bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of a Novel Orienting Technology Leads to Oil Gains From Short String Through Tubing Re-Perforation in the Niger Delta
Authors: Ogunnifa A. , Ene E. , Umurhohwo J. 
Published: December 2007

Abstract
This paper presents the application of a new technology for rigless short string perforating operations. The use of this technology has led to quick and cheap oil gains from wellbores which otherwise have been traditionally programmed for more expensive major rig workover. Added to this is the elimination of complicated logistics and the achievement of a safer, faster and cheaper means of perforating reservoirs accessed via the short string in dual completions.
This new system for short string perforations eliminates most of the previously identified problems with existing perforating systems, without compromising performance, reliability and repeatability. Its use involves the electric line deployment of perforating guns below an electromagnetic orienting and correlating tool in the short string. The orienting and correlating tool detects the long string as the tool is rotated. The perforating gun can then be oriented 180
degrees away from the long string thus allowing for the safe detonation of the gun. The system provides a positive identification of the long string without requiring chart corrections or multiple string rig-ups.
This technique was successfully applied in the short strings of six dual completion oil wells located offshore in the Niger-Delta region by asset teams in Chevron Nigeria.
This paper describes the field performance of this tool, discusses the job planning process, the execution process, and presents production performance data available from three of the wells.
Modelling Channelized Systems: A Robust Approach
Authors: Chike Ikechukwu , Onyekonwu Mike 
Published: December 2007

Abstract
The importance of capturing the architecture of depositional facies within a system cannot be overemphasized. For a channel system as in most cases in the Niger Delta, the problem of accurately describing the geometry of these channels exists. Ideally, object based models are best suited to reproduce facies architecture, but this is generally hindered by the rigidity of this algorithm. Moreover, the application of outcrop analogue in the object model to reproduce the subsurface could be stalled by the differences in diagenesis between the outcrop and the reservoir. Thus, the need to modify the algorithm in modelling the system arises.
We adopted a robust object and pixel based model to capture the reservoir heterogeneity while honouring hard data. The approach includes integrating several available options for a particular channel setting in the software used (for the object based model) to come up with a flexible descriptor. Depositional trend were also built to capture the upward fining sequence of tidal channel sands. This was accomplished by building a complex transformation sequence to ensure accurate petrophysical description within the facies using a pixel model.
The result is a model that incorporates morphologic information and petrophysical trends from analogue while accurately describing the rock and fluid property using well data.
Displacement Efficiency of Supercritical CO2 Flooding in Tight Carbonate Rocks Under Immiscible and Miscible Conditions
Authors: Zekri A. Y. , Almehaideb R. A. , Shedid S. A. 
Published: December 2007

Abstract
Carbon dioxide flooding is currently being investigated as possible EOR processes in UAE candidate reservoirs. The major reasons for selecting CO2 flooding as an EOR process were low permeability and heterogeneity of these reservoirs that resulted in poor response to traditional water injection. In this study, immiscible CO2 displacement efficiency of low permeability carbonate rocks of a selected UAE field is evaluated experimentally. Laboratory tests were conducted on seven tight cores extracted from the selected oil field with a permeability range from 0.16 to 11.99 mD and porosity range from 7.72 to 18.63%. The effects of pressure, permeability, and initial oil saturation on the residual oil saturation after flooding at immiscible conditions were investigated in this study. The pressure was varied from 1600 to 4000 psi, and permeability was varied from 0.16 to 11.99 mD at constant pressure of 1600 psi. All runs were conducted at isothermal condition of 127 °F while the initial oil saturation ranged from 0.334 to 0.79 % pore volume.
Experimental results indicated that immiscible supercritical (SC) CO2 is capable of mobilizing oil in the very low permeability environment (0.16 mD) with reasonable displacement efficiency. Also, higher displacement efficiencies could be obtained if we start the flooding process earlier, i.e. at higher oil saturation, as there is a critical starting oil saturation required to optimize the displacement efficiency. Side effects from the process are that notable asphaltene precipitation was observed and SC CO2 injection in limestone cores results in the precipitation of calcite in the downstream area. Scanning Electron Microscope (SEM) was used to provide accurate description of pores prior and post CO2 flooding experiments and Energy Dispersive X-Ray Spectrometer (EDS) was used to evaluate the composition of the deposited asphaltene.
Gage Design—Effects of Gage Pad Length, Geometry and Activity (Side Cutting) on PDC Bit Stability, Steerability, and Borehole Quality in Rotary Steerable Drilling Applications
Authors: Mensa-Wilmot G. , James B. , Aggarwal L. , Luu H. Van , Rueda F. 
Published: December 2007

