bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of Immobile Phase Saturations in Tertiary Oil Recovery
Authors: Kasraie Mahnaz , Farouq Ali S. M. 
Published: December 2007

ABSTRACT
The presence of an immobile phase – oil, water, or gas – can influence the performance of an oil recovery process, adversely under most conditions. Furthermore, the flood velocity exerts an additional effect on the role of the immobile phase.
The paper discusses the effect of an immobile phase on dispersion in porous media. Specifically, solvent flooding is examined in the context of immobile oil, water, and gas phases. The phase saturations were reduced below the critical values to study an extended saturation range. Also tested was the effect of entrained polymer on dispersive mixing.
Although the studies were primarily conducted in a miscible displacement framework, the results are examined in the context of other recovery methods as well, such as micellar and alkaline flooding. Solvent flooding of very viscous oils is also considered, wherein the dispersion behavior is controlled by the dissolution of an initially immobile oleic phase.
The results obtained show that dispersion in a porous medium tends to decrease in the case of wetting immobile phase. The behavior is opposite if the immobile phase is nonwetting (oil or gas). For wetting phase saturations below the critical, the mixing coefficient first decreases then increases with an increase in saturation. The opposite behavior is observed in the case of nonwetting phase. In all cases the mixing coefficient is rate-dependent, the direction of change being governed by the type and magnitude of the immobile saturation.
The practical implications of the above observations from the point of view of tertiary oil recovery processes are discussed.
Factors Affecting Solvent Slug Size Requirements in Hydrocarbon Miscible Flooding
Authors: Chen Shing-Ming , Allard D. R. , Anli Jun 
Published: December 2007

ABSTRACT
Selecting an optimum solvent slug size is critical in the proper design of a hydrocarbon miscible flood. It has been common practice in the industry to calculate slug size requirements using a dispersion model. However, this method often yields slug sizes that are much smaller than the minimum requirements suggested by many field test results. This paper reviews the assumptions and limitations of the dispersion models and proposes many other important factors which must be taken into account when designing solvent slugs.
More specifically, the paper suggests possible modifications to the dispersion-capacitance model, as it is applied to carbonate reservoirs exhibiting dual porosity. As well, the influence of the following factors on slug requirements is examined: (1) water blocking of solvent at high water saturations, (2) residual solvent within and behind the solvent bank, and (3) the multiple-contact miscible displacement process.
A Predictive Model for Water and Polymer Flooding
Authors: Jones R. S. , Pope G. A. , Ford H. J. , Lake L. W. 
Published: December 2007

Abstract
A predictive model (PM) has been developed for water and polymer flooding for use in screening studies and feasibility analysis. The PM requires only a fraction of the computing time of numerical simulators, but includes most of the phenomena which affect flood performance. This is accomplished by combining a two-dimensional crosssectional model (using vertical equilibrium), with areal sweep correlations, and injectivity functions which gives results (oil rate versus time) which are suitable for economic analysis.
The paper presents validations of the PM against simulator, analytical, and field results. A brief sensitivity analysis concludes the paper.
Evaluation of CO2 Flood Performance, Springer "A" Sand, NE Purdy Unit, Garvin County, OK
Authors: Fox M. J. , Simlote V. N. , Beaty W. G. 
Published: December 2007

Abstract
This paper describes and presents results of an overall program of monitoring and evaluation of a carbon dioxide flood being conducted in the Northeast Purdy Springer "A" Sand Unit in Garvin County, Oklahoma. The response of one specific five-spot pattern is described through detailed reservoir simulation utilizing data from observation well logging, pressure transient analysis, carbon dioxide injection profiling, sampling of produced fluids, and monitoring of production rates. A reservoir description satisfying primary, secondary and tertiary performance is also described in detail.
History matching of the carbon dioxide flood performance is being utilized to define the effects on reservoir performance of waterblocking, viscous fingering and residual oil saturation to carbon dioxide flooding. These parameters are not laboratory defined. Sensitivity work was conducted to design the best process.
In-situ saturation changes obtained from an observation well logging program are presented and correlated with model calculated saturation changes and indicate that oil is being mobilized as predicted by the simulator. A comparison of carbon dioxide injection profiles to water injection profiles and the results of observation well logging indicates that the carbon dioxide is flooding certain reservoir layers that were not waterflooded. The model reservoir description was modified to include these layers. Results of compositional analyses of produced fluids are presented.
Chateaurenard Field Test Recovery Mechanisms and Interpretation
Authors: Bourdarot Gilles , Sardin Michel , Putz Antide 
Published: December 2007

