bluuebunny/crossref_metadata_2025_split huggingface dataset:
CO2-Foam Mobility Tests at Reservoir Conditions in San Andres Cores
Authors: Prieditis John , Paulett G. S. 
Published: December 2007

ABSTRACT
The development of a foam technology for CO2 flooding has been an active research area with a large emphasis in finding effective surfactants. A number of surfactants have been suggested in the literature as effective CO2 foaming agents.
Reported here are foam mobility reduction tests which were conducted at reservoir conditions in restored field cores from the San Andres formation of west Texas. Tests were also conducted in San Andres outcrop rock material. In contrast to most previous studies, an attempt was made to establish both a representative wettability and a CO2 flood residual oil saturation prior to conducting the foam tests.
Many surfactants were tested, and most of them, including those previously identified as especially good foaming agents, did not generate effective foam in representative west Texas rock. The limited number of surfactants which did reduce CO2 mobility substantially are identified. Foam behavior in the restored field cores is also discussed. The best surfactants reduced gas mobility by less than a factor of ten. Some surfactants were found to change core conditions so that subsequent tests with previously ineffective surfactants showed mobility reduction. Successful results with cationic surfactants are also reported. An extremely important limitation of a surfactant's usefulness is its level of adsorption on rock surfaces; consequently, adsorption tests were conducted for some of the surfactants.
Successful results using sacrificial agents to reduce adsorption are also reported.
Improving Oil Recovery Through WAG Cycle Optimization in a Gravity-Overide-Dominated Miscible Flood
Authors: Pritchard D. W. L. , Nieman R. E. 
Published: December 2007

ABSTRACT
In the Judy Creek Hydrocarbon Miscible Flood (HCMF) like many other miscible floods, ultimate oil recovery is limited by gravity segregation. This phenomenon is severest in thick vertically permeable sections of the reservoir. Various initiatives have been pursued in Judy Creek to prevent this gravity override, including an effort to identify modifications that could be made to the injection schedule during miscible flooding to improve oil recovery. The Judy Creek HCMF is a staged flood which has been subject to an extensive reservoir surveillance program. Early data interpretation revealed the dynamic nature of the miscible process. Simulation was thereafter employed to examine the dynamics occurring during Water-Alternating-Gas (WAG) flooding and to identify potential recovery enhancements. Previous WAG cycle design procedures used steady state methodology and accepted industry rules of thumb. The use of a simulator permits a more rigorous analysis to optimize WAG cycle parameters such as bank size, cycle time and WAG ratio. Results indicate enhanced performance from high injection rates at low WAG ratios in the early stages of the flood followed by an increased WAG ratio during later solvent injection. Properly sized banks and timing of injected chase gas can optimize oil recovery and injectant utilization. Field production and surveillance data substantiate these results. These modified WAG techniques have been incorporated into the operating strategy of the miscible flood at Judy Creek. As much as 1% incremental recovery in OOIP is anticipated from these refinements to the miscible flood operating strategy. Further development of simpler design methods is required for broader application of these concepts.
CO2 Miscible Flood Simulation Study, Roberts Unit, Wasson Field, Yoakum County, Texas
Authors: Hindi Rached , Cheng C. T. , Wang Ben 
Published: December 2007

ABSTRACT
This paper describes the procedures of a simulation study to design an optimum CO2 flood process for the Texaco operated Roberts Unit located in the Wasson Field, Yoakum County, Texas. The designing process includes geological study to define flow units, CO2 target area selection, model area determination, fluid characterization, model calibration by history matching waterflood performance, compositional simulation forecasting for tertiary recovery, and economic analyses.
An equation-of-state (EOS) compositional simulator was used for both waterflood history matching and CO2 flood predictions.
Phase behavior of the CO2/Hydrocarbon system was calibrated by matching laboratory PVT test results. Tertiary forecasts were run for various continuous, water-alternating-gas (WAG) and hybrid modes of operation. Simulation results were scaled to represent the entire Roberts Unit CO2 target area. An economic indicator was then used to determine the optimum method of CO2 injection.
Study results revealed that hybrid mode of injection consisting of a 10% hydrocarbon pore volume (HCPV) initial slug followed by 1:1 WAG for a total CO2 injection of 40% HCPV yields optimum economics. The ultimate tertiary oil recovery in the target area is estimated at 14.1%- original oil-in-place.
The majority of the simulation study was performed on the RISC 6000 model 320 workstation. This study provides an insight to compositional simulation on a workstation platform.
Impact of Permeability and Lithology on Gel Performance
Authors: Seright R. S. 
Published: December 2007

