bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geological Features of Fault Block Oil Fields with Multiple Rock Salt Layers and their Development by Water Flooding
Authors: Yang Shoushan 
Published: December 2007

ABSTRACT
Oil fields located in salt lake fault basins, affected both by the faults and rock salt, have their unique geological features. As wellas Certain production characteristics and special problems in the development by water flooding. The disadvantages are salt and gypsum precipitation and serious corrosion, and the advantages are the good conformance in reversed cyclothem oil reservoir and high oil displacement efficiency of the salt water. Thus it is obviously favorable to develop oil reservoirs with steep structure with high salt content by peripheral water injection. Good results have been made in Jianghan oil region by giving reasonable development and scientific management according to the geological features of such oilfields.
Production Technology of Daqing Oil-Field During its High Water-Cut Stage
Authors: Wang Demin , Tand Jiali 
Published: December 2007

ABSTRACT
This paper discusses the development characteristics and production technology of Daqing Oil Field in its high water-cut stage. Emphasis is placed on the importance of the complete set of technologies of electrical submersible pumps and high volume rod pumps during the transformation of the production mode of Daqing oil wells from flowing to artificial lift. Also, the results of application of the other three production technologies during the high water-cut stage are expounded.
Parameter Estimation in a Naturally Fractured Reservoir by the Method of Cybernetics
Authors: Qi Yufeng , Zhang Xin 
Published: December 2007

ABSTRACT
This article presents an approach for solving the transient flow equations. By means of semi-discretization an approximate analytical solution of a set of partial differential equations describing the compressible fluid flow through naturally fractured formation is derived in a clear and applicable form
P(t)   =   P(O)   +   W(t)Q(O)   + ∫ o t W(t-) Q ¯ · (τ)d
under the most general conditions the details of derivation and the physical concepts of each parameter in that expression are given. Based on those equations, some important parameters such as transmissibility between wells from one porevolumes of each block as well as the location of some faults can be identified by conventional data or well testing data. This method is a new development in the interpretation of well testing data. This paper is a generalization of paper (1)(2) into three dimensions and doubleporosity media.
The Effect of Rock Bit Cutting Structure on Rock Breaking Efficiency
Authors: Hou Jikang , Luo Zhaofeng 
Published: December 2007

ABSTRACT
A study of the effect of rock bit cutting structure on rock breaking efficiency was made with full scale bits for soft to medium formations on a laboratory testing rig. An analysis of the relationship between rock breakage and cutting structure based on the drilling rate, bottom hole pattern and operating parameters revealed the advantages and weak points of the cutting structures. Improvement of cutting structure for some of the tested bits will be adopted in new designs. This approach is also suitable for studying bits for medium to very hard formations.
Single-Well Tracer Test in Complex Pore Systems
Authors: Deans H. A. , Carlisle C. T. 
Published: December 2007

Abstract
About 22 single-well chemical tracer tests have been performed in carbonate formations since 1971, to determine residual oil saturation after water flooding. The results in almost every case have been very different from equivalent tests run in sandstone reservoirs.
The tracer profiles observed in carbonate tests show a set of characteristic distortions. Among these are poor apparent material balance; excessive early dilution of tracers; early arrival of poorly defined peaks for tracers that were displaced away from the well during injection; and abnormally large mean retention volumes, caused by extended concentration tails.
A modified form of the "dead-end" pore model has been shown to reproduce all of these features. The various parameters examined in the model relate to the fraction of the pore space which is non-flowing, connected to the flowing fraction only by diffusion paths. Diffusion of each tracer in the non-flowing pore fraction is a function of tracer distribution coefficient; mixing length in the flowing fraction, equivalent to the usual dispersion parameter; and the residual oil saturation in both pore fractions.
This model has been used to simulate single-well tracer tests in west Texas dolomites, Canadian reefs, and other carbonate formations. The best-fit values of non-flowing fraction of pore space have been 0.40–0.75. The observed diffusion effects, which are a ratio of test duration to the characteristic time of diffusion of tracer in the non-flowing pores, varies from less than 0.5 to more than 5, depending on the test. In the higher range of the diffusion parameter, the tracer profiles approach ideal shape. This indicates that the distribution of tracer between the two pore fractions is near equilibrium. For low values of the diffusion parameter, the profiles are extremely distorted. Slow diffusion limits the access of the tracers to the non-flowing fraction of the pore space.
Characterization of Sandstone Reservoirs for Enhanced Oil Recovery: The Permian Upper Minnelusa Formation, Powder River Basin, Wyoming
Authors: Schenk C. J. , Schmoker J. W. , Scheffler J. M. 
Published: December 2007

