bluuebunny/crossref_metadata_2025_split huggingface dataset:
HF Acidizing Returns Analyses Provide Understanding of HF Reactions
Authors: Shuchart Chris E. 
Published: December 2007

Abstract
Numerous sets of well returns after HF acidizing treatments were analyzed to better understand the chemistry involved in HF acidizing. This understanding has led to more effective and efficient fluid designs. Returned samples were analyzed with various analytical techniques, including X-ray diffraction, inductively coupled plasma (ICP), and 19F nuclear magnetic resonance (NMR) spectroscopy. The combination of ICP and l9F NMR determined fluoride distribution on silicon and aluminum in the samples and the extent of HF fluid reactions.
The bottomhole static temperature (BHST) of the treated formation dominates the HF fluids’ extent of reaction in sandstone reservoirs. Analyses showed significant amounts of silicon (as silicon fluoride complexes) in returns from low-temperature formations (75°F), indicating that the secondary reaction did not go to completion. At 135°F, small amounts of silicon fluorides were present in the return samples, depending on the residence time of the fluid in the formation. At higher temperatures (150 to 200°F), the Si content of the samples was low, and no silicon fluorides returned from the wells. The overall F/Al ratios in the return samples ranged from 0.5 to 1.6, depending on the BHST, concentration of HF, concentration of HCl in the HF fluid, and contact time. Along with a better understanding of HF chemistry, the analyses presented numerous problems and concerns during the treatments, such as brine incompatibilities, complete consumption of the acid through the HF reactions, and reactions with carbonates. In most cases, these problems can easily be avoided in subsequent treatments. Close analysis of HF acidizing returns indicate that improved fluid designs can provide more effective and efficient stimulation treatments.
Laboratory Acid Effectiveness Evaluation is the Key to Productivity Improvement by Acidizing in the Clayey Agbada Formation of the Niger Delta
Authors: Abuya Ohen Henry , Nnabuihe Larry , Ososanwo Dunni 
Published: December 2007

ABSTRACT
This paper presents data that attest to the need for acid effectiveness evaluation for determining Formation specific optimum acid recipes prior to acid work in the Niger Delta reservoirs. The results of a complete acid effectiveness evaluation study for two oil reservoirs (A and B) and one aquifer system (C) show that the regular mud acid (RMA) commonly used for stimulation in the Niger Delta may be damaging under many circumstances, The extent of damage by the regular mud acid and the improvement through properly designed recipes are shown by laboratory analytical tests which are scaled to field and well condition. The analytical work includes characterization of the reservoirs.
The hydraulic unit (HU) concept that combines the geological (texture and mineralogy) and petrophysical (porosity, permeability and capillary pressure) controls of the rock quality was used to delineate the reservoirs into units with similar fluid flow characteristics, This zonation enabled the determination of the acid recipes by hydraulic units and thus facilitated the extrapolation to uncored intervals or wells.
The optimum acid sequences for each hydraulic unit were determined on the basis of pre- and post stimulation indices, compressive strengths and critical velocities. Visual observation of core material at the end of the acid flush and iron sequestrant analysis were also used as interpretation tools.
Improved Minifrac Analysis Technique in High-Permeability Formations
Authors: Dusterhoft Ron , Vitthal Sanjay , McMechan David , Walters Harold 
Published: December 2007

