate, and drilling costs will also be discussed.