bluuebunny/crossref_metadata_2025_split huggingface dataset:
Foam Drilling Simulator
Authors: Paknejad Amir , Schubert Jerome J. , Amani Mahmood 
Published: December 2007

Abstract
Although the use of compressible drilling fluids is experiencing growth, the flow behavior and stability properties of drilling foams are more complicated than those of conventional fluids. In contrast with conventional mud, the physical properties of foam change along the wellbore. Foam physical and thermal properties are strongly affected by pressure and temperature. Many problems associated with field applications still exist, and a precise characterization of the rheological properties of these complex systems needs to be performed. The accurate determination of the foam properties in circulating wells helps to achieve better estimation of foam rheology and pressure.
A computer code is developed to process the data and closely simulate the pressure during drilling a well. The model also offers a detailed discussion of many aspects of foam drilling operations and enables the user to generate many comparative graphs and tables. The effects of some important parameters such as: back-pressure, rate of penetration, cuttings concentration, cuttings size, and formation water influx on pressure, injection rate, and velocity are presented in tabular form.
A discretized heat transfer model is formulated with an energy balance on a control volume in the flowing fluid. The finite difference model (FDM) is used to write the governing heat transfer equations in discretized form. A detailed discussion on the determination of heat transfer coefficients and the solution approach is presented.
Estimation of Permeability From Wireline Logs in a Middle Eastern Carbonate Reservoir Using Fuzzy Logic
Authors: Abdulraheem A. , Sabakhy E. , Ahmed M. , Vantala A. , Raharja I. , Korvin G. 
Published: December 2007

Abstract
Permeability is one of the most difficult properties to predict, especially in carbonate reservoirs. The most reliable data of permeability, obtained from laboratory measurements on cores, do not provide a continuous profile along the depth of the formation.
This paper presents the use of fuzzy logic modeling to estimate permeability from wireline log data in a Middle Eastern carbonate reservoir. In this study, correlation coefficients are used as criteria for checking whether a given wireline log is suitable as an input for fuzzy logic modeling. The coefficients are enhanced if they are evaluated with respect to the logarithm of core-based permeability values of the given well.
After training the fuzzy model on a layer in a given well, permeability predictions were made for other layers in the same well. These predictions were in excellent agreement with permeability values obtained from cores. It was also observed that Subtractive Clustering technique gives better predictions of permeability when compared with Grid Partitioning technique.
A parametric study was also conducted to see the effect of type and number of membership functions, combination of log input parameters, and data size on predictions of permeability. The possibility of training the fuzzy program on one well and testing it for other wells in the same formation is also explored.
Critically-Stressed-Fracture Analysis in Naturally Fractured Carbonate Reservoir–A Case Study in West Kuwait
Authors: Verma Naveen K. , Al-Medhadi Fahed , Franquet Javier A. , Maddock Robert , Natarajan D. , AL-Mayyas Eman 
Published: December 2007

Abstract
This paper presents the methodology to identify critically stressed fractures, CSF, in naturally fractured reservoirs. A natural fracture is considered to be critically stressed if the ratio of shear and normal stresses acting on the fracture surface exceeds the frictional strength of the reservoir rock. The main objective is to identify the critically stressed fracture trends in the reservoirs in order to design wellbore trajectories that efficiently intersect theses fracture trends. In addition, geomechanical analysis for drilling scenarios under depleting reservoir conditions addressing well-bore stability is attempted to formulate drilling and completion strategy.
Critically stressed fracture identification has several important implications on fluid flow behavior through naturally fractured porous media. It has been shown that fluid flow in fractured rocks is largely controlled by critically stressed fractures; therefore, critically stressed fracture analysis may enable to systematically identify producing fractures in the reservoirs that mainly produce through natural fractures.
The CSF analysis includes the mechanical property characterization of the formations and the in-situ stress tensor description acting on the reservoirs. The fracture orientations from core description & borehole image log interpretation were used for the CSF analysis because fracture dip and strike are needed for the stress calculation on fracture planes. This analysis is particularly useful where several fracture trends are identified in a reservoir, with some trends more likely to be open and productive due to horizontal stress anisotropy. The case history illustrates application of CSF Analysis in conjunction with geomechanical wellbore stability analysis in selection of optimal well trajectory and formulation of drilling and completion strategy for producing a naturally fractured carbonate reservoir.
The Identification of Condensate Banking With Multiphase Flowmeters – A Case Study
Authors: Theuveny B. C. , Maizeret P. D. , Hopman N. S. , Perez S. 
Published: December 2007

