bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrocarbon Production from the Devonian Shale in Letcher and Knott Counties, Eastern Kentucky
Authors: Kemper J. R. , Frankie W. T. , Moody J. R. , Johnston I. M. 
Published: December 2007

ABSTRACT
The Kentucky Geological Survey (KGS) at the University of Kentucky is conducting a research project funded by the Gas Research Institute (GRI) to study hydrocarbon production from the Devonian shale in eastern Kentucky. The primary objectives of this project are to develop an understanding of the relationship between local geology and hydrocarbon production from the Devonian shale, to create a comprehensive Devonian shale data base of well information, and to prepare an oil and gas report for each county in the study area. Project data have been compiled from the KGS oil and gas well record files, the GRI Eastern Gas Data System (EGDS), files from the U.S. Department of Energy (DOE), and records from cooperating oil and gas companies operating within the study area.
Gamma-ray logs were found to be the most valid means of identifying the stratigraphic units within the Devonian shale. Temperature logs are used to locate gas shows in order to determine which interval to stimulate. The combined use of the temperature log to find the gas shows, and the gamma-ray log to identify which stratigraphic unit the gas is coming from, is an invaluable method for determining the treatment interval.
The two most common methods of stimulating production in Letcher and Knott Counties are explosive shooting and hydraulic fracturing. Comparison of the initial potentials both before and after treatment indicates that hydraulic fracturing is preferable to borehole shooting for improving production in the Devonian shale.
Data compilation in Letcher and Knott Counties is complete. An extensive data base of information on the 1,412 Devonian shale wells in Letcher and Knott Counties has been compiled. Using this information, detailed stratigraphic cross sections within the Devonian-Mississippian shale sequence have been constructed, as well as structure, isopach, and isopotential maps.
Analysis of the maps and cross sections suggest two relationships. There appears to be a direct relationship between areas of high Devonian shale initial open-flow potential and 1) the location of shallower hydrocarbon production, and 2) the location of linear features determined from LANDSAT imagery.
The preliminary results of this study provide the petroleum industry with valuable guidelines for the future exploration of natural gas in the Devonian shales of eastern Kentucky.
Dimensionless IPR Curves for Predicting the Performance of Fractured Gas Wells
Authors: Chase R. W. , Williams M. A. T. 
Published: December 2007

Abstract
Dimansionlees IPR curves have been developed for predicting the performance of fractured gas wells. The equation for pressure drawn-down in a gas reservoir producing under pseudo-steady state conditions was solved utilizing an equation which related fracture length and skin factor to wellbore radius, yielding two distinct dirrensionless IPR curves. Fractured wells with zero and negative skin factors exhibit the sane dirrensionless IPR behavior reported by Mishra and Caudle for unfractured gas wells. Fractured wells having a positive skin factor, while less commonly observed in actual field practice, yield a linear dirrensionless IPR curve. The resulting curves provide the engineer with a method for predicting gas well deliverability from a single stabilized flow test and shutin, thus eliminating the need for multi-point tests.
A Comparison of Two Approaches to Compositional and Black Oil Simulation
Authors: Wong T. W. , Firoozabadi A. , Nutakki R. , Aziz K. 
Published: December 2007

Abstract
This paper examines the relative strengths and weaknesses of solving a fully compositional isothermal three phase numerical simulator by two fundamentally different approaches. One of the methods considered is based on the standard Newton-Raphson procedure where the partial derivatives for all the pertinent equations are written with respect to a selected set of primary variables in a Jacobian matrix. This model can be solved fully implicitly as Coats did, or implicitly for pressure and explicitly for saturation and composition (IMPEM) as Fussell and Fussell or Young and Stephenson did. The alternative method, first proposed by Acs et al., is based on a volume balance where in each simulator block, the pore volumes are equated with the fluid volumes. As originally proposed, this method was also an IMPEM one, but Watts later extended it to include a sequential step implicit in saturation. As yet, no computational results have been published for this volume balance method.
The Young and Stephenson model is compared with the IMPEM method of Acs et al. as well as the sequential method of Watts. The main area of comparison is the relative ease or difficulty with which each simulator handles various compositional problems. The advantages and disadvantages of using either method under different circumstances are discussed. As well, the performance of these simulators in their corresponding black oil forms is compared.
Both models can be run using either the Peng Robinson, Soave-Redlich-Kwong, or Schmidt-Wenzel equations of state. All the derivatives needed in both models can be solved explicitly from analytical expressions that have been derived from these equations of state.
A Thermal Simulator for Naturally Fractured Reservoirs
Authors: Chen W. H. , Wasserman M. L. , Fitzmorris R. E. 
Published: December 2007

