bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deepwater Drillship Operations and Upgrade
Authors: De Bonnafos O. , Zijderveld G. H. 
Published: December 2007

Abstract
Since 1999 the two drillships Pride Africa and Pride Angola have been operating in Angolan offshore waters. From their initial startup both vessels have been deployed in a deepwater field development role and operated under long term contracts.
This paper describes the operational experience since the start up of both vessels within their field development role; the successes and the shortcomings resulting in lessons learned which formed the base of a project plan to further enhance the operability of the vessels.
Late in 2004 and early in 2005 both vessels were docked in Cape Town for the 5 yearly special survey and maintenance upgrades. Works were executed which reflected additional requirements requested by the operator as well as upgrades planned by the drilling contractor.
The paper will address the following key elements in operating and upgrading these deepwater vessels successfully (1) Implementing of the lessons learned with respect to the originally installed systems on both units, both from a marine and operational perspective, and improvements made based upon these experiences; (2) the development of a project execution plan indicating key elements for upgrade; (3) the preparation of the docking of both vessels, specifically with respect to timing, logistics and the docking itself; (4) the actual execution of the docking with the lessons learned; (5) the subsequent operational and maintenance experience as a result of the upgrade process of both vessels.
Principle of a New Flow-Unit Auto-Subdividing Method and Its Application in DaQing Oilfield
Authors: Zhang Fuming , Shao Cairui , Li Hongqi , Jiao Cuihua , Liu Hongtao , Li Yuanjiang 
Published: December 2007

Abstract
This paper discusses the method on how to subdivide the reservoir into zones based on flow-units. Based on the thought of "inner homogeneity" in flow-unit, a new and reasonable auto-subdividing method named "slicing-merging" was proposed in this paper. And the main characteristic parameters used by this method, such as FZI (Flow zone indicator) and RQI (Reservoir quality index), were obtained based on core-analysis and well-logging data. This technology can be used to subdivide the reservoir into flow-units and identify the type of flow-units simultaneously. This paper analyzed the rationality and petroleum geological meanings. Its application was shown by some examples from DaQing Oilfield.
Wellbore Stress Indicators while Drilling: A Comparison of Induced Features from Wireline and LWD High-Resolution Electrical Images
Authors: Lindsay G. , Ong S. , Morris S. , Lofts J. 
Published: December 2007

Abstract
Wellbore stability analysis utilising wireline borehole images is well established. Today high resolution while drilling (LWD) images are available and they offer information in real time as well as the opportunity to acquire time-lapse information through re-logging while tripping. This paper discusses the usefulness of applying LWD image logs versus wireline image logs for determining wellbore stress through actual well examples. We discuss some benefits to early data acquisition as well as benefits due to technology.
We observe that the comparison of post-drilling images with detailed wellbore images acquired at time of drilling indicates that different features can be observed. These differences relate to the dynamic drilling environment and changes in the wellbore surface with time. In one example, both break-out and tension induced fractures are observed together, indicating an instability not predicted by traditional pore pressure models or seen in post-drilling wireline logs.
Today's drilling practices are continually pushing well design boundaries, for example in the areas of extended reach drilling, high pressure and geometrically complex well design. These scenarios require increasingly sophisticated wellbore stability management. With the real-time information within while-drilling high resolution images, a method is proposed for real-time incorporation in to well bore stability management that will reduce risks in these challenging well conditions.
Improved Well Construction Enabled by Next-Generation Top-Drive Casing Running and Drilling Tools
Authors: Abrahamsen Egill , Reid Doug 
Published: December 2007

