bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interwell Heterogeneity Representation and its Effect on Steamflood Performance
Authors: Kumar Mridul 
Published: December 2007

ABSTRACT
Interwell heterogeneous reservoir properties for a California heavy oil field were obtained using geostatistical techniques. Fine-grid, cross-sectional and three-dimensional steamflood simulations were then conducted to evaluate how small-scale heterogeneities and methods to represent them affect predicted performance (steam breakthrough time and oil recovery). Actual log-derived properties (which were first calibrated against core measurements) were used.
Results show that oil recoveries during intermediate times (0.6 to 1.2 pore volume cold water equivalent steam injection) differ by 15-25% when small-scale heterogeneities are included (using kriged or conditional simulation) compared with when uniform properties are used. The difference in predicted recoveries between the kriged and conditional simulations were smaller (generally less than 10%). Inclusion of small-scale heterogeneities resulted in higher recovery and delayed steam breakthrough compared to the uniform permeability case when permeability variations were uncorrelated between the injector and producer. On the other hand, it resulted in lower recovery and earlier breakthrough when permeability variations were large and correlatable. Three-dimensional (3-D) heterogeneous flow simulation results show that oil recoveries using kriged geological models are generally higher than those from conditional models. Predicted recovery using the 3-D model has a shape similar to and compares reasonably with field data.
Promoting Subsurface Pump Efficiency and Developing Working Conditions of Mechanical Oil Production System by Means of Real-Time Numerical Control Technology
Authors: Li Yugeng , Zhu Shaozeng 
Published: December 2007

Abstract
Both the stroke length and the stroke per minute of the conventional pumping unit remain constant under the given working conditions. Therefore, it is impossible that the working conditions of the surface pumping unit and the subsurface pump are all in a state of the optimum match. The subsequent results are low efficiency of subsurface pump, large impact load, high energy consumption, and low production rate.
A new-type N/C pumping unit is under development. The following new technologies are used: —Microcomputer controlling the operation procedure of pumping unit by means of the numerical control technology.—AC frequency conversion and speed regulation technology.—High power and low electricity consumption motor in which the rotor is made of rare earth metal.—Framework for long stroke pumping unit and precision mechanical driving system.
The sample pumping unit is 6m in stroke length. In fact, it is easy to refit into the N/C pumping unit with 10m or longer stroke length. The new type pumping unit is both adjustable at will in the stroke length and stepless variable in the stroke per minute.
A cycle movement of the N/C pumping unit consists of the following four processes which are shown by curves: —"S shape" acceleration process at the beginning.—Uniform speed ascending process.—"Reversal S shape" counter direction acceleration process.—Uniform speed descending procees.
During the whole cycle movement, the computer continuously measures and analyses the holebottom conditions and regulates the movement parameters of the pumping unit, thus enabling necessarily the well to obtain the optimum oil production result.
The World Conservation Strategy As It Affects The Energy And Petroleum Industries
Authors: Holdgate Martin W. 
Published: December 2007

Abstract
The important thing about this Conference is that it is to be practical: to improve the performance of the energy, and especially the petroleum and gas industries, in che fields of health, safety and environment.
The purpose of this paper is to describe the World Conservation Strategy as it affects these industries - and, in particular, sets specific targets for then to address. The following sections: (a)explain what the World Conservation Strategy is, and what it says;(b)examine its message for industry in more detail;(c)proceed to a narrower consideration of the energy and petroleum industries; and(d)discuss practical issues that should feature in the dialogue between the industry, government and environmental scientists.
Horizontal Well Gravel Compaction Simulator Tests With Rotary Vibration in a Water Packing System
Authors: Solum J. R. 
Published: December 2007