Abstract
This paper describes an experimental investigation of the effects of rock permeability and lithology on the performance of several gels, including those formed from resorcinol-formaldehyde, colloidal silica, Cr3+(chloride)-xanthan, and Cr3+(acetate)-polyacrylamide. During these experiments, particular attention was paid to (1) the importance of pH to gelation, (2) gel performance as a function of fluid velocity, and (3) the use of tracers to assess the fraction of the pore space that was occupied by gel.
During core experiments, the "strongest" gels were found to reduce the permeability of all cores to approximately the same value (in the low microdarcy range). Tracer studies indicated that these gels occupied most of the available pore space. Flow experiments were performed in rectangular micromodels to determine whether these gels have some inherent permeability to water. The permeabilities for five gels were found to be less than- or equal to 60μD.
For "weaker" gels (i.e., those leaving a significant permeability), residual resistance factors generally decreased with increased rock permeability. Tracer studies indicated that these gels occupied a small fraction of the pore space in a core. Experiments revealed that gelation in the porous rock was often far less complete than that in a bottle. For unbuffered gelants in porous rocks, the pH at which gelation occurs may be determined more by rock mineralogy than by the pH of the injected gelant. Thus, the buffering action of reservoir rocks should be considered when evaluating gel performance in the laboratory. The immense buffering capacity of limestone can effectively preclude the propagation of unbuffered Cr3+(chloride)-xanthan gelants- or CrCl3 solutions through porous limestone.
Cyclic Gas/Steam Well Stimulations: Field Results
Authors: Stashok Y. I. , Drampov R. T. , Antoniady D. G. , Garushev A. R. 
Published: December 2007

ABSTRACT
The paper is an addition to those presented at and published by the 5th and the 6th European Simposia on Improved Oil Recovery held in Hungary and Norway. Included in the paper are results of laboratory and field studies on cyclic stimulation of bottom-hole formation zones containing high-viscosity oil by gas-steam heat-carrier. The paper presents the last data on performance of the wells after the 1st and the 2nd cycles of stimulation of bottom-hole formation zones. Cyclic stimulations were conducted in a pilot area of Zybza-Gluboky Yar oil field, Krasnodar Territory. Pontian deposits of the field contain oil of 300÷420 cp @ 325K at the depths of up to 500 m.
The paper presents results of laboratory studies on oil viscosity variation by dissolving CO2 in the oil for the temperature range of 298-373K at 8 MPa pressure.
There are also data on gas-steam generating unit performance under extreme northern conditions in Usinsk oil field (Komi Republic) in the paper. The field contains high-viscosity oil that occurs in carbonate reservoirs at depths of above 1500 m. The paper presents results of field testing of the gas-steam generator and variants of both surface and well-bottom operation. Provided by the paper are analysis and generalization of the obtained results.
Aerobic Microbial Enhanced Oil Recovery for Offshore Use
Authors: Sunde Egil , Beeder Janiche , Nilsen R. K. , Torsvik Terje 
Published: December 2007

ABSTRACT
Aerobic microbial enhanced oil recovery (MEOR), based on the ability of oil degrading bacteria to reduce the interfacial tension between oil and water, is reviewed. This process implies pumping water containing oxygen and mineral nutrients into the oil reservoir to stimulate growth of aerobic oil degrading bacteria.
Based on core flood experiments, the amount of bacterial biomass responsible for dislodging the oil is calculated.
The results show that the process is limited by the amount of oxygen available for bacterial oil degrading and that on a weight/weight basis the bacterial biomass was more efficient than synthetic surfactants in dislodging the oil.
Calculations show that it is feasible, on most offshore platforms, to instal equipment to handle the process.
Further, calculations have been performed on the economics of the process, and the results indicate a cost of 0.84 to 4.6 US$ per incremental m3 oil produced.
Interfacial Tensions of Microbial Surfactants Determined by Real-Time Video Imaging of Pendant Drops
Authors: Herd M. D. , Lassahn G. D. , Thomas C. P. , Bala G. A. , Eastman S. L. 
Published: December 2007

ABSTRACT
This paper describes an instrument to measure the interfacial tension (IFT) of aqueous surfactant solutions and crude oil. The method involves injection of a drop of fluid (such as crude oil) into a second immiscible phase to determine the IFT between the two phases. The instrument is composed of an AT-class computer, optical cell, illumination, video camera and lens, video frame digitizer board, monitor, and software. The camera displays an image of the pendant drop on the monitor, which is then processed by the frame digitizer board and non-proprietary software to determine the IFT. Several binary and ternary phase systems were taken from the literature and used to measure the precision and accuracy of the instrument in determining IFTs.
The instrument has been used to determine the IFTs for several bacterial supernatants and unfractionated acid precipitates of microbial cultures containing biosurfactants against medium to heavy crude oils.
These experiments demonstrate that the use of automated video imaging of pendant drops is a simple and fast method to reliably determine interfacial tension between two immiscible liquid phases,- or between a gas and a liquid phase.
MEOR, the Suitable Bacterial Inoculum According to the Kind of Technology Used: Results from Romania's Last 20 Years’ Experience
Authors: Lazar I. I. , Stefanescu M. M. , Dobrota S. C. 
Published: December 2007

ABSTRACT
The paper represents, mainly, a review on the state of the art concerning the suitable bacterial inoculum used during the last 15 years in the field trials carried out in Romanian's oil fields.The experience accumulated during the last 35 years, mainly in countries as USA, Russia, Cechoslovakia, Hungary, Poland, Germany, Romania, China, Canada,Australia and Great Britain proved that the bacterial inoculum is one of the basic components for the success of the MEOR method. It was also, already proved that the MEOR method from the technological point of view has a few possibilities of application in the field literature as: 1) microbial wellbore cleanup; 2) microbial well stimulation: 3) microbial enhanced waterflooding; 4; microbial permeability modification; 5) microbial polymer flooding; 6) microbial mitigation of wellbore; 7) activation of the strata and injection water microflora.In addition to these technologies of MEOR method, a few other could beadded as: Microbial Fracturing fluids Recovery, Microbial Paraffin Removal Treatment,etc, hut the above ones seems to be most representative and already proved to be of future.
In Romania during the period 1971-1991 the laboratory and field activity on MEOR method carried out without any interruption. In the laboratory the activity was much more complex, and continuously, while in the field in two periods (1975-1980 and 1986-1990) were carried out field trials, using the technologies mentioned above that ones nominated at points 1, 2 and 3, In framework of these technologies it was used generally the same kind of bacterial inoculum namely: "Adapted Mixed Enrichment Cultures" (AMEC), which proved to have a very good growth under reservoir conditions with temperatures up to 55°C» salinity up to 100-150 g/1, deepness up to 1000-1500 m and oil viscosity up to 50 cp.During the last two years it was concluded that a mobile unit- or a special equipment with all the technical facilities for isolation, adaptation, characterisation and multiplication of such a bacterial inoculum - straight in the field, is very necessary. Such kind of equipment was recently designed in Romania, and is recommended to be used in future.
Commercial (Pilot) Test of Microbial Enhanced Oil Recovery Methods
Authors: Matz A. A. , Borisov A. Y. , Mamedov Y. G. , Ibatulin R. R. 
Published: December 2007

ABSTRACT
The technology of enhanced oil recovery based on reservoir microflora activation through periodic activation of the injected water with mineral salts of nitrogen and phosphorus added to it, was developed.
As a result, intensification of microorganisms takes place. The microorganisms create such oil displacing products as CO2, CH4, fatty acids, alcohols, surfactants and etc. The method was tested at 7 pilot areas of oil fields in different regions of the country. It allowed to recover 70 thousand tonnes of additional oil.
A New Approach for Small-Scale Simulation of Multiphase Flow in Naturally Fractured Reservoirs
Authors: Palatnik B. M. , Shandrygin A. N. , Segin T. N. 
Published: December 2007

Abstract
The numerical simulation of one-phase and two-phase gas and liquid filtration within fractured porous reservoirs in micro-scale on the level of several reservoir blocks was carried out. The results of obtained calculations permit to establish the unknown earlier peculiarities of filtration flows within fractured porous reservoirs including the character of exchanging flows between reservoir media. It was established that the ail existing present time mathematical models of two-phase filtration do not take into consideration many physical phenomenons taking place on the reservoir porous block boundaries.
The Use of Advanced CAD Techniques and Innovative Relational Database Programming in Developing a PC-Based Well Operations Tool kit
Authors: Murray Phil , Barry T. S. 
Published: December 2007

Abstract
Having reliable and readily accessible information on production wells and associated operations and being quickly able to analyze this data is the key to optimising production and maximising safety. Based on this understanding, BP in conjunction with Petrotechnics have developed a PC based Well Operations Tool Kit. The aim of the tool kit is to allow the engineers and supervisors responsible for operating the wells to input, collate and analyze data quickly and easily.
Much of the data associated with wells is best presented in a graphical format eg. logs, Xmas Trees and Completion Equipment etc. However, to analyze the equipment's performance, the data also needs to be entered in a relational type database. Unfortunately this level of dual data entry is not acceptable to an engineer. This problem was overcome by both developing software that would release the power of CAD to an engineer with no CAD training and by automatically linking the data stored in any drawing to a relational database.
An additional system using PCs offshore linked via a mainframe was also developed to log and analyze the data associated with day to day well operations. This included a well operations log, a SCSSV operations log, a well integrity package and a tool tracking system.
This paper aims to demonstrate how, by recognising operational problems, using a multi-discipline team, including well operations engineers and utilising the latest IT technologies a system of real operational value can be implemented.
Petrotechnical Computing Strategy
Authors: Hood J. l. 
Published: December 2007

Abstract
In the late 1980's BP EXPLORATION acquired controlling interest in Britoil and Standard Oil. The resultant company inherited a range of approaches to petrotechnical systems. and a complex portfolio of systems which did not fit easily together and were often duplicated, in some cases as many as six separate systems performing the same functions.
The management of systems development and procurement was diverse. Each geographical operating unit and the two technology centres in London and Houston had systems development and support groups and their own budget and views on direction.
The resultant expenditure on Information Technology was very large, equivalent to approximately 11% of the expenditure on exploration and field development in 1989.
In 1989 a study was conducted which reviewed the petrotechnical component of systems expenditure and identified the key elements of a strategy which would deliver material benefits to the company. This paper describes these key elements and progress to date.
New Clay-Controlling Technology Addresses Problems Encountered in Cement Design and Performance
Authors: Dillenbeck R. L. , Nelson S. G. 
Published: December 2007

ABSTRACT
With the ever present emphasis on reducing exploration and production costs, oil and gas operators must continue to look at all aspects of drilling, completion, and production for new methods and/or technologies to help achieve enhanced performance while still improving economics. When focusing specifically on drilling, one area offering room for advancement is in wells with zones containing clays or shales (which are) sensitive to fresh water in general, and cement filtrate in particular.
Historically, either sodium chloride (salt) or potassium chloride (KCl) have been the primary materials of choice to yield a filtrate less damaging to these zones. However, the deleterious effects of salt on cement have been extensively documented, and recently published material has also detailed the negative impact KCl can impose on cements. This paper will address a new material for use as a cement clay control additive. Laboratory data is presented to detail the effectiveness of the material on sensitive clays and shales, as well as its effect on cement fluid loss, viscosity, thickening time, and compressive strength development. The material shows superior clay controlling properties without the undesirable side effects of either sodium or potassium chloride, and it exhibits this elevated level of performance while maintaining economic and environmental advantages as well.
A Standard Integrated Data Model for the Petroleum Industry
Authors: Karcher Bruno , Aydelotte S. R. 
Published: December 2007

Abstract
The Petrotechnical Open Software Corporation (POSC), as an industry-wide consortium, is building a software integration platform, a specification of standard interfaces between technical applications that allows greater portability and inter-operability. A standard data model is a primary component of the software integration platform, providing the common vocabulary and rules for information of interest to exploration and production (E&P).
This paper describes the motivation and rationale behind a standard E&P data model, describes the procedures being used in its construction, and presents several of the innovative concepts being incorporated. When released publicly in early 1993, the E&P data model will provide a much needed tool for applications developers, end users and data administrators by providing an integrated structure that bridges the currently unconnected islands of information found throughout the industry.
Geoshare: An Emerging Industry Standard for Geoscience Data Exchange
Authors: Breedlove J. R. , Guthery S. B. , Landgren K. M. , McAdoo Stewart 
Published: December 2007

Abstract
The process of finding and producing hydrocarbons has historically been the province of five major disciplines: geology, geophysics, petrophysics, reservoir engineering, and drilling engineering. A contemporary trend in this effort is the move toward integrated exploration and production, where specialists in the different disciplines work as a part of a team, using data from all the disciplines to gain a better understanding of the exploration or production problem, and to arrive at a better solution than has been the case in the nonintegrated approach.
Interpretation software tools covering the broad domains of geoscience have been developed by many sources, including both vendors and oil companies. It is a goal of the modem interpretation team to have the flexibility to use any of these tools, while maintaining the ability to share data and results across domains that is needed for integrated interpretation.
This may be accomplished by loosely integrating the independent systems. Loose integration automates the process of moving data between application programs, but does not require that the application programs be rewritten to use a different database. Geoshare provides a way to accomplish this kind of integration.
The Characterization of Drilling Operations and Their Representation in Relational Databases
Authors: Brannigan J. C. 
Published: December 2007

Abstract
It is proposed that drilling operations be characterized in four ways. First, each individual drilling operation is characterized by the current rig activity. Second, the phase of drilling is assigned to one or more drilling operations. Third, some drilling operations may also be characterized as belonging to a problematic operations group. Finally, every drilling operation belongs to some scope of work group.
These four fundamental characterizations of drilling operations are unified using the relational database model.
Details of the implementation of this approach are provided. In addition, the approach is compared to several alternatives.
Application of 3D Visualization Software to Reservoir Simulation Post-Processing
Authors: Austin A. Z. , Choo Y. K. , Smith M. E. , MacDonald D. G. 
Published: December 2007

Abstract
Thorough analysis and interpretation of the results of reservoir simulations is an important step in evaluating oil fields. Interpreting the hundreds of thousands of lines of computer output from each simulation run is very time consuming and impractical. The interpretation of conventional 2D areal and cross-sectional maps was an improvement upon the original method of reviewing the numerous lines of output, but it has limitations too.
The ability to transform the vast amounts of simulation results into easily understood 3D images helps in our data checking and understanding of reservoir processes.
This paper describes the use of a state-of-the art and "off- the-shelf" 3D visualization software in BPX reservoir simulation studies, as exemplified by three Kuparuk River Unit models.
Computational Aids to Reservoir History Matching
Authors: Watkins A. J. , Parish R. G. 
Published: December 2007

Abstract
This paper is based on the central themes that computational aids in reservoir history matching are best used in conjunction with engineering experience, and that these powerful resources should complement each other. We consider one system which seeks to exploit the potential for interaction between one algorithm for history matching, and input available from a reservoir engineer’s assessment of a study.
The discussion is illustrated with examples which show that this interaction can result in history matches acceptable in engineering terms, and produced with relatively efficient use of all resources.