Abstract
Technical and operational success, in rotary steerable drilling (RSD) programs, requires optimization of the following performance qualifiers (PQ)1 – stability, rate of penetration (ROP), steerability, durability and borehole quality. Bottom hole assembly (BHA) design and drill bit development must aid in the optimization process.
Rotary Steerable Systems2,3 (RSS), based on their design and operational principles, exhibit different functional characteristics. This realization necessitates the need for specialized PDC bits4,5, for the different RSS tools. Technologies and/or features incorporated in these bits must enable optimization of the identified PQs.
Three of the listed PQs - stability, steerability and borehole quality6 - are directly influenced by a bit's gage design and configuration. This observation has created an intense industry debate on the contributions of gage design, as they relate to the functionality, dynamic behavior and overall performance of different RSS tools.
This paper will isolate and evaluate the effects of gage design concepts in RSD applications. The discussions will relate gage designs to PQ optimization, based on specific RSD programs.
Gage design theories, and functional characteristics, will be supported by extensive field data.
State-of-the-Art Training for State-of-the-Art Rigs—Options in Training for Cyber Rigs in New Locations
Authors: Cormack D. 
Published: December 2007

Abstract
Almost without exception new build offshore drilling rigs these days are mechanized or sequenced to some degree. This is particularly the case on new build offshore platforms regardless of where in the world they are to operate. For new and remote regions simulator and vendor equipment training along with a high degree of cultural awareness and basic minimum standards training are therefore critical elements in the pre-operational phase of any new build offshore platform project.
Historically equipment training is not included in the tender process for new build rigs and consequently has to be worked out after the event, usually by the first drilling contractor to operate the equipment. This can work out well when the drilling contractor has experience of simulators and understands the range of possible solutions.
Key to success in such projects is flexibility. Flexibility in choice of simulator solutions. Flexibility when scheduling personnel on training. Flexibility in how the cultural aspect is tackled. Flexibility in ensuring how basic minimum standards are attained. Flexibility from training providers to adapt to local conditions.
This paper reviews how one drilling contractor approached crew training for three new build offshore cyber rig projects in three different areas of the world.
PDC Bits: All Comes from the Cutter/Rock Interaction
Authors: Gerbaud L. , Menand S. , Sellami H. 
Published: December 2007

Abstract
PDC drill bit performances in hard rock has been greatly improved during the last decades by innovations in PDC wear, impact resistance and better vibrations understanding. The bit design is generally done by balancing the bit, distributing uniform wear along the profile and achieving high drillability and steerability. To obtain required drilling performances, drill bit designer adjust features such as profile shape, gage and mainly cutter characteristics (shape, type and orientation). Cutter rock interaction model became a critical feature in the design process. But previously used models considered only three forces on a cutter based on the cutter-rock contact area: drag force, normal force and side force. Such models are no longer valid with the introduction of PDC cutters with chamfer and special shape.
This paper presents a new cutter rock interaction model including some several improvements. It is based on the presence of a build-up edge of crushed materials on the cutting face often described in the literature. In addition, the chamfer, which significantly affects bit Rate Of Penetration (ROP), is taken into account (shape and size). Forces applied on the back of the cutter and due to the rock deformation and back flow of crushed materials are considered in the model. Finally, results of numerous single cutter tests (under atmospheric and confining pressure) are presented and compared to the new cutter rock interaction model predictions. An analysis of the influence of the PDC characteristics (shape, size, chamfer, back and side rake angles, ….) is presented.
The model has been applied to optimize the cutting efficiency and bit steerability and some design rules are given to minimize the specific energy and maximize the rate of penetration. Finally, full scale laboratory drilling tests and field results indicate that the use of accurate cutter rock interaction model can help the drill bit designer to find the best drill bit for a specific application. Standard laboratory full scale drilling procedures have been developed. The tests have shown that drillability, stability, steerability and wear can be improved and controlled by acting on the cutter characteristics, cutter setup, trimmer characteristics and gage type.
From 0 to 500 in Under 3 Years—The Caspian Recruitment Challenge
Authors: Richardson R. , Steel T. 
Published: December 2007

Abstract
In early 2003, the drilling contractor was awarded the final in a series of operations and maintenance contracts for 4 "cyber" platform rigs which were at the time in various stages of engineering design and construction with the first to start operations in September 2004 offshore Azerbaijan in the Caspian Sea.
While Azerbaijan has one of the longest histories of oil exploration and production, this was largely on old rigs under Soviet style leadership, operational and safety standards. The Operator's corporate objectives of no harm to people and delivering continuous improvement in drilling operations performance required a safe, effective and trouble free start-up and world leading safety and operational standards delivered through competent highly motivated personnel.
The recruitment challenge in sourcing some 500 expatriates and Azerbaijani nationals to deliver these objectives required a new approach so the contractor assembled a cross-functional project team to identify and solve the potential problems ahead.
This paper will demonstrate how the company's approach to recruitment and retention, particularly the extensive project planning and management up front, can be directly linked to performance in the platform rig start-up. It will conclude by showing how the lessons learned from this approach can be transferred to other start-ups and recruitment campaigns providing opportunities for optimising recruitment and retention strategy, and associated cost and efficiency savings.
Rotary Liner Drilling Application in Deepwater Gulf of Mexico
Authors: Mota J. , Campo D. , Menezes J. , Smith P. , Jackson T. 
Published: December 2007

