bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prolog - A Computerized Wellsite Log Analysis System
Authors: Frost E. , Fertl W. H. , Wichmann P. A. 
Published: December 2007

ABSTRACT
The Prolog computerized wellsite log analysis is designed to enhance the information obtained from Dresser Atlas Computerized Logging Service (CLS) Units.
Two basic analysis packages, Wellsite CRA for complex reservoir analysis and Wellsite SAND for clastic sediment sequences, present detailed formation evaluation in a four-track format supported by depth shift routines, a true vertical depth option, data edit routines including borehole and environmental log corrections, and crossplot routines.
The Prolog programs along with field examples are discussed.
Kick-off Problems in Central Oman (Haushi Producers)
Authors: Antheunis D. 
Published: December 2007

ABSTRACT
In the Middle East few oil fields produce from accumulations in siliciclastic sediments. It was, therefore, considered useful to review some aspects of operating problems experienced in Oman with wells completed on such type of reservoirs.
The majority of wells in Central Oman producing from Haushi sandstone reservoirs have high skin factors as a result of –drilling and–workover fluids and/or–bridged formation fines in the vicinity of the wellbore.
The wells thus produce at reduced deliverability causing quitting and kick-off problems, early requirements for gas lifting and in the longer term possible problems in maintaining offtake levels. One of the current operations activities is, therefore, directed towards the resolution of kick-off problems.
This paper concentrates on the kick-off problems as experienced in the Central Oman area during the last two years.
The first class of kick-off problems showed up after workovers. The second category appeared after the quitting of a number of flowing wells, most of which were producing below ideal PI and with increasing watercuts.
Obviously, at fields where gaslift facilities are available, i.e. at all producing Central Oman fields except at Saih Rawl, the utilisation of gaslifting is straightforward and relatively easy and has of course been applied. In addition to gaslift assistance for kick-off purposes use was made of fluid lifting techniques, coiled tubings and swabbing and an in-situ nitrogen generation process was tested in oil well Ghaba North-2.
In this context of kick-off methods, the results of a field test of PDO's modification of the Navi-drill down-hole mud motor, with a view to flow wells to surface during drill-stem tests, is also reported.
Optimization of LPG and LNG Production from a Middle East Crude Oil
Authors: Al-Ameeri Rasheed S. 
Published: December 2007

ABSTRACT
A computer simulator was designed to optimize the operating conditions of gas-oil processing systems. The separator off gases were utilized in the production of liquified petroleum gas (LPG) and liquified natural gas (LNG) and other byproducts. The mathematical model developed took into consideration all the variables affecting the operating conditions and a parametric study was conducted to determine the effect of the various variables on the final results, optimal solutions were found for systems processing crude oils of varying API gravity, feed temperature and pressure. Gas-oil processing systems consisting of different number of stages were analysed. The results indicated that as the number of stages decreased and as the specific gravity of the well fluid decreased the objective function became more sensitive to the operating conditions.
Injection Water Problems Identified by Laboratory Analysis
Authors: Ostroff A. G. 
Published: December 2007

ABSTRACT
When water is injected into a subsurface formation, one or more operational difficulties may be encountered. A few examples of these are corrosion, scale formation, microbiological activity, formation of deposits, pollution considerations and rock property characteristics. Information necessary to defining these problems and mitigating them is usually obtained from a laboratory, A laboratory can provide the necessary information in a form pertinent to overcoming these problems or it can return information of questionable value in solving the problem. A cooperative effort between the engineer responsible for operation of the system and the laboratory offers the best chance for successful problem solving. Examples of some production related problems that illustrate involvement of the laboratory with the field engineer to find a solution are given.
Sucker Rods Failure Mechanisms, Methods of Avoiding them
Authors: Aly Eid Nabil Mohamed 
Published: December 2007