Abstract
Interest in fracturing high-permeability formations to control sand production and bypass formation damage has recently increased. These treatments typically require a "tip screenout" design, followed by efficient proppant packing, to achieve the high conductivities required to achieve optimum results. The need for a tip screenout and the relatively short treatment pumping times require that fluid loss characteristics of the formation must be very well defined before job execution.
Borate-crosslinked fluids and linear HEC gels are by far the most commonly used fluids for high-permeability fracture treatments. Extensive laboratory testing has shown that the fluid loss behavior of these fluids can be very different from that described by conventional fluid loss models. Traditional minifrac analysis techniques fail to account for the correct fluid loss behavior of these gels. As a result, use of these techniques can lead to severe errors in the estimation of the leakoff parameters, resulting in over- or under-designed jobs. This paper presents a novel minifrac analysis technique that more accurately accounts for the fluid loss characteristics of the fracturing fluid, allowing for better design.
This analysis has been verified against actual treatments and shows excellent agreement with the observed ‘net’ pressure response for the minifrac and the actual treatments. Several case histories are provided to illustrate the method. This technique has broad applications to low and intermediate-permeability fracturing applications as well.
Application of Chemicals in Prevention and Treatment of Asphaltene Precipitation in Crude Oils
Authors: Groffe P. , Voile J. L. , Ziada A. 
Published: December 2007

Abstract
Damages due to asphaltene deposits both in the formation and in equipment is a well-known problem in production operations.
Asphaltenes have been thoroughly described and analyzed, but very few articles introducing surfactants as asphaltene flocculation inhibitors have yet been published.
As surfactants can adsorb on the surface of asphaltenes, thus preventing their flocculation, Anticor Chimie and Elf Aquitaine Production have set up a system of surfactants that allows asphaltene dispersion in crude oil. A specific formula has to be designed for each case, usable with current oil production processes.
Two different applications have been carried out:
– On the first oilfield, damage was due to the plugging of the surface equipment and the difficulties in breaking down emulsions. The use of a suitable surfactant formulation has prevented plugging and allowed effective water/oil separation at the well head – On the second oilfield, plugging occurred in the vicinity of wellbore, which caused a decrease in production and the formation of deposits inside the tubing. Wireline scraping had to be carried out twice a week.
A field trial squeeze was carried out, and resulted in a flow rate increase of 26 %. The surroundings of the hole were unplugged. Wireline scraping was stopped as deposits no longer appeared (during the treatment period).
MOLEX - The Oil Reservoir Characteristics Dependent Well Performance and Completion Model
Authors: Soleša Mišo , Cveticanin Snežana 
Published: December 2007

Abstract
The MOLEX was conceived and developed in the attempt to arrive at a well performance and completion model which will override the deficiencies of the available simulation models by integrating the many reservioir controls with the effects of well and perforations geometry.
The mathematical groundwork of the MOLEX considers oil flow dynamics in heterogenous pore space and perforations, expressed in terms of mathematical oil inflow equations valid for conventional (vertical) and unconventional (slant and horizontal) wells.
Heterogeneity effects are accounted for by three modifiers, i.e. the transformation matrix of anisotropic pore space into its homogenous equivalent (TT), the integral hydrodynamic factor (IKHF) and the composite skin factor (SCOMP).
Comprehensiveness is the feature of the model which makes it unique and original. This quality allows the combined action of reservoir characteristics to be analysed and the productivities of various well types, productivity ratios, reservoir and well parameters significance and cut-offs to be evaluated.
Using the built-in basic rules, the MOLEX simulation model pieces together the many facets of the oil well performance and completion problem. The right solution is offered by ways of stepwise and discriminating analyses of well productivites subject to reservoir characteristics.
The validity of the MOLEX has been tested on two selected cases, that of Turija Sever and Jermenovci fields. The calculations and analyses indicate that the optimum engineering solution for the future operation of these fields are slant and horizontal wells, respectively.
An Object Oriented Tool for Modeling Production Data Associated with Reservoir Simulation
Authors: Esau Richard , Wells Michael , Leiknes Jorgen 
Published: December 2007