Abstract
Upper Minnelusa sandstones form a complex group of reservoirs because of variations in regional setting, sedimentology, and diagenetic alteration. Structural lineaments separate the reservoirs into northern and southern zones. Production in the north is from a single pay sand, and in the south from multi-pay sands due to differential erosion on top of the Upper Minnelusa. The intercalation of eolian dune, interdune, and sabkha sandstones with marine sandstones, carbonates, and anhydrites results in significant reservoir heterogeneity. Diagenetic alterations further enhance heterogeneity, because the degree of cementation and dissolution is partly facies-related.
Mobility-Controlled Steam Drive "MCSD" by the Application of Additives Soluble in Hot Water
Authors: Heinemann Z. , Kratzer D. , Steiner P. 
Published: December 2007

Abstract
Oil recovery by steam and hot water flooding is improved by the application of chemicals which precipitate at the steam or temperature front by conversion from the vaporized or liquid state into the solid crystalline form. The precipitated chemicals form a temporary substance zone in which the permeability for steam and hot water is reduced. The crystallized chemicals are again sublimed or dissolved by the spreading steam/hot water front. The chemicals improve the displacement efficiency of hot water and the sweep efficiency of steam and hot water.
Tricritical Points and the Design of High-Salinity Surfactants for Low-Tension Enhanced Oil Recovery
Authors: Smith D. H. 
Published: December 2007

ABSTRACT
A major objective of low-tension, surfactant-polymer flooding is the design of surfactants for high-salinity reservoirs. In this technology the irreducible oil saturation, hence the recoverable oil, depends on the interfacial tension between the aqueous and oleic phases.
In the three phase systems that are usually employed, the "oil-water" tension depends on the thermodynamic distance of the system from a tricritical point, which is a point Where all three of the phases become a single phase. The tension, γol-aq, varies as γol-aq ~ |T − Ttc|2, where T is the reservoir temperature and Ttc is the temperature of the tricritical point.
Hence, optimal high-salinity surfactant design requires the ability to create systems with tricritical points at temperatures and salinities that are set by each individiual oil reservoir. The development of this ability requires methods for the prediction and control of the locations of tricritical points.
Tricritical points can only occur in phase diagrams with at least four dimensions, which makes their study difficult. Many of these difficulties can be overcome by means of a step-by-step consideration of critical points and phase behavior in diagrams of lower dimensionalities. A step-by-step approach to tricritical points and lines is described.
Analysis of existing data shows that tricritical points of commonly used "cosurfactants" (alcohols and nonionic surfactants) are at "negative" reservoir salinities. For such materials interfacial tensions must inevitably increase and oil recoveries fall as they are used in reservoirs of increasing salinity, even if the "optimal salinity" of the surfactant matches the salinity of the reservoir in all cases.
Addition of an ionic surfactant (eg, petroleum sulfonate) creates a tricritical point at zero (rather than negative) salinity, but this amount of improvement is too small to be satisfactory.
In the most desireable behavior, the lines of critical endpoints converge with increasing salinity and the tricritical points are at positive, controllable salinities. For this behavior optimal interfacial tensions decrease and oil recoveries can increase as the surfactants are used in reservoirs of greater and greater salinity.
Surfactant designers should measure and report critical endpoints at different temperatures (not just optimal salinities at a single temperature), so that the thermodynamic limits on high-salinity surfactants can be better ascertained.
Screening and Evaluation of Enhanced Oil Recovery at Teapot Dome in the Shannon Sandstone: A Shallow, Heterogeneous Light-Oil Reservoir
Authors: Chappelle H. H. , Emsurak G. P. , Obernyer S. L. 
Published: December 2007