Abstract
Because of the relatively heavy oil (8 − 12° API) encountered in many naturally fractured reservoirs, thermal recovery processes could be viable recovery techniques to produce oil from these reservoirs. To facilitate the simulation of these processes, a simulator to model thermal effects in naturally fractured reservoirs has been developed. The model uses the double porosity concept and is three dimensional, three phase, and compositional. It allows the rock matrix block to be subdivided into a two-dimensional (r−z) grid block in order to study effects of gravity, capillary pressure, and mass and energy transfer between fractures and matrix blocks. The simulator is fully implicit and has a coupled wellbore mathmatical formulation, and simultaneously solves the unknowns for fractures and matrix blocks. An efficient solution procedure is implemented so that the cost of modelling naturally fractured reservoirs is not significantly greater than the cost of conventional single porosity thermal simulation.
An example, steam injection into a five-spot pattern, is included to illustrate the significant effects of physical properties and model construction. Oil recovery predictions are sensitive to capillary pressure values, the number of cells used to divide the matrix block, and the size of the matrix blocks.
Computing Absolute Transmissibility in the Presence of Fine-Scale Heterogeneity
Authors: White C. D. , Horne R. N. 
Published: December 2007

Abstract
This paper presents an algorithm to compute transmissibility when there is permeability heterogeneity and anisotropy at the subgrid scale. The need for a tensor representation of macroscopic transmissibility in order to scale properly the effects of microscale permeability variations is demonstrated. Methods for computing tensor transmissibility and the use of tensor transmissibility in reservoir simulation are described. The proposed method is applicable even when the variance of permeability is large and the principal directions of the transmissibility tensor are not aligned with the coordinate axes. Examples demonstrate that the general tensor scaling procedure can give accurate, efficient production estimates on a coarse grid.
Pseudofunctions in Formations Containing Discontinuous Shales: A Numerical Study
Authors: Davies B. J. , Haldorsen H. H. 
Published: December 2007

Abstract
Discontinuous shale-bodies are one of the commonest forms of heterogeneity in productive formations, and may have a significant effect on the response of a field to waterflooding or other oil-recovery operations. The problem of describing these shale-bodies in a multiphase simulation model may be addressed by applying stochastic modelling and pseudofunction technology. The description of shale-body effects at the coarse-grid scale is affected by dynamicity and representative elementary volume considerations.
Least-Squares Finite Elements for Convective Transport Problems
Authors: Carey G. F. , Jiang B. N. 
Published: December 2007

ABSTRACT
Convective transport problems have been difficult to treat with Galerkin-type finite-element methods, and this has led to upwind Petrov-Galerkin and Taylor-Galerkin variants of the method. Here, we develop a novel approach to the problem based on a least-squares formulation for first-order systems. The method is shown to lead to a discrete problem similar to that of the Taylor-Galerkin approach and to produce excellent results for purely convective transport (infinite Peclet number) in one dimension. The further extension of the method to nonlinear problems is described and test results for a model problem given.
Simulation of Flow in Naturally Fractured Reservoirs
Authors: Douglas J. , Leme P.J. Paes , Arbogast T. , Schmitt T. 
Published: December 2007