ABSTRACT
The CHATEAURENARD micellar/polymer field test was conducted between 1976 and 1980 in the south part of the PARIS Bassin. Pilot design, operations and oil production results have already been presented. We present a detailled analysis of the effluents. It appears that surfactant, most of wich remained trapped in the reservoir, is associated with calcium in the oil when produced, as a result of sodium exchange with the calcium associated with the clay in the reservoir sand. Supporting phase studies and floods through sandpacks are presented to quantify this cation exchange and investigate its influence on oil recovery and phase trapping.
The Relative Permeability Function for Two-Phase Flow in Porous Media: Effect of Capillary Number
Authors: Ramakrishnan T. S. , Wasan D. T. 
Published: December 2007

Abstract
Expressions for both drainage and imbibition relative permeabilities for wetting and nonwetting phases have been derived using the cut and random rejoin approach. The pore structure is modeled by using information about the pore size distribution that determines capillary pressure. The nonwetting phase is considered to be present as both connected and disconnected fluid. The appropriate permeability equations are then obtained by considering laminar flow equations for the randomly formed pore throat constrictions. Based on the classical percolation theory for mobilization of disconnected nonwetting phase and data on entrapment of connected nonwetting phase, the relative permeability equations are presented for varying capillary numbers.
The theoretical results of relative permeability for both natural and synthetic porous media agree with the available experimental data for drainage as well as imbitition. Moreover, the limited experimental data for high capillary numbers corroborate the basic considerations of the model.
The injection or in situ generation of surface active agents alters the fractional flow of oil in a reservoir due to an increase in the (local) capillary number. This change in the fractional flow is also dependent upon the initial connected and disconnected nonwetting phase saturations. The present approach takes both of these factors into account and therefore can be put to direct use in modeling surfactant and caustic flooding processes.
Concepts Pertaining to Reservoir Pretreatment for Chemical Flooding
Authors: Meyers K. O. , Salter S. J. 
Published: December 2007

Abstract
In this paper, a model is proposed which details how preflush chemicals in the aqueous phase are transported through an oil-containing porous media. The example preflush process chosen is monovalent/divalent, cation-exchange. Initially, the chemistry of ion exchange is summarized. This is followed by a careful system of core characterization designed to determine as many of the ion-exchange characteristics of the chosen porous media as possible, independent from specific preflush experiments. A series of preflush experiments, run with zero and waterflood residual oil saturations are then described. Finally, a mathematical model is proposed to describe the preflush process. This model is solved numerically and compared with the experimental results. The model is shown to be successful in both a matching and predicting mode over a wide variety of conditions. This success verifies many of the ion-exchange and flow concepts used in formulating the model.
Enhanced Oil Recovery by Nitrogen Injection: The Effect of Increased Temperature and the Amount of Gas in Solution
Authors: Alcocer C. F. , Menzie D. E. 
Published: December 2007

ABSTRACT
The results of laboratory research conducted to study displacement of crude oil by high-pressure nitrogen injection are presented in this paper. The objectives of this research were to study the effect of temperature and original gas-oil ratio in solution on crude oil recovery and the miscibility process in high-pressure (H-P) nitrogen injection. Also in addition, the effectiveness of nitrogen injection after waterflooding and the effect of nitrogen-driven propane slugs was examined. Nine experimental tests were performed using crude oil of 42.3° API recombined with natural gas. The experimental tests were made using two temperatures (70°F and 120°F) and three gas-oil ratios in solution (575 SCF/STB, 400 SCF/STB and 200 SCF/STB). The reservoir model used was a stainless steel tube 125 feet long and 0.435 inches in diameter, packed with sand consolidated to give an average permeability of 910 md. The model was provided with five sampling valves to collect vapor samples. The vapor samples were analyzed by using a gas chromatograph. A temperature control system was built based on the results obtained from a heat transfer mathematical model specifically prepared for this research. The results obtained in this study suggest very strongly that crude oil recovery and miscibility in this kind of oil depend on temperature and oil-gas ratio in solution. Multiple-regression equations to predict crude oil recovery using temperature and gas-oil ration in solution were developed based on the experimental data.
Diagnostic Tools for Mapping EOR Processes
Authors: Wayland J. R. , Leighton A. J. 
Published: December 2007