Abstract
This paper discusses casing installation methods with a new generation top drive casing running system versus conventional and mechanized casing running methods. The enabling technology provides opportunities for change in conventional well construction methods by using the option to rotate casing strings at high speed, instantly circulate and reciprocate when required, and even push down the rotating casing into the well. The paper highlights how this technology, when combined with drilling with casing tools and expertise, can significantly reduce well construction costs, thereby providing earlier production at less risk.
Applications include: drilling with casing from rigs with top drives; casing installation in predrilled wells; risk mitigation for casing installation in extended reach, deviated, and troublesome wells; removing flat spots in the well construction curve through methods such as "hole cleaning with casing," drilling and reaming with casing, and more.
Results, Observations, and Conclusions:
The top drive casing running system enables improved safety through simpler and less personnel intensive operations, by combining several conventional casing tools into one system: Power tong, main hoisting elevator, single joint elevator, fill-up and circulation tool, weight compensator and, casing stabbing.
Lab and field test results have proven that the new technology provides greater casing running efficiency, increased safety through personnel reduction and remote operation, and drilling with casing capabilities.
Significance of Subject Matter:
Step change in technology allowing oil & gas operators to increase drilling performance, improve safety, and reduce well construction costs.
Recent Metal-to-Metal Sealing Technology for Zonal Isolation Applications Demonstrates Potential for Use in Hostile HP/HT Environments
Authors: Garfield Garry , Mackenzie Gordon 
Published: December 2007

Abstract
Zonal isolation tools, including bridge plugs and straddle systems, using metal-to-metal sealing technology in place of conventional elastomers may radically challenge existing engineering philosophies by providing a pressure sealing system capable of exceeding the limitations of other existing sealing technologies and eliminating many traditional failure modes. Metal-to-metal sealing technology is an innovative type of high expansion seal that uses expanding metal to form a high integrity pressure seal and incorporates an extraordinary seal performance envelope that cannot be achieved by conventional elastomeric seals. The seal design utilizes the controlled application of load to expand the metal seal to achieve a fully formed pressure barrier which allows for the metal-to-metal seal in bores of up to 160% of the original seal diameter.
The metal-to-metal seal has the potential to change the way downhole equipment provides pressure integrity in HPHT environments. In the well servicing market, recent applications of the metal-to-metal seal and the latest lab testing have suggested the prospective of the technology for products in the HPHT arena. Metal-to-metal sealing technology could make well suspensions and intervention possible in hostile HPHT wells that were previously deemed inoperable by the complete removal of elastomers from the design. Ideal for HP/HT applications, metal-to-metal sealing devices can be easily deployed on slickline, electric wireline, coiled tubing, or drill pipe to save operator rig time in areas where cost savings are critical.
Case studies of the high performance characteristics of the metal-to-metal sealing technology in terms of design, testing, and implementation will recognize the alignment to the increased demands of HP/HT applications.
First Gas Field Developed Using Exclusively Dope-Free Casing and Tubing Connections—Statoil Snøhvit
Authors: Carcagno Gabriel , Castiñeiras Tomás , Eiane Dag Johan 
Published: December 2007

Abstract
The recent development of dope-free solutions for tubing and casing premium connections provides a real and proved alternative to traditional thread compounds like the well known API Modified thread compound(1), and the proprietary environmentally-friendly thread compounds. Among other advantages, the selected dope-free solution allows to solve the legal limitations to operate with standard compounds in very environmentally-sensitive areas as the Barents Sea, while providing a performance that fulfill nowadays requirements for tubing and casing applications, for different materials as C-steels, 13Cr and Corrosion Resistance Alloys. This paper describes the main concept and features of Dopeless™, a fully dry dope-free solution developed through extensive testing and laboratory evaluation, and the first 100% extensive field application of this solution in the Sn0vhit field of Statoil in the Barents Sea. In such field, all the tubing and casing strings were ran with dope-free proprietary premium connections, becoming the first field worldwide in adopting this technology for all the tubing and casing strings. The challenges of a new technology application in a very demanding initial experience were managed through a good communication and cooperation between the Dope-free connection manufacturer's development team and the operator technical team, which allowed to understand and to manage the features and challenges of not only a new product but a real new technology. As result of the experience, 40 tubing and casing strings of dope-free premium connections from 7" to 14" were run, using a floating rig equipped with automatic handling, with very acceptable results in terms of running performance, and without any particular event related to this. The results obtained, as well as the lessons-learnt and possible improvements are analyzed and discussed.
Recovery of a Damaged Jackup Following Hurricane Rita
Authors: Stonor R.W. P. , Hoyle M.J. R. , Brekke J. N. , Keaton C. 
Published: December 2007