SUMMARY
Pilot testing results and geologic characteristics have been used to identify methods by which oil recovery may be increased in the Shannon sandstone at Naval Petroleum Reserve NO. 3 (NPR-3), and to identify reservoir zones amenable to enhanced oil recovery (EOR) application. Extensive natural fractures have been found to be the prime influence on fluid flow and pressure distribution in this shallow reservoir. Thermal processes of in-situ combustion and steam drive have been successful in displacing potentially economic quantities of oil while immiscible displacement processes of waterflood and polymer-improved waterflood have not. A geologic characterization study based on facies description has identified the potential resource for further development of the reservoir/including the possible application of EOR. These findings will be used to determine the development of this reservoir by infill drilling and enhanced recovery.
Investigation of Phase Behavior Predictions With a Chemical-Association Equation of State
Authors: Li Y.-K. , Nghiem L. X. , Heidemann R. A. 
Published: December 2007

Abstract
An approach of applying the chemical-association theory to a cubic equation of state to model nonideal behavior is proposed. In this approach, the molecules in solution are assumed to interact with each other to form new chemical species which are in chemical equilibrium. The parameters of the chemical-association model are obtained by fitting the equation of state to experimental data for binary pairs. The approach is tested against experimental data for mixtures containing CH4, CO2, H2S and H2O. Improvements in liquid composition prediction are obtained over the usual cubic equation of state. A stagewise procedure for phase and chemical equilibrium is also proposed.
Prediction of Vapor and Liquid Viscosities from the Lawal-Lake-Silberberg Equation of State
Authors: Lawal A. S. 
Published: December 2007

ABSTRACT
A difficulty in modeling multicontact miscibility processes is achievement of consistent, stable convergence of gas and oil phase compositions, densities, and viscosities as the critical point is approached. The use of an equation of state offers the advantage of a single, consistent source of calculating K-values and phase densities. The criterion of stable convergence viscosity in the vicinity of critical regions is not often met without fine tuning with laboratory data as phase viscosity correlations are usually developed independent of each other.
The present study extends the van der Waals model to viscosity by drawing an analogy between the graphs of PVT and PμT. Vapor and liquid viscosities based solely upon pure component critical data and acentric factor were derived from the Lawal-Lake-Silberberg (LLS) equation of state for methane through eicosane, i-butane, neo-pentane, carbon dioxide, and nitrogen. The 6718 experimental data used cover a range of temperatures from −183°F to 482°F and pressure up to 20,000 psia. For the twenty-four components, the average absolute deviation of the predicted viscosities from experimental is 5.9%. A mixing rule which relates mixture parameters to composition and pure component constants is proposed and comparisons of 9,000 experimental data with computed viscosities for several binary, multicomponents, natural gases and complex systems resulted in an average absolute deviation of 3.5%. The extension of the mixing rules to predictions of reservoir oil viscosity was generally within +8% of the experimental values. Extensive comparisons of the LLS viscosity equation with other methods of predicting reservoir oil viscosity are made and found to be generally superior in ease of use and in accuracy.
The prediction of vapor and liquid viscosities from the LLS equation of state makes the present work very attractive for compositional reservoir simulators and other applications which are repetitive in nature. The use of an equation of state to predict phase viscosities offers an opportunity to make calculations in the critical region without the computational problems commonly associated with that effort. The internal consistency and the convergence of vapor and liquid viscosities at the critical point have heretofore been unattainable.
Case History of a Successful Rocky Mountain Pilot CO2 Flood
Authors: Hoiland R. C. , Joyner H. D. , Stalder J. L. 
Published: December 2007