ABSTRACT
Success of an EOR process is often dependent upon determining the extent of oil desaturation in an area and early discovery of detrimental flow paths by injected fluids. Early detection of these, and alteration of production and injection schedules (and other measures) can reduce costly bypassing and production of excess displacing fluids and can maximize oil recovery and project economics. The criteria given for selection of the best diagnostic tool at project inception can reduce costly and ineffective trials and produce more useful information at lower cost. This paper presents the essential principles and significant parameters for the principal techniques for determining fluid distributions, flow patterns, and fronts for oil recovery methods which are displacement mechanisms. Several new geophysical methods are included. Microseismic measurements are being tested in Canadian thermal recovery projects. New electromagnetic techniques for monitoring subsurface movement of thermal fronts and injected fluids are considered. Single well and interwell tracer tests are finding increased application in water floods, chemical floods, and chemically aided steam floods. Pressure transient tests are used to define reservoir continuity and provide directional permeability for preferred fluid movements. Physical description of each system as well as information obtained and required analysis are provided along with the advantages and disadvantages of each system and cost. Tables are formulated to indicate which diagnostic methods work best in different sets of reservoir-recovery system combinations. The engineer is then able to select one or more candidate techniques for further evaluation and possible use. Numerous references are provided. Field applications of most of the methods covered showing the use and significance of the data are described. In the emerging techniques, results from comparable subsurface applications are mentioned. Where possible, laboratory studies are described which aid in identifying the phenomena to provide validity of interpretation of field results.
Testing and Development of the Beowawe Geothermal Field
Authors: Epperson I. J. 
Published: December 2007

ABSTRACT
Since the initial drilling in 1959 within the Beowawe Geothermal field in north-central Nevada, USA, a total of 16 wells have been drilled. The source of the hot low salinity fluid is believed to be in Lower Paleozoic carbonates at depths approaching 20,000 to 30,000 feet (6100-9100 m). The geothermal fluid flows upward from the carbonates by way of a complicated series of faults, charges permeable horizons along the way and finally discharges at the surface. Numerous flow tests, buildups, interference tests, and injectivity tests have been conducted on eight of these wells. All data indicates that the geologically complicated 3eowawe system is very prolific and fed by a very large reservoir.
Impact of Perforation Variables on Well Productivity at Prudhoe Bay
Authors: Twyford L. R. , Tyler T. N. 
Published: December 2007

ABSTRACT
Numerical models and laboratory studies have been performed by other investigators to define the impact of various perforation parameters on well productivity. Field verification of these findings is difficult due to uncontrolled factors such as charge performance, drilling invasion, and reservoir quality.
Using information from Prudhoe Bay, a study of perforation parameters affecting well productivity was undertaken in an effort to identify the most significant perforation variables in terms of initial and long term well performance. Findings from the study of field data verifies that perforation penetration is the most significant factor affecting well performance. Wells perforated with deep penetrating casing guns have lower drawdowns and significantly lower decline rates than wells perforated with through tubing guns. The high decline rates at Prudhoe Bay are a result of calcium carbonate scale buildup, which is exacerbated by perforations of poor quality. The data also suggests that 0° gun phasing is comparable to other phasing when perforating in deviated, large diameter well bores.
An Evaluation of Options for Prudhoe Bay Natural Gas
Authors: Corley D. I. , Marsden S. S. 
Published: December 2007

ABSTRACT
This study investigates some of the reasons why the natural gas which is produced along with the oil at Prudhoe Bay is not being delivered to a market and three of the possible methods of delivering this gas energy to a market. These three alternatives include a proposal to build a natural gas pipeline through Canada, a liquefied natural gas (LNG) proposal and a proposal to manufacture fuel grade methanol from the natural gas at Prudhoe Bay which would be shipped through the existing Trans Alaska Pipeline System. A brief review of the engineering, economic, environmental, supply/demand and market aspects, and most importantly the political considerations affecting the selection of any of these three alternatives is presented.
The concern over marketability of gas delivered through the proposed pipeline through Canada is responsible for this proposal being held in abeyance, even though it was politically selected as the Alaskan Natural Gas Transportation System in 1977. If an alternative System is to be selected, action should be taken before there is a political decision to force the construction of the pipeline through Canada.
From virtually every viewpoint the methanol proposal is the most reasonable method of delivering the Prudhoe Bay gas energy to a market. It is shown that either of the other alternatives would result in the cost of the Prudhoe Bay gas energy being higher than the cost of energy from imported oil or natural gas.
Prediction of Fracture Extension During Waterflood Operations
Authors: Kuo M. C. T. , Hanson H. G. , DesBrisay C. L. 
Published: December 2007

ABSTRACT
A fracture extension mechanism was proposed to explain daily surface injection pressure behavior observed in a waterflood project located in the Somatito Field A fault block in the Talara Area of Northwest Peru. Daily surface injection pressure data indicated a repeating phenomenon, i.e., formation pressure increasing slowly along a general trend as the flood continued (called normal formation recharge). Surface injection pressure occasionally built up above this trend value because of fracture plugging. Then the injection pressure dropped back sharply to the general trend (called fracture extension). The mechanism repeats again and again in the same sequence until water breaks through at a producer. Fracture propagation theory (Geertsma and de Klerk1) was applied to calculate incremental fracture length, or, the time interval during the fracture extension period. Combining the information of fracture extension frequency and incremental fracture length, expected breakthrough dates can be predicted at producers along the fracture azimuth. Water breakthrough sensitivity analysis is a useful technique to identify fracture azimuths or preferential permeability trends.
Given daily surface injection pressure data, a simple method was developed to allow engineers to predict premature injection water breakthrough in tight reservoirs. This simple procedure is especially useful to reservoir and field engineers involved in secondary and tertiary recovery projects.
The Transport of Bacteria in Porous Media and Its Significance in Microbial Enhanced Oil Recovery
Authors: Jang Long-Kuan , Sharma M. M. , Yen T. F. 
Published: December 2007

