bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field Limitations of Liquid-Additive Cementing Systems
Authors: Grant W. Hal , Rutledge John M. , Christy Roger H. 
Published: December 2007

Summary
The use of liquid additives has become prevalent in cementing operations, especially where logistics is a problem. Several precautions must be taken with these additives to ensure adequate performance in field operations. This paper compares the performances of several liquid-additive cementing systems with those of dry-blended-additive systems. Cement-slurry thickening time, fluid loss, free water, and compressive strength are examined; and sensitivity to changes in slurry density is illustrated. Laboratory data demonstrate the liabilities of the liquid-additive system, and three case histories are discussed. A cost analysis comparing dry- and liquid-additive systems with equivalent design criteria shows that liquid-additive systems are more expensive. A prejob quality-control checklist for use of liquid additives is presented, and a dry-blending procedure is recommended and illustrated. If followed, the procedure greatly increases the likelihood of uniform dry-blended additives in quantities as small as 0.2% by weight of cement (BWOC).
Cement Quality-Control Program Shows Substantial Savings
Authors: Bergeron Henry A. , Grant W. Hal 
Published: December 2007

Summary
This paper shows improved results and savings from a quality-control program that emphasized controlled cement slurry properties and good field practices, including the use of spacers, controlled displacement rates, proper centralization, casing movement, and close monitoring of the cement blending. This study focuses on eight onshore and offshore fields in southern California. Roughly 135 wells with more than 180 casing strings were analyzed. These wells, drilled from 1980 to the present, range in depth from 2, 000 to 14, 000 ft [610 to 4270 m]. Two-thirds of the wells were drilled before the cement quality-control program was initiated in Aug. 1985.
Performance Comparison of Rolling-Cutter Bits With Alternative Nozzle Designs
Authors: Moffitt Stuart R. , McGehee David Y. 
Published: December 2007

Summary
Controversy exists regarding the optimum nozzle design for rolling-cutter bits. This paper describes the use of controlled laboratory conditions to isolate the true benefit of various hydraulic designs. Tests were conducted in a pressurized drilling environment with 9⅞-in. [251-mm] tooth and insert bits in Mancos shale. Hydraulic designs include combinations of standard- and directed-nozzle bits with center jets and long and short extended-nozzle bits. Results indicate that directed nozzles provide substantially better bit cleaning and rate of penetration (ROP) than the standard- and short extended-nozzle designs and a slightly faster ROP than long extended-nozzle designs.
Reservoir Simulation of Cyclic Steam Stimulation in the Cold Lake Oil Sands
Authors: Beattle C. I. , Boberg T. C. , McNab G. S. 
Published: December 2007

Summary
Steam injectivity during cyclic steam stimulation (CSS) at Cold Lake can be achieved only by injecting at pressures high enough to fail the formation mechanically. The reservoir also exhibits water/oil relative permeability hysteresis. This paper describes enhancements made to a thermal reservoir simulator to incorporate these Cold Lake physics. The geomechanical model allows both localized fracturing and global reservoir deformation (dilation and history-dependent recompaction). This representation allows the simulator to match injection and production pressures that are otherwise difficult to reproduce. The history-dependent relative permeability hysteresis model calculates gridblock relative permeabilities that always lie on or between input imbibition and drainage bounding curves. The model makes it possible to use laboratory-derived relative permeabilities in a simulation and still match field WOR's.
History Matching of High- and Low-Quality Steamfloods in Kern River Field, California
Authors: Johnson R. S. , Chu Chleh , Mims D. S. , Haney K. L. 
Published: December 2007

Summary
History matches of high-and low-quality five-spot steamfloods were developed for the Kern River field. A uniform set of guidelines was then developed for predictive purposes. Oil and water production rates and cumulative productions were matched. Satisfactory predictions of steam breakthrough times, oil saturation profiles, and temperature profiles were also achieved. Increased vertical transmissibility at the injectors, relative permeability curve modifications, and accurate reservoir descriptions were required to achieve the matches.
An Experimental Study of Casing Performance Under Thermal Cycling Conditions
Authors: Maruyama Kazushi , Tsuru Eiji , Ogasawara Masao , Inoue Yasusuke , Peters Ekwere J. 
Published: December 2007