ABSTRACT
When a steel bridge collapses, criticism is confined to the person responsible for the design-never to the mill that rolled the steel. This is true and justified because steel as turned out by modern mills is of closely controlled quality. It is one of our most exacting engineering materials whose mechanical properties are reproducible within close limits.
Conversely, when a String of sucker rods fails, the comment most frequently heard is that "they must have been rolled from a bad heat of steel". This is not justified nor logical since sucker rod steel is rolled under far more restrictive requirements than is ordinary structural steel. Practically all rod failures are the result of misapplication, mishandling, or are service induced. Failures due to faulty steel are so rare as to be practically nonexistent.
Finally, a reasonable understanding of well conditions and rod stresses leading to good string design, a knowledge of the causes of sucker-rod failures and the corrective practices required, and an updated selection of materials based on the most recent developments can pay big dividends in longer sucker-rod life.
Expensive down time, lost production, and. unnecessary maintenance costs are the usual results of bad-practice shortucts in handling sucker rods. A knowledge of the nature of sucker-rod failures, and causes leading to them, will show the reasons for using good practice and the false economy of using bad practice.
This article reviews sucker-rod failure mechanisms and suggests ways of avoiding them. Particular attention is paid to handling, running, pulling practices, material selection, and recent improvements.
Control and Repair of Offshore Well after its Wellhead Damage
Authors: Abdel-Mota'al Ahmed A. 
Published: December 2007

ABSTRACT
This paper presents the operations conducted by an operating company in the Arabian Gulf, to put under control a gas well which its wellhead platform was accidentally damaged. Also, the conclusions are given which reflects the experience gained from the plans preparation for the well control operations and the results obtained during the implementation of these plans.
Effects of Production Rate on the in Situ Energy Utilization of Dry and Condensate Gas Reservoirs
Authors: Sarathi Partha S. , Tiab Djebbar 
Published: December 2007

ABSTRACT
The objective of this study is to investigate the effect of production rate upon the utilization of primary reservoir energy. To achieve the above objective the problem was approached from the thermodynamic angle. In this investigation the first and second laws of thermodynamics together with the steady state flow principles were utilized to derive interpretive equations to calculate a thermodynamic value, namely the reversible maximum work function. The choice of the maximum work function as a working tool for analyzing the "response of a gas reservoir system to production practices" is justified by the fact that maximum work is independent of the path followed and hence can be utilized to establish production efficiency standards.
Three cases were studied in detail: (1) a volumetric dry gas reservoir system; (2) a dry gas reservoir system under water drive influence and (3) a volumetric gas condensate reservoir. Material balance relationships were used to simulate the reservoir pressure production history. The variation of well pressure with production is then systematically employed to compute the reversible work and to analyze the effect of production rate on the in situ reservoir energy utilization.
The volumetric and thermodynamic properties of the hydrocarbon mixtures were predicted using the modified BWR equation of state of Lee and Kesler. Hydrocarbon phase behavior is predicted using the concept of fugacity. Methods for computing the parameters to account for the interaction between the molecules of the mixture are also discussed. Techniques for predicting the reservoir pressure in these thermodynamic systems are developed.
The pressure prediction techniques and the thermodynamic property evaluation procedures are incorporated into a straight forward simulation scheme. Example cases studied indicated that the dry gas and condensated reservoirs are rate insensitive, while a reservoir subject to water drive is rate sensitive. for such reservoirs the natural energy is better utilized at lower production rate than at higher rate.
Viscosity Correlations for Compositional Reservoir Simulators
Authors: Saeedi Jawais , Rowe Allen M. 
Published: December 2007

