bluuebunny/crossref_metadata_2025_split huggingface dataset:
EOR Prospect Evaluation Using Field Manufactured Polymer
Authors: Milton H. W. , Argabright P. A. , Gogarty W. B. 
Published: December 2007

ABSTRACT
Prospect evaluation starts with laboratory studies of various enhanced oil recovery (EOR) processes. Results of EOR floods in waterflooded cores are given for caustic, dilute surfactant, mi cellar solution flooding, and polymer augmented waterflooding. In this work, partially hydrolyzed polyacrylamide (PHPA) was used as the mobility control agent. A pilot scale PHPA manufacturing plant, built in the field, supplied polymer for both lab and field testing. Results are presented from a polymer injectivity test at a water injection well. The injection well completion and surface facilities used in the test are described. Water to polymer injectivity is compared as a function of polymer concentration. Pressure data are used to establish the effect of polymer on solution mobility in the reservoir. Computer modeling was also used to match the lab and field results and to predict field oil recoveries for making economic calculations. Economic studies are the final step in the prospect evaluation procedures. Economic results using the same example field project for two different EOR methods are presented.
Evaluation of a Direct Contact Downhole Steam Generator in a Field Environment—Final Results
Authors: Marshall B. W. , Moreno J. B. , Muir J. F. 
Published: December 2007

ABSTRACT
A test program to demonstrate the operation of downhole steam generators (DSG) in an oil field environment was conducted in the Wilmington Field at Long Beach, CA. Two DSG design variations were used. One burned diesel fuel in air and was placed downhole; the other burned diesel in oxygen and was located on the surface. Gas communication was established with all wells in the production patterns. Relative rates of movement of nitrogen, CO2 and CO were inferred and the wells were monitored for any production changes. Operating lifetimes of both prototype units were limited by the corrosion of various system components. Metallurgical analyses of degraded components of the generator and support systems have been completed.
Porosity and Permeability of Mesaverde Sandstone Core from the U.S. DOE Multiwell Experiment, Garfield County, Colorado
Authors: Randolph P. L. 
Published: December 2007

Abstract
As received water saturation was measured and several dry core analyses were performed on 32 Mesa Verde sandstone core samples from depths between 1496 m (4910 ft) and 2475 m (8118 ft) in Garfield County, Colorado. Eight of the higher permeability samples were then selected for determination of the effect of fractional water saturation upon permeability.
The samples were from 13 sandstone intervals covering four depositional environments (fluvial, coastal, paludal and marine). The dry core analyses measured porosity, Klinkenberg permeability, Klinkenberg slope, and pore volume compressibility at net stress representative of the midpoint of reservoir drawdown. In addition, pressure was measured using a conventional mercury injection porosimeter.
Klinkenberg permeabilities for the samples dried to constant weight at 60°C and 45% relative humidity at 1 atmosphere pressure averaged 1.9 μ darcy at net stress representative of the midpoint of reservoir drawdown. Porosities under these same stress conditions varied between extremes of 4.4 and 11.4% with an average of 7.2 %.
The decline in permeability to gas with increasing fractional water saturation was found to be surprisingly sharp. For net confining stress representative of the midpoint of reservoir drawdown, water saturations required to reduce relative permeability to 0.01 were in the range of 40% to 55% with an average of 46%. Of the 8 samples, only two exhibited Klinkenberg permeability in excess of 0.1μ darcy for water content equal to the as received" value.
Measurement of the variation in permeability to gas as functions of net stress and water content revealed a dramatic difference between fluvial samples with high pore volume compressibility and paludal samples with lower pore volume compressibility.
Viscosity of Surfactant-Polymer Solutions
Authors: Hornof Vladimir , Neale G. H. , Chaaraoui Ali 
Published: December 2007