Abstract
An object oriented, cross platform, C++ application has been successfully developed for the manipulation of production data associated with reservoir engineering and reservoir simulation data. The application supports all the main categories of production data necessary for simulation including historical production and injection volumes, well deviation surveys and reservoir events such as completion data.
Particular emphasis is placed on the rapid generation of accurate and representative simulation controls. Key features include time varying connection factors where parameters are calculated from perforation data specified in terms of measured depths and formations, a flexible timestep framework and the handling of deviated wells, partially penetrating wells and multiple completions within a single simulation cell.
The paper will discuss how the development of this and associated applications has shown it is possible to efficiently build sophisticated, cross platform products if the appropriate tools, suppliers and methodology are used.
Finally the paper will address how the application and corresponding application development environment helps address future uncertainties including the continuing hardware and software revolution, the move towards keywordless, "gridless" simulation on a geological model and the existence of multiple integration platforms.
An Object Oriented Expert System to Enhance the Log Analysis of the Colombian Basins
Authors: R. Soto B. , C. Soto T. 
Published: December 2007

Abstract
This paper describes an Expert System developed to predict whether a pay zone will produce hydrocarbon or water. This Expert System was applied to the Caballos and Villeta Formations in the Putumayo basin and the Mirador Formation of the Cusiana Field, both in Colombia. Log analysis "rules" relating the combination of logs (SP, GR, caliper, resistivity, density, neutron, sonic, etc.) and basic information are included in the knowledge base.
The Expert System uses the Kappa-PC Shell and is composed of three sub-systems: 1) an inference engine, 2) a knowledge base, and 3) a user interface. We also consulted human experts to formulate and expand the knowledge base. Additionally, each formation was characterized using a Log Interpretation System (QLA2). The results from each characterization were used to develop cross plots. The QLA2 cross plots provided practical correlations from which to formulate "rules" for the Expert System.
Logs from nine wells in the Cusiana Field were used to evaluate the Expert System. The recommendations of the Expert System agreed with conventional log analysis theory as well as with the known field results. Furthermore, it minimized the time and cost required to evaluate the pay zones. In conclusion, this Expert System can be used to predict whether or not a zone will produce oil or water with a high degree of accuracy.
CriTi-CAL: A Computer Program for Critical Coiled Tubing Calculations
Authors: He Xiaojun 
Published: December 2007

Abstract
A computer software package for simulating coiled tubing operations has been developed at Rogaland Research. The software is named CriTi-CAL, for Critical Coiled Tubing Calculations. It is a PC program running under Microsoft Windows.
CriTi-CAL is designed for predicting force, stress, torque, lockup, circulation pressure losses and along-hole-depth corrections for coiled tubing workover and drilling operations. CriTi-CAL features an user-friendly interface, integrated work string and survey editors, flexible input units and output format, on-line documentation and extensive error trapping. CriTi-CAL was developed by using a combination of Visual Basic and C. Such an approach is an effective way to quickly develop high quality small to medium size software for the oil industry.
The software is based on the results of intensive experimental and theoretical studies on buckling and post-buckling of coiled tubing at Rogaland Research. The software has been validated by full-scale test results and field data.
Computer Generation and Application of 3-D Model Porous Media: From Pore-Level Geostatistics to the Estimation of Formation Factor
Authors: loannidis M. , Kwiecien M. , Chatzis I. 
Published: December 2007

Abstract
This paper describes a new method for the computer generation of 3-D stochastic realizations of porous media using geostatistical information obtained from high-contrast 2-D images of pore casts, The stochastic method yields model porous media with statistical properties identical to those of their real counterparts. Synthetic media obtained in this manner can form the basis for a number of studies related to the detailed characterization of the porous microstructure and, ultimately, the prediction of important petrophysical and reservoir engineering properties. In this context, direct computer estimation of the formation resistivity factor is examined using a discrete random walk algorithm. The dependence of formation factor on measurable statistical properties of the pore space is also investigated.
Determination of Casing Setting Depth Using Kick Tolerance Concept
Authors: Santos Otto , Adasani Ibrahim , Azar J. J. , Escorihuela Francisco 
Published: December 2007