ABSTRACT
Compositional dependence of viscosities of reservoir fluids, where in-situ inter-phase mass transfer dominates, warrants judicious selection of correlations to be used in compositional reservoir simulators. Two of the selection criteria are that the vapor and liquid phase viscosities approach each other in the vicinity of the critical point and they should be well behaved functions of pressure, temperature and composition. As vapor and liquid phase viscosity correlations are usually developed independent of each other these criteria are not often met for most of the reservoir fluids encountered. Some of the viscosity correlations are phase density dependent which further require a consistent set of vapor and liquid phase density correlations or a reliable equation of state to predict both the phase densities.
Five sets of critical composition data are chosen for analysis. The choice is such so as to encompass reservoirs which may be candidates for compositional simulation and is also based on the mo lal average boiling points of the mixture. Each of these critical compositions are flashed along the critical isotherm at suitable pressure intervals, upto the critical point. Densities and viscosities are then computed for liquid and vapor phases at each pressure level using suitable correlations.
Specific correlations are recommended for usage in phase viscosity computation, for each composition used in this study, supplementing the necessity of fine-tuning their parameters for specific reservoir fluids from laboratory derived fluid data. The suitability of phase density correlations, to be used in conjunction with viscosity correlations, is also discussed.
The Use of Foamed Acid in Fracture Acidizing
Authors: Ford William G. F. 
Published: December 2007

ABSTRACT
Dynamic laboratory testing of foamed acid on limestone cores has established the effectiveness of foamed acid as a stimulation fluid. Effects of foam quality, foam stability, and chemical compatibility on fluid loss and fracture flow capacity were investigated. Recommendations are presented for deriving maximum benefits from a foamed acid treatment. Field results are presented that show the effectiveness of foamed acid in fracture acidizing treatments of both oil and gas wel1s.
Application of Computer Data Base Techniques for Reservoir Management
Authors: Smith Michael D. , Lucas Charles D. 
Published: December 2007

ABSTRACT
An engineering work station is described which includes a mini-computer, an interactive colorgraphics terminal and a four color pen plotter integrated with a well data base and reservoir performance models. This combination of technical models and data management software is a powerful tool for predicting reservoir performance and ultimate recovery of reserves. In addition, to increase the efficiency and effectiveness of technical personnel, the work station substantially reduces the amount of time required for these personnel to collect, store, retrieve and process production and engineering data.
Screening Tests for Enhanced Oil Recovery Projects
Authors: Burnett David B. , Dann Michael W. 
Published: December 2007

ABSTRACT
Laboratory Screening Tests are suggested to evaluate potential enhanced oil recovery projects. Standardized procedures are used to study the feasibility of (1) miscible/CO2 projects, (2) thermal processes, and (3) chemical processes.
The Screening Tests are divided into four sections: crude oil characterization, injection water studies, reservoir core characterization, and displacement studies in porous media.
These Screening Tests augment geologic and engineering studies and supplement (but do not replace) the more commonly known core analysis programs.
Evaluation of Air Injection as an IOR Method for the Giant Ekofisk Chalk Field
Authors: Stokka S. , Oesthus A. , Frangeul J. 
Published: December 2007

Abstract
The Ekofisk fractured chalk reservoir located in the North Sea south-west of Norway has been exploited successfully for more than three decades, largely due to injection of sea water. In a study concluded in 2004, air injection was evaluated as a method for additional hydrocarbon recovery beyond the secondary waterflood recovery. Supported by the European Commission through the fifth framework program, the Ekofisk Field owners joined forces with leading European research institutes and a contractor to investigate the potential of air injection as a cost effective IOR method. Through screening studies, extensive laboratory experiments, reservoir simulations, design of processing facilities and project feasibility evaluations, an extensive knowledge base of the air injection process for light oil fractured reservoirs was established.
In the present paper technical results will be presented. Recovery mechanisms related to an air injection process in a fractured light oil reservoir have been studied through laboratory experiments and reservoir modeling. The laboratory experiments verified air injection as a potential IOR method for a light oil fractured chalk field. Laboratory experiments were performed in order to study kinetic properties such as activation energies and ignition temperatures. In addition, diffusion coefficients were estimated through laboratory experiments and verified by numerical simulations. Potential weakening of the chalk due to heat and CO2 was evaluated based on laboratory experiments and geo-mechanical modeling. Combustion tube experiments were conducted in order to study propagation of the combustion front through porous media.
Finally, a field scale air injection feasibility study was performed. The outcome of this study, including an evaluation of potential production benefits and main cost items involved in an air injection project, is presented.
Analyzing Well Performance XII
Authors: McCoy James N. 
Published: December 2007