Abstract
Horizontal well tests for gravel packing completions have been run for the last 10 months. This simulator was designed to create above ground, the same events and conditions that occur beyond the curve in horizontal and near-horizontal bore holes. The mock-up, forty four feet in length, consists of 18 feet in clear lucite tubing in three equal sections, connected alternately to 4 sections of 8-5/8″ casing. Located on each casing section are two 12″ by 1/2″ I.D. lucite tubes, one vertical and one horizontally mounted, with stainless steel needle valves for leak-off testing measurements. A 5″ slotted liner runs inside the full length of the simulator, and two rotary compactor vibration tools are placed inside the liner for evaluation of die vibraton factor.
Optimization of the Drilling Performance in the 6-in. Section of Development Wells in the Paris Basin, France
Authors: Besson Alain , Pontneau Bernard , Leseultre André 
Published: December 2007

ABSTRACT
The 6" PDC bits application of development wells in the Paris Basin (France) has been carried out for a long time. A long directional 6" section of about 1600 meters composed of chalk, sand, shales, hard limestones, with dolomite and anhydrite stringers is currently drilled. In spite of the good results already obtained, several problems were still remaining, the major one was a hard stringer that could not be drilled by PDC bits and was forcing the operator to pull out or to destroy the PDC bit, beside that, nozzle plugging was very frequent.
An engineering study was performed and the analysis of the problems encountered led to the choice of new PDC bit body profile with new cutting structure and nozzles design. These choices were improved by means of hydraulic tests run in laboratory and specific methods of cutters positioning.
Collapse Pressure of Oval Coiled Tubing
Authors: Newman K. R. 
Published: December 2007

Abstract
Coiled Tubing (CT) is sometimes used in applications where the pressure outside the CT may be higher than the pressure inside the CT. These applications include operations in high pressure wells1 and reverse circulation operations where a fluid is pumped down the annulus and returns are taken up through the CT. If the difference between the internal and external pressures becomes too large, the CT will collapse. CT collapse could lead to serious well control problems.
During its life CT becomes oval due to bending around the reel and over the gooseneck. This ovality reduces the collapse pressure of the tubing. The pressure and tension limits for CT were analyzed in reference 2. The need for further work to understand the affect of ovality on the collapse pressure of CT was mentioned and is the purpose of this paper.
First an analysis was made to develop an analytical method for calculating the collapse pressure of an oval tube. Then testing was performed to validate this method.
Practical Considerations of Horizontal Well Fracturing in the "Danish Chalk"
Authors: Owens K. A. , Pitts M. J. , Klampferer H. J. , Krueger S. B. 
Published: December 2007

Abstract
Placement of a propped hydraulic fracture in a horizontal well is dependent on several parameters. These parameters include topics such as reservoir conditions, drilling practices, and completion techniques. This paper outlines some of the practical considerations that must be accounted for during the placement of proppant in a horizontal well. In describing a propped fracture treatment on an offshore horizontal well, the paper discusses treatment design considerations and verifies the operational and logistical improvements which can be made by utilizing a state-of-the-art stimulation vessel.
Oil Shale As A Potential Source Of Liquid Fuels
Authors: Katell Sidney 
Published: December 2007

Abstract
Oil shale is a potential source of liquid fuels, and the vast known reserves in the West have served as an impetus for utilizing this reserve. The economics of a system using oil shale in the production of liquid products is examined in this paper. Included production of liquid products is examined in this paper. Included are mining, retorting, and refining to produce the salable product. Capital cost, operating cost, and a financial analysis are detailed.
Introduction
Oil shale deposits are available in many parts of the world and at one time were one of the major sources of petroleum-like products in several localities. The Scottish deposits were utilized on a commercial scale starting in the 1850's and were still being utilized until about 1964. In this country the Eastern shales associated with coal were used as a source of both oil and gas prior to the Drake well discovery. Between 1916 and 1920 there was a flurry of activity in the Western oil shale fields when there was some feeling that crude oil production was lagging behind an increase in consumption. Imports were available, chiefly from Mexico, but were not sufficient to make up the deficit. The discovery of the oilfields in Oklahoma, California, and Arkansas in the early 1920's, accompanied by the recession in that period, almost completely obviated the experimental effort in Colorado.
The oil shale resources of Colorado, Utah, and Wyoming occur in over 11 million acres and it has been estimated that 1.8 trillion barrels are available (having a grade of at least 10 gallons per ton) under the classification of "known reserves." Recently, interest in these reserves has been reactivated, largely because of the anticipated need to broaden the resource base to supplement conventional crude petroleum. This need to fill the gap between energy supply and demand petroleum. This need to fill the gap between energy supply and demand is anticipated before 1980, by both government and industry.
Study of Mechanisms for Naturally Occurring Radioactive Materials and Souring in Gas Production Facilities in the Antrim Shale of the Michigan Basin
Authors: Ortiz Isaias , Anthony R. V. , Oddo J. E. , Pope D. H. , Frank J. R. , Becker D. M. 
Published: December 2007

