bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and Application of a 3D-Wellbore Visualization System for Hydraulics Analyses
Authors: Zamora Mario , Simpkins Douglas
Published: December 2007

Visualization technology has evolved into an important G&G tool to view and interpret seismic data, 3D logs, geocellular models, grids, horizons, and well placements. Directional drillers also benefit from visualizing complex placements in 3D; however, this is one of very few drilling applications that currently exists for this technology. Introduced in this paper is software that for the first time permits interactive 3D visualization of the inside of a virtual wellbore. In this initial offering, downhole drilling hydraulics and related conditions can be critically examined while navigating the well from surface to TD using a standard PC and a joystick. The new software system has application for interpreting large data sets, mitigating drilling problems, training, and encouraging collaboration among multi-disciplinary teams.

Stunning 3D perspective rendering can show internal and side projections of well tortuosity, cuttings beds, drill string (including eccentricity), annular velocity profiles, formations (texture, rugosity, and breakout), downhole engineering parameters (temperature, ESDs, etc.), and downhole tools, among others. "Intelligence" is incorporated that can direct the software to automatically find, display, and visually inspect anomalies and potential hydraulics-related problems. Simulated data are provided by an advanced hydraulics program;a real-time version is planned that also will include other key drilling and wellbore parameters. Both options are suitable for use in real-time drilling centers.

The purpose of this paper is to discuss the development, application, and opportunities of this wellbore visualization software. Special emphasis is placed on the quality and uncertainty of models, and methods used to drive the 3D graphics. The design, development, and implementation of the fit-for-purpose graphics platform also are discussed.
Using a Flexible, Expandable Sealant System to Prevent Microannulus Formation in a Gas Well: A Case History
Authors: El-Hassan H. , Sultan M. , Saeed A. A. , Johnson C. , Belmahi A. , Rishmani L.
Published: December 2007

Long-term zonal isolation of gas reservoirs is a difficult problem. This paper summarizes the implementation and evaluation of a new sealant system designed to overcome this problem by preventing formation of a microannulus across the gas zone. A case history of its use in a well in the United Arab Emirates demonstrates the successful application of the flexible, expandable sealant material to prevent microannulus and maintain cement sheath integrity in the production casing section.

In one well, a conventional cement slurry formulation was used for the 9 5/8-in. section. The section was then tested to 3,000 psi pressure. Cement-bond logs showed clear deterioration of cement sheath quality behind the casing. A similar result for upcoming casing sections was a concern, so the sealant was redesigned to accommodate downhole stresses across the interval. The new design, which was used in the 7- in. liner section in the same well, enabled mechanical and expansion properties to be engineered to withstand downhole stresses and minimize the debonding effect. After successful isolation in the first well, the flexible, expandable sealant material was established as standard practice in similar wells.
New Water-Based Mud Balances High-Performance Drilling and Environmental Compliance
Authors: Dye William , Daugereau Ken , Hansen Nels , Otto Michael , Shoults Larry , Leaper Richard , Clapper Dennis , Xiang Tao
Published: December 2007

A new water-based mud system has been successfully introduced as a high-performance, environmentally compliant alternative to oil and synthetic emulsion-based muds (OBM/SBM). Historically, emulsion muds have been the "systems-of-choice" when drilling challenging onshore, continental shelf and deepwater wells in order to minimize risk, maximize drilling performance and reduce costs. However, environmental constraints, a high frequency of lost circulation and the high unit cost of emulsion systems often negate the benefits of their use. Conventional water-based mud (WBM) offer the benefits of environmental compliance, attractive logistics and a relatively low unit cost but consistently fail to approach the drilling performance of OBM and SBM.

The new high-performance water-based mud (HPWBM) is designed to close the significant drilling performance gap between conventional WBM and emulsion-based mud systems. The system has undergone extensive field testing on very challenging onshore, deepwater and continental shelf wells that would otherwise have been drilled with oil or synthetic-based muds. This paper provides a detailed technical overview of the new system, discusses its inherent environmental advantages and presents case histories comparing performance to offset wells drilled with emulsion and conventional WBM systems.
When Should We Worry About Supercharging in Formation Pressure While Drilling Measurements?
Authors: Chang Yong , Hammond Paul S. , Pop Julian J.
Published: December 2007

A model is described that is capable of simulating in detail the time variation of formation pressures measured while drilling, in situations where supercharging is significant. Simulation results are shown that illustrate the variation of supercharging pressures with formation permeability, drilling fluid filtration properties, and drilling fluid hydraulics. The model is used to explore how drilling operations influence the levels of supercharging when drilling two formations, widely separated along the well trajectory, and of significantly different permeabilities. The forward simulation capability presented is believed to be a useful aid to the planning, understanding and interpretation of formation pressure measurements while drilling.
A Laboratory Investigation of Temperature Induced Sand Consolidation
Authors: Ross C. M. , Rangel-German E. R. , Castanier L. M. , Hara P. S. , Kovscek A. R.
Published: December 2007