Abstract
Many wells drilled today have complex well paths or are drilled through depleted or problem formations. In these wells, the liner may have to be reamed or drilled in, either to pass through the previously drilled hole or to make a new hole in the problematic formation. In many cases, the liner cannot be run to bottom as planned because unexpected problems are encountered. This situation can cost millions of dollars due to the required remedial work and deferral of production.
This paper will discuss a rotary liner drilling application utilizing an expandable liner hanger in the Gulf of Mexico. The primary objectives of the trial were to develop a better understanding of the status of current technologies and how these apply to the challenges of this type of application.
How To Unify Low-Shear-Rate Rheology and Gel Properties of Drilling Muds: A Transient Rheological and Structural Model for Complex Well Applications
Authors: Herzhaft B. , Ragouillaux A. , Coussot P. 
Published: December 2007

Abstract
Due to their complex formulations, Drilling Fluids and especially Oil base Muds exhibit very complex rheological properties. They are commonly described as thixotropic shear thinning fluids with a yield stress. A set of standards established by the American Petroleum Institute is available for the rheological characterization of these fluids and classical descriptions with non-Newtonian fluids such as yield power law models are typically employed. Although these descriptions and measurements are adequate for classical drilling situations, they reveal to be insufficient to describe more complex phenomena as barite sag, or pressure peak due to transient gel breaking on restart. In particular ultra low shear rate rheology has been early accepted as a key parameter for determining sag potential, and is poorly described by the classical models and measurements. On the other hand, time-dependent behavior (classically apprehended in static conditions through Gel 0 and Gel 10 measurements), which can be very significant even in dynamic conditions, is not quantitatively linked to the rheological description.
This paper describes how a simple thixotropic and structural model is able to describe completely all the features of the rheological behavior of drilling muds. The parameters of the model can be simply deduced from on site measurement using Fann 35 rheometer. We show that mud viscosity results at any moment from the competition between aging and shear rejuvenation. As a consequence, viscosity bifurcation (abrupt transition towards complete stoppage or rapid shear) may appear at low shear, which might explain the occurrence of barite sag. Finally, it is shown how any transient phenomena like pressure peaks when starting a pump after circulation stoppage may be adequately predicted by using this model in hydraulic calculation.
Innovative Systems Approach Enables Smart Intervention Solutions
Authors: Ellzey T. , Heisig G. , DeGeare J. P. , McGurk M. , McNicol J. 
Published: December 2007

Abstract
One of the most frustrating and costly aspects of any wellbore intervention operation is when little or no progress is made during a trip in the well and tools are returned to surface showing no visible signs of performing work. Conversely but equally frustrating is when a downhole tool becomes worn or damaged beyond its useable life and the operator continues to try to make progress based on readings from traditional surface-based indicators and gauges. These situations are becoming more common as wells become deeper, more complex and technically challenging to intervene.
To address these problems, a "smart intervention" system has been developed that provides a new level of process control to the operator while intervention work is being carried out. The system incorporates a short, modular MWD-style sensor sub that is integrated into the bottom hole assembly (BHA). Measurements such as weight on bit, torque, RPM, bending moment, vibration, annular and bore pressures are gathered downhole to provide a clearer picture of what is occurring at and around the downhole tools. Information is then transmitted to surface using mud pulse telemetry and viewed on a rig floor monitor. The system allows the operator to make informed decisions and take immediate action to optimize the intervention being performed.
This paper discusses initial system integration and field testing, benchmarking and analysis, as well as results of, and lessons learned from, early field case histories. The tests and field runs demonstrate the potential of this systems approach to provide economic benefits through significantly improved efficiency, reduced uncertainty, better reliability and less wear and damage to downhole tools and equipment.
Method To Reduce Milling and Trip Times During the Recovery Operations of Permanent Production Packers
Authors: Haughton D. B. , Connell P. 
Published: December 2007