ABSTRACT
Naturally occurring radioactive materials (NORM) and souring have been observed in certain gas production facilities associated with wells producing from the Antrim shale in northern Michigan. The results of a study managed by the Gas Research Institute have shown that only 1 of 99 wells surveyed had detectable radioactivity while the separators had considerable radioactivity. Only four wells had high sulfate levels. Most of the other wells had low to moderate amounts of barium. The data suggest that barium sulfate scaling (with co-precipitation of NORM) does not occur until produced waters containing sulfate are co-mingled with waters containing barium. Above ground this occurs principally in the common piping, separators and tanks. High sulfate wells were not correlated with wells having evidence of corrosion nor with activities of acid producing bacteria. High sulfate levels were found in wells along the steeply folded and possibly faulted flanks of anticlinal structures. These wells also had aerobic bacteria. It can be inferred from these observations that sulfate may be associated with waters migrating into Antrim wells from underlying formations (e.g., Traverse where anhydrite (CaSO4) layers may lie close to the Antrim) possibly through faults, natural fractures or up wellbores drilled to the deeper formations. The role(s) of the aerobic bacteria are presently unclear. Their presence may, however, support the water migration model. More work is needed to confirm or deny these models.
Souring was not positively correlated with high sulfate wells, but was positively correlated with sulfate reducing bacteria levels. Possible mechanisms for souring are: sour wells are fractured (naturally or by completion) into portions of the deeper formations which contain sour gas but not sulfate or that much of the migrated sulfate is converted to sulfide either by microbial activities in the wellbores, or reactions with organic material in the black shales.
The Development of a Novel Scale Inhibitor for Severe Water Chemistries
Authors: Sweeney F. M. , Cooper S. D. 
Published: December 2007

ABSTRACT
For several recently developed oil fields conventional scale inhibitor chemistry has been found to be ineffective in controlling/preventing scale formation. The failure of these scale inhibitors has been due to several factors; most notably a combination of high barium and calcium ion levels with low bottomhole pH and high reservoir temperatures. BP operates one such field, the Miller reservoir. The development of a suitable scale inhibitor for Miller was considered essential to enable the field to be produced effectively without the use of more sophisticated and costly facilities, such as reverse osmosis units for seawater treatment prior to injection.
The development of more effective scale inhibitors was progressed by identifying a relationship between inhibitor performance and molecular structure. From this relationship, several inhibitors were developed which showed significant improvement over commercially available products when evaluated in the laboratory. The best inhibitor, PO-85, has now been produced under licence by a major chemical manufacturer, and is ready for deployment on Miller.
Formate Brines: Novel Drilling and Completion Fluids for Demanding Environments
Authors: Downs J. D. 
Published: December 2007