Abstract
This paper describes two models for simulating flow in naturally fractured petroleum reservoirs, one for single phase flow of a fluid of constant compressibility, and the other for two-phase, incompressible, immiscible flow. Both models are based on the dual porosity concept, in each model the flow in an individual matrix block is simulated using the standard equations describing flow in unfractured media, and the matrix/fracture interaction is based on the imposition of proper boundary conditions on the surface of the block. The models are presented in an easily parallelizable form.
Parallel Iterative Linear Equation Solvers: An Investigation of Domain Decomposition Algorithms for Reservoir Simulation
Authors: Killough J. E. , Wheeler M. F. 
Published: December 2007

ABSTRACT
The use of parallel iterative techniques for the linear equations associated with reservoir simulation was investigated. A technique is described in which a lower dimensional problem is used as a correction to the preconditioned generalized conjugate residual method with the domain decomposition technique as the overall preconditioner. For the cases investigated the method proved to be both robust and efficient.
Three example matrices, including a highly heterogeneous example, an example from the SPE/SIAM comparative solution project, and a nonsymmetric IMPES reservoir simulation example, are presented to validate the method. Several comparisons are made with other well-known preconditioners including incomplete LU and reduced system/incomplete LU factorizations. For the examples considered the domain decomposition technique was the most efficient in a nonparallel environment; in a parallel computational environment the algorithm was several times more efficient than the other techniques. An analysis was made concerning both vector and parallel computational aspects of the domain decomposition method. Numerical experiments showed that the effect of the number of domains on the convergence rate is small. Corrections using a lower dimensional problem, known as line corrections, were found to be necessary for the rapid convergence of the method. Finally, the three dimensional domain decomposition algorithm was efficiently implemented in parallel computational environments using multitasking and microtasking on both the CRAY X/MP 48 and IBM 3090/400 four-way parallel supercomputers.
Equation of State Compositional Modeling on Vector Processors
Authors: Young L. C. 
Published: December 2007

ABSTRACT
Previously, large simulation problems have not been feasible with equation of state (EOS) compositional models. This paper describes an approach for efficient EOS calculations. Tests of a simulator based on the approach, show that large problems can now be solved. For example, a problem composed of 9-components, 20,000 grid points, and 1,000 time steps can be solved in approximately 40 minutes of CPU time on a Cray X-MP.
Efficient Fluid Behavior Computations in a Sequential Compositional Reservoir Simulator
Authors: Subramanian G. , Trangenstein J. A. , Mochizuki S. , Shen E. l-C. 
Published: December 2007

ABSTRACT
A compositional reservoir simulator using a sequential formulation of the fluid flow and phase equilibrium equations requires that the phase equilibrium and associated derivatives of the dependent phase equilibrium variables with respect to the pressure and moles of individual components be computed every time step for all the grid blocks in the system. The phase equilibrium calculations are computation intensive, since they solve a nonlinear system of equations and are thus iterative in nature.
This paper describes techniques for implementing the phase equilibrium and the associated derivative calculations in a sequential compositional reservoir simulator designed for large reservoir models. These techniques use strip mining and optimal strategies for treating gridblocks at similar mathematical convergence or physical states and have been very successful in reducing computation times and memory requirements for iterative computations in the simulator, both on the CRAY and IBM computers.
The derivative calculations are unified in that a single matrix can be used to generate derivatives of phase equilibrium variables with respect to any of the dependent variables used in the flow/conservation steps used in the simulator. Results are presented to illustrate various cases.
The Use of Vectorization and Parallel Processing for Reservoir Simulation
Authors: Chien M. C. H. , Wasserman M. L. , Yardumian H. E. , Chung E. Y. , Nguyen T. , Larson J. 
Published: December 2007