Summary
We investigated the behavior of casing pipe body and connections under simulated thermal recovery conditions. The study, performed in a new computer-controlled thermal-well simulator, examined the thermal stress behavior and leak resistance of pipe and connections at temperatures up to 354°C [670°F] under severe loading conditions similar to those encountered in thermal wells. We also studied the biaxial collapse resistance of the casing under the large axial tension that would exist after the cooling period in a steam-stimulation process. Results indicate that in a steam-injection process in which the casing is maintained at its maximum temperature for a period of time, stress relaxation can occur in a constrained production casing, resulting in the development of excessive tensile stress during the cooling period. Premium connections with metal-to-metal seals maintained gas leak resistance at temperatures up to 354°C [670°F], whereas the connections without metal seals did not. The biaxial collapse resistance of casing under large axial tension depended on the stress/strain characteristics of the material. Hot-rolled Grade K55 casing with work-hardening characteristics showed a biaxial collapse resistance higher than that predicted by the von Mises yield criterion. From results of this study, we concluded that heavyweight Grade K55 casing with premium connections is a good candidate for thermal well completions.
Effect of Capillary Heterogeneity on Buckley-Leverett Displacement
Authors: Chang Jincal , Yortsos Yanis C. 
Published: December 2007

Summary
The Buckley-Leverett (BL) equation has been routinely used for the description of immiscible displacement in laboratory Dperations and for parameter estimation and prediction. Recent advances, however, have led to a serious challenge of the validity of many of the traditional theories. For the case of BL displacement, most studies have examined heterogeneity effets as they relate to. viscous fingering. In this paper, we investigate the effects of capillary heterogeneity induced by variations in permeability in the direction of displacement. We study a variety of heterogeneity profiles, both uncorrelated and correlated spatially. We find that capillary heterogeneity significantly affects the saturation distributions, which closely follow the heterogeneity variation. The saturation response is stronger at lower rates, at more unfavorable mobility, under drainage conditions, and for smaller spatial correlations. The results are in agreement with available experimental data for primary drainage and secondary imbibition. They may be useful in the interpretation of saturation profiles and the identification of heterogeneity.
Evaluation of Dual-Injection Methods for Multiple-Zone Steamflooding
Authors: Hight M. A. , Redus C. L. , Lehrmann J. K. 
Published: December 2007

Summary
For multiple-oil-zone reservoirs, steamflooding two zones at the same time is advantageous. Three methods for dual injection through a common wellbore were tested at Texaco's Kern River field in Bakersfield, CA. Because dual injection results in an excessive amount of heat transfer between injection streams, it was imperative to predict steam quality or water temperature at the sandface for each injection stream. To evaluate the merits of each method adequately, a computer model was developed to predict downhole temperatures, steam qualities, and pressures for each injection stream. Field tests of the three injection configurations provided measurements necessary for validation of the model. This paper describes the computer model, the field test, and the results from the three dual-injection scenarios.
Obtaining the Minimum Horizontal Stress From Microfracture Test Data: A New Approach Using a Derivative Algorithm
Authors: Jones Colin , Sargeant J. P. 
Published: December 2007

Summary
This paper presents a new approach to the interpretation of pressure-decline data from microfracture tests. The objective is to determine a representative value for the fracture closure pressure, which we relate to the minimum horizontal stress, σHmin. The method uses a derivative algorithm to identify different flow regimes that may occur during a pressure decline (e.g., wellbore storage and infinite- and fmite-conductivity fracture flow). High-quality data are a prerequisite for this method, but it is simple to use and the necessary computations can be performed easily with modern well-test-analysis software. This method has been applied successfully to data from the North Sea for a number of rock types with permeabilities ranging from effectively zero (claystone) to several darcies (sandstone). Results from different pressure declines for the same interval agree well, and a value often can be quoted for closure pressure to within ±0.5 bar. Several examples are included to demonstrate the advantages of this method. Guidelines for microfracture testing highlight what is important for obtaining test data for this method.
Selection and Application of BaSO4 Scale Inhibitors for a CO2 Flood, Rangely Weber Sand Unit, Colorado
Authors: Shuler P. J. , Freitas E. A. , Bowker K. A. 
Published: December 2007

Summary
The objective of this study was to develop a cost-effective scale-control program for the Rangely field CO2 project. The primary challenge was to identify scale inhibitors to control an existing barium sulfate (BaSO4) problem at the new, low-pH conditions caused by CO2 injection. A secondary concern was the change in produced-water composition and increased calcium carbonate (CaCO3) scaling tendency caused by the dissolution of carbonate minerals in the reservoir rock by the low-pH CO2 injection water.
Laboratory evaluation identified several polymer-based and phosphonate scale inhibitors for the low pH (estimated 4.5) at CO2 production wells and near-neutral pH conditions in the surface facilities. Field tests show a good correlation to laboratory results. Suitable phosphonate products are preferred to polymer inhibitors because their residual concentrations may be determined accurately, they are generally cheaper, and they have a longer squeeze treatment life.
Capillary Pressure Curves From Centrifuge Data by Use of Spline Functions
Authors: Nordtvedt Jan-Erik , Kolltveit Kristofer 
Published: December 2007

Summary
This paper presents a new parameter-estimation method to obtain a capillary pressure curve from centrifuge data. The wetting-phase saturation is regarded as a function of the capillary pressure curve and is approximated by a spline function. The average wetting-phase saturation can then be calculated analytically if the coefficients in the spline function are known. We formulate an optimization problem and show how to determine these coefficients—i.e., how to determine the capillary pressure curve. Neither numerical integration nor differentiation is performed at any stage in the calculation. The method fits a capillary pressure curve to the data in the interval given by the experiments without the use of the irreducible-wetting-phase-saturation concept. The presented method compares very well to synthetic data and fits a capillary pressure curve to experimental data with a high degree of accuracy. We compare the method to the Hassler-Brunner and Bentsen-Anli procedures for experimental data from a North Sea reservoir rock.
Cake Filtration With Particle Penetration at the Cake Surface
Authors: Corapcioglu M. Yavuz , Abboud Nelly M. 
Published: December 2007

Summary
Particles in drilling muds build a filter cake on borehole walls and can migrate into the adjacent porous formation and cause formation damage. This study analyzes cake formation, including particle penetration at the cake surface. Mass-balance equations for captured and suspended particles and the fluid phase are averaged along the cake thickness, taking into account conditions on the surface and the septum. Capture mechanisms, such as surface straining, and internal cake erosion and particle capture are included in the analysis. The results are ordinary differential equations in terms of thickness, average particle concentration, average porosity, and such operational parameters as slurry concentration, injection rate, and volumetric solid fraction. Results show that during early stages of cake formation, penetrated-particle concentration peaks and then declines rapidly shortly thereafter. Comparison of predicted cake thickness with experimental data showed an excellent match.
Measuring Interfacial Tensions in a Gas-Condensate System With a Laser-Light-Scattering Technique
Authors: Haniff M. S. , Pearce A. J. 
Published: December 2007

SummaryA laser-light-scattering technique was used to measure a range of interfacial tensions (IFT's) from 1 to 10-3 mN/m in a methane/propane gas-condensate system. The data were compared with the Weinaug-Katz (WK) and the Hough-Stegemeier (HS) correlations. Results show that the HS correlation performed better when used on the critical isotherm. On other isotherms, the WK correlation gave the better fit.
On-Site Flow Calibration of Turbine Meters for Natural Gas Custody Transfer
Authors: Ting V. C. , Schexnayder L. L. , Conkling D. B. 
Published: December 2007

Summary
This paper presents the design criteria, performance characteristics, and calibration procedures relating to a turbine-meter flow-calibration facility used in the high-volume custody transfer of natural gas. The facility, located in Venice, LA, is owned and operated by Chevron U.S.A. Inc. and is used to meter sales volumes of up to 500 MMscf/D [14.16 × 106 std m3/d] at a nominal operating pressure of 1, 000 psig [6.9 MPa]. The system includes three 12-in. [30.48-cm] turbine meters used for sales-volume measurement, a bank of sonic nozzles, and a master turbine meter connected in series with the sales meters. The sonic nozzles and master meter serve as flow-proving and -calibration devices. Sonic nozzles are recommended by the turbine-meter standard for meter calibration.
This paper examines the performance of on-site calibration of gas turbine meters. The Venice facility successfully demonstrated that on-site calibration of gas-metering devices can ensure accurate gas-flow measurement under field conditions.
Field Verification of Drilling Models and Computerized Selection off Drill Bit, WOB, and Drillstring Rotation
Authors: Maidla E. E. , Ohara Shiniti 
Published: December 2007