ABSTRACT
After more than 30 years of development and refinement, the technology for formulating halide-based brines for drilling and completion-fluid duty is relatively mature. Nevertheless, the halide brines still exhibit certain performance deficiencies that can significantly limit their utility.
Laboratory tests indicate that a series of organic brine systems based on the alkali metal salts of formic acid have a promising range of properties that are superior to those of the halide brines in nearly all respects. The outstanding features of the formate salts are: –They can provide high-density brines that are non-hazardous and appear to be compatible with oilfield hardware.–They are environmentally responsible and readily biodegradable.–As powerful anti-oxidants, they can protect viscosifiers and fluid-loss polymers against thermal degradation up to temperatures of at least 150°C–They are compatible with formation waters containing sulphates and carbonates.
It is anticipated that formate brines will soon find application as high-performance drilling and completion fluids in a number of demanding operational environments where conventional fluids have difficulties in meeting the required performance specifications.
Optimization of Oil-Base Mud Chemistry for Cementing
Authors: Harder C. A. , Carpenter R. B. , Freeman E. R. , Brookey T. E. , Gandy R. G. 
Published: December 2007

ABSTRACT
Oil base muds (OBM) and their formulation can have a pronounced impact on cement performance in wellbores. This occurs when cement and OBM become mixed during normal well cementing operations. Increased mud contamination can ultimately compromise cement integrity. To minimize these mixing effects, the ability to improve compatibility of the mud system becomes paramount to completion success. The OBM base oil and the type and concentration of emulsifier can be especially crucial.
The most common type of OBM primary emulsifier is a fatty acid which reacts with calcium hydroxide to form a calcium soap. A partially water soluble emulsifier (an alkanolamide) is used as a secondary emulsifier in most OBMs because it keeps the emulsion stable even if the calcium source is depleted, but it is rarely used as a primary emulsifier. When employed as a primary emulsifier, the alkanolamide has shown the ability to reduce the effects of OBM contamination on cement. In a correlative work similar benefits have also been realized by mixing a water soluble surfactant with cement.
Proper design and management of an OBM system provides better cement performance. Although using an alkanolamide as the primary emulsifier costs slightly more than using a fatty acid, reducing the impact of OBM/cement contamination can more than offset the increased cost.
Colloidal Structure of Asphaltene Solutions and Heavy-Oil Fractions Studied by Small-Angle Neutron and X-Ray Scattering
Authors: Espinat D. , Ravey J. C. 
Published: December 2007

ABSTRACT
Asphaltene and heavy oil colloidal structure were studied by small angle X-ray and neutron scattering (SAXS – SANS). Different suspensions were analysed: *asphaltene after n-heptane precipitation; effect of different good solvents on the asphaltene macrostructure, effect of n-heptane on the state of molecular aggregation, temperature effect.*resins, after fractionation, in solution in toluene, and effect of the addition of a small amount of n-heptane,*in order to precise the effect of resins on asphaltenes in solution, we studied mixtures of the two kinds of molecules,*Safanya vacuum residuum (VR), we foccussed our attention on the effect of temperature.
We have shown that asphaltene are flat aggregates whose size and molecular weight mainly depend on the solvent and the temperature. As temperature increases, we noticed a decrease of the molecular weight; then asphaltenes follow an aggregation equilibrium. The n-heptane addition induces an increase of the molecular weight.
The resins behavior is singular; SANS experiments showed that resins suspensions are heterogeneous, exhibiting concentration fluctuations. As temperature increases, the system becomes more homogeneous.
We observed a decrease of the asphaltene molecular weight when we added a small amount of resins.
Scattering spectra of VR dilutions in toluene are quite similar to those of pure resins in the same solvent and at comparable concentrations. Pure VR exhibits a very strong scattering at small Q-values which suggest important density fluctuations in the medium. As temperature increases, the scattering decreases due to more homogeneous system.
Wax Deposition Mechanism Under High-Pressure and in Presence of Light Hydrocarbons
Authors: Hamouda A. A. , Viken B. K. 
Published: December 2007

Abstract
When a waxy crude oil is cooled, i.e. in a submarine pipeline, the crude oil temperature reaches the ambient temperature. At temperatures below die cloud point/wax appearance point (WAP), paraffins start to crystallize.
The wax precipitated from oil mixtures primarily consists of C18 to C36 (paraffin waxes) or C20 to C60 (microcrystalline waxes), both made up of aligned paraffinic and naphtenic molecules(1)). Paraffin waxes are also called macrocrystalline(2).
The wax may be deposited in pipelines at higher temperatures than those measured in the laboratory where the pipeline wall roughness and/or presence of nucleation sites, such as solids, corrosion products etc., play great role for depositing wax from undersaturated fluids.
A Study of In Situ Combustion in a Segregated System
Authors: Khelil Chakib 
Published: December 2007

Khelil, Chakib, Member AIME, D.R. McCord and Associates, Inc.