ABSTRACT
Analyzing well performance is an important step toward increasing profits by improving production techniques. The analysis is made by field tests and examination of well data. The acoustic liquid level instrument offers valuable information since downhole pressures can be determined from the depth to liquid measurement.
Fluid flow in a reservoir is caused by movement of fluid from a high-pressure area to a low-pressure area. Fluid flow into a wellbore occurs when fluids present in the wellbore are removed so that the pressure is decreased in the wellbore. Then, fluid from an area of higher pressure flows into the lower pressure wellbore (Fig. 1).
Fluid flow increases as the differential pressure increases. Vogel1 presents a curve for predicting flow rates based upon the ratio of the wellbore pressure to the reservoir pressure. This curve is shown on the Well Analysis Sheet. Note: approximately 70% of the maximum flow rate will occur when the wellbore pressure is one-half of the reservoir pressure. Also note, 90% of the maximum flow rate will occur when the wellbore pressure is 25% of the reservoir pressure.
Selection and Qualification of Materials for HPHT Wells
Authors: Brownlee J. K. , Flesner K. O. , Riggs K. R. , Miglin B. P. 
Published: December 2007

Abstract
Interest in sour, high-pressure high-temperature (HPHT) wells and in ultra-HPHT wells, i.e. those with bottom hole temperatures greater than about 300° F (150° C) and wellhead pressures greater than about 10,000 psig (690 bar), is increasing worldwide. Due to the desire to monetize reserves more rapidly and due to the aggressiveness of sour, HPHT and ultra-HPHT environments, these wells are likely be completed using large diameter casing and tubing that is manufactured from solid, high-strength corrosion resistant alloys (CRAs). Wellheads will likely be manufactured from high strength low alloy steel that is clad internally with CRAs.
The combination of corrosion resistance and strength offered by solid CRAs and CRA-clad steels has spurred decisions to produce otherwise uneconomic sour, HPHT and ultra-HPHT wells around the world for several decades now. However, current levels of conservatism in materials selection and evaluation and in design of HPHT well equipment is not likely to be sustainable in the future. Thus, this paper provides a review of the knowledge gained from previous HPHT developments with the dual aims of extending the safe and successful development record of the E&P industry related to HPHT wells and improving the cost-effectiveness of future CRA completion designs.
Increasingly aggressive conditions are beginning to expose limitations in current design methodologies for tubing and casing strings, connections, seals, downhole jewelry, and valves. Linear elastic design methodologies are likely to be supplanted by elastic-plastic, fatigue, and fracture mechanics based methodologies in the near future, and this will likely result in a need for detailed data related to CRA materials properties including flow stress, fracture toughness, and low-cycle fatigue resistance, data that is largely nonexistent at present. Therefore, this review also examines the limitations of current CRA test methods and identifies gaps in materials property data that is likely to be required if advanced design methods for critical well equipment are to be successful.
High bottomhole pressures in HPHT wells are likely to result in a need to use large-diameter, heavy-wall tubing strings. Thick, large diameter CRA tubes are generally limited to short lengths, which results in an economic trade off between the increased gas production that can be achieved by using large diameter tubing and greater completion costs that result from more connections and longer completion times. Thus, this paper will also examine size and strength ranges of CRA tubulars that are currently available, and these ranges will be compared with the anticipated needs of HPHT well owners and operators to identify whether critical gaps exist in current CRA manufacturing technology.
North Kern Front Field Steam Drive with Ancillary Materials
Authors: Eson Rodney L. , Fitch Jon P. , Shannon Albert M. 
Published: December 2007