ABSTRACT
Viscosity effects occurring in aqueous solutions containing a combination of surfactants, polymers and salts are of considerable interest in enhanced oil recovery operations. High molecular weight polymers, which are normally employed to improve sweep efficiency, lose much of their viscosity because of mechanical degradation and other adverse conditions in the reservoir. The mixing of the surfactant slug with the polymer slug in micellar flooding may lead to phase instability and low recovery efficiency.
The formation of surfactant-polymer aggregates on the other hand, might have a positive effect on recovery. Such association complexes do not lose their viscosity permanently due to shear as they are quickly rebuilt upon cessation of shear forces. The present work shows that significant viscosity increases can be obtained by combining a petroleum sulfonate surfactant with a low molecular weight polyethylene oxide. For example, an addition of Carbowax®−20M to 4% Petrostep®−420 at 1.5% NaCl salinity first results in a viscosity increase with a maximum at about 0.2% of polymer. After this, the viscosity drops sharply reaching a minimum at 0.5% of polymer. Beyond this point, the viscosity begins to rise again at a rate which is somewhat higher than that observed for the polymer solution alone. The behavior observed with Carbowax®−6000 was similar although the increase in viscosity was smaller. No discernible effects were observed with Carbowax®−600. The magnitude of the viscosity increase observed at 0.2% of polymer was found to be strongly dependent on salinity.
Characterization of Hydrocarbon-Su rfactant Systems by Alcohol-Brine Titration and Hydrocarbon Displacement Experiments
Authors: Terry R. E. , Robinson J. C. , Mandel R. S. 
Published: December 2007

ABSTRACT
Shah1 and Shah, et al2 presented a correlation of a property of the pseudo-ternary (isopropanol, brine, and a constant ratio of surfactant to hydrocarbon) phase diagram with the equivalent alkane carbon number (EACN) of the hydrocarbon phase. The work suggested a new approach to characterize hydrocarbon-surfactant systems. Their work was performed on pure alkanes and mixtures of pure alkanes.
The work reported in this paper extends the correlation to pure and mixtures of pure alkylcyclohexanes and alkylbenzenes and to mixtures of these types with each other and with alkanes. The correlation was found to hold for the systems studied.
In another phase of the research, an attempt was made to compare the behavior of pure alkanes and mixtures of pure alkanes in displacement experiments in sandpacks. The hydrocarbon saturated sandpacks were flooded to residual saturation with a brine flood. The sandpacks were then flooded with a surfactant system to displace the residual oil. The results indicate that, for the EACN values studied, the mixtures and pure components behave similarly in displacement experiments.
Adsorption of Sulfonate on Kaolinite and Alumina in the Presence of Gypsum
Authors: Somasundaran P. , Ananthapadmanabhan K. P. , Viswanathan K. V. 
Published: December 2007

ABSTRACT
Loss of surfactants by adsorption and precipitation that can occur during enhanced oil recovery by micellar flooding is a complex phenomenon dependent not only on solution properties such as pH and salinity, but also on the presence of even minor mineral constituents such as gypsum and limestone. In this paper, the results on adsorption of isomerically pure decyl-benzenesulfonate on gypsum, kaolinite and alumina are presented. Sulfonate abstraction by kaolinite and alumina in the presence of trace amounts of gypsum is also determined.
Adsorption of sulfonates varied significantly from mineral to mineral. Gypsum exhibited a sharp increase in adsorption above 4-6×10−5 kmol/m3 of residual sulfonate. Tests using the supernatant of gypsum showed sulfonate precipitation by the dissolved mineral species to be a major factor responsible for the high uptake.
A thermodynamic analysis of the solubility and stability characteristics of gypsum and anhydrite is presented. The sharp rise in abstraction has been shown to correspond to the onset of sulfonate precipitation. Presence of trace amounts of gypsum either with alumina or kaolinite is found to markedly increase the sulfonate uptake by these minerals. It is shown that in kaolinite-gypsum and alumina-gypsum mixtures, the total abstraction at high sulfonate levels is due to adsorption on alumina and kaolinite and precipitation caused by gypsum.
Chemical Separation and Structural Identification of EOR-Active Compounds in Water-Soluble Petroleum Sulfonate
Authors: Rajan K. S. , Chettur Govindan , Kamath K. I. 
Published: December 2007