Current open-hole, gravel-packed, slotted-liner completions for wells drilled in unconsolidated and weakly consolidated sandstone are relatively expensive and result in greatly reduced operational flexibility of the well. On the other hand, a novel well completion method for both horizontal and vertical wells is to cement and consolidate sand grains in situ. During this completion process, a well is cased and cemented, limited-entry perforations are shot, and high-temperature, high-pressure steam (1600 psi, 600°F) is injected to create grain-cementing precipitates. Empirical field experience (Wilmington, CA) has shown that certain high-temperature minerals precipitate preferentially near the wellbore, cementing sand grains, but without appreciably reducing formation permeability and producibility.

This study delineates the mechanisms of the sand consolidation process by duplicating in the laboratory the governing geochemical processes resulting from injection of hot, alkaline water into sand. High-pressure, high-temperature pressure vessels are packed with quartz sand according to the grain-size range observed at Wilmington. Sand packs also contain typical per-volume concentrations of concrete resulting from perforating a cased and cemented well. Analysis is made of the evolution of sand-pack pore structure that occurs as a result of dissolution and subsequent precipitation. Pore structure and precipitate characterization is determined by means of scanning electron microscope imaging and compositional analyses. Results show that hot alkaline water injected at constant rate indeed results in precipitates that cement loose grains. Casing cement plays a crucial role in that it is the source of calcium silicates appearing in various pore-lining precipitates. The laboratory investigation teaches that the conditions for effective sand consolidation are not necessarily formation specific and the process can be altered to improve cost effectiveness, flexibility, and longevity of the completion technique.
Reservoir Management of the Njord Field
Authors: Talukdar S. , Brusdal L. H.
Published: December 2007

The Njord Field is one of the most complex reservoirs in the Norwegian North Sea. A large number of faults, and uncertainties associated with structures, fault transmissibilities, fluid contacts, rock and fluid properties pose a great challenge for reservoir management.

The main development philosophy was to minimize uncertainties based on drilling and production/injection experiences. The uncertainty was managed to a great extent by limiting the number of pre-drilled wells. The early experiences, particularly from a horizontal well led to radical changes in the well designs. The concept of drilling high amplitude sinusoidal wells was very successful for safe penetration of all reservoir intervals in multiple fault compartments. It also eliminated the need for a large number of wells.

An active visualization assisted geosteering together with biostratigraphy was successfully applied to drill a complex three-branched well in the most faulted area of the field. Another well was drilled in an area where pressure depletion was in excess of 300 bar in some of the fault compartments.

State-of-the-art seismic interpretations have been performed on various data sets to identify and locate reservoir intervals and faults. Reservoir simulations assisted by 4D seismic have identified remaining oil pockets. A low cost solution for drilling relatively small, sparsely located infill targets using the through tubing rotary drilling technology has been considered.

Systematic reservoir monitoring through collection of various types of data, such as, PLT, RFT/MDT, tracer, production/injection, bottom hole pressure, 4D seismic, etc. has been an effective tool to devise reservoir management strategies. In addition to unique well designs, selective perforation, re-perforation, gas injection, zone isolation and infill drilling have improved the oil recovery significantly.

This paper summarizes the reservoir management challenges, techniques and technologies applied to evaluate and monitor the reservoir performance, strategy to manage uncertainty, practices for improved recovery, successes and failures.
Isubs: A New Generation of Autonomous Instrumented Downhole Tool
Authors: Desmette Sébastian , Will John , Coudyzer Christophe , Richard Thomas , Le Phi
Published: December 2007

The paper describes a short autonomous instrumented downhole tool (Isub) which incorporates multiple sensors (accelerometers, strain gauges, and magnetometer), a complete data acquisition line, a microprocessor, memory chips and batteries. The tool, available in three sizes (7", 9" and 10" 1/4) can be located anywhere within the BHA even behind a mud motor or rotary steerable system as its total exposed length is of 350 mm. The tool records at a scanning rate of 50 Hz (up to 250 Hz) several tens of hours (100 to 300 hours) forces, moment as well as centripetal, tangential and axial accelerations used to reconstruct the instantaneous bit kinematics (RPM, off axis rotation, side acceleration).

Due to its high scanning rate and precision (each sub is fully calibrated) on all channels, the Isub has many benefits, it offers a complete vibration diagnosis: nature (torsional, lateral, axial), amplitude (stick-slip, backward and forward whirl, bouncing), susceptibility to surface control parameters (WOB, RPM), tracking of bit efficiency and wear, and assessment of downhole equipment "real" performance: hydraulic motor or turbine (power delivered, staling events), rotary steerable system (side force, vibrations).