Abstract
The identification of condensate banking has always been a challenge. Furthermore, large productivity losses can result from the absence of early detection of a condensate bank in the near well bore area of the well. The traditional means of detecting a condensate bank range from comparison of the dew point to downhole pressure measurements, identification of composite radial models and quantification of skin using pressure transient analysis. One of the methodologies that have been more theoretical than practical has been the detection of a leaner stream of effluent at the well head during production. This type of approach has been quite challenging in the past, as a high resolution measurement of the condensate to gas ratio is essential to a successful diagnostics of condensate banking.
The paper presents a case of analysis of the development of a condensate bank during a well test. The multiphase flowmeter identified a gradual reduction of the condensate to gas ratio with increasing choke sizes. The methodology of diagnostics is demonstrated, in particular with the discrimination against liquid loading issues.
The PVT compositional analysis provides a verification of the analysis, and the observation of the evolution of the phase diagram leads a further understanding the downhole and near well bore thermodynamic phenomena.
The degradation of the productivity of the well is also analyzed, with a significant drop of gas productivity observed even on smaller choke sizes at the end of the test.
Finally the paper presents a numerical simulation match of the data and provides a number of recommendations for the utilization of single well - near well bore compositional models to help interpreter to obtain better and simpler matches.
This paper provides a new methodology to make full use of the benefits of the dual energy gamma Venturi multiphase flowmeters in the evaluation of gas wells.
Identification of High-Porosity Reservoir Sands From 3D-Seismic Attributes Using Neural Network Technique in South Umm Gudair Field, Kuwait
Authors: Thakur Ram Kumar , Duval Frederic , Boibien Claude , Pages Gilles 
Published: December 2007

Abstract
The South Umm Gudair Field is a multi-accumulation structure with the most prolific production of oil from a Ratawi Oolite reservoir (Neocomian). The historic ultimate seal held by the thick Ratawi Shale Member, displays embedded multilayered oil bearing reservoir sands. Sands were sedimented as thin tidal bars anastomosed with distributary and tidal channels deposited under pro-deltaic to delta front environment.
To delineate this complex reservoir, a neural network technique was applied to estimate effective porosity integrating well information and 3D multi-attributes between seismically mapped sequences. This method is more efficient than conventional estimation with the ability to build a non-linear relationship between seismic traces and target porosity logs for interpolation. The combination of 20 seismic attributes including impedance derived by model based inversion was selected on the basis of ranking of error factors.
The network was trained with effective porosity available at well locations. It subsequently recognized not only that pattern, but also similar patterns by generalization in the study area. The effective porosity cube was generated by the processing of 3D seismic data with this trained network. The representative sections extracted from this volume highlight the limited extent of reservoir sands within the sequences which has also been supported by the simulations of lithofacies with Sequential Gaussian method using well data. The trajectory of the proposed lateral wells are designed in sequences-2 & 4 to intersect the porous sand at the optimum location to ensure good drainage of these reservoir units. The reservoir sand corresponding to upper sequence-4 shows widespread development in the western part of the area of interest with better connectivity, but is shaling out eastward of the field.
The paper focuses on the methodology of identification of thin lenticular high porosity reservoir sands to plan for side-tracking existing deeper wells and drilling appraisal & delineation wells.
The Next Major Step in Total Hands-Free Pipe Handling—No Derrickman in the Derrick Racking and Unracking Pipe
Authors: Richard Dave 
Published: December 2007

Abstract
The paper identifies the challenges that were overcome to realize hands free tripping, racking and un-racking of drill pipe and collars in medium and large land based drilling rigs through the development of a new technology racking board pipe handling system. The steps of development and design involving Mechanical, Electrical and Robotic Motion Control Engineering Technologies combined with drilling operations knowledge and experience are laid out to show how adapting these new ideas to existing double and triple drilling rig masts without any structural mast modifications was achieved. A comparison to offshore racking board pipe handling systems highlights the technical and economic difficulties experienced in applying the land based systems successfully with frequent moves, weight/size restrictions and reliability concerns. Field gathered tripping and connection test times in comparison to a human Derrickman working the racking board are put forward. Field tests further describe how drilling hands on the drill floor typically needed to set pipe back and lead pipe into well center during tripping in-hole and out-hole are eliminated. The paper looks at how conventional robotic motion control technology has resulted in reliable "Nintendo-style" control operation with smooth solid control of moving pipe. Further discussions in the paper examine the current obstacles that remain to completely remove drilling personnel from the harms way on the drill floor. Finally, the paper will show how this direction of design development and implementation in safe drilling rig equipment is necessary to keep employees healthy, productive, profitable and working in the drilling industry.
Drilling Without WOB: Dream or Reality? An Effective Field Test by Total Angola
Authors: Simon Christophe , Goyallon David , Poloce Jean-Paul , Sellami Hedi , Gerbaud Laurent , Dourfaye Alfazazi 
Published: December 2007

Abstract
Recent developments in PDC bit modelling and single cutter analysis have enabled to design a new generation of cutting structures – based on the optimization of a specific interactive cutting mode – that generates, by the mere drilling action of the cutters, an axial force oriented in the drilling direction: a negative weight on bit.
This paper presents the application of this new PDC bit design and shows that WOB can be significantly reduced in a wide range of formations. A monobloc 8″1/2 PDC bit was designed, tested in laboratory, and self penetration was clearly achieved in field conditions.
A full PDC bit design methodology using a new PDC cutters geometry optimized for a maximum thrust effect, along with specific manufacturing procedures for high-level precision in cutter positioning, were developed for this specific new bit generation.
Laboratory tests showed that it was possible to drill without WOB at a high rate of penetration and with a small increase in specific energy. Preliminary field tests in cement demonstrated that self penetration – drilling with the neutral point just above the bit – was possible with specific surface control, and a first operational application was conducted by Total E&P Angola.
This new bit technology has the potential to increase bit performance, specifically in operating conditions where power is available but WOB is limited due to friction, buckling or reduced vertical depth. The ability to drill with reduced WOB – or even without any WOB – should extend the potential of existing drilling technologies such as Extended Reach Drilling, Coiled Tubing or Steerable Motor in sliding mode and reduce axial vibration, thus increasing the MTBF of downhole tools.
PDC Casing Drilling Improves HS&E, Cuts Drilling Costs—West Africa
Authors: Hartsema Klaas , Gabon Shell , Aliko Enis , Campos Jaime , Clark Lester , Delgado Franck , Folling Peter , Wingate John 
Published: December 2007

Abstract
Conventional drilling techniques were utilized by the operator in Gabon to drill surface-hole through fractured carbonates prone to severe losses up until 2004. At that time, the operator launched a series of cost-cutting initiatives, one of which was the employment of Casing Drilling technologies.
Casing/Liner drilling is the process of drilling or reaming down a casing/liner interval utilizing a Casing Drill Bit. The casing/liner replaces the drill-pipe and is rotated at surface by the rig's top-drive. This system enables problematic zones to be drilled and sealed-off in one run reducing potential non-productive time (NPT) associated with hole problems, eliminating tripping-time for conventional drill-pipe and bottom hole assemblies (BHAs) and improved rig-floor safety by eliminating the risk associated with pipe handling.
The bit company recommended a polycrystalline diamond compact (PDC) – drillable Casing Drill Bit that is screwed onto the bottom of the casing. This simple, yet robust tool would ensure the greatest chance of success. Three Casing Dill Bit sizes have been run successfully to date on six wells; 12-1/4" (modified to 12-3/4") and 16".
Early runs raised some concern as to whether the casing connections could withstand the torque levels required to drill with casing. The first three runs used a 12-1/4" Casing Drill Bit run on 10-3/4" casing. Total mud losses and high torque levels were experienced during these runs. The Casing Drill Bit size was subsequently increased to 12-3/4" thereby increasing the annular clearance, reducing borehole friction and potential losses. The modification proved successful with the fourth well drilled without losses and torque levels reduced by half compared to the first three runs.
The fifth and sixth runs employed a 16" PDC Casing Drill Bit conveyed on 13-3/8" casing. On the fifth well the bit was pulled-out prematurely due to formation problems. The bit came out in excellent condition with no wear and only one missing PDC cutter. The same bit was re-run on the sixth well where it drilled to section total depth (TD) with full returns throughout the run.
The paper will describe the PDC Casing Drill Bit system, its performance in Gabon plus the systems positive economic impact and safety benefits.
Hydraulic Blowout Control Requirements for Big-Bore and HP/HT Developments: Validation With Field Experience
Authors: Oudeman P. 
Published: December 2007

Abstract
Although advances in drilling and well intervention technology have made blowouts a rare phenomenon, their consequences are often of such a magnitude that for each development a contingency plan should be available aimed at limiting the damage and regaining control over the outflow of the well rapidly. This plan should consider all possible blowout scenarios and the corresponding response. When capping, the most efficient method, is not an option, e.g. for subsea or underground blowouts, downhole injection of kill fluids through an existing conduit or relief well(s), the hydraulic or "dynamic" kill, is the next best alternative. To plan for such an operation prior to actually spudding the development wells, a number of parameters needs to be known such as the required number and dimensions of relief wells, kill fluids and kill rates, pump capacity etc. For HPHT and big bore developments, these requirements cannot be derived from experience.
It is shown here that the requirements depend on a limited number of factors such as the pressure regime of the blowing formation and flow resistance of the blowing well. This allows formulation of guidelines for hydraulic blowout control for (un-) conventional developments, even when the exact circumstances of a blowout are not known, as is the case in contingency planning.
A comparison with selected field cases of blowouts demonstrates that the formulated guidelines match the experience with actually killing these blowouts in terms of the number of wells, pump rates, and kill fluids etc. that were eventually required. This gives the confidence that the guidelines are a good starting point for contingency planning. The case of a giant North Sea gas field is discussed to demonstrate this.
Survey Accuracy Extends Well Displacement at Minimum Cost
Authors: Landry Bart , Poedjono Benny , Akinniranye Goke , Hollis Mike 
Published: December 2007

Abstract
The increased use of horizontal exploitation of formations for improved resource recovery has resulted in a trend towards denser well spacing and extended lateral lengths. The resulting reduction in distance between wellbores has intensified the need for accurate data on wellbore positions and trajectories. This paper explores the challenges of developing reliable positioning data and examines various mechanisms for ensuring optimum well separation distances essential to optimize waterflood sweep efficiency. Case histories from land drilling operations will be discussed to demonstrate the design and application of a well survey program that is both highly accurate and cost effective.
Among the program components to be discussed are methods for determining the accuracy of existing wellbore data and statistical analysis to assess how closely predictive models match actual well placements. Support data for analysis was generated from existing reservoir models and statistical gyro surveys. Additional insights were gained by examining the causes of measurement-while-drilling (MWD) errors, and accuracy was increased by finding new ways to minimize magnetic errors induced by the bottom hole assembly (BHA). A database was compiled to compare raw MWD data with corrected survey data, with two goals in mind:
■ Reduce the average level of destructive anomalies per well by investing in more accurate processing for each BHA. ■ Increase the lengths of the lateral wells by 50% for more efficient resource recovery.
By better understanding the extent and cause of existing survey inaccuracies, and developing improved methodologies for reliable data collection and analysis, this study has contributed to both the safety and the economic viability of today's increasingly complex drilling programs.
Intelligent-Well Technology Used for Oil Reservoir Inflow Control and Auto-Gaslift, Offshore India
Authors: Konopczynski Michael , Tolan Mike 
Published: December 2007

Abstract
The use of intelligent well technology is growing as Oil and Gas operators try to improve the management of hydrocarbon reservoirs and exploit the recovery of reserves more efficiently. The abilities to monitor conditions down-hole in real time, and control the flow of fluids between the reservoir and the partitioned wellbore without physical intervention, inherent in intelligent well technology enable the operator to achieve these objectives. One method of employing intelligent well technology is to commingle, in a controlled process, the production from a gas reservoir or gas cap with the principle production from an oil reservoir in order to reduce the hydrostatic head of the produced fluids in the production conduit and enhance production of the oil. We call this process, "Auto-gaslift". Use of auto-gaslift reduces the capital investment required to construct the infrastructure (compressors, separators, dehydrators, distribution lines) necessary for conventional gaslift.
Intelligent well technology is necessary to effectively control the auto-gaslift process by monitoring the performance of the oil and gas sources, and by controlling the addition of gas to the production in order to optimize the production of fluids. The optimization process is similar to methods of conventional gaslift. With auto-gaslift however, unlike conventional gaslift, the productivity of the gas source is uncertain, and pressure and productivity can change with the life of the well. Additional attention must be applied to the design of the downhole flow regulating valve on the gas zone to ensure that it is properly sized for the application over the range of gas and oil reservoir performance, fluid compositions and reservoir pressure for the life of the well.
This paper describes a multi-well application offshore India in the Panna oil field using SmartWell technology for auto-gaslift, as well as to control inflow from a segmented horizontal wellbore in the oil reservoir. The paper describes the SmartWell completion design to control inflow of unwanted effluents from a horizontal well, and to use auto-gaslift to maximize production.