ABSTRACT
A general purpose reservoir simulator was developed as a vehicle to investigate vectorization and parallel processing on the Cray XMP/48. The simulator can model black oil, compositional and steam injection processes. It includes both fully implicit and IMPES formulations. Microtasking is used for parallel processing in order to maintain the portability of the code.
The simulator calculations other than linear equation solution were structured to facilitate vectorization and parallel processing. Several issues concerning parallel processing are discussed. These include task granularity, load balance, synchronization, memory contention, and balance between vectorization and arallel processing.
Based on three test problems, the speedup of the calculations due to vectorization ranges from 5.3 to 10. The speedup can be augmented by as much as 3.3 times through parallel processing. The scheme proposed here is general enough to be applicable to other vector and parallel processing computers.
A General Purpose Chemical Flood Simulator
Authors: Scott T. , Sharpe S. R. , Sorbie K. S. , Clifford P. J. , Roberts L. J. , Foulser R. W. S. , Oakes J. A. 
Published: December 2007

ABSTRACT
A new advanced and versatile chemical flood simulator has been developed for modelling polymer and surfactant oil recovery processes. The simulator takes into account many important fluid properties and includes a sophisticated treatment of phase behaviour. The modelling of temperature effects forms an integral part of the program, allowing for heat transfer between fluids and reservoir formation. Other important features include non-Newtonian rheology, chemical reaction and component degradation, adsorption of components, velocity dispersion effects, and fluid and rock compressibility.
The scope of the simulator is illustrated by application to several representative polymer and surfactant examples. These give an overview of the extensive range of problems which can be handled by the program including studies at the field and laboratory scales.
A Framework for Multiphase Nonisothermal Fluid Flow in a Deforming Heavy Oil Reservoir
Authors: Tortike W. S. , Ali S. M. Farouq 
Published: December 2007

ABSTRACT
The problem of multiphase (oil, water, gas), non-iso-thermal fluid flow in a heavy oil reservoir is of great interest in thermal recovery operations, especially steam injection. The much more complex problem of simultaneous stress-strain calculations in the reservoir and adjacent media, and reservoir compaction or dilation is of great importance in regions of Canada, Venezuela and the U.S.A. Such an extended problem is the theme for this paper.
The subject problem is being solved by the finite element method (FEM) for a three dimensional system. Flow of oil, water and a gaseous phase including steam, with the flow of heat, and simultaneous reservoir deformation is expressed by the appropriate partial differential equations (PDEs). The flow equations are formulated by the Petrov-Galerkin technique applied to the weighted residual method, and the stress-strain equations are solved by standard finite element techniques.
The simulator is being developed on the CDC Cyber 205 vector processor, which provides the high computational speeds needed for such a complex problem. The computational effort required by the finite element method has limited its wider use in reservoir simulation, where finite difference methods are the norm.
Borehole Stresses: Plasticity and the Drilled Hole Effect
Authors: Mitchell R. F. , Goodman M. A. , Wood E. T. 
Published: December 2007

ABSTRACT
Borehole stresses and deformations can be the cause of numerous high cost drilling, completion, and production problems, including:
Drill string and casing sticking through borehole contraction, Gas migration due to ineffective sealing between casing, cement, and borehole wall, Breakdown and possible mobilization of formation material leading to impaired productivity/injection, Borehole destabilization with possible sand production, and Overestimation of porosity from logs due to dilatation around the borehole.
This paper presents an elastic-plastic model that predicts borehole movement and quantifies the effects of yield around the borehole as the hole is drilled. Results are reduced to a family of dimensionless curves incorporating key variables of mud weight, rock properties, hole geometry, and in-situ stresses. Borehole unloading during drilling and also reloading during cementing and completion operations can be evaluated. Qualitative comparisons to case histories are provided to demonstrate the borehole movement relationship and to explain behavior observed in specific wells.
An Analysis of Discrepancies Between Gyro Surveys
Authors: Thorp M. 
Published: December 2007

