bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbonated Water Imbibition Flooding: An Enhanced Oil Recovery Process for Fractured Reservoirs
Authors: Perez J. M. , Poston S. W. , Sharif Q. J.
Published: December 2007

Water imbibition studies were conducted on core plugs at confining pressures of 2,000 psi. Water was enriched with CO2 at different carbonation pressures, ranging from 50 to 500 psi. Conventional displacement as well as Nuclear Magnetic Resonance (NMR) methods were used to study the effects of carbonated water imbibition on oil recovery rate and ultimate recovery.

The major factors influencing oil recovery by carbonated water imbibition displacement appear to be:

An increase in oil mobility. An increase in core permeability in carbonate cores A reduction in the operating pressure below the

bubble point pressure after the core had been allowed to imbibe the carbonated water induced a solution gas drive effect which substantially increased recovery.

Carbon dioxide dissolved into the water being imbibed by the rock was found to accelerate oil recovery rates and increase ultimate oil recovery when compared to unadulterated water imbibition. Recovery rate and ultimate recovery increased as a function of the amount of CO2 dissolved into the imbibed water. Recovery time was reduced to one third when the gas liberation process was applied cyclically. This new method holds promise to increase oil production rates and oil reserves from fractured, low matrix permeability, low gas-oil ratio, oil reservoirs.
Electric Preheating in Low-Injectivity Tar Sand Deposits
Authors: Glandt C. A. , Hsu Chia-Fu
Published: December 2007

Lack of steam injectivity is one of the most serious obstacles in the thermal recovery of tar sands and oil shale deposits. Electric heating offers a technically viable option which has been the subject of studies and field tests in the last 10 years. This paper discusses the application of electric heating to reservoirs with electric resistivities ranging from 100 ohm-m (tar sands) to 10,000 ohm-m (oil shales). A numerical model is constructed to solve Maxwell's electromagnetic field equations.

The model is used to study the electric preheating of a tar sand reservoir using horizontal electrodes to develop steam injectivity. After preheating, electrodes are converted into conventional injection/ production wells to be used in a subsequent steam recovery process.
A Procedure for Scaling Heavy-Oil Combustion Tube Results to a Field Model
Authors: Marjerrison D. M. , Fassihi M. R.
Published: December 2007

Combustion tube experiments are conducted in the laboratory to determine the burning characteristics of a particular oil in a rock matrix. These characteristics include fuel laydown, air-fuel ratio, H/C ratios and the adiabatic combustion temperature. The combustion tube experiment can then be numerically modeled so that a suitable reaction scheme and other data necessary for field simulation can be determined. The data obtained from history matching the tube experiment cannot be used directly for field simulation. Grid blocks used for a tube simulation are on the- order of inches thick, while grid blocks for a field simulation will be 100 to 1,000 times larger. Also, the estimated kinetics data from a combustion tube history match are time and temperature dependent and will not produce similar results in large grid blocks. This paper outlines a new method of history matching the results of a semi-adiabatic combustion tube experiment and scaling them to a form that can be used for field simulation. The shortcomings of current thermal simulators and the suggested remedies also are discussed in this paper.
CO2-Foam Mobility Tests at Reservoir Conditions in San Andres Cores
Authors: Prieditis John , Paulett G. S.
Published: December 2007

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Cataloging: The First Step to Data Management
Authors: Taylor B. W.
Published: December 2007

Time management is one of the biggest problems which we face in our industry today. At every turn we are faced with the need to become more effective and efficient in the things which we do.

The largest single factor precluding good time management for Engineers and Geoscientists today is data management. The truth is we simply spend too much time, and money searching for, collecting and pre-processing data before we can even begin the analysis phase of our work. Recent studies indicate as much as 80% of our Engineers and Geoscientists' time can be spent in these efforts.

Correct data management practices can be a tremendous help by doing the following things: Making a complete catalog or index of all data available to all users.Providing data management support staff to perform appropriate functions at much lower salary rates than those of technical professionals.Minimizing cost and access time through standard procedures.Minimizing cost through project planning.
Data Management: A Case Study
Authors: Meek J. , Lowry P. H.
Published: December 2007

A successful field evaluation and enhanced oil recovery (EOR) program design was accomplished with the aid of a field database system. Rigorous date handling, date screening and a date entry front-end were concluded to strongly influence the utility of the working database. Versatile manipulation of the database allowed the extraction of date in a variety of forms. Mapping of die date reveal»! production patterns and indicated reservoir dynamics. The results were an accurate assessment of the remaining reserves and the formulation of an appropriate EOR program.
Training Simulations for Petroleum Engineers
Authors: Reese R. D.
Published: December 2007

New training technologies being developed for petroleum engineers are discussed. Present capabilities of personal computers make it possible to simulate life-like situations in the classroom. A training simulation of an oilfield will be demonstrated together with comments on experiences using this model in classroom training. New directions in computer-aided training will be discussed.
Assessing the Productivity Enhancement and Economic Impact of Geopressure Evaluation Computer Software
Authors: Proehl T. S. , Onyia E. C. , Herkommer M. E.
Published: December 2007

Economic efficiency, cost control, and productivity enhancement are strong themes in the petroleum industry as the decade of the 90s emerges. Multidisciplinary teams are being used successfully to address fundamental issues impacting the profitability of all kinds of projects. It is generally accepted that computer hardware and software contribute to enhanced productivity, which in turn, tends to maximize profitability.