Abstract
Earlier research by Kamath et al1 has indicated that the ability of certain water-soluble petroleum sulfonates for successfully recovering tertiary oil from water-flooded Berea sandstone cores can be traced to the presence in them of certain specific but yet-unidentified minor components. This paper summarizes the results of a closely integrated interdisciplinary research consisting of physicochemical and EOR-activity studies directed toward isolating the active components from a commercial petroleum sulfonate (Witco's Pyronate-40) and identifying their chemical structure. Following a pre-extraction with n-hexane and isopropyl alcohol, samples of Pyronate-40 in the acid, sodium salt and methyl ester forms were fractionated chromatographically on a silica gel (Florisil) column using gradient elution, initially with 100% acetonitrile and incrementally adding methanol to a final composition of 100% methanol. The EOR-activities of the chromatographic fractions were determined by means of core flood tests using Berea Sandstone core, 1-1/2" diameter × 8" long, and a small slug of the sodium sulfonates in 2% brine at pH ∼10.10 mg samples of the most EOR-active fractions gave an oil recovery of 0.8-1.6 ml which correspond to 4.4 to 2.2 lb respectively of the sulfonate for producing one barrel of tertiary oil. The EOR-active fractions were subjected to further resolutions by means of Flash chromatography using octadecylsilanized (ODS) silica gel column followed by reversed phase High Performance Liquid Chromatography (HPLC). GC/Mass Spectral examination of the EOR-active fraction (which corresponded to 2% of the starting sample of Pyronate-40) has indicated the presence of a number of components amongst which the identifiable ones corresponded structurally to the synthetic alkylaryl sulfonates such as, 5-(4-ethylbenzene-3-sulfonic acid)-dodecane. A critical discussion is presented on the chromatogrpahic resolution of such a complex mixture to a point where structural identification of EOR-active fraction could be meaningfully undertaken.
Chemistry of Precipitation and Scale Formation in Geological Systems
Authors: Katsanis E. P. , Krumrine P. H. , Falcone J. S. 
Published: December 2007

Abstract
Although the chemistry of scale formation and inhibition downhole and in surface equipment for oilfield and geothermal applications continues to be studied extensively, the mechanism by which it occurs has not been given sufficient attention. In this paper, the chemistry of precipitation and scale formation in geological systems is discussed in terms of precipitation (solubility) domains for the sodium silicate system alone and in the presence of salt and hardness ions. The regions which delineate the conditions under which precipitates form are very sensitive to time, hydrogen ion and salt concentrations, and hardness ions present. Calcium and magnesium ions at concentration levels of only 100 ppm each change the shape and position of the silicate domains by several pH units and several orders of magnitude in the concentration of SiO2 needed for precipitation to occur. In an alkaline flood there are a number of mechanisms contributing to the presence or absence of various ions in solution whose composition is constantly changing as it moves through the formation. Ions can go into solution by several mechanisms, including the dissolution of and ion exchange with clays and other minerals. A theoretical model has been developed which takes into account the ion exchange reactions of Ca+2/Na+ and Na+/H+ that can occur in strata formations during an alkaline flood. These reactions can deplete the alkaline slug and change its composition and pH value to levels where precipitation and scale formation occur.
Areal Sweep Efficiency Determination in Steam-Drive Projects Utilizing Chemical Tracers
Authors: Cooke R. W. 
Published: December 2007

Abstract
Ever since continuous steam injection (steam drive) became a viable recovery technique nearly three decades ago, attempts have been made to accurately determine areal sweep efficiencies. Until recently, the ability to determine the areal movement of steam was limited to radioactive techniques. By using common chemical tracer materials containing nitrate, bromide, iodine, or thiocyanate ions, the need for specialized radioactive materials and handling equipment is eliminated. This paper documents the efforts to use safe, inexpensive and readily detectable chemical tracer materials to determine the areal steam distribution in steam drive patterns.
The work described herein was part of the work conducted under a DOE cost sharing contract in conjunction with Stanford University Petroleum Research Institute; Chemical Oil Recovery Company of Bakersfield, California; and Petro Lewis Corporation of Denver, Colorado.
Improvement in Sweep Efficiencies in Thermal Oil-Recovery Projects Through the Application of In-Situ Foams
Authors: Eson R. L. 
Published: December 2007