This paper illustrates by two examples some of the insight to the drilling response of the system such tool can provide. The data reveal the occurrence of phenomena (vibrations, motor performance) neither detected nor suspected on surface. It also captures all inappropriate drilling practices.

The analysis shows strong evidences of the tremendous potential of such tool not only to gain a better understanding of the drilling process but also to provide a non-bias measure of the drilling performance. Eventually, such tool should help in improving drilling performance and build best drilling practices rules.
Gravel Pack Placement Limits in Extended Horizontal Offshore Wells
Authors: Calderon A. , de Magalhães J. V. M. , Martins A. L.
Published: December 2007

Long horizontal section wells are economical requirements for heavy oil fields in deepwater environments. This article discusses the operational limits for gravel pack placement in such wells, considering the maximization of the horizontal section extension in low fracture gradient scenarios. A parametric study on the variables governing the gravel pack operations indicates that careful hydraulic design and detailed operational procedures can guarantee a successful job. Alternative strategies are proposed to extended hydraulic limits in critical conditions.
Vacuum Insulated Tubing Design and Performance Evaluation for Deepwater Completions
Authors: Nowinka Jaroslaw , Xie Jueren , Kis Peter , Hensley Rodney , Gonzalez Manuel , Williams Darryl
Published: December 2007

This paper presents a methodology and a software program for mechanical design of vacuum insulated tubing (VIT) strings. It also presents findings of a technical and experimental evaluation of a VIT candidate product under conditions typical for ChevronTexaco's Tahiti project in the Gulf of Mexico.

The design-and-evaluation methodology consisted of an initial feasibility study of VIT thermal properties and service loading conditions, a closed-form solution of the VIT stress-strain state under combined loading, a parametric finite element analysis (FEA) with simulation of interactions within VIT end connections, and a full-scale test of a VIT specimen under cyclic thermal and mechanical loads that were anticipated in field service.

A complex experimental set-up was developed to apply the required combined loads to a full-length VIT joint. The test specimen was instrumented with strain gauges to measure the VIT deformation in a fully submerged environment.

The paper presents examples of data acquired in all phases of this design-and-evaluation program. The results were used for assessment of structural integrity, sealability, and thermal insulation performance of the VIT candidate product. The experimental data agreed well with analytical and numerical predictions. The paper also shows how these results were further used to develop a VIT string design program, which calculated stresses and safety factors in function of VIT geometry and loading conditions.

The conclusions of this paper include recommendations for VIT design and performance verification. Following these recommendations should result in higher reliability and more cost effective wells in completion programs utilizing VIT for deepwater applications.
Development and Field Results of a Unique Drilling Fluid Designed for Heavy Oil Sands Drilling
Authors: Warren B. K. , Baltoiu L. V. , Dyck R. G.
Published: December 2007

Drilling Heavy Oil Sands are traditionally fraught with many technical challenges. Stability of the wellbore, accretion of the tar on drill string and solids control equipment, torque-drag considerations, extreme temperature conditions, as well as the handling of oily solids are just some of the challenges that need to be met.

This paper describes the development and testing of a new drilling fluid designed to meet these challenges. The water-based fluid is based upon two guiding principles, the ability to incorporate the bitumen into the mud itself, and the capability of the system to later break the bitumen from the mud system. Incorporation of the bitumen into the mud is via a direct emulsification and results in zero accretion, virtually oil-free sand from the solids control equipment, fast drilling rates and good hole stability. The post drilling breaker allows for the oil/bitumen/tar to be skimmed from the surface of the drilling fluid allowing for conventional disposal of the liquid fraction.

Data from a six well horizontal heavy oil program in Northeastern Alberta shows the robustness and effectiveness of the system. The new oil in water direct emulsion system drilled 1100 meter average horizontal wells 35% faster, when compared to conventional inhibition salt technology based drilling fluids. Highlights include sand from centrifuging operation containing < 0.5% oil, elimination of accretion and common foaming problems, fluid reuse from well-to-well, as well as simple land disposal of liquid mud wastes. Total well costs, drilling fluids costs and disposal costs were significantly less than those wells drilled with conventionally inhibited drilling fluid systems.
Intelligent Drill String Field Trials Demonstrate Technology Functionality
Authors: Reeves Michael E. , Payne Michael L. , Ismayilov Anar G. , Jellison Michael J.
Published: December 2007

Intelligent drill string components capable of transmitting data at rates up to 2-megabits per second have been developed and successfully tested in commercial drilling applications.

This paper details the lessons learned during intelligent drill string field trials, with focus on the overall network performance during drilling operations, physical handling ease and integration of existing down-hole measurement tools into the network.

This is the first publication of information from such field trials, and the first discussion of down-hole tool data transmission through the intelligent drill string network.

The paper includes discussion regarding the potential impact of intelligent drill string technology on the drilling and completion process.