Two major barriers to the use of software are skepticism and lack of functionality. The potential software user wants to know precisely what he or she can expect to gain before making a commitment to learn a program. Potential users also want functionality which automatically leads them into the investigative and design aspects of a particular problem. Software products such as word processors, spreadsheets, and graphics packages greatly assist individuals and teams engaged in the operational aspects of problem solving, including data collection and reporting. However, these software products are generally designed to facilitate business communication, hence they lack the specific functionality required to investigate technical problems in a cost-effective manner.

One technical problem which often appears in a multidisciplinary setting is the issue of pore pressure and fracture gradient analysis. Pore pressure regimes in the subsurface greatly affect drilling and completion designs, well costs, and prospect or project economics. Pore pressures can be analyzed in several ways.1-10 One of the most reliable technique is based on well log data1-5 and this is the method preferred by many drilling engineers and explorationists.
The Application of a New Drilling Model for Evaluating Formation and Downhole Drilling Conditions
Authors: Jogi P. N. , Zoeller W. A.
Published: December 2007

A new drilling model has been developed for the interpretation of downhole drilling conditions using surface and downhole drilling data. This model is based on the analysis of the interaction of the drill bit (PDC or impact) and the formation under in situ pressure conditions. It combines downhole and surface drilling data with MWD formation measurements to provide detailed drilling analyses for real-time applications.

An expression for Drilling Response developed from the model provides information on lithologic changes and allows interpretation of downhole drilling conditions. Drilling Response is a function of lithology, pore pressure, mud pressure and bit properties and is computed from the following drilling parameters: rate of penetration, bit revolutions, and downhole weight and torque on bit. Techniques and expressions allowing computation of formation porosity and pore pressure on a foot by foot basis have also been developed based on the Drilling Response.

Another key feature of the model is the identification of inefficient drilling conditions. Inefficient drilling conditions are expressed in the form of Drilling Alerts for real-time applications, allowing the operator to take the necessary action to rectify the problem at the wellsite. Drilling Alerts also allow the operator to continuously monitor the effects of any remedial actions.

Bit condition is evaluated using Drilling Response and torque analyses. This allows the operator to assess bearing and tooth wear conditions for impact bits and cutter wear for PDC bits.

Field Examples from sedimentary basins illustrate the usefulness of the model and its applications at the wellsite and in post-drilling analysis.
Inversion of a Lateral Log Using Neural Networks
Authors: Garcia Gerardo , Whitman W. W.
Published: December 2007

A technique using neural networks is demonstrated for the inversion of a lateral log. The lateral log is simulated by a finite difference method which in turn is used as an input to a backpropagation neural network. An initial guess earth model is generated from the neural network, which is then input to a Marquardt inversion. The neural network reacts to gross and subtle data features in actual logs and produces a response inferred from the "knowledge" stored in die network during a training process. The neural network inversion of lateral logs is tested on synthetic and field data. Tests using field data resulted in a final earth model whose simulated lateral is in good agreement with the actual log data.
Software Showcase: Pressure Transient Analysis Programs
Authors: Baldwin J. O. , Norris S. O.
Published: December 2007

The 1992 SPE PETROLEUM COMPUTER CONFERENCE introduced a new concept, the SOFTWARE SHOWCASE. This new program is intended to be similar to the "COMPARATIVE SOLUTIONS IN RESERVOIR SIMULATION" project that has been a popular feature of the SPE Symposium in Reservoir Simulation for a number of years. The Program Committee chose pressure transient analysis software as the SHOWCASE topic for the initial outing. A total of four (4) problem sets were developed from actual field data-sets from CONOCO and TEXACO.

Ten vendors and service companies answered the call for papers and the results of their efforts are presented in this paper. We should point out that there is no "correct" or "unique" to the four sample problems based upon the information furnished to the participants. The overall intent of this paper is NOT to present either a direct or implied endorsement of any one software product but to spur spirited discussion in the are of well testing software and to provide a service to SPE members who might be involved in the evaluation of transient pressure analysis programs.
The Power of Time-Sharing Computers in Forecasting Field Performance
Authors: Chesnut Dwayne A.
Published: December 2007

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers Office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Time-sharing computers, such as the SDS 940, respond almost instantly to action by the user (e.g., when he makes a change in his program or supplies new data). They also accept new programming languages that are easily learned programming languages that are easily learned and natural to use. These features of time sharing make it easy for engineers to develop special-purpose programs to solve specific problems (as illustrated by a program especially problems (as illustrated by a program especially written to forecast oil production from the Mission Canyon reservoir, Cabin Creek Field, Fallon County, Montana).

