bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Optimization of Slant-Well Drilling in the Lindbergh Field
Authors: Vrielink H. J. , Hlppman A. M. 
Published: December 2007

Summary
Since 1985, Dome Petroleum Ltd. has developed slant-well drilling in the Lindbergh heavy-oil field in east-central Alberta. The oil-bearing sands occur in the lower Mannville formations of the Cretaceous period. To date, four pads, each consisting of 15 or 16 wells, have been completed. The experience gained in completing these projects has allowed us to make optimum use of slant-well technology in multiwell pad applications.
The heavy-oil reservoirs in the Lindbergh field contain oil with a gravity of 0.98 g/cm3 [12.5° API]. The reservoir is at a vertical depth of 600 m [1,970 ft]. The wells are drilled on 4-ha [10-acre] spacing and placed on primary production for 2 years, after which steam stimulation is used for EOR. This primary production of cold oil has significant economic impact on the development of this field because capital recovery is achieved for drilling and completion before the massive investment into steam generation and distribution facilities. Maximizing this primary recovery requires that low-dogleg-severity (DLS), "straight" holes be drilled.
The Lindbergh area is characterized by high agricultural land use. With slant-well technology, the required spacing unit is achieved with minimum surface land usage, optimum hole quality, and minimum environmental impact. In this application, slant-well drilling provides an attractive alternative to conventional directional multiwell pad projects.
In the initial stages of slant-well development, drilling times of 5.5 days/well and costs** of $315/m [$81/ft] were experienced. Through an optimization process involving pad design, drilling equipment, casing design, bits and hydraulics, and directional/survey assemblies, significant savings in drilling time and cost were realized. To date, 71 slant wells have been drilled. In the latest project, drilling time averaged approximately 2 days/well and costs were reduced to $177/m [$45/ft]. These savings were achieved with an improvement in directional control and overall hole quality. This paper describes the optimization process and the techniques used to realize these savings.
Field Test Results With Alkaline Potassium Solutions To Stabilize Clays Permanently
Authors: Sloat Ben F. 
Published: December 2007

Summary
The use of concentrated KOH to stabilize clays is becoming a common practice in Wyoming. Seventy-two injection wells, ranging from single pilots to fieldwide programs, have been treated and monitored since the technology was first introduced in Aug. 1984. This paper summarizes test results that fall into three broad categories: (1) those that increase recoverable reserves, (2) those that speed the rate of waterflood oil recovery, and (3) those that do more harm than good. Wells in the first two groups are examined starting with treatment design and wellsite preparation and moving on through the pumping stages to final evaluation of the results. The mixing and handling of highly alkaline solutions are covered from the service company and operator safety viewpoints, and with respect to the fluid-quality, chemical, and metallurgical requirements for proper placement of the solutions. Two wells are singled out for their special contribution to the learning-curve aspect of this new technology and for their value in helping to avoid making the same mistakes again.
Planning Directional Wells Through a High-Density Cluster of Existing Wells
Authors: Wang Zhihua , Inglis Tom A. 
Published: December 2007

Summary
This paper describes a method for determining the optimum well path through a high-density cluster of existing wells by considering the close proximity of the other wells. A simple 2D or 3D path is proposed, checked for proximity to the other wells, and then modified if necessary according to dogleg severity and the proximity of neighboring wells. An example using North Sea data is presented.
Annulus Corrosion in High-Temperature Gas Wells
Authors: Sutanto Henry , Semerad V. A. W. 
Published: December 2007

Summary
This paper details experience with corrosion in the annuli of wells in the Aran field, north Sumatra, Indonesia. Wells in this field characteristically have high production temperatures, rates, and pressures, and the produced fluids contain the potentially corrosive constituents CO2 and H2S. The field has been in production for about 10 years, and a number of wells have been worked over once or even twice. These workovers have detected corrosion problems that have led to changes in completion practices and have focused attention on methods to monitor and to detect ongoing annular corrosion.
It is normal practice to fill the annulus between the last cemented casing in a well and the production tubing with a noncorrosive "packer" fluid. Various types of packer fluid have been used in the Arun wells, and some of these fluids have caused unforeseen corrosion problems, which led to workovers to replace the problem fluid.
Use of Barometric Response to Obtain In-Situ Compressibility of a Coalbed Methane Reservoir
Authors: McKee Chester R. , Bumb Amar C. , Horner D'Arcy M. 
Published: December 2007

