bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fuzzy Logic Applied to Lithofacies and Permeability Forecasting Case Study: Sandstone of Naricual Formation, El Furrial Field, Eastern Venezuela Basin
Authors: Hambalek Nancy , Gonzalez Reinaldo 
Published: December 2007

Abstract
Lithological description and permeability values estimation using core-derived information of wells with just electric logs is an old problem in reservoir characterization. In essence, the problem consists in finding some explicit relation between log and core data in those wells that contain both types of information. Then, describe reservoir features (derived from core data) of wells with log information only. There are many methodologies (and concepts) that have attacked this subject with major or minor success: statistical techniques, hydraulic units, petrofacies, geostatistical methods, neural nets, fuzzy logic, etc.
Applied fuzzy logic is the matter of this article. Fuzzy logic allows quantifying qualitative information and modeling complex not lineal relations. It invites the use of "partial truths" between the "completely false" and "completely true" alternatives and allows the consideration of the whole spectrum of possibilities between these alternatives. When it is applied to reservoir characterization, it accepts the premise that any interpretation is possible although some interpretations are more likely than others. Consequently, values can be proposed to the whole gamut of variations present in the prediction of rock parameters.
In this paper, fuzzy logic theory is applied in order to establish a narrow relation between well logs and the seven rock types (lithofacies) of the sedimentological model that describes a very complex reservoir in eastern Venezuela. Core analysis of five wells and the established fuzzy relations are used to get the lithofacies description and possible values of permeability in eighteen wells of the same area having only electrical logs.
On the other hand, the efficiency of the algorithm here developed is verified against a control well with both log and core data. In addition, sensibility analysis was done considering the number of cores involved in the data base, and taking into account the capability of this approach describing from the most basic lithology (sand or shale), to the most detailed seven categories above mentioned. The results are very satisfactory and open the possibilities for future research and applications.
Application of Aphrons Technology in Drilling Depleted Mature Fields
Authors: Rea Anthony B. , Alvis Efren Cuellar , Paiuk Benjamin P. , Climaco Juan Miguel , Vallejo Manuel , Leon Eduardo , Inojosa Jorge 
Published: December 2007

Abstract
Depleted zones are intrinsic to most mature reservoirs throughout the world. The associated issues of effective, safe and economically viable well construction, completion and workover within low pressure environments become more challenging on a daily basis.
This paper discusses the application of aphron drilling fluid technology, which offers a unique alternative option that can significantly improve the operational and economic aspects for continued development of these marginal assets. The authors will detail the development of the unique micro-bubble technology and its successful application in a mature and depleted field in Mexico.
Advanced Drillstring Dynamics System Integrates Real-Time Modeling and Measurements
Authors: Chen David C-K. , Smith Mark , LaPierre Scott 
Published: December 2007

Abstract
This paper presents a newly developed drillstring dynamics system designed to avoid resonance and to reduce vibrations. The system integrates real-time dynamics modeling with real-time downhole vibration data to provide accurate modeling results and data analyses. Unlike conventional BHA dynamics software that is run for well planning or post-run analysis, this system uses real-time data (e.g., WOB, inclination, DLS) to produce real-time updates of critical rotary speeds. The updates are then displayed along with the rotary speed to show if the rotary speed is too close to one of the predicted critical rotary speeds. In addition, the modeling results can be compared with actual real-time downhole vibration data to corroborate the actual downhole condition. This paper will show why real-time modeling is more accurate than the conventional stand-alone modeling. Field runs of the new system in the GOM have demonstrated the accuracy of modeling is critical in avoiding harmful vibrations.
Increasing Solid Expandable Tubular Technology Reliability in a Myriad of Downhole Environments
Authors: Escobar Carlos , Dean Bill , Race Brian , Waddell Kevin 
Published: December 2007

Abstract
Since the spectacular arrival of solid expandable tubulars four years ago, customers have embraced this technology as a revolutionary well constructionand production solution. Through innovative technical development and equipmentreliability, solid expandable tubulars continue to grow in acceptance anduse.
Solid expandable tubulars have been used successfully to reach requiredtotal depth (TD) with adequate completion size, slim the well constructionprocess, and overcome abnormal pressures encountered down hole while drilling.In addition, this technology has been used to rejuvenate wellbores for welldeepening, casing reinforcement for stimulation, as a solution for corrosionproblems, and to cover leaks and perforations. As a result, the overall cost ofdrilling and production operations has been reduced.
This expansion process requires the successful integration of the followingconditions and equipment: casing capable of surviving in-situ reformingfriction reduction between the expansion cone and the casingexpandable flush joint connectioncontainment of hydraulic pressures during the entire expansion processsurviving expansion in downhole environment
During the last four years, solid expandable tubulars have been installed inmore than 113 wells. Reliability has improved from an average of 67% in 2000, to 83% in 2001, to over 95% in 2002. In the past, the reliability of solidexpandable tubulars has been measured by a limited set of criteria for jobsuccess. The reliability definition should be expanded to include otherperspectives of the total system.
This paper will discuss actual downhole conditions, including well control, lost circulation, and high temperature/high mud weight, in which solidexpandable tubulars were used as a successful solution. This paper will alsodiscuss additional measurement perspectives with the goal of creating a 100%reliable technology.
A Method for Isolating Pressure-Depleted Zones with Solid Expandable Tubulars
Authors: Moore Melvin J. , Wright Jon C. , Winters Warren J. , Chan Daigle 
Published: December 2007