This new technology can improve well productivity, reduce drilling time/costs and enhance well control safety. The paper addresses these issues and provides a forward-looking view regarding large-scale introduction of the system and the anticipated time-line for commercial availability.

The intelligent drill string system incorporates a high-speed data cable protected in a high-pressure conduit that runs the length of each joint. The cable terminates at inductive coils that are installed in grooves machined in the secondary torque shoulders of double-shoulder connections at each end of the joints.

The system's design supports high-speed, high-volume, bi-directional data transmission to and from hundreds of discrete measurement nodes. As a result the system offers an opportunity to capture critical data along the full length of a drill string, not just at the bit, in addition to supporting the use of high-resolution LWD tools and providing instantaneous control of down-hole mechanical devices. The system offers robust, reliable operation and is virtually transparent to standard rig procedures.
Operational Aspects of Formation Pressure Measurements While Drilling
Authors: Pop Julian , Laastad Harald , Eriksen Kåre Otto , O'Keefe Michael , Follini Jean-Marc , Dahle Tone
Published: December 2007

The emergence of formation pressure measurements in the Logging-While-Drilling (LWD) market has highlighted the challenge of analyzing and interpreting the pressures acquired. The dynamic condition of the borehole and the freshly built mudcake add new variables to the problem and contribute in making the measurement more complex to interpret compared with measurements made by conventional wireline-conveyed methods.

This paper presents several formation-pressure-while-drilling case studies conducted in the North Sea. Formation pressure measurements were repeatedly performed under different well conditions and at different times after the bit penetrated the formation. The impact on the measurement of various parameters is analyzed, most notably, the time after drilling and changes in the measurement sequence.

The results obtained with the formation pressure while drilling tool are compared to measurements performed with conventional wireline formation testers (WFTs) conducted at the same depths and at various times after drilling. Analysis of formation cores taken in the same intervals as the pressure tests were performed allows a better understanding of the while drilling-derived mobility measurements. Suggestions are made on how to improve the quality and accuracy of the measurements.
Reservoir-Geomechanics Coupled Simulations: A Powerful Tool for Well Design and Operation in an HP-HT Environment
Authors: Marchina P. , Onaisi A.
Published: December 2007

The unusual stress and depletion levels encountered in HP-HT fields make engineering wells in such an environment a technical challenge. The major reason for this is that all the aspects of the well's life, from well design and completion issues to operating philosophy, are significantly impacted by the mechanical behaviour of the reservoir. It is therefore important to be able to assess with accuracy the evolution with depletion of the in-situ stresses and rock deformations across the entire field, in order to optimise the design of the development wells. In that context, the use of reservoir-geomechanics coupled simulations becomes a corner stone to the well engineering philosophy.

In this paper, numerous well design issues will be presented that could be successfully addressed thanks to a reliable prediction of the state of stress throughout the depletion history of the reservoir. They include basic mud weight window (MWW) calculations, the optimisation of well trajectories across faults, the risk of casing failure and most importantly the determination of the allowable time window for drilling wells. The benefits of the availability of the results of the coupled simulations for other aspects of the field development having a strong impact on the development strategy and planning, such as sanding risk assessment, will also be briefly discussed.
Eliminating the Need for Manriding Operations in Drilling Operations
Authors: Cadigan Mike , Croft Sam , Dalgarno Kevin , Korver Johan
Published: December 2007

Manriding operations, hoisting personnel above or below the rig floor with a winch to perform rig maintenance, are considered a part of normal routine operations by many companies in the drilling industry. However, Noble Corporation believes that this practice is inherently high risk and has focused significant efforts on eliminating the need for manriding in its operations and hoisting personnel only when no other safe alternative exists.

This paper discusses the creative techniques that Noble has employed to avoid manriding operations in select locations, as well as its worldwide efforts to improve the safety of manriding when it is unavoidable. These efforts include standardizing worldwide on dedicated manriding winches and developing strict policies and procedures for use of the winches. The paper also describes the techniques that Noble Corporation's European Division has employed to reduce the need for manriding in select locations and provides statistics on the success of these operations to date. Some of these practices include:

Installing access platforms to eliminate the need for manriding above the rig floor. Relocating remote equipment to areas that provide access through existing platforms and walkways. Installing special scaffolds and platforms to eliminate the need for manriding around blowout preventers.

Because of the dramatic results of these operations, and the reduction in both the number and duration of manriding lifts, Noble Corporation is implementing these practices throughout its entire fleet, further reinforcing its core safety values.
Unique ROP Predictor Using Bit-specific Coefficient of Sliding Friction and Mechanical Efficiency as a Function of Confined Compressive Strength Impacts Drilling Performance
Authors: Caicedo Hector U. , Calhoun William M. , Ewy Russ T.
Published: December 2007

It has become standard practice to plan wells and analyze bit performance by using log-based rock strength analysis and/or the specific energy theory. The most widely used characterization of rock strength is unconfined compressive strength (UCS), but this is somewhat problematic because the apparent strength of the rock to the bit is typically different than UCS. Those who understand bit performance are aware of this problem, but to date there is not an industry standard or widely used methodology to address it. The specific energy theory has been used for bit performance assessment for years. One of the challenges of application of the specific energy theory, however, is uncertainty or lack of consistency in reasonable values for the input variables.

Globally applicable solutions and methods to address these problems have been developed and implemented by ChevronTexaco. A new method to calculate rock confined compressive strength (CCS), based on both conventional and somewhat innovative rock mechanics principles, has been developed. A new method to determine input variables for bit performance prediction based on the specific energy theory and CCS has been developed. These have been integrated to provide new capability for rapid and accurate log-based determination of the expected or achievable rate of penetration and operating parameters for all bit types. The new models have proved valuable, improving drilling performance and reducing well cost by improving bit performance prediction, bit selection, and the determination of optimum drilling parameters. The methods are robust, based on fundamental and/or first principles, and require little or no calibration. Any required calibration is intuitive and simple. This document presents background, theory, research results, new methodolo gies, and field and lab data that validate and illustrate the methods.
Advanced Safety Leadership, A Safety Course Designed Specifically for Well Site Leaders
Authors: Werngren O. , Stewart D. , Staley B. , West P. , Sawaryn S. J.
Published: December 2007

During discussions prompted by their contractors, Shell and BP well engineering managers agreed that to further improve performance, safety had to become personal. Early in 2003 the companies established a joint working group to develop common expectations of Safety Leaders involved in Well Engineering activities. The group comprised Drilling, Well Services and HSE representatives from BP, Shell and the key contractors supported by an independent safety consultant.

Over the course of several months the safety leadership expectations were condensed to straightforward and achievable standards of personal safety behaviour and communication skills. These built on the industry STEP change "Leading for Safety" guidelines and were used to develop a two day workshop where participants explore what it takes to be a safety leader. The program was titled Advanced Safety Leadership (ASL) and has been in place since December 2003. To date over 1100 of the Shell/BP Well Engineering community have participated.

The ASL programme builds on the fundamentals of good leadership by exploring safety leadership requirements in a personal way. Training aspects are highly interactive. Through team leader participation, personal action plans and follow-up coaching it provides long term sustainability in creating an environment in which unsafe acts are challenged and safe behaviours are promoted – a workplace without harm.

Feedback from both staff and contractors attending the course has been very positive. Initial metrics suggest the course is strongly influencing behaviours, helping to reduce incident rates. In parallel, BP and Shell are also sponsoring a PhD project at Aberdeen University to help assess and improve the effectiveness of the course.

This paper describes why such a course is needed and summarises its contents and delivery. The paper will be of interest to all managers and supervisors in companies or businesses wishing to build a belief based safety environment.
Using Proven Milling Technologies and New Methodologies to Create Simple Level 4 Multilateral Wells
Authors: Pasicznyk Adam , Redlinger Thomas , Saras Ivan Jesus , Martin Renaldo , Bruzual Guillermo , Nessier Daniel
Published: December 2007

Traditional Level 4 multilateral technology has focused on high-end applications with the intent of creating a foundation for conversion to Level 5 functionality. The Level 4 junctions are typically evaluated on three core capabilities: connectivity, isolation, and accessibility. As the evaluation criteria focuses on junction performance, little attention has been spent on reducing installation risks, junction hardware, and complexity. Recently, the effort to re-invent the Level 4 multilateral junction as a simple, low cost, low risk installation has been initiated. This new, back-to-basics approach to constructing a cemented junction has been developed by reverting to proven milling & completion techniques.

This paper will introduce this new method for installing a Level 4 junction by detailing the lessons learned from a Venezuelan field trial. The paper will show how standard milling and completion techniques can be used innovatively and reliably to create simple multilateral junctions. In addition, it will explore the extensive testing and simulations needed to ensure consistent mainbore access creation while emphasizing installation simplicity. Lastly, the field trial will be compared to other Level 4 installations in the region.
Solid Expandable Tubular Technology: The Value of Planned Installation Vs. Contingency
Authors: Carstens Chris , Blasingame Kate
Published: December 2007

Narrow pore pressure/fracture gradient windows often necessitate additional casing strings to reach deeper objective depths. Operators are constrained by the number of strings of conventional casing that they can run through subsea or surface wellhead equipment. Planning solid expandable tubulars into the well design allows the operator to run additional casing strings and drill to deeper objectives.

Using a solid expandable tubular system in the upper sections of the well design preserves hole size from the onset and allows more casing strings to be run without having to push casing points to the frac-gradient limit. Preserving hole size contributes to drilling efficiency, reduces equivalent circulation density (ECD), and minimizes risk associated with small hole size in deeper sections of the wellbore.

Another application for solid expandable tubulars is with surface stack technology. Early surface stack systems were designed around a subsea stack blowout preventer (BOP) system placed on top of a 13-3/8 in. drilling riser. After setting the 13-3/8 in. riser, only one or two casing strings could be run through the riser, which precluded reaching deeper geologic objectives.

This paper will look at two case histories. The first case history compares two deepwater offset wells in Mississippi Canyon. One well used expandable casing as a contingency, and the other well incorporated the casing as part of the base design. The second case history will evaluate a well where solid expandable tubular technology allowed up to three additional casing strings to be run in a surface stack application. This paper discusses how combining solid expandable tubular technology with surface stack technology has pushed the technical limits of surface stack drilling into deeper water and deeper formations.
Modeling Ultra-Deepwater Blowouts and Dynamic Kills and the Resulting Blowout Control Best Practices Recommendations
Authors: Noynaert Samuel F. , Schubert Jerome J.
Published: December 2007

In response to the drilling industry breaching new frontiers, specifically ultra-deep waters (5,000 ft or more of water depth), new blowout control measures are necessary. This paper outlines a study into the control of ultra-deepwater blowouts using the dynamic kill technique.1

The study was conducted using a newly developed dynamic kill simulator, COMASim, to model blowout initial conditions and blowout control in simple wellbore geometries. The simulator was validated theoretically through textbook examples.1

The simulation runs first entailed initial condition analyses of the various blowout conditions for an array of wild well conditions. Next, the simulator was used to determine the dynamic kill requirements to control these blowouts based on a range of relief well parameters.1

The results showed that ultra-deep waters definitely have an effect on the blowing conditions due to the increased hydrostatic pressure of the water. Initial conditions were also significantly affected by the length of openhole section.1

The dynamic kill requirements were adversely affected as the projected relief wells became longer. In addition to relief well parameters and blowout flowrate, the dynamic kill requirements were also related to the wild wellbore drillstring status.1

This study has highlighted several key trends and interesting future research topics in the area of ultra-deepwater blowouts and control of these blowouts.1
Urban Operations: Drilling and Completing a Gas Well on a Downtown University Campus
Authors: Spady D. W. , Poole J. Michael
Published: December 2007

It started as a simple concept: donate to the local university a wellbore, through which they can produce their own gas to offset rising utility bills. The final result - a successful well which required a tenuous journey through geological identification, regulatory hurdles, resident opposition, logistical restrictions, location stability concerns, drilling surprises and reclamation procedures. The process brought together a regional independent gas producer and six of its major vendor partners, each donating their portion to a project that earned strong community support. This paper will journal the steps of the process, as well as outlining a template for future projects in sensitive environments.
Compaction Considerations for the Gulf of Mexico Deepwater King West Field Completion Design
Authors: Li Xu , Tinker Steven J. , Bruno Mike , Willson Stephen M.
Published: December 2007

This paper summarizes reservoir compaction and long-term well integrity studies conducted for the deepwater Gulf of Mexico King West Field. These studies were undertaken to: ensure a robust completion design to withstand the compaction load throughout the economic life of the well; andprovide one of the key inputs, i.e. the mechanical well life, for the optimization of the overall reserves recovery strategy for the field.

A large part of the work presented follows an established work flow for assessing compaction, subsidence and long term well integrity1. In addition, a numerical model was built to simulate a 600ft long section of formation, casing, and completion. The purpose of this simulation model was to further address the following concerns: How does differential depletion between the reservoir sand and inter-bedded shale impact the casing and completion?Is the telescoping joint effective in relieving the compaction strain in the completion throughout the well life?What steel-strength rating is needed for the screen and base pipe materials?

The study results indicated the King West production well has a moderate to low risk of compaction related completion integrity problems because of the moderate (2600 psi) depletion and relatively homogeneous pay intervals. By using a telescoping joint and a high crushing resistance screen design, 13Cr-95 base pipe was deemed sufficient to maintain the integrity of the completion throughout the economical well life of this well. The high strength corrosion resistant alloy (CRA-125) was not necessary. This prevented the unnecessary spending on high cost CRA base pipe with an incremental cost of about $50,000 for this well.

The study provided a technical basis for completion engineers to make informed decisions in terms of mitigating compaction risk, while at the same time avoiding unnecessary over-design conservatism. It also provided valuable input for assessing the overall economics of the field, in addition to well operation and intervention strategies.
Factor Identifies Hydrocarbon Recoverability and Type
Authors: Hamada G. M.
Published: December 2007

Resistivity data is normally used to evaluate water saturation using porosity values from porosity logs (neutron and density). Determination of initial oil (gas) in place is based on hydrocarbon saturation, porosity and thickness obtained from openhole logging data for a given drainage area. It is important not only to determine the initial hydrocarbon in place, but also to define the existing hydrocarbon moveability, indicating the recoverable hydrocarbon and its type.

This paper presents a new approach of hydrocarbon moveability factor (HCM). This factor is derived from shallow and deep resistivity data. The relation F = a/?m is correct in water saturated zones, in partially saturated zones this relation becomes invalid and it will give the apparent formation resistivity factor (Fa). Based on this idea the hydrocarbon moveability factor (HCM) has been derived. With scale goes from 0.0 to 1.0. It is found that for HCM less than 0.75, hydrocarbon is moveable and for HCM greater than 0.75, the hydrocarbon is immoveable. When HCM is less than 0.25, the moveable hydrocarbon is gas and for HCM greater than 0.25 and less than 0.75, the moveable hydrocarbon is oil. Field examples have been analyzed with the HCM factor. These field examples demonstrated the contribution of HCM in the field of hydrocarbon type identification and determination of hydrocarbon moveability from openhole resistivity logging.
Effect of Water Cut on Sand Production – An Experimental Study
Authors: Wu B. , Tan C. P. , Lu N.
Published: December 2007

It has been commonly acknowledged in the petroleum industry that water-cut increases sand production risk. A number of possible mechanisms have been proposed. This paper presents the results of a series of laboratory perforation collapse tests aimed at demonstrating and quantifying the water-cut effect on perforation failure and sand production.

The laboratory perforation collapse tests were conducted on weak sandstones obtained from both downhole and outcrop. The tests were performed under simulated in-situ effective stresses and drawdown conditions. Water was introduced into the flowing stream of either oil or gas at various stages of the tests to simulate water-cut. The failure and sand production processes were observed and recorded using a borescope in real time.

The results showed that the effect of water-cut on perforation strength and sand production depends on the mineralogical composition of the sandstone and the degree of residual water saturation. The effect is most significant for sandstones with high clay content and low residual water saturation and less significant for clean sandtones or those with high residual water saturation. The experimental results are discussed based on the chemical interaction between water and rocks, capillary stress and relative permeability. It is concluded that water saturation-induced rock strength reduction is the most significant factor governing peroforation failure and sand production. Although, perforation failure is a pre-requisite for sand production, the failure does not always lead to sand production.
Running of 13%Cr OCTG with dope-free premium threaded connections
Authors: Roberts Alun , Leech Andrew
Published: December 2007

Experiences of dope-free OCTG (Oil Country Tubular Goods) connections to date have been limited to carbon or low alloy steel threads1. However the higher galling tendencies inherent in stainless steel threads create a different challenge to their successful dope-free running. This study describes the successful development of a dope-free system for 13Cr and corrosion resistant alloy (CRA) connections from the initial development trials of a superior surface treatment system through to the deployment of a dope-free 13Cr offshore production string.
Coiled-Tubing Reverse Circulation - An Efficient Method of Cleaning Horizontal Wells in a Mature, Pressure-Depleted Field
Authors: Kumar P. S. , Al-Amri B. , Kouli P. , Van Gisbergen S. , Shidi S. , Ferdiansyah E. , Mowat P.
Published: December 2007

Several methods of cleaning deviated and horizontal wells have been developed over the years. One of the most common methods is running in with coiled tubing and circulating the solids out with a liquid or multiphase fluid. Solids tend to settle at the bottom or low side of the wellbore in highly deviated or horizontal wells. This makes the cleanout process inefficient in bringing the solids to the surface. In this field, most of wells are horizontal. One of matured fields in the northern directorate of Petroleum Development Oman manily produces from horizontal wells. The produced water is injected back into the reservoir. Scale is found in injectors and producers. The acid insoluble materials in these scales vary from 4% to 22%. Hence, cleanout of the horizontal hole is required in this field to keep the wells producing/injecting at their potentials. Various methods of cleaning like coiled tubing cleanout and reverse circulation through workstring during hoist/rig operations were tried in cleaning the horizontal wells. However, they were not successful in cleaning the horizontal hole. One of the main reasons is the loss of kill/completion fluid into the formation during well operations. In order to establish an effective cleaning method in this environment, it was decided to experiment the coiled tubing reverse circulation process in cleaning horizontal openhole injectors so that the same process could be extended for cleaning out horizontal producers.

This paper presents the results of coiled tubing reverse circulation trials carried out in three horizontal openhole injectors. The cleanout method was a combination of venturi junk basket and reverse circulation, with an initial venturi run being made to identify the top of fill and to remove the larger fill particles, followed by reverse circulation to remove the smaller particle out of the wellbore. Post cleanout injection rates increased on an average of 15% over the pre cleanout rates. Further to evaluate the effectiveness of this method, spinner runs were made along the horizontal openhole section before and after the cleanout jobs. The results revealed that injection was more uniform along the horizontal openhole section after the reverse circulation when compared to the few points of injection before the cleanout. Implementation of this reverse circulation process is now planned for producers in which it is not possible to remove acid insoluble materials by normal cleanout methods.
Identifying, Characterizing, and Locating Conductive Fault(s): Multiwell Test Analysis Approach
Authors: Al-Obaid R. , Al-Thawad F. M. , Gill H. S.
Published: December 2007

This paper presents a successful multi-well test analysis approach to identify and locate the geological feature(s) responsible for inter-reservoir communication between Lower and Upper reservoirs in ABQQ field. The study resulted in locating and identifying the nature of conduit(s) responsible for the direct communication between Lower and Upper reservoirs. Conductive fault(s) is/are observed repeatedly by five offset wells and clearly running between the two reservoirs. The location of the fault/faulted zone was predicted via an integrated approach including analyzing all the wells in the vicinity of the area under study and reviewing the drilling, logging and production data.

An interference test was conducted after producing Lower injected water from Upper reservoir. The test indicated a direct communication through five hundred feet of nonreservoir formation between the two reservoirs.

Many hydrocarbon bearing reservoirs are faulted, yet little information is available about the actual physical characteristics of the faults. Loss circulation while drilling horizontal wells, along with production logs provided tangible evidence of existing conductive faults. Drilling horizontal wells also indicated the existence of sub-seismic faults which cannot be detected by the 3D seismic resolution.

Better reservoir management decisions and more focused development strategies can be achieved through the utilization of the quantitative pressure transient analysis of those tests.
Krylov-Secant Methods for Accelerating the Solution of Fully Implicit Formulations
Authors: Klie H. , Wheeler M. F.
Published: December 2007

The present work is devoted to accelerate the nonlinear convergence of Newton-Krylov methods for solving fully implicit formulation in multiphase flow. The basic approach is to perform secant (Broyden) updates restricted to the Krylov subspace generated by the GMRES iterative solver. This approach is introduced as Krylov-secant methods. One of the most attractive features of these methods is to perform a sequence of rank-one updates without explicitly recalling the computation or action of the Jacobian matrix. Implications of these updates in line-search globalization strategies, computation of dynamic tolerances (forcing terms) and in the use of preconditioning strategies are presented. Numerical results show significant improvements over traditional implementations especially in those cases where nonlinearities increase due to stringent pressure and saturation changes.
Abrasive Cutting Technology Deployed Via Coiled Tubing
Authors: Loving S. W. , Ferguson A. , Hart R.
Published: December 2007

This paper will discuss the development of abrasive cutting technology deployed via coiled tubing for cutting production tubing, drill pipe, drill collars, exotic stainless steel completion components, single strings of casing and multiple strings of casing. This technology is performed utilizing a sealed bearing, positive displacement motor and a cutting head along with conventional coiled tubing tools and conventional coiled tubing. This technology gives operators an additional tool when severing of the drill string or production tubing is required.

Additionally the paper will discuss perforating tubing and casing using abrasives, particularly in horizontal wells where conventional wire-line operations are not possible.

The paper will discuss: Utilizing a positive displacement motor to perform abrasive cuts via coiled tubing,Design and testing phases of the abrasive cutting system,Initial field runs to prove the viability of this technology,Total jobs completed to date,Lessons learned throughout the process,Where this technology leads from here.

The paper will also discuss future applications for this technology which include cutting casing for plug and abandonment programs, permanent packer retrieval, and abrasive perforating all deployed via coiled tubing.
OPEC: Floating Supply for a Balanced & Stable Market
Authors: Talabani S.
Published: December 2007

OPEC was formed as a joint action between five countries in 1960 in Baghdad to set a fair price for crude oil in the world market.Today, eleven members account for 40% of world oil production and 65-70% of proven oil reserves.

OPEC members regularly discuss oil prices and set crude oil production quotas. OPEC revenue has grown over the last year, but instability in revenue has been repeatedly related to geopolitical crises, instability in one or more OPEC member states, or lower world demand.OPEC pricing is set based on an arithmetic average of a basket of seven crude types; in practice, this is unhealthy for the crude price and always fails to follow the market.Furthermore, there is one trillion barrels of crude worldwide awaiting cost effective technology to make it ready for production.This would possibly results in better price stability in the crude oil market.

OPEC price, based on basket trading, was set for 10 -20 days as $22.0 - 28.0 for adjustment.This has not been forced in the market since it was accounted.

Until the European Union created a unified currency, the US dollar has been (and still is) the dominant currency since 1945 and handles over 70% of world official exchange reserves.

Will this state of affairs change? Will the oil (and possibly gas) price become stable whilst subject to rules other than that of supply and demand? Can the Euro replace the Dollar in the trading of crude oil?Would it be better for OPEC members to base production quotas on regulations other than those currently used?

Most forecasts of prices and quotas face difficulties in finding rules to follow. This paper discusses ways and means for better crude market stability.