Abstract
The paper describes the analyses and procedures used to recover a jack-up which had been hit by Hurricane Rita and though still standing took on a tilt of three degrees and suffered some leg damage. Initial recovery attempts resulted in further leg damage at which stage it was decided to apply temporary leg strengthening and undertake a more detailed evaluation and analysis of the best methods of recovering the unit. The strength of the soils was found to be providing restraint which helped to support the tilted configuration but was also having the effect of resisting the leveling of the unit and thereby causing further leg damage. The analysis identified the need for a hold-back force during the recovery procedure to prevent further bracing damage in the legs and avoid a complete collapse mechanism developing. A suitable barge pull-back system was developed and in December the operation to recover the unit took place successfully.
Application of Small Vibration Logging Tool Yields Improved Dynamic Drilling Performance
Authors: Perez Daniel , Lockley Russ , Clarke Alan J. , Hanley Chris M. 
Published: December 2007

Abstract
The oil industry is increasingly interested in drilling dynamics as a primary cause of drilling inefficiency. It has become ever more important to be able to both accurately predict and detect downhole vibration/instability throughout the entire drill string. The drill bit is often assigned as the cause, and frequently bears the scars of dynamic drilling problems. Historically bit manufacturers have used a combination of dull grades and surface data to speculate on cause and effect of downhole events with insufficient attention to what may be occurring in between.
A small vibration logging tool has been employed in hundreds of applications worldwide. This paper discusses the implementation of this device and its flexibility for placement of multiple tools in various locations, such as specific built subs and/or existing tools, within the drillstring. The versatility of this tool design offers the possibility to be run with any type of bit, fixed cutter or roller cone, regardless of manufacturer thus making it transparent to drilling operations throughout the entire drilling assembly.
Specific field cases will be presented including; validation of pre-run dynamics modeling software, rotary steerable tools, concentric and eccentric hole opening tools, and response of different BHA configurations. This type of data is important to further the understanding of drill bit, drillstring component, and overall drillstring dynamic performance.
Integrating Safety Leadership and Cultural Change
Authors: Siokos George , Karish John 
Published: December 2007

Abstract
Getting to a position of an incident free workplace requires a multi-faceted approach that involves investment in ensuring the integrity of equipment, systems and people's behaviour.
Consistent leadership that embraces the need to address the above is a pre requisite for success. Moreover, a consistent leadership philosophy, supported by a clear vision and values for success is also required.
Experience suggests that most people in leadership positions want to do the right thing in relation to achieving a safe workplace. Perhaps the real issue is not ‘how’ to make this happen.
This paper focuses on the work done by ENSCO International, Inc., a major international offshore drilling contractor, to enhance its culture through a Corporate Safety, Health & Environmental (SHE) Leadership Development Program and strategy designed to develop leaders who are able and willing to make a difference in safety.
What makes this work different?
Firstly, the Program and strategy integrates prescribed leadership competencies aligned with the organization's vision, values, strategies and safety management system.
Secondly, it involves the top 150 operations leaders in the organization, as a way of giving depth and spread of the safety culture it wants to create.
Thirdly, there is focused follow up to assist leaders put into place changes required for effective safety outcomes.
Fourthly, the leadership strategy is linked to other local business unit safety leadership programs to ensure alignment and synergy.
Fifthly, the SHE Leadership Development Program challenges participants with personal feedback on their SHE leadership competencies and behaviors and encourages the development of a personal leadership development action plan that supports the safety culture demanded by the organization.
This strategy has already delivered observable and valued results.
A Literature Review on Smart-Well Technology
Authors: Gao Changhong , Rajeswaran T. , Nakagawa Edson 
Published: December 2007