AbstractA method called "scoping" for installing solid expandable tubular (SET) drilling liners across pressure-depleted zones has been developed and demonstrated. High overbalance pressures associated with pressure-depleted zones are known to interfere with conventional SET expansion. Scoping is a dynamic expansion method that keeps the expandable tubing in continuous motion thus reducing risk of stuck pipe and SET failures related to differential sticking. This paper describes how scoping is performed and how it worked in a test well.
Benchmarking: Can it be Applied to Government Regulation of the Energy Sector?
Authors: Bradshaw-Niles Penelope , Ellis Ruel 
Published: December 2007

Abstract
Benchmarking is one of the most successful management strategies being employed in all industries, including the public sector today. The successes enjoyed by public sector officials have made governments more receptive to the fact that corporate style benchmarking may be applied to the public sector.
The continued importance of the energy sector in Trinidad and Tobago's economy makes it essential that the regulatory framework for the industry is current and responsive to the changing needs of an industry where dynamism and technological changes are the norm. Appropriate management tools should be identified and employed to achieve this.
This paper examines the use of benchmarking to identify opportunities for improving organisational effectiveness at the Trinidad and Tobago Ministry of Energy in its regulation of specific aspects of the upstream sector. The factors to be considered in selection of benchmarking partners are also discussed.
The findings suggest that benchmarking is useful in recognizing best practices, determining areas for organizational improvements and also for achieving institutional strengthening through relationships with benchmarking partners.
A Process for Planning New Developments in an Upstream Gas Business
Authors: Maharaj Shivanand , Hennington Eric , Daniel Michael , Wibowo I. Tenny 
Published: December 2007

Abstract
BP Trinidad and Tobago LLC (bpTT) has an upstream gas business with large process and export capacity, significant market growth opportunities, and a large portfolio of development and exploration opportunities. With such an asset, there must be a process to facilitate and guide capital spending decisions that underpin a strategy for delivering a gas growth agenda. The process must encompass development engineering and subsurface assessment to a level of accuracy so as to identify pre-investment opportunities that can be leveraged towards future growth. In the short to medium time frame, the questions of timing and volume of next gas supply are key questions to be answered. The process must include a mechanism to value exploration prospects so that the ordering of opportunities recognises multiple, risked outcomes, and hence, assists in the framing of longer-term developments. A successful process can reveal the future in terms of critical decision points, key drivers that impact financial performance, optimal capital spending profiles, and help guide the pace of growth. The subject of this paper is the process that bpTT is using to help guide its aggressive gas growth agenda.
Making Great Decisions in Development and Exploration Mexico Fields, Applying Bright Lights of the Latest and Multidisciplinary Well Completion Technology
Authors: Ballinas Javier 
Published: December 2007

Abstract
Technology is and always has been nothing more than the application of the human mind to the task of finding a new or better way. The development and application of a wide array of sophisticated technologies will be the hallmarks of the successful of many companies in future decades.
The industry is using now multidisciplinary technology such as 3D and 4D seismic, high propped hydraulic fracturing, tubingless well designs, multiple completions, high resolutions logging tools, reservoir numerical simulation, expert systems, and optimized multiple perforating systems for hard rock, etc.
Just in Mexico North Region wells, the tubingless completion integers advanced stimulation practices with reservoir analysis to improve production results from low permeability formations. Stimulation procedures still depend on the well completion method utilized.
Propellants use incorporates better results on early production of the treated wells and improve the benefits before and after propped frac jobs. The concept of combining the propellant into a sleeve form with the perforating gun is unique and this technology shows promise of solving many of the inherent perforating problems for which solutions have been needed.
Gun perforating and well stimulation have been inseparably entwined from the beginning. Shaped charges have been established as the most efficient method of obtaining communication between a cased borehole and the formation of an oil or gas well.
The most significant problem encountered in high propped frac jobs has been the presence of fracture entry restrictions arising from perforation friction, flow tortuosity and fracture friction. The combination perforating/propellant systems have met with encouraging results both as a perforation breakdown method, and as a tortuosity/near-wellbore damage stimulation method before a propped frac operation.
The industry will employ these excellent technologies to improve the prospects of locating new reservoirs and then to enhance the capabilities to produce them most efficiently. This paper will address differents topics and field applications in Mexico and worldwide of the innovative technology described.
Reservoir Aspects of Smart Wells
Authors: Glandt Carlos A. 
Published: December 2007