INTRODUCTION AND GENERAL CONCLUSIONS

This report does riot contain any new theory for analyzing and predicting reservoir performance. It does give a hint of the new power performance. It does give a hint of the new power that time-shared computing can add to conventional methods of analysis. This new potential arises from the two most important operating differences between time-sharing and ordinary computer usage:

The user is linked directly with the computer by an ordinary teletype terminal. This gives him closer and more responsive control than he has in the usual "batch" operation of a computer. New programming languages are available with the time-sharing computers. These are easier to learn and more natural for engineers to use than FORTRAN, the most common technical programming language.

As a result of these differences, an engineer, who usually does not have the time to become a programming expert, can readily develop special-purpose programs using the approach he thinks is best suited for solving a particular problem. His engineering skill particular problem. His engineering skill can be used more effectively because he will no longer find it necessary to rely mainly upon "canned" programs that do not quite fit his problem, or upon programmers who understand computers but not engineers.

Just how easy is it to develop a special program on a time-sharing computer? Perhaps program on a time-sharing computer? Perhaps a partial answer can be given by discussing one partial problem. Less than two working days' time was needed to write, debug, and run the computer program for solving this problem.
Drilling Time Analysis: A Total Quality Management Tool for Drilling in the 1990's
Authors: Kadaster A. G. , Townsend C. W. , Albaugh E. K.
Published: December 2007

This paper discusses the methodology and the two associated spreadsheet templates developed to evaluate and quantify the drilling performance in both international and domestic operations for Amoco Production Company. This methodology allows the timely monitoring and analyzing of Drilling Time Distribution on all wells, by tracking and quantifying trends in Normal Drilling, Evaluation & Completion and Unscheduled Events categories (Figures 1 & 2). The ultimate goal is to improve the bottom line performance in drilling costs by mobilizing the appropriate resources to develop solutions to critical problems and inefficiencies in a very short timeframe and by eliminating the repetition of past mistakes. Other goals also include developing an objective and consistent method of assessing the impact of any changes or solutions that are implemented; evaluation of service contractor performances; identifying internal and external performances to be "benchmarked"; and for "empowered drilling teams" to use for goal setting, scorekeeping, and as a self-assesment tool.

This methodology and the two spreadsheet templates developed with it provide the essential "Performance Measurement" and "Statistical Diagnostic" tools for implementing a "Total Quality Management" (TQM) technique, such as that developed by W. Edwards Deming(1), in drilling operations. Oilfield drilling operations have historically utilized a number of performance measures, the most universal ones being the "Days versus Depth" curves, "Cost per Foot" data, and "Feet per Day" data. Historical data collection and analysis is routinely performed in engineering analyses or optimization of specific operations or problems, usually, on a retroactive basis. Although drilling time data has been available on the daily drilling reports for decades, collating the data on a timely basis and in a format suitable for applying the TQM methodology within a drilling organization or operation is a more recent phenomenon, which is rapidly gaining acceptance and producing results.
Drilling Wastes Evaluated in Plant Growth Study
Authors: Wilton B. S. , Bloys J. B. , Watts R. D. , Hipp B. W.
Published: December 2007

Managing the disposal of drilling wastes from onshore operations is an escalating concern for the petroleum industry. Many wells are drilled in agricultural areas, posing concerns to the public with respect to disposal methods for drilling wastes. It is critical to appropriately evaluate these wastes to preempt negative environmental impact from improper disposal. The careful selection of drilling fluids and treating chemicals may allow operators flexibility in selecting disposal methods. An attractive option for disposal of onshore drilling wastes is through land treatment or "landfarming". In some cases, environmental quality may be enhanced by the application of wastes that have a positive impact on plant growth. This paper presents the results of a greenhouse plant growth study designed to evaluate the potential for landfarming drilling wastes in agriculturally active areas. Drilling wastes were collected from two wells where a non-halide potassium based product was used to formulate the drilling fluid. The fluid and associated wastes (drill cuttings) were used to conduct replicated growth tests of 2 plant species in 3 geographically different soils at 5 loading concentrations. Plant growth was monitored for over 70 days with intermittent cuttings taken at specific periods. Parameters measured included growth rate, growth index, soil electrical conductivity and exchangeable and leachate potassium in the soils. At the conclusion of the growth period, samples from selected cuttings were dried, digested, and analyzed for metals uptake as compared to the control plants. In addition, non-replicated tests were conducted where germination rates were evaluated at wet waste loadings of up to 50% by volume. Static bioassays were also conducted with two different species using whole mud samples. The results of this study indicate that downhole wastes, when generated with a properly formulated drilling fluid, may be landfarmed and have no adverse effects on growth potential when applied at specific loadings.
Use of a Kick Simulator as a Well Planning Tool
Authors: Leach C. P. , Wand P. A.
Published: December 2007