Summary
A computer program was developed for the simultaneous selection of a roller-cutter bit, bit bearing, weight on bit (WOB), and drillstring rotation that minimizes drilling cost per foot for a single bit run. Two drilling models were tested with data from five wells located offshore Alagoas, Brazil. Results show that the rate of penetration (ROP) of the fifth well can be predicted with coefficients calculated from the four previous wells, resulting in cost savings.
Corrosion-Resistant Alloys for Hot, Deep, Sour Wells: Properties and Experience
Authors: Asphahanl A. I. , Prouhèze J. C. , Petersen G. J. 
Published: December 2007

Summary
Nickel-based, corrosion-resistant alloys (CRA's) were subjected to extensive corrosion testing and evaluation for potential use in hot, deep, sour wells. The Ni-Cr-Mo-W system was used in sour-gas wells in south Mississippi, Wyoming, and Mobile Bay. Corrosion data, mechanical properties, and resistance to environmental stress cracking are described for several oil country tubular goods (OCTG). Better understanding of metallurgical factors and of the role of alloying for enhanced resistance to corrosion, along with advances in materials processing, are reviewed in terms of their impact on OCTG product reliability, improved safety, and cost-effectiveness.
Stabilization of Montmorillonite Clay in Porous Media by High-Molecular-Weight Polymers
Authors: Zaitoun Alain , Berton Nicole 
Published: December 2007

Summary
A dynamic method is proposed for checking the stability of clay in porous media for different brine conditions and the stabilizing effect provided by several anionic and nonionic high-molecular-weight polymers. The method consists of injecting brine at decreasing salinity levels into clayey sandpacks until unstabilized permeability reduction is reached from the dislodging of clay particles that become trapped in pore restrictions. The last stable state before clay destabilization is characterized by a critical salinity concentration (CSC). As expected, montmorillonite clay 5% dispersed in a sandpack is more stable in the presence of KC1 than NaCl brines, giving CSC values of 5, 000 and 27, 500 ppm, respectively. Polyacrylamides are much better clay stabilizers than carboxymethyl cellulose (CMC) or xanthan gum (XG), lowering the CSC of KC1 to 1, 000 to 2, 000 ppm and the CSC of NaCl to 6, 000 to 7, 000 ppm. A low-molecular-weight shear-degraded polyacrylamide is shown to keep good stabilizing power without inducing the high permeability reduction values obtained after adsorption of high-molecular-weight products. In addition to preventing clay migration, polyacrylamides are also shown to inhibit clay swelling.
Analysis of Cementing Turbulators
Authors: Wells M. R. , Smith R. C. 
Published: December 2007

Summary
This paper presents the results of a study to determine the ability of commercially available mechanical aids called "turbulators" to alter the flow profile and thus enhance the displacement efficiency of typical cementing operations. Results are presented for both the predictions and the measurements showing the effects of pump rate, viscosity, density, and turbulator blade geometry on the induced flow angle along the pipe axis (thus effective swirl length). The results indicate that mud-displacement efficiency can be improved dramatically with mechanical aids that alter the flow profile in the annulus between the casing and the hole. Simple guidelines are provided for spacing turbulators, and two case histories are presented that substantiate the laboratory findings.
Pore-Scale Heterogeneity From Mercury Porosimetry Data
Authors: Yuan H. H. 
Published: December 2007

SummaryThis paper describes a quantitative method of determining pore-scale heterogeneity with constant-rate mercury porosimetry data from the apparatus for pore examination (APEX). Besides being used as a measure of heterogeneity, APEX pore-scale information can be used to assess quantitatively the effect of rock texture or pore geometry on the efficiency of any process, such as EOR, aimed at recovering waterflood residual oil. The paper shows a method for calculating EOR displacement efficiency from APEX poroshmetry data. Berea sandstones and San Andres dolomites are used as examples.
Permeability Modification by In-Situ Gelation With a Newly Discovered Biopolymer
Authors: Vossoughi Shapour , Buller C. S. 
Published: December 2007