Abstract
Even though steam drive is the most successful of all EOR processes, accounting for nearly 74% of all of the United States’ EOR production, it is not without its problems. Gravity segregation (steam override) and poor areal and vertical sweep efficiencies have limited recoveries in many heavy oil reservoirs since the first thermal projects were initiated in the 1960's. In many instances the injected steam prematurely breaks through into producing wells creating steam channels. It has been shown3, 7, 8, 9, 10 that in-situ steam foams have proven effective at reducing the mobility in these steam channels and diverting the injected steam into alternate flow paths, thus improving the sweep efficiency of the steam drive process.
This paper looks at the sweep efficiency improvement in three separate injection patterns utilizing in-situ steam foams. In each pattern, a slight variation in the application technique and material utilized is experienced. To determine the effectiveness of these three different approaches, radioactive injection profiles, production and the cost per incremental bbl of oil produced will be compared.
Paraffin Deposition and Rheological Evaluation of High Wax Content Altamont Crude Oils
Authors: Matlach W. J. , Newberry M. E. 
Published: December 2007

ABSTRACT
The Altamont area in Utah produces one of the highest wax content crudes anywhere in the world. These high pour point and hard to handle crude oils are an even tougher problem because of their location in a geographical area subject to very low ambient temperatures. Millions of dollars are spent each year heating these crudes in order to expedite their production and transportation. Crude oil samples from the area have been tested using a variety of techniques. Paraffin deposition, viscosity, cloud point, pour point, yield values, wax extraction and GLC tests have been conducted in order to characterize the crude oil samples. The effects of various chemical additives were then analyzed using the same tests. The effective paraffin inhibitors not only reduced the quantity of wax deposited, but dramatic shifts in molecular weight range and configuration were also apparent. GLC data indicates that effective chemical structures all reduced the quantity of C40-50 molecu1-ar weight waxes contained in the resulting paraffin deposits.
A Six-Year Simulated-History Match of The Piper Field
Authors: King P , Robinson T , Abdullah A A , Waldren D , Brindle D , Dake L P 
Published: December 2007

ABSTRACT
This paper describes the techniques applied and the results achieved in matching the six years of production and pressure history of the Piper field. Although Piper is an excellent oilfield it is nevertheless a difficult one to model using numerical simulation techniques. There are complex fluid-flow patterns across non-sealing faults between the offset sand sequences, together with a variable degree of vertical communication across the main reservoir unit. With six years of field data to match, the task was a large one and the question is raised – that, even though a satisfactory history-match was achieved, to what extent can it be regarded as unique?
Field Examples of Production-Logging Problems in Large-Diameter Deviated Wells with Biphasic Flow and their Implications on Reservoir Management
Authors: Scrimgeour J A , King P A , Kelman J F 
Published: December 2007

ABSTRACT
This paper discusses field examples of production-logging problems in large-diameter, deviated wells, with bi-phasic flow. Two distinct flow regimes that tend to make flow-profile evaluation somewhat problematic have been identified. The paper gives examples of both flow regimes and details of how the existence of these particular phenomena can be predicted. The paper discusses the problems that these phenomena can cause in reservoir management and gives a brief discussion of the flow-loop research project that has been initiated at Robert Gordon's Institute of Technology in Aberdeen. The project is designed to simulate the complex flow regimes that exist in large-diameter deviated holes and, by means of the visual and mechanical aspects of the loop to aid in developing tools or interpretation techniques to help overcome the problem.
Fibre Optics Improving Deepwater ROV Pipeline Inspection
Authors: MacGregor D 
Published: December 2007

ABSTRACT
Pipeline inspection is a complex test requiring a variety of sensors, a typical array being illustrated in Fig. 1.
The trend in recent times has been to fit, simultaneously, all of the above sensors to a vehicle in order to maximise data collection from the pipeline in a single pass. This data is then processed in real time as the ROV travels the pipeline. Thus, a chart representing all the available data can be made available shortly after completion of a dive.
The current generation of ROVs uses umbilicals containing various combinations of power conductors, co-axia and twisted pairs to carry the sensor data. These umbilicals, however, have inherent disadvantages which become apparent as sensor data increase in quantity and complexity. This disadvantage is the incompatibility of required high quality-data being transmitted to the surface and the large amounts of electrical energy demanded by the vehicle. Another disadvantage is the incompatibility between sensor signals in terms of frequency and power. However, to eliminate these problems, and to provide for future developments in ROV technology, the new generation of ROVs utilise fibre-optic conductors, the advantages being that they are immune from electro-magnetic interference, they offer wider band-widths with lower power losses {typically 5 dB or less per km) than conventional copper conductors, and are easier to handle as umbilicals lengthen due to demand for vehicles to reach greater depths. Typically, these new umbilicals will be 1.5 km in length.
The Fatigue Resistance and Hysteresis of Man-Made Fibre Ropes
Authors: Parsey M R 
Published: December 2007