Abstract
There are many situations that require the removal of a production packer from a wellbore, whether it is a planned workover or a stuck packer during the completion process. In all cases, the packer must be washed over and recovered or milled up and pushed down to the bottom of the wellbore.
Most of the methods used today are the same tools and techniques that have been in use for the last 30 or so years. These methods incorporate a shoe or milling head with a specific type retrieving tool to catch the packer after milling away the slips, and were designed for packers that came with millout extensions or blank bottoms. Today, however, packers are being run with seal bore extensions instead of millout extensions. Packers are being manufactured with more exotic materials and high chrome metals. These materials present a milling challenge -- not only do they create longer milling times, but they also usually require two or more trips to mill and recover the packer.
A new method of milling has been specifically designed to reduce milling and trip times in these modern packers. This new method allows an operator to engage a smooth packer bore and completely remove all of the packer material and slips rather than removing only the outside material and leaving the packer mandrel. This milling procedure is quicker and produces smaller amounts of debris, therefore reducing milling times. The milling heads can be dressed with the most up-to-date cutting structures that will optimize the removal of the packer material depending on whether it is standard grade or of a high-tensile, high-chrome content.
This paper will discuss the process and operational procedures pertaining to this new method, along with case histories. The paper will detail the advantages of this method and the tools used, as opposed to the conventional methods and tools that are widely used through out the world today.
Pipe Rotation and Hole Cleaning in an Eccentric Annulus
Authors: Hemphill T. , Ravi K. 
Published: December 2007

Abstract
The drilling community generally believes that pipe rotation helps hole cleaning during both drilling and cementing. However, there has been a lack of reliable calculations to describe the effect and application in engineering and design and deployment. This paper discusses the effect of pipe rotation on velocity profile and pressure drop in concentric and eccentric annulus during the axial flow of non-Newtonian fluid. The calculations are applied to the design of hole cleaning during drilling and cementing.
In the absence of reliable calculations one can only guess the impact of pipe rotation on hole cleaning. This work gives an engineer the tool to design for improved hole cleaning and hence save time and money during well construction and production.
Pipe rotation is all the more important in an eccentric annulus to remove the drill cuttings and the gelled drilling fluid from the narrow annulus. This is because in an eccentric annulus, in the absence of pipe rotation, the fluid flows preferentially through the wider annulus. The pipe rotation speed (i.e., the RPM) required to move the gelled drilling fluid and the drill cuttings in various annulus configurations and eccentricities are presented. The results discussed in this paper can be applied for effective hole cleaning during drilling and cementing, which should save nonproductive time (NPT) during drilling and cementing and also reduce remedial and intervention costs during well production.
An Operator's View of the Choices for Deepwater Intervention
Authors: Browning G. M. , Moss J. H. 
Published: December 2007

Abstract
Well thought out concept selection is critical in developing a future deepwater intervention system that will be both technically and commercially successful. Short term solutions that are developed for part-time usage may get by but should eventually lose out to systems designed for full utilization. This paper will address critical concept issues and provide one Operator's recommendations for long term success.
Novel Approach To Predict Potentiality of Enhanced Oil Recovery
Authors: Jian H. , Wenfen H. 
Published: December 2007

Abstract
The potentiality prediction of enhanced oil recovery (EOR) is the basis of EOR potentiality analysis as well as the robust guarantee of the reliability of analysis results. In the light of statistical learning theory, establishing an EOR predictive model substantially falls within the problem of function approximation. According to Vapnik's structural risk minimization principle, one should improve the generalization ability of learning machine, that is, a small error from an effective training set can guarantee a small error for the corresponding independent testing set. The up-to-date results from studies on statistical theory in recent decades even recent years are firstly applied to EOR potentiality analysis. The applications of group method of data handling (GMDH), Improved BP artificial neural network, and support vector machine (SVM) are discussed. The comparison of the results from three methods indicates that SVM can pay more attention to both the universality and extendibility of a model when the samples are very limited, which shows a good prospect of its application. A method used to generate a set of sample theoretically is developed in this research by combining quadrate designing, reservoir simulation, and economical evaluation.
An Efficient Model for Gas-Rate Forecasting in Complex Reservoirs
Authors: Jordan C. L. , Fenniak M. J. , Smith C. R. 
Published: December 2007

Abstract
This paper presents a simple, but accurate, computer method for predicting the performance of multiple gas wells in complex reservoir scenarios. Real life gas reservoir characterization and forecasting can be accomplished with the substantial reduction of effort when compared to numerical simulation and a substantial increase in accuracy when compared to traditional decline methods. Conventional analytical methods in many cases are highly unsuitable for new field development, in-fill drilling, or long-term production planning. Numerical simulation methods often require impractical pre-processing or computational time. With the method presented in this paper, production profiles can be generated for arbitrary shaped gas reservoirs with multiple wells. The model presented overcomes many limitations of traditional methods, and extends analytical modeling into multiple well scenarios with interference effects, arbitrary reservoir shapes, and perhaps even varying rock properties.