Summary
A theory is presented for calculating the constrained (matrix) compressibility for aquifers from responses to tides and changes in surface pressure when both gas and water are present. With this theory, a new method to determine matrix compressibility without a pump test is developed. The method is then applied to a coalbed methane well in the Piceance basin.
Full-Field Compositional Modeling on Vector Processors
Authors: Young L. C. 
Published: December 2007

Summary
Large full-field simulations have not previously been feasible with equation-of-state (EOS) compositional models. This paper describes an approach for efficient EOS calculations. The approach is based on a model formulation that minimizes the number of calculations together with vector processing to maximize the calculation rate. Tests of a simulator based on the approach show that large problems can now be solved. For example, a problem composed of nine components, 20, 000 gridpoints, and 1, 000 timesteps can be solved in as little as 15 minutes of CPU time.
Cleaning the Valhall Offshore Oil Pipeline
Authors: Marshall G. Robert 
Published: December 2007

Summary
Severe wax deposits built up in the 20-in. [500-mm] Valhall subsea crude oil pipeline over a period of years. The successful program to remove these deposits gradually but completely with a series of foam and mechanical pigs is described, including details on equipment and procedures. The unique risks and difficulties associated with solids removal in offshore pipelines are discussed.
Resistance of Cemented Concentric Casing Strings Under Nonuniform Loading
Authors: El-Sayed A. A. H. , Khalaf Fouad 
Published: December 2007

Summary
This paper discusses the case of two opposing unidirectional collapse loads uniformly distributed along the diameter of a single casing string and two cemented concentric casing strings. The stress distribution in the casing and cement and the deformation of the pipe are determined by adapting known solutions in the mathematical theory of elasticity to the problem of single- and dual-casing strings subjected to this type of loading. Results were obtained for the case of uniform hydrostatic radial collapse loads for the two casing sizes (9⅝ and 7 in.) and their cemented structures. The resistance of the single pipe to this type of nonuniform loading may drop to 11 % of its design resistance to uniform hydrostatic collapse pressure. The resistance of the cemented concentric strings under uniform and nonuniform loads is about the sum of the steel pipe resistances under the same conditions. The paper also includes the superposition of uniform and nonuniform collapse loads and the practical implications of these results. We conclude that nonuniform loading should be considered in casing design, especially opposite salt formations.
Downhole Casing Corrosion Monitoring and Interpretation Techniques To Evaluate Corrosion in Multiple Casing Strings
Authors: Watfa Mohamed 
Published: December 2007

Summary
This paper reviews new developments in monitoring the corrosion of downhole casings. The results presented are based on corrosion-monitoring data from a large number of wells. The interpretation procedure outlines techniques for estimating metal losses, corrosion rates, and detection of holes in single and multiple casing strings.
Corrosion and Stress-Corrosion Cracking of Aluminum Alloy Drillpipe in a Water-Based, Low-Solids, Nondispersed Drilling Mud
Authors: Ciaraldi Stephen W. , Grimes David R. , Nichols Henry F. , Moore Steven O. 
Published: December 2007

Summary
Corrosion and stress-corrosion cracking (SCC) tests were performed on aluminum drillpipe Alloy 2014-T6 in a water-based, low-solids, nondispersed (LSND) drilling mud. Variables examined included chloride concentration, temperature, state of aeration, and effects of galvanic coupling to tool-joint steel. Electrochemical corrosion test results suggested that the aluminum alloy has adequate corrosion resistance to at least 71°C [160°F], even when it is galvanically coupled to steel in aerated muds. However, SCC susceptibility of the alloy in aerated muds was clearly demonstrated by slow-strain-rate and rising-stress-intensity/SCC tests. SCC did not occur in deaerated muds. We concluded that oxygen scavenging and monitoring are important to the successful performance of aluminum alloy drillstrings in chloride-containing, water-based, LSND drilling muds. These conclusions were confirmed by excellent field performance.
Instrument Performance Models and Their Application to Directional Surveying Operations
Authors: Thorogood John L. 
Published: December 2007

SummaryWhen planning, monitoring, or checking the results from a directional surveying program, one must be able to predict the probable errors associated with the different survey tools used. An "instrument performance model" is a mathematical algorithm that, when combined with a set of independently validated parameters describing the particular survey instrument in question and information about the well, enables the directional uncertainty to be computed at any point in a survey run. Randomization caused by axial rotation of the tool significantly affects the size of the predicted errors. The analysis accounts for rotation and incorporates a new depth-measurement-error treatment. Performance models have many practical uses in survey operations management and wellsite quality control. They enable research to be focused accurately and objective comparisons to be made between different instruments.
Effects of Wellbore Steam Segregation on Steamflood Performance
Authors: Kumar Mridul , Hong K. C. 
Published: December 2007

Summary
The effect of steam segregation within the wellbore on the distribution of steam over the injection interval and on the resulting steamflood performance was numerically investigated. Results show that, because of gravity segregation, steam mass and heat distribution are nonuniform over the injection interval. The effect of steam segregation on predicted performance was important for heavy-oil reservoirs, especially when the vertical permeability was small compared with the horizontal permeability. In general, the segregation effect was more pronounced for reservoirs with high horizontal permeability (specific injectivity).
A Numerical Study of Viscous Instabilities: Effect of Controlling Parameters and Scaling Considerations
Authors: Kelkar Mohan , Gupta Surendra P. 
Published: December 2007

SummaryAn accurate finite-element simulator with a very fine 2D grid was used in this study of viscous instabilities. The simulator has negligible grid-orientation and numerical-dispersion effects and treats longitudinal and transverse dispersivities separately. The simulator was validated by comparing numerical results with the analytical solution for unit-mobility-ratio miscible displacements under varying longitudinal and transverse dispersivities and was further tested by simulating the results of published laboratory displacements under adverse-mobility-ratio conditions. A good match was obtained between the simulated and experimental results for recovery and effluent-concentration profiles for adverse-mobility-ratio displacements. A permeability variance of only 0.1 or an inlet concentration perturbation for a homogeneous system was enough to initiate the effects of viscous fingers seen in laboratory displacements.Results showed that the parameters that control unstable displacements are the permeability variance (Dykstra-Parsons coefficient), the size of heterogeneity (scale length), the mobility ratio, and the dimensionless transverse Peclet number, NPet. It was concluded that the instabilities increase with increases in the permeability variance, the scale length, and the mobility ratio. With increased instability, the recovery decreases and the breakthrough time decreases. For NPer&lt; 0.01, the displacement remains unstable. In addition, the effect of longitudinal dispersivity is negligible. As long as the parameters (mobility ratio, permeability variance, and size of heterogeneities, NPer&lt;0.01) were the same, the effect of the size of the modeled medium on recovery and effluent profiles was insignificant. This implies that the effects of viscous instabilities can be scaled within the range of parameters investigated.
Well-Test Analysis for Solution-Gas-Drive Reservoirs: Part 3—A Unified Treatment of the Pressure-Squared Method
Authors: Serra Kelsen V. , Peres Alvaro M. M. , Reynolds Albert C. 
Published: December 2007

Summary
This work considers the analysis of radial-flow, well-test pressure data under multiphase flow conditions. We show that drawdown- and buildup-pressure data can be analyzed to obtain estimates of effective permeability and the skin factor with a semilog plot of pressure squared vs. time. It is shown that the liquid Matthews-Brons-Hazebroek (MBH) functions can be used to obtain an approximate estimate of average reservoir pressure. A theoretical explanation for a semilog analysis method based on the pressure-squared method is presented.
Electromagnetic Propagation Logging While Drilling: Theory and Experiment
Authors: Clark Brian , Allen David F. , Best David L. , Bonner Stephen D. , Jundt Jacques , Lüling Martin G. , Ross Mike O. 
Published: December 2007