ABSTRACT
MEOR is a tertiary recovery process which has only recently been accepted as a technically feasible alternative to other EOR processes in certain shallow, highly permeable reservoirs. The transport of injected bacteria in the porous media is among the problems which need to be resolved before a MEOR process can be successfully applied in a candidate reservoir. In order to contact trapped oil with active metabolites generated in situ, potential strains of bacteria must be transported deep into the reservoir. The problem of transport of bacteria is linked closely with the success or failure of an MEOR process.
This paper presents a bench-scale investigation of bacterial transport in sandpack columns and sandstone cores and its relationship with oil recovery efficiency. Various oil recovery processes utilizing Bacillus subtilis (a bio-surfactant producer) have been attempted: (a) Continuous flooding with bacterial culture, (b) inoculation of bacteria followed by injection of nutrient, (c) inoculation followed by repeated cycles of static incubation, pressure release and nutrient (or water) drive. Experiments revealed that the above processes recovered 30%-40% of the heavy oil (Ranger Zone, Long Beach, CA) in the sandpack column remaining after secondary water-flooding. It was found that bacteria are able to migrate 1 ft/day through the sandpack column saturated with nutrient broth.
The transport of bacteria (or spores) in process (c), which is tentatively thought to be the most feasible among the three processes, is achieved through injection with nutrient followed by a period of static incubation during which cells mutiply and migrate. Separate experiments simulating the two stages of bacterial transport revealed that bacterial spores of B. subtilis and C. acetobutylicum are most easily pushed through the sandstone core while B. subtilis cells migrate through the core faster than Pseudomonas putida during static incubation. This suggests that the procedure developed in this work provides a criterion of selecting bacterial cells with favorable transport properties in porous media.
Unconventional Pilot Steam Drive, Tar V Sand, Long Beach Unit, Wilmington Field, CA
Authors: Jung K. D. 
Published: December 2007

ABSTRACT
This paper reviews the design, implementation and history of the unconventional pilot steam drive (greater than 2,500 ft measured depth) that has been underway since December 24, 1980 in the Tar V reservoir in the Long Beach Unit, Wilmington Field, Los Angeles County, California. This paper describes the project through November 30, 1983.
The Tar V reservoir is a series of interbedded sands, siltstones and shales in the Middle Repetto formation of lower Pliocene age. The Tar V reservoir in the Long Beach Unit is approximately 200 acres in areal extent, has a vertical gross thickness of 185 ft and a maximum vertical net oil sand thickness of 90 ft comprised of 8 to 10 separate sand units. Oil in place is estimated at 27 MMbbl of stock tank oil.
The study area is 9.2 acres in areal extent with an average net oil sand thickness of 81.7 ft. The pilot steam drive was originally installed as an isolated 5.6 acre inverted 5-spot pattern. The 9.2 acre study area includes two off-pattern wells that have been affected by the steam drive process.
Injection started December 24, 1980 in A-662I. The injector and all wells in the study area are directionally drilled from Island Grissom or the Pier J site. Inzone hole angle averages 50°. Well measured depths average 3,256 ft. The top of the Tar V reservoir is approximately 2,100 ft vertical subsea.
Tank oil-in-place in the 9.2 acre study area at the start of injection is estimated at 1,171 Mbbl. Oil recovery from the study area from start of injection to November 30, 1983 is 210.8 Mbbl or 18.0% of the oil originally-in-place. Oil recovery from the study area prior to start of injection is 23.4 Mbbl or 2.0% of the oil originally-in-place.
Production from the six-well study area in November, 1980 was 475 B/D gross, 118 B/D net, 75.2% cut. Peak oil rate was in June, 1982 at 1,969 B/D gross, 413 B/D net, 79.0% cut. The November 1983 rate was 710 B/D gross, 87 B/D net, 87.7% cut. Cumulative injection of steam and/or hot water is 572 Mbbl into A-662I the pattern injector, and 172 Mbbl into the six producing wells for thermal stimulation. Total injection is 744 Mbbl for a cumulative oil-steam ratio of 0.28 and 0.40 pore volumes injected.