A kick simulator was used to plan for well control situations on a deep high pressure well. Results from the simulations were used to identify requirements and modify rigsite well control procedures. The result of the work is safer rig-site operations at little extra cost. Extension of this work to well design in general suggests the potential for safer well operations and simultaneous cost savings.
Top-Hoie BOP: From Design Through Offshore Qualification
Authors: Nergaard Arnfinn , Garder J. R. , Freyer Jan , Askeland Rune , Larsen Vidar
Published: December 2007

The paper describes the development and testing of a tool that prevents shallow gas influx from developing into an uncontrolled blowout. After having isolated the gas downhole the tool may be used for circulating in new mud to regain control of me well.
Drilling Through Highly Fractured Formations: A Problem, a Model, and a Cure
Authors: Santarelli F. J. , Dardeau Claude , Zurdo Christian
Published: December 2007

It is usually accepted that wellbore instabilities are caused by either or both an excessive stress concentration at the borehole wall and the chemical reactivity of the formation. Assuming good hole cleaning, common cures for such instabilities are therefore mud density increase and/or change of the mud system. However, even though these methods have proved highly successfull when drilling through intact formations, the same may not stand when it comes to highly fractured rocks. The purpose of this paper is to describe the studies performed in order to allow the safe drilling of a particularly troublesome, highly fractured formation which had led previously to several successive side tracks.

The efficiency of the different attempts at solving the problem are analysed in the light of the various side tracks. The core taken during one of these side tracks was analysed, showed that the formation was highly fractured and chemically inert, and provided many parameters for the modelling of the problem which was performed by a discrete element programme. Further modelling was performed on the mud hydraulics. Both theoretical and field data show that density increase has, in such a case, a negative role on borehole stability while filtrate reduction and mud rheology enhancement are highly positive.
Drilling and Completion Practices for Deep Sour Gas Wells in the Madden Deep Unit of Wyoming
Authors: Crow Ron , Craig B. D.
Published: December 2007

This paper presents the drilling and completion practices for two deep hot sour gas wells in the Madison formation of the Madden Deep Unit of Wyoming. The wells were drilled to almost 25,000 feet (7625 m). The drilling program, casing program, well test data and completion programs are discussed and compared to other sour gas fields such as Mobile Bay, Alabama. The gas composition, bottom hole pressure and temperature and production rates exceed those in Mobile Bay making the conditions some of the worst in the world. The high bottom hole temperature, and CO2 and H2S content necessitated the use of corrosion resistant alloy (CRA) completions. The CRAs selected and the respective equipment in which they were used are discussed. The analysis and prediction of elemental sulfur precipitation is also discussed.
Planning and Execution of Severely Misaligned Subsea Wellhead Tiebacks: A Case History of Garden Banks Block 189
Authors: Pecue W. W. , Jenkins R. W.
Published: December 2007

Texaco successfully completed three subsea wellhead tiebacks to a fixed (conventional) platform at Garden Banks Block 189 in late 1991. These three wells in 718 feet of water were the second deepest subsea wellhead tiebacks (38 feet less water depth than the present record) attempted in the world, and the deepest tiebacks ever attempted using 24″ conductor pipe. In addition to involving near-record water depths, the project dealt with unprecedented misalignment conditions which could have easily jeopardized any chance of success. This paper will present a case history of the successful tieback operation for the #1, #2, and #3 wells.
Hazardous Waste Elimination and Minimization in Exploration and Production Operations
Authors: Haynes K. G. , Redweik R. J.
Published: December 2007

In an effort to protect the environment and to reduce liabilities associated with hazardous wastes, a Waste Management Program was developed to eliminate and minimize the hazardous wastes generated in exploration and production operations. This involved field visits to operating locations and disposal facilities. The program reviewed the types of hazardous wastes generated by operating locations and exploration activities. Methods to eliminate and reduce hazardous waste production were implemented. Training for all personnel associated with waste management was provided. The program also required a knowledge of the regulations that govern solid and hazardous waste disposal.

The Waste Management Program resulted in an overall reduction of hazardous wastes by 93% over a period of six years. This program demonstrates that in reducing the volumes of hazardous wastes, we not only reduce the liability, but we also have the added benefit of reducing waste disposal costs.

The following discussion of the Waste Management Program includes topics on the methods for hazardous waste elimination, product substitution, minimization, and recycling. Specific examples include solvent distillation, painting operations, and batteries.