Abstract
Some or the field pilot studies made to date have indicated that forward combustion proceeds in a segregated manner in oil proceeds in a segregated manner in oil reservoirs and that surfaces at which combustion is occurring develop both parallel and perpendicular to the general direction of air injection.
Although mathematical studies or combustion in a segregated system have been made, no experiments involving such a system have ever been attempted.
The objectives of this investigation are to study experimentally the factors affecting oxygen consumption and oil recovery in a segregated system and to provide a better mathematical means than those now available for estimating the distribution of temperature, oxygen and fuel throughout the reservoir. The mathematic model is also useful in studying the effects of some factors not examined experimentally.
Nine combustion tube runs were made wherein all of the factors involved in the process were studied. The objectives of this study were then fulfilled by correlating the data obtained from material balance by means of a multiple regression analysis program.
The results obtained showed that burning in a segregated system is characterized by the fingering of the coke zone, the formation of secondary surfaces of combustion, low pressure gradients, and migration of oil into the gas cap. There is more even oxygen consumption at low than at high flux and pressure. Oxygen consumption increases as flux, pressure, clay content, water saturation and oil gravity increases. The recovery of initial oil in place also increases as crude oil gravity place also increases as crude oil gravity increases. It is also noted that recoveries in this type of system are substantially the same as those in similar vertical tube runs but differ in the time of oil breakthrough.
The mathematical model has been developed to simulate burning in a segregated reservoir. The models presented by previous authors are shown to represent particular cases of this model.
The mathematical study shows that a more rapid burning in the horizontal direction is caused by one or several of the three following factors:heat losses to the surroundings from the oil zone,an increase in gas cap thickness, anda decrease in air flow rate through the oil zone.
It is also found that a decrease in gas cap porosity leads to lower heat transport through the gas cap and consequently to slower burning in the horizontal direction.
Advanced Asphaltene and Paraffin Control Technology
Authors: Bernadiner M. G. 
Published: December 2007

ABSTRACT
Asphaltenes and paraffins deposit in the wellbore zone, tubing, downhole pumping equipment, pipelines, and in surface equipment, and, also, cause a high viscous stable water-in-oil emulsion inside the tubing and surface equipment, dramatically decreasing well productivity. Modern asphaltene and paraffin control technologies and demulsification methods usually do not correspond and even may contradict each other, resulting a high cost and ineffectiveness of oil production. The advanced way to utilize the technological methods in the most efficient manner is creating a common technology to put on line several asphaltene and paraffin problems.
The current paper discusses an optimal stimulation method recovering the mentioned above problems by using just one treatment. The method consists of a periodical application of detergent designed to remove the deposit and simultaneously to destroy the water-in-oil emulsion. In addition, the detergent adsorbing on the equipment surface prevents further asphaltene and paraffin deposition.
The Efficacy of Formaldehyde for the Control of Biogenic Sulfide Production in Porous Media
Authors: Kriel B. G. , Crews A. B. , Burger E. D. , Vanderwende E. , Hitzman D. O. 
Published: December 2007

ABSTRACT
The souring of reservoirs by microbial activity has become a major concern to the oil and gas industry. In the present study, core flood experiments were used to evaluate the efficacy of periodic formaldehyde injection for the control of in situ biogenic reservoir souring. In these floods two reservoir environments were simulated: the near-injection well, and the deep-formation. Formaldehyde treatments were demonsrated to control souring in both enviroments; if the formaldehyde can be transported through the reservoir, in situ biogenic souring should be mitigated.