ABSTRACT
Data on the fatigue life of man-made fibre ropes is updated and the various mechanisms of rope fatigue discussed.
One of these mechanisms, internal hysteresis heating, is examined a little further. Such internal heating should be unimportant in cycling polyester and nylon ropes at non-resonant periods over 24 seconds and at loads of up to 50% of break.
But internal temperatures sufficient to cause internal degradation in initially wet size 24 ropes cycled to 28% of break for 24 hours at wave period are predicted from simple theory which agrees well with existing data on smaller ropes.
Operators working in such extreme conditions should bear this in mind in defining hawser construction and material.
Case History of Large-Volume Fracture Stimulations in a West Texas Waterflood
Authors: Ilseng J. R. , Cortez M. J. 
Published: December 2007

ABSTRACT
A very successful fracture stimulation program in a mature West Texas waterflood is documented in this paper. Amoco's Anton Irish Clearfork Unit (AICFU) has undergone a 100 well fracture stimulation program since 1979 which has resulted in significant increases in oil production.
Hydraulic fracturing has gradually evolved over the years at the Anton Irish field due to experience gained in new stimulation techniques. Fracture stimulations in the 1970's involved pumping 105,000 gallons of gelled water with 65,000 pounds of 20-40 mesh sand at rates as high as 200 barrels per minute. Although nearly all were initially successful, production increases were sometimes not sustained, due possibly to the insufficient amount of sand/proppant utilized in hydraulic fracturing large 400' dolomite pay sections. Fracture stimulations since 1979 have involved pumping 200,000-300,000 pounds of 20-40 mesh sand in 90,000150,000 gallons, of cross-linked gelled water at 50 barrels per minute (concentrations as high as 14 pounds of sand per gallon of fluid) to create propped fractures which have resulted in sustained production increases from the affected wells. One hundred eighty days after the workover, average per-well production increases of 38 B0PD yielded payouts of 3-1/2 months.
This paper will specifically address fracture stimulation results, quality control measures, and mechanical considerations in beam or electrical submersible pumping equipment, as well as post appraise the economics associated with the $8 million program.
Case History: A Multizone Tight Gas Completion Technique for the Blocker Cotton Valley Field, East Texas
Authors: Hinn R. L. 
Published: December 2007

ABSTRACT
A case history relating to the testing and selection of a multizone completion technique applicable to tight gas sand reservoirs is detailed. This "Bridge Plug Separation" technique (BPS), developed for use in the low permeability Cotton Valley formation of East Texas, has for this operator, proven to be an efficient means of maximizing multizone gas production.
An Industry Perspective: A Case for Optimism
Authors: Miller John R. 
Published: December 2007

Abstract
I WELCOME THIS OPPORTUNITY TO ADDRESS A GROUP OF PEOPLE WHO ARE KNOWLEDGEABLE ABOUT THE PETROLEUM INDUSTRY AND INTERESTED IN THE FORCES SHAPING ITS FUTURE. THE SOCIETY OF PETROLEUM ENGINEERS CERTAINLY FITS THAT DESCRIPTION.
THE ACTIVITIES OF THIS SOCIETY AND THE COLLECTIVE EXPERTISE OF ITS MEMBERS HAVE SERVED THE INDUSTRY WELL FOR MANY YEARS. AND I'M SURE WILL CONTINUE TO DO SO.
MUCH OF OUR INDUSTRY'S STRENGTH STEMS FROM THE PRACTICAL APPLICATION OF ADVANCED TECHNOLOGY, SUCH AS THAT EXHIBITED AT THIS CONFERENCE. IN FACT, THE VALUE OF THIS EVOLVING STATE-OF-THE-ART TECHNOLOGY WILL ULTIMATELY BE DETERMINED BY THE EXTENT TO WHICH IT CAN BE APPLIED TO THE CHALLENGES THAT LIE AHEAD. SUCH IS THE ROLE OF THE ENGINEERS HERE TODAY -- AND A VITAL ROLE IT IS.