Abstract
Since steam injection became a viable recovery technique nearly three decades ago, the problems of gravity segregation and poor areal and vertical sweep efficiencies have limited recoveries in many heavy oil reservoirs. In many instances the injected steam prematurely breaks through into producing wells creating steam channels. It is believed that overall recoveries of a steam drive can be improved if the steam channeling can be controlled. This paper documents efforts under a Department of Energy cost sharing contract to reduce steam channeling in a conventional steam drive using ancillary materials.
A steam foam solution and a steam foam encapsulated in a polymer gel are being introduced in four steam injection patterns in the North Kern Front Field near Bakersfield, California. The ability of the ancillary materials to improve recovery will be determined through injection profiles, chemical tracer surveys, casing vent gas analysis, core and log data, and residual oil saturation data, as well as through temperature and production data.
It has been shown that in-sitυ steam foams can be used to alter the steam injection profiles to prevent excessive steam channeling. The results of early production data have indicated that as much as 125 B/D of incremental oil is being produced by the four chemical treated patterns.
High Pressure Model Studies of Oil Recovery by Carbon Dioxide
Authors: Doscher Todd M. , El-Arabi Mahguib 
Published: December 2007

Abstract
Linear scaled physical model studies were designed and carried out to study the recovery of crude oil by the injection of carbon dioxide. Viscous and gravity forces and molecular diffusion were explicitly scaled to field conditions. Mechanical dispersion was not scaled, and is exaggerated in the models.
The basic prototype considered in this study is a homogeneous reservor with a permeability of 20 millidarcies and a distance between injector and producer of 462 feet and an equivalent thickness of 28 feet.
Because both the line drive, in contrast to a radial pattern, and the low permeability of the prototype reduce the relative influence of gravity segregation, and the exaggeration of mechanical dispersion in the model reduces the effects of viscous fingering and gravity override; the results of these studies yield optimistic results in comparison with those that may be expected under field operating conditions.
The results reveal that two factors dominate the recovery process: the high mobility of the carbon dioxide, and its solubility in the subject crude oil. The latter in turn appears to be a function of the density of the carbon dioxide.
The effects of pressure, temperature, oil saturation, and slug size on recovery were studied in some detail, and the effect of the composition of the oil to a limited extent. A degree of criticality is observed with respect to the size of the slug on its influence on recovery and the carbon dioxide required to recover a barrel of crude oil. By controlling the slug size, about half of the residual oil can be recovered at ratios of less than 10 MSCF/B whereas continuous injection will recover more of the residual oil but only at ratios in excess of 20 MSCF/B.
No banking of the crude oil is observed and carbon dioxide production occurs rapidly and concomitantly with oil. The complex phase behavior of carbon dioxide, the separation of the heavy fractions and solution of the light fractions in the dense carbon dioxide gas, occurs only after the carbon dioxide has reached a high saturation in the system, and therefore contributes little to the up-front (economic) recovery of residual oil.
Scaling of Flow Parameters for Miscible Gas Flood Simulation Studies
Authors: Breit Vernon S. , Graue Dennis J. 
Published: December 2007

ABSTRACT
This paper outlines the steps involved in determining reasonable flow parameter values for a typical miscible gas flood simulation study using a "mixing-rule" type miscible flood simulator1. In each step we are striving for consistancy between the performance predictions of a coarse grid history matched waterflood model and a miscible gas flood model which usually requires a much finer grid.
A technique is described for calculating the correct imbibition water and oil relative permeability curves to be used in a fine grid study from the set of imbibition relative permeability curves used to obtain a history match of waterflood performance with a coarse grid black oil model. These curves will assure that the fine grid model predicts the same waterflood performance as would be predicted by the history matched model.
Finally, a discussion of the important considerations which must be accounted for in the selection of proper flow parameters to be used in each of the four flow regimes which occur in a typical gas flood: (1) water displacing gas behind the tertiary oil bank, (2) gas miscibly displacing oil at the back of the tertiary oil bank, (3) oil immiscibly displacing water at the leading edge of the oil bank, and (4) water displacing oil in front of the tertiary oil bank.