ABSTRACT
Conoco Inc. conducted a miscible CO2 pilot flood in the Shannon formation in the West Sussex Unit, Johnson County, Wyoming, starting in August, 1982. The test involved one injection well and three producing wells encompassing 9.6 acres. A five-month water preflush with a tracer preceded injection of 206 MMSCF of CO2 (about 30% PV) which was trucked as a cryogenic liquid from the McCallum Field in northern Colorado. A water post-flush (about 70% PV) completed the test in late 1985. Computer simulations predicted the test should produce 19.5 Mbbls of enhanced oil recovery, but only two of the three producing wells showed significant response during the test yielding a 16.0 MBO tertiary recovery. The test demonstrated the ability of carbon dioxide to mobilize and displace additional oil volumes from the Shannon reservoir, following waterflooding operation, in spite of adverse permeability variation and complex reservoir faulting. This paper discusses reservoir history and description, pilot operations, performance, pressure transient testing, tracer testing, and implications for commercial CO2 flood expansion in the area.
Chemical Consumption During Alkaline Flooding: A Comparative Evaluation
Authors: Cheng K. H. 
Published: December 2007

ABSTRACT
Chemical consumption under alkaline flooding conditions can be significantly decreased with the use of Na2CO3. We have found significantly lower ion exchange and mineral dissolution in the presence of Na2CO3 as compared to caustic and silicate. These results are based on laboratory studies with alkaline solutions in the presence of Wilmington sand, Ottawa sand and dolomite. Furthermore, Na2CO3 offers an additional advantage upon contact with hard water. The resulting carbonate precipitates do not adversely effect permeability as compared to the precipitates of the hydroxides or the silicates. It is therefore suggested that the use of Na2CO3 for alkaline flooding will result in shorter alkali breakthrough times and increased tertiary oil recovery.
New Polymers for EOR Applications
Authors: Ryles R. G. , Cicchiello J. V. 
Published: December 2007

ABSTRACT
New water-soluble polymers for use both as mobility control reagents and in profile modification systems are described. They have excellent long-term thermal stability properties even in the presence of high concentrations of divalent metal ions.
Additionally, the mobility control reagents have improved resistance to mechanical degradation, excellent injectivity, low adsorption and generate cost effective resistance to flow in porous media.
The thermal stability of hydrogels prepared from a new polymer and polyvalent metal ions is compared with Xanthan and anionic polyacrylamide analogs. The Xanthan gels were found to be unstable at temperatures &gt;50°C. The polyacrylamide system could be optimized to give good long-term stability at 90°C. Above this temperature, degradation of the gel was observed. The new polymer composition gave gels which were stable to at least 120°C.
Field-Scale Polymer Flooding at Remote Site Presents Special Challenges
Authors: Hoelscher L. E. , Tan H. C. , Fullbright B. M. 
Published: December 2007

ABSTRACT
Establishment of a polymer-augmented waterflood in the Twin Peaks (Strawn, Upper) Field in King County, Texas required overcoming several major technical and logistical problems caused largely by the remote field location. This field, located on the S. B. Burnett Estate Lease, had been waterflooded for approximately five years prior to the decision to begin polymer-augmented waterflooding to improve the mobility ratio and areal sweep of injected fluids.
Problems concerning the absence of a fresh water source and supplying/transporting polymer to a remote field location were solved through the development of (1) a portable on-site automatic polymer manufacturing plant, and (2) a method for treating the available source brine for use as polymer mix water. These developments, along with detailed analysis of Twin Peaks (Strawn, Upper) Field -- including geology, development, performance, and reservoir engineering -- illustrate the feasibility of conducting polymer-augmented waterflood operations, even in remote field locations.
The Chateaurenard (France) Industrial Microemulsion Pilot Design and Performance
Authors: Chapotin D. , Lomer J. -F. , Putz A. 
Published: December 2007