Summary
The compensated dual resistivity (CDRSM) tool is an electromagnetic propagation tool for measurement while drilling. The CDR tool provides two resistivity measurements with several novel features that are verified with theoretical modeling, test-tank experiments, and log examples.
Pressure-Transient Analysis of Fractal Reservoirs
Authors: Chang Jincai , Yortsos Yanis C. 
Published: December 2007

Summary
We present a formulation for a fractal fracture network embedded into a Euclidean matrix. Single-phase flow in the fractal object is described by an appropriate modification of the diffusivity equation. The system's pressure-transient response is then analyzed in the absence of matrix participation and when both the fracture network and the matrix participate.
The results obtained extend previous pressure-transient and well-testing methods to reservoirs of arbitrary (fractal) dimensions and provide a unified description for both single- and dual-porosity systems. Results may be used to identify and model naturally fractured reservoirs with multiple scales and fractal properties.
Quantitative Determination of Rod-Pump Leakage With Dynamometer Techniques
Authors: Nolen Kenneth B. , Gibbs Sam G. 
Published: December 2007

Summary
This paper describes new methods for quantifying pump leakage that extend the effectiveness of dynamometer analysis and can lessen the dependence on well tests in determining the degree of pump leakage. Actual examples are included to illustrate the techniques. Traveling- and standing-valve leakage checks are also described.
An Improved Finite-Difference Calculation of Downhole Dynamometer Cards for Sucker-Rod Pumps
Authors: Everitt T. A. , Jennings J. W. 
Published: December 2007

Summary
This paper presents a finite-difference representation of the wave equation developed for diagnostic analyses of sucker-rod pumping systems. A consistent method of computing the viscous damping term associated with the damped-wave equation is also presented.
Study of Gas Condensation in Transmission Pipelines With a Hydrodynamic Model
Authors: Mucharam Leksono , Adewuml Michael A. , Watson Robert W. 
Published: December 2007

SummaryA nonisothermal, 1D, compositional, two-fluid, multiphase hydrodynamic model is used to describe the incipient formation and dynamic behavior of condensate in a natural-gas pipeline with undulating topology. The 26-in. [66-cm] -diameter case-study transmission pipeline traverses 180 elevation changes in its 30.72-mile [49.4-km] span. Results demonstrate the predictive and descriptive potential of the model in field applications and the significant effect of inclination and inclination changes on the hydrodynamics of gas/condensate flow in transmission pipelines. The model presented can serve both predictive and design purposes.
Laboratory Studies of Capillary Interaction in Fracture/Matrix Systems
Authors: Horie Tadashi , Firoozabadi Abbas , Ishimoto Koichiro 
Published: December 2007

SummaryCurrent study of fractured petroleum reservoirs often is based on the assumption of capillary discontinuity between matrix blocks. Both theoretical analysis and examination of the field performance of some fractured reservoirs, however, indicate a degree of capillary interaction between matrix blocks. Experiments performed to gain an understanding of the capillary continuity across a stack of matrix blocks are described. Three matrix blocks with a total length of 3 ft [90 cm] were stacked and placed in a transparent core holder. Before the experiments with stacked blocks were conducted, rock properties, capillary pressure, relative permeabilities, and the aperture/overburden relationship were measured. Drainage capillary pressure data showed a threshold height of the same size as each of the individual matrix blocks.Experimental results showed a strong capillary interaction (capillary continuity) between the neighboring blocks. Recovery from the top two matrix blocks far exceeds that from the same blocks when the assumption of capillary discontinuity is used. We believe that incorporation of the capillary-continuity concept in dual-porosity models will result in more realistic simulation of fractured reservoirs.
Studies Relating to the Predictiveness of Corrosion-Inhibitor Evaluations in Laboratory and Field Environments
Authors: Hausier Rudolf H. , Stegmann Donald W. 
Published: December 2007