ABSTRACT
Several gyro survey systems have been introduced recently with claims of high accuracy. Only limited data have been published in support of the claims, and it has generally been in unchallenging wells (low angle, latitude, temperature, depth). This paper presents data from 12 Ninian Field wells with hole angles of up to 65°, depths to 18500′ and a latitude of 61°N.
Two companies surveyed each well. The bottom line and claimed accuracy of each survey is summarised. Horizontal differences between the tools vary from less than one foot to over 200 feet at T.D. A statistical analysis is presented comparing observed and expected discrepancies. Chi-squared and Student's ‘t’ tests are applied to the data and suggest that neither tool suffers from a systematic error relative to the other; the spread of errors does, however, indicate that the differences are statistically surprising.
Without a benchmark survey one cannot prove that either system is wrong. What is done instead is to derive working accuracy values based on which the observed discrepancies are no longer surprising.
In five of the wells an inertial navigation tool was run in the 133/8″ casing in addition to the two other systems which were run at T.D. The data at equivalent depths is presented and a similar statistical analysis is applied.
UL's Third-Party Approach to Intrinsic Safety Testing
Authors: Bartkus A. A. 
Published: December 2007

ABSTRACT
The use of intrinsically safe instrumentation and wiring reduces the potential of fire and explosion hazards due to ignition by electrical arcs or high temperatures of flammable gas mixtures that may be released during the drilling operation. To determine compliance with national or international standards, the inspection authorities usually require that such equipment be third-party listed, approved or certified.
Underwriters Laboratories Inc. (UL) third-party evaluation of intrinsically safe circuits and instrumentation for use on drilling rigs is described. Examples are given of the types of instrumentation available to monitor the drilling process, designation of the hazardous locations, and how the instruments are constructed to be intrinsically safe – meet the requirements in the ANSI/UL/NFPA 4913 standard.
The principles of the intrinsic safety method of protection are explained and shortcut approaches for evaluation and design are discussed. The electrical and thermal energy available in the intrinsically safe instruments and circuits is so low that under normal operation, or fault conditions, they are not capable of causing ignition of the flammable mixture. The intrinsically safe circuits are separated from any higher energy circuits both inside the instrument and during field installation.
Additionally, the UL investigatory procedures for intrinsically safe instrumentation to international and foreign national standards are reviewed, along with the highlights of the recently developed UL Certificate program aimed at facilitating acceptance of such products overseas. The information contained in a certificate is examined.
A Contractor's History of Drillstring Failures in the Anadarko Basin
Authors: Hampton S. D. 
Published: December 2007

ABSTRACT
Helmerich & Payne International Drilling Co. has developed a data base of drill string failures experienced in the Anadarko Basin over a two year period. The analysis of this data has led to some operational changes in an effort to minimize drill string problems. This paper discusses the drill string failures experienced as well as the courses of action taken in an effort to reduce future failures.
Significant conclusions have been drawn from both the drill collar failures as well as the drill pipe failures. The drill collar failure analysis shows that a minimum bending stength ratio of 2.4 is recommended to avoid drill collar connection problems in the Anadarko Basin. Analysis of the drill pipe failures revealed that 43% of the failures occurred within the first 15 joints above the bottom hole assembly· As a result, H & P has increased the use of heavy walled drill pipe above the bottom hole assembly.
A Potassium-Base Derivative of Humic Acid Proves Effective in Minimizing Wellbore Enlargement in the Ventura Basin
Authors: Pruett J. O. 
Published: December 2007

ABSTRACT
A potassium-base derivative of humic acid has been designed and developed for water-base drilling fluids. The product has proven successful as a rheology control agent in both dispersed and non-dispersed potassium muds.
This organopotassium complex additive:
is an effective deflocculant, provides source of potassium ion for inhibition, can be used in low/high pH, fresh/seawater muds.
In addition, the 3 mud system formulated with OPC has favorable aquatic toxicity levels when compared to alternative potassium-base mud systems.
Initially OPC was used to replace the traditional lignites and lignosulfonates in KOH/lignite and KOH/lignosulfonate systems. After being laboratory tested for thinning ability and inhibitive characteristics, OPC was field tested. Field application on wells in the Ventura Basin resulted in improved hole size and excellent primary cement bond logs. Compared to offset wells drilled in the area, combined drilling and cementing costs were reduced.
This paper covers the development and initial field application of OPC. Both the theory behind its design as well as system formulation are included.