AbstractA well equipped with intelligent components is considered SMART only when it maximizes its value over the life of the project. The definition of the adequate level of intelligence is the outcome of a multidisciplinary discussion that focuses on the well and reservoir management. To effectively realize the value associated with these technologies Shell set up a Global Implementation Smart Wells Team at its E&P Technical Center. Jointly with asset teams from around the world it has reviewed more than 80 projects over the last 3 years. The main result of this work is a faster and more meaningful implementation effectively realizing the value associated with these technologies. An important byproduct of this work is a list of identified well and reservoir opportunities where smart completions can add significant value. This paper reviews these opportunities and provides selected examples.
The Use of Aisi 4320 Sucker Rods at Corrosive Environments as a Field Experience
Authors: Ramírez G. , Poli M. , Salas F. , Olmos D. , Ameglio A. , Tapia R. 
Published: December 2007

Abstract
The present paper has for purpose to describe the experience with the use of AISI 4320 steel sucker rods in the corrosive environments of Unidad Económica Rincón de los Sauces (Neuquén - Argentina) of Repsol-YPF and show the results obtained until now.
Oilfield Scaling - Part II: Productivity Index Theory
Authors: Bedrikovetsky P. G. , Gladstone P. M. , Lopes R. P. , Rosário F. F. , Silva M. F. , Bezerra M. C. , Lima E. A. 
Published: December 2007

Abstract
Barium sulphate scaling during waterflooding causes formation damage mostly near to production wells, because high velocity near to wellbore provokes intensive mixing and accelerated chemical reaction between barium and sulphate ions.
The mathematical model for steady state oil-water flow towards producers accounting for chemical reaction is developed, and an analytical solution is found. It allows obtaining a productivity index formula for PI decline prediction.
The main result of the work is proportionality between the inverse to productivity index and time.
Introduction Of A New Generation Of Induced Gas Flotation Equipment-A Case Study
Authors: Movafaghian Shaya , Chen James , Wheeler Stephen Scott , Guidry R. W. 
Published: December 2007

Abstract
Induced Gas Flotation (IGF) technology is well known in the oil industry for its effective treatment of produced water to meet environmental oil-in-water discharge requirements.
This paper presents technical considerations for development of a new generation of IGF units, a discussion of the process kinetics, and actual operating data and performance analysis of a full size four-cell WEMCO® cylindrical depurator.
A pilot test program was developed and executed in collaboration with ChevronTexaco Overseas Petroleum on platform Gathering Station Mike, located offshore in Cabinda Province, Angola. Pilot data indicates the flotation kinetic rate for the oil removal from a four-cell cylindrical depurator is comparable with a conventional depurator.
Geosteering Horizontal Wells using Resistivity Anisotropy obtained in an Offset Vertical Well
Authors: Coutinho M. R. , Matsdorf M. , Ortiz A. , Reynolds L. , da Silva A. C. 
Published: December 2007

Abstract
Traditional resistivity logging instruments, when logged in vertical wells through horizontal beds, evaluate the horizontal resistivity (Rh) of the formation. The response of the laterolog tool in the same environment, however, is also sensitive to the vertical resistivity component (Rv). Used alone neither tool is able to resolve the thin beds or evaluate resistivity anisotropy. However, with computer inversion software, data from both tools can be combined to quantify zones of resistivity anisotropy, as well as accounting for various environmental effects such us invasion and shoulder beds improving bed boundary definition.
This paper proposes a new approach, combining NMR logs data with the above technique, in order to obtain improved geological and petrophysical models, using field data. The models, with more accurately parameterized vertical, horizontal, true and invaded zone resistivity values (Rv, Rh, Rt, Rxo), as well thin bed boundary definition, are coherent across a range of reservoir formation types, and are then applied to help drill more precisely (and evaluate more accurately), a horizontal well in the same formation.
New Pump Schedule Generator for Hydraulic Fracturing Treatment Design
Authors: Gu H. , Desroches J. 
Published: December 2007