Summary
We attempted to understand the performance characteristics of various inhibitors under different conditions to determine realistic concentrations for field application. In all, 10 inhibitors drawn from five distinctly different chemistry classes were evaluated in four different test procedures of increasing severity of CO2 corrosion. From the performance/concentration curves established for each inhibitor in each test, effective concentrations were defined as the concentration necessary to achieve a certain target performance level—e.g., 0.1 mm/a [4 mils/yr]. Test procedures and inhibitors were then compared on the basis of effective concentration. It was found that the generally accepted wisdom regarding inhibitor testing is simply not valid—i.e., an inhibitor's ranking under one test condition is not predictive of its ranking under other conditions. As the severity of corrosion increases, effective inhibitor concentration also increases. Field data were available for two inhibitors. A comparison with laboratory data showed that laboratory tests were reasonably predictive for one inhibitor, but for the other inhibitor, laboratory tests seemed to overestimate the effective concentration for field use.
A Successful Treatment cf Formation Damage Caused by High-Density Brine
Authors: Cikeš Marin , Vranješevic Branka , Tomic Mihovil , Jamnicky Oljeg 
Published: December 2007

Summary
This paper presents reservoir description, treatment design and execution, and pretreatment and posttreatment analyses of a well completed in Yugoslavia. Chemical aspects of calcium sulfate (CaSO4) scale dissolution by Na4EDTA are also given.
Scaling Up Heterogeneities With Pseudofunctions
Authors: Kossack Charles A. , Aasen Jan O. , Opdal Svein T. 
Published: December 2007

SummaryThis paper describes a multistep pseudofunction-generation process designed to incorporate several scales of heterogeneities into one set of final pseudofunctions to be used in large gridblocks for field simulations. A detailed description of the multistep scale-up process is provided. The calculational procedure and the results of an extensive numerical scaling-up experiment from Kyte and Berry pseudofunctions are described. Three geological descriptions involving random permeability variations are used. The effect of three scales (sizes) of heterogeneities on a standard oil/water relative permeability curve is determined from a three-step pseudofunction-generation process. Ranges of mobility ratios, viscosity/gravity ratios, and viscosity/capillary ratios are used in the displacements to provide a guide to the effect of various types and scales of heterogeneities on fluid flow in several regimes.
Extensions to Dietz Theory and Behavior of Gravity Tongues in Slightly Tilted Reservoirs
Authors: Fayers F. John , Muggeridge Ann H. 
Published: December 2007

Summary
This paper investigates accuracy implications in the modeling of unstable gravity tongues in slightly tilted, anisotropic reservoirs. An extended form of Dietz's equation is examined and its range of validity established by reference to high-resolution simulation. The theory is also used to investigate the onset of viscous fingering with a new viscous-to-gravity number.
The Effect of Firing on Berea Sandstone
Authors: Shaw Jerry C. , Churcher Peter L. , Hawkins Blaine F. 
Published: December 2007

Summary
The petroleum industry uses Berea sandstone as a standard testing material. It is often fired to desensitize indigenous clays. Here, we study the effect of firing by comparing unfired Berea to samples fired at 1000°C for 5 hours. The observed changes in the petrographic and petrophysical parameters are then related to single- and two-phase coreflood data.
New Solutions for Well-Test-Analysis Problems: Part 1—Analytical Considerations
Authors: Ozkan Erdal , Raghavan Rajagopal 
Published: December 2007

Summary
Point-source solutions are derived in the Laplace-transform domain and an extensive library of solutions is documented to obtain pressure distributions and well responses for a wide variety of wellbore configurations: partially penetrating vertical wells, horizontal wells, and fractured wells (complete or limited entry). Wells may be located in infinite or bounded systems (rectangular or circular reservoirs). Several combinations of closed and/or constant-pressure boundary conditions are considered at the vertical and lateral reservoir boundaries. These solutions may be used to examine homogeneous or naturally fractured reservoirs.