Abstract
This paper presents a methodology for designing setting depths of surface and intermediate casing strings in oil wells using the concept of kick tolerance. The methodology was implemented in a microcomputer program written in FORTRAN. The results are plotted to the microcomputer screen through a graphical interface written in C that calls Windows API functions.
The proposed algorithm uses an iterative procedure to define the shallowest casing shoe setting depth employing the kick tolerance concept. It compares the curve of fracture pressure equivalent density with the pressure generated inside the wellbore during a well control operation to estimate the casing shoe setting depth. The kick tolerance concept is applied in two ways: (a) for the well containment and (b) during the gas kick circulation.
In situation (a), the calculation procedure considers the wellbore pressure just after the well closure. In (b), a two-phase flow kick simulator is applied to predict wellbore pressure generated during the gas kick circulation from the well.
Two examples are elaborated to show the application of the proposed methodology and the computer program. The results are presented graphically to illustrate the use of the graphical interface.
FORTRAN: From Mainframe (to PC) with Love
Authors: McDowell Edward R.H. 
Published: December 2007

Edward R.H. McDowell. Jr.

Abstract
In 1993, PipeSoft Corporation ported 250,000 lines of FORTRAN code in 600 subroutines written for IBM 370 mainframes to the PC. This process produced PipeSoft's PC-based multiphase fluid flow simulator. PIPESOFT-2. The original simulator was developed by Chevron between 1976 – 1992. The new PC-based simulator, PIPESOFT-2 provides the same functionality as the mainframe version.
The wide acceptance and power of the PC makes porting legacy mainframe systems a realistic alternative to designing and building software from scratch for the PC. Porting not only extends a program's useful life, but also increases distribution opportunities. And, once ported to a mainstream platform the software can continue to be improved without loss of the original investment.

The Plan
PSC would receive a tape containing the FORTRAN source, quality control data and run results. A Unix workstation would serve as PSC's "mainframe."
Our plan was simple: get the code running under Unix and compare Unix OC results to IBM OC results. Then port the code to the PC and compare PC OC results to Unix OC results. (This double port wasn't quite as ambitious as it seems - Chevron had already ported the code to a Cray.)
Since PIPESOFT-2 is dynamically dimensioned we felt that recoding platform specific memory management routines would be the biggest obstacle.
PIPESOFT-2 actually consists of 10 modules. Three of which run sequentially and provide pre-processing of data. The fourth module (or more) run depends on selected modeling options.
We chose to use Microsoft FORTRAN PowerStation because:–A large, flat, 32 bit address space was necessary for the program.–A prior attempt to port the program to a PC using a different FORTRAN compiler encountered difficulties.–We anticipate that Microsoft will migrate support of their FORTRAN offerings to other platforms (e.g. Windows NT) in the future.
We anticipated this effort to be straight forward because the code was originally written with then current programming techniques, such as "modularization," and "top down structured programming." The code, on the whole, is well constructed.
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Latest Concepts in Offshore Lift Crane Design
Authors: Barber Donald E. , Bonneson Garland W. 
Published: December 2007

Abstract
This presentation describes how offshore operators were instrumental in developing specifications for marine lift cranes and how their specifications were translated into a new crane configuration especially suited to the ocean environment. The resulting crane design represents an effort to improve the safety and reliability of material handling offshore.
Historically, the stationary cranes used in offshore service have generally been adaptions of land crane upper works. Recognizing that this type of adaption might not fully meet the special needs of the offshore industry, field studies were conducted to determine the features and performance required for cranes in offshore service. A summary of this industry study and the resulting new lift crane designs are contained in this paper.