Summary
In a typical gelled polymer process, a polymer reacts with a metal ion to yield a 3D crosslinked system. The success of the process depends on monitoring a large number of variables, including the concentrations of the metal ions, polymer, and reducing agent. Controlling these variables in field-scale tests is extremely difficult, if not impossible. Devising a process with fewer variables is therefore desirable. The in-situ gelation process in this paper uses a newly discovered biopolymer produced by Cellulomonas flavigena Strain KU. The bacteria produce the biopolymer when cultured in a simple salts medium containing any one of a variety of hexoses, pentoses, disaccharides, or such inexpensive substrates as starch or molasses as the carbon and energy sources for growth. The polymer produced remains associated with the producer bacteria, causing them to aggregate and to settle out from the growth medium. The polymer is extracted from the bacteria easily by suspension in dilute alkali. Upon neutralization of such extracts, the polymer precipitates as a hydrogel. The gelation process is reversible, and the hydrogels are stable at high temperatures. A linear coreflood was performed to reveal the feasibility of using the microbial polymer for the in-situ gelation process. The core initially was waterflooded and then flushed with acid. The subsequent injection of an alkaline solution of the polymer resulted in in-situ formation of hydrogels.
Permeability Reduction by a Xanthan/Chromium (III) System in Porous Media
Authors: Hejri Shahab , Francois Jousset , Green D. W. , McCool C. S. , Willhite G. P. 
Published: December 2007

Summary
This paper presents an experimental study on gelation of a xanthan/chromium(III) system in unconsolidated sandpacks at frontal velocities between 3 and 120 ft/D. High flow resistance developed at specific locations in the sandpacks in experiments conducted at velocities up to 35 ft/D; the locations correlated with velocity. No significant flow resistance developed in the sandpacks at frontal velocities of 83 and 118 ft/D. The effects of flow and shear rates and permeability on development of high flow resistance in the sandpacks are discussed. A conceptual model of the gelation process that incorporates filtration of gel aggregates is presented.
Performance Review off a Miscible CO2 Tertiary Project: Rangely Weber Sand Unit, Colorado
Authors: Hervey J. R. , Iakovakis A. C. 
Published: December 2007

Summary
A miscible CO2 flood was initiated in the Rangely Weber Sand Unit (RWSU) in Colorado in Oct. 1986. The project calls for injection of a 30% slug of CO2 at a 1:1 water-alternating-gas (WAG) ratio. Ultimate incremental recovery is estimated to be 114 million STB. Current incremental recovery accounts for 34.5% of production.
Design of a Major CO2 Flood, North Ward Estes Field, Ward County, Texas
Authors: Winzinger Rudi , Brink J. L. , Patel K. S. , Davenport C. B. , Patel Y. R. , Thakur G. C. 
Published: December 2007

SummaryThe reservoir engineering aspects of the design of a major west Texas CO2 flood are presented. The design included a detailed fieldwide geologic study, a CO2 injectivity test, laboratory work, and reservoir simulation. CO2 flooding is predicted to recover an additional 8% of the original oil in place (OOIP).
Liberation of Solution Gas During Pressure Depletion of Virgin and Watered-Out Oil Reservoirs
Authors: Kortekaas Theo F. M. , van Poelgeest Frits 
Published: December 2007

Summary
Multipurpose experimental equipment was constructed to investigate the buildup of gas saturation during depressurization of virgin and watered-out oil reservoirs at representative conditions. The measured dependencies of critical gas saturations on gas/oil interfacial tension (IFT), amount of dissolved gas, pressure-decline rate, and structure of the porous medium are discussed. In addition, experimental results indicating significant reductions of waterflood residual oil saturation (ROS) owing to the presence of a gas saturation are presented.
Predicting Temperature Profiles in a Flowing Well
Authors: Sagar Rajiv , Doty D. R. , Schmldt Zellmir 
Published: December 2007

Summary
A simple model suitable for hand calculations is presented to predict temperature profiles in two-phase flowing wells. The model, developed with measured temperature data from 392 wells, assumes that the heat transfer within the wellbore is steady-state. Comparisons between the model's predictions and field data indicate that the model is highly accurate within its range of application.