ABSTRACT
The Industrial Microemulsion Pilot (I.M.P.) test is an application to a significant part of the Chateaurenard field of the enhanced recovery technics already used with success on a small scale during the first Method Pilot.
The method involves the injection of a microemulsion slug displaced in the formation by viscous solutions of polymers.
The I.M.P. has been initiated by Elf Aquitaine in 1983: the prime objectives were to assess the efficiency of the recovery mechanisms on a large pattern and evaluate the economic constraints of chemical flooding in an industrial environment.
The test is implemented on a four adjacent five spot panel, with an enclosed pore volume of 224,000 m3 (1.4 × 10 bbl); the spacing between the production wells is 280 m on average.
The chemicals injected consist of a microemulsion of petroleum sulfonates, alcohols, field oil and brine, displaced by solutions of partially hydrolyzed polyacrylamides diluted with field water. The amount of surfactant active matter has been reduced to 0.36 % of the exploitable pore volume, in comparison with 1.02 % on the Method Pilot.
The exploitation started in June 1983; the microemulsion injection phase lasted 40 days. The injection of the concentrated polymer buffer amounting to 0.41 of the enclosed pore volume has been completed; it is now being followed by an equal volume of gradually more diluted solutions.
A significant increase in oil production has been observed on 7 of the 9 producers of the pilot, with the arrivals of very well defined oil banks on these wells. Between June 16, 1983 and December 31, 1985, the total oil production rose to 35,100 m3 (220,700 bbl) of which 18,800 m3 (118,200 bbl) are attributed to chemical injection; at that time, the overall injection was 142,000 m3. The total cumulated production predicted by numerical simulations is 57,000 m3 (358,500 bbl), i.e. 52 % of the remaining oil in place at the start of the operation.
From an economic analysis of the operations, and with the particular cost structure associated with the operation of this field, the cost of tertiary oil is about 40 US $/barrel for micellar recovery. A breakdown of the costs involved shows that the chemical products represent 41 % of the expenses and are a heavy burden to the project. Reducing the amount of chemicals would thus be of great benefit for the chemical process. Recent laboratory studies have shown this could be achieved in Chateaurenard conditions through the injection of an alkaline preflush, ahead of the micellar slug.
In-Situ Polymerization Controls CO2/Water Channeling at Lick Creek
Authors: Woods P. , Schramko K. , Turner D. , Dalrymple D. , Vinson E. 
Published: December 2007

ABSTRACT
In the Lick Creek Field of Bradley County, Arkansas, Phillips Petroleum Company has used a single stage, nonionic polymer treatment to combat severe channeling problems in a CO2 water-alternating-gas (WAG) operation. After treating two of the 23 injection wells in the field, production has increased by 65 bbl/day.
The field, consisting of 23 injection wells and 38 producers, was unitized in 1976 to initiate CO2 injection into the reservoir. Alternating CO2 and water (WAG) flooding techniques have been used. Channels had developed throughout the field and flooding was becoming uneconomical. Previous E0R treatments using an anionic polyacrylamide were successful for only a few cycles of CO2-water injection. Failure was attributed to the inability of anionic crosslinked polymer to withstand the acidic environment created by CO2.
The successful treatments were composed of single stages of injection of a low viscosity monomer solution containing an organic crosslinker. The rigid polymer gel which is formed in-situ to block high permeability channels has remained stable in the CO2 environment.
Laboratory studies dealing with the CO2 resistance of the polymer, tracer surveys, job design considerations, and field results are presented.
Development of Effective Methods for Placing Competent Cement Plugs
Authors: Bour D. L. , Sutton D. L. , Creel P. G. 
Published: December 2007

ABSTRACT
A problem that has existed in oil well drilling operations is the successful placement of competent cement plugs at desired well depths. Repetitive attempts and failures in obtaining good cement plugs have cost many oil companies a considerable amount of capital both in extra rig time and service company expenses. This problem has recently been investigated with a unique 1/3 scale test model that allows visual observation of cement flow path and behavior of various well fluids during an actual job simulation. Test procedures and results are presented and discussed. Included in the results is a newly developed method which provides for successful plug jobs in severe well conditions. Field results of this method, which are also presented, confirm the results and demonstrate its value in field operations.