THE OFFSHORE INDUSTRY SURVEY
The twofold purpose of the survey of offshore operators was first to determine the needs and wants of the offshore industry and second to learn from the experience of longtime operators in the business. Using their stated-requirements and suggestions, crane specifications were gradually developed as the program progressed. When machine specifications appeared reasonably well established, preliminary machine designs were developed.
These preliminary designs and the supporting specifications were further refined through continuing interviews until it was determined that final designs could be established.
Over a period of 18 months, more than 50 interviews were conducted with people involved in specifying, purchasing or operating lift cranes purchasing or operating lift cranes in the offshore and marine industries.
Cold Lake Profitability Improvement
Authors: Boone D. J. , McGregor K. J. 
Published: December 2007

Abstract
For over 30 years, Imperial Oil Limited has been pioneering the extraction of a very heavy grade of oil known as bitumen from the Alberta oil sands in the Cold Lake area. For close to 10 years, a world scale commercial project has operated, employing a thermal recovery process known as "cyclic steam stimulation" (CSS). This process involves alternating periods of steam injection and production, both through the same wellbore.
The Cold Lake operation faces two challenges not typically experienced by conventional operations. First, substantial costs are incurred to generate steam, and treat water. Also, bitumen sells for less than light sweet crude. Consequently, margins are tight, and continuous unit cost improvements essential.
This paper describes the Cold Lake operation along with many of the innovations that have led to a one-third reduction in operating costs over the past decade.
Cogeneration Potential in Western Canada
Authors: Berry J. P. , Good W. K. 
Published: December 2007

Abstract
Western Canada has very large heavy oil and bitumen resources, the recovery of which will require the application of thermal recovery processes in most cases. The most common thermal process involves injection of large quantities of steam. Steam generation accounts for approximately 30 percent of the costs of recovering heavy oil and bitumen. Reduction of this cost, therefore, is a very important factor in the economics of recovering heavy oil and bitumen and affects the amount that will be ultimately recovered.
Cogeneration of steam and electricity has been implemented at a number of projects in California and other places. It has proven to be one method of improving the energy efficiency and reducing costs of both electricity and steam. An industry-supported study of cogeneration as it would apply to Canadian operations was undertaken in 1992. Typical small, medium, and large heavy oil or bitumen thermal recovery projects of 4,000, 15,000, and 50,000 BOPD were identified and conceptual cogeneration designs, cost estimates, and economic evaluations were carried out for 10 scenarios. Sensitivity analyses were conducted to illustrate the relationship between the power buy-back rate and fuel costs on the economics of potential cogeneration projects. The simple cycle gas turbine configuration applied to medium and large volume projects was shown to have potential applicability.
The design, cost estimates, economics, and other factors that must be considered in developing a cogeneration project are discussed.
Oil Sands: Strategies For Future Development - An Overview
Authors: Yildirim Erdal 
Published: December 2007

Abstract
Alberta Chamber of Resources has represented the resource industries in the Province of Alberta for almost 60 years. The Chamber's primary objective is to promote and support the orderly development of Alberta's natural resources.
In the early 1980's, the Chamber identified Alberta's oil sands as the priority mineral resource for further development during that decade. Towards this end, a Task Force of industry and government representatives was set up in 1984 to promote oil sands development. One objective of the Task Force was to identify and publicize the social and economic benefits of oil sands operations.
In 1993, a "National Task Force on Oil Sands Strategies" was formed by the Alberta Chamber of Resources, on behalf of both the government and the private sector. The Task Force's objective is to act as a catalyst for the further development of Canada's immense oil sands resources. During the last two years the Task Force has carried out its mandate to identify a clear vision for growth and to develop strategies and plans for long-term implementation.
This paper summarizes briefly the formation and the mission of the National Task Force and focuses on impediments and opportunities for development and offers strategies and recommendations for the future.

2.0 NATIONAL TASK FORCE ON OIL SANDS STRATEGIES
During 1992, the ACR Executives have had a series of meetings with the senior officials of the Alberta and Federal Energy departments for the formation of a National Task Force to formulate a set of strategies for oil sands development. The ACR proposals were well received and fully supported by both levels of government. Early in 1993, a Steering Committee was formed by the representatives of the Alberta and Federal governments and the industry.
This committee accepted the responsibility to carry out its mandate and formulated its mission statement as follows:
To be a catalyst for further development of Canada's oil sands resource through identification of a clear vision for growth and preparation of a plan of action.
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