Abstract
A typical hydraulic fracturing treatment executes a pump schedule that includes pad fluid volume and proppant stage concentrations. The automatic generation of such a schedule by a computer program is highly desirable. The generation of a pump schedule for hydraulic fracturing is an inverse problem. The fracture length and the proppant distribution inside the fracture are specified as input, together with formation and fluid properties, and a pump schedule generator (PSG) determines the amount of fluid and proppant needed in every stage of the schedule.
In this paper, a lag-length concept is implemented in a new PSG to control the distance between the proppant flow front and the fracture tip. The lag-length is necessary to prevent premature bridging and screenout in many situations. In this new PSG, the lag-length is automatically determined to generate an optimum schedule that uses the minimum pad volume to avoid premature screenout. The PSG is based on a pseudo-3D fracture model, and schedules can be designed for conventional (non tip-screenout) or tip-screenout treatments.
The schedule generator has been used to study the effects of proppant size and fluid types on the fluid and proppant stage volumes in a schedule. Lag-length is dependant on proppant size and other treatment conditions. The results of this study show that the application of the new PSG can benefit the fracture treatment design process. In particular, they highlight that changing the proppant size cannot be significantly changed independently from other pumping parameters.
The schedule generator is also shown to be a valuable tool in the selection of fracturing fluids. By comparing pump schedules required for a particular fracture performance - as given by desired length and proppant pack characteristics - the selection of a particular fluid can be made based on the optimum pump schedule for each fluid rather than using a fixed, or "typical," schedule in a particular field for different fluids.
Ultimately, the PSG is a primary tool to select the means to achieve a desired fracture conductivity within given operational constraints. It allows to compare all potential options: changing the proppant size, attempting a tip screen out design or changing the fluid system.
Analysis of Collapse Failures on Production Tubing During Steam Injection Process Assisted by Computer Simulations
Authors: Inciarte G. , Nieto L. , Bello A. 
Published: December 2007

Abstract
The alternate steam injection consist in force the reservoir to a cyclic sequence of heating and cooling process injecting hot water steam (500°-600° F) in order to improve the mobility for the extra-heavy crude in the reservoir, this is a very common practice for secondary recovery on the Tía Juana and Lagunillas fields, located in the eastern side of the Maracaibo Lake.
A destructive collapse failure on the production tubing was observed over the last wells exposed to this injection process. The investigation of the failure includes field visits, laboratory tests, and the computer simulations.
The study was prepared using a computer program able to create the different temperature profiles for the different scenarios and link them with the simulations for load cases, the results demonstrate the deterioration effect of temperature on the mechanical properties of the tubing, with particular interest on the expansion of the fluid trapped between the casing and the injection tubing, leading the collapse failure (AFE Analysis).
The analysis of the production tubing movement and buckling due to the thermal effect, ballooning and Hook's law is also included.
Comparison between Local Refinement and Open Boundary Techniques for Simulation of Large Oil Fields
Authors: Risso V. F. , Schiozer D. J. , Wendland E. 
Published: December 2007

Abstract
The use of computer models allows the forecast of the behavior of oil fields and the optimization of the production process. Usually, the simulation is hindered by the size of the field, the number of wells, the complexity of the system, and the amount of data necessary to guarantee the reliability of the model. This work addresses the reduction of computational effort, maintaining the level of precision of more complex simulations, when the interest is just in a certain area of the field, for example, in the forecast of the behavior of mature fields. There are several ways to accomplish fast simulations of this type of problem. Two techniques were studied in this work: local refinement and the simulation with open boundaries. For the evaluation of local refinement technique several different grids were tested. For the analysis of the simulation with open boundaries, the original field was decomposed in smaller units and the flows through the boundaries were represented by virtual wells. Models with variable number of virtual wells in each boundary were tested. Using the developed methodology it was possible to reduce significantly the time of simulation maintaining a reasonable precision.
Gas Lift Trouble Shoot Analysis Using Fuzzy Logic
Authors: Mata Daniel , Hernandez Ali , Chirinos Nicolas , Montoya Diego , Strefezza Miguel 
Published: December 2007

Abstract
Trouble shoot analysis of wells on gas lift is a very complex task, which requires knowledge and experience on behalf of the production optimization personnel. The complexity of the diagnostic process stems from the fact that a considerable number of possibilities can take place in a normal operation of a well on gas lift and the ever-present uncertainties of the quality of the data needed for the calculations.
The goal of a trouble shoot analysis is to determine the cause of any malfunction of the gas lift equipment or any other component of the completion that is limiting the well's production capability. The result of the analysis will determine the type of action needed to be taken in the field, which will eventually translate into maintenance cost.
The gas lift trouble shoot analysis is based on the fact that any of the valves installed in the well can be the operating valve. For a given point of injection, a force balance determines which valves could be open. If a valve is open and the gas pressure at depth is greater than the tubing pressure, the gas flow rate through the valve is calculated depending on how open the gas lift valve is. For the same given point of injection, the flowing bottom hole pressure is calculated and compared with the one predicted by the inflow equation. Then, for each possible point of injection or scenario, using fuzzy logic the gas injection mass balance and deviations from what the inflow equation predicts are used to determine the most probable point of injection.
This paper describes the most important principles underlying a gas lift trouble shoot analysis and how it can be integrated using fuzzy logic analysis to handle the complexity of the lifting process and the uncertainties of the data.