Abstract
Smart well technology is one of the most significant breakthroughs in production technologies during recent years. It enables operators to actively monitor, remotely choke or shut selected zones with poor performance without intervention. During early stages of development, electrical control systems and electronic sensors were applied. However, the service companies abandoned these earlier systems due to their poor reliability. Recently, innovation in fiber optic sensors and hydraulic control systems has significantly improved the reliability, and the market adoption of this new technology is accelerating. This paper describes the typical components of smart well systems from the major service providers. Several typical field applications are reviewed, including cases in North Sea, offshore England, and offshore Brunei.
Sensitivity Study on the Main Factors Affecting a Polymeric RPM Treatment in the Near-Wellbore Region of a Mature Oil-Producing Well
Authors: Vazquez O. , Singleton M. , Sorbie K. S. , Weare R. 
Published: December 2007

Abstract
This paper describes a sensitivity study on the main factors affecting a polymeric Relative Permeability Modifier (RPM) treatment in the near wellbore region of a mature oil producing well. The study is divided into several parts where various factors, which affect the application of RPM technology in a chosen field base case well, are studied. These factors include the effects of instantaneous vs. kinetic adsorption for the treatment and the further influence of treatment properties, reservoir fluid properties and the reservoir formation. From the sensitivity study, we can conclude that the most influential factors in the treatment response, i.e. the water cut reduction, are the combination of polymer adsorption type (kinetic or equilibrium) with method of application of the resistance factors (threshold or variable), resistance factor ratio, reservoir fluid properties and reservoir layout. On the other hand, the polymer viscosifying effect is not such an influencing factor, and neither are the shear stress, salinity, hardness and pH that subsequently affect this property.
The sensitivity study was carried out using a model capable of describing RPM treatments in the near wellbore region. The model is a radial, isothermal, two-phase, multi-component and multi-layer mathematical model. The model considers the immiscible displacement of the oil and water phases along with polymer transport in the aqueous phase. The various phenomena that describe polymer flow through a porous medium are also considered and modelled. For each of the various physical phenomena (e.g. adsorption, fluid rheology, resistance factor, etc.), we must then make decisions about its behaviour, which is simulated by choosing certain models and the parameters in these models. For multi-layer systems, the model considers no vertical communication between layers, thus the pressure drop across the various layers remains equal. The model includes kinetic adsorption and the application of resistance factors based on a polymer adsorption threshold, which are not normally available in other models. The model has been verified by comparison with both analytical solutions and Eclipse 100 results and novel observations of kinetic and equilibrium adsorption in radial coordinates are described.
A Detailed Comparison of Experimental and Numerical Data on Hydraulic Fracture Height Growth Through Stress Contrasts
Authors: Jeffrey R. G. , Bunger A. P. 
Published: December 2007

Abstract
This paper compares height, length, width, and pressure data from a laboratory experiment to predictions from a planar 3D hydraulic fracture model for the case of a fracture propagating in a lower stress payzone region bounded by two symmetric higher stress barrier regions. A laboratory method that creates step-like stress changes on an interface between two transparent PMMA blocks is described. A fracture is propagated along this interface while measuring fracture geometry and full-field fracture width (opening) by analysis of the light intensity in images of the growing fracture. The fracture grew in overall height to 1.7 times the pay height and in half-length to 3 times the pay height. Results from a planar 3D numerical model match closely to the experimental data for overall fracture shape, height growth, and injection pressure. The data are presented so that other numerical models can compare with these detailed measurements.
New Experience in Water Wells Aquifer Section Drilling With Saturated Sized Salt Fluid System on Kharyaga Oilfield, Timan-Pechora Region of Russia
Authors: Bulgachev R. V. , Pouget P. 
Published: December 2007

Abstract
Drilling water wells on Kharyaga oilfield, Timan-Pechora region of Russia, often resulted into poor water production due to aquifer formation plugging with weighting materials and drilled solids and insufficient filter cake removal.
Bentonite-based drilling fluids have been traditionally used for water wells drilling in this area. Bentonite particles invasion into the unconsolidated sand water-bearing horizons is almost impossible to prevent and cure, so in most of the cases actual water production rates achieved proved to be lower than estimated ones. Also, when the wells were put on production considerable sand control related issues often occured. During the drilling phase, when passing through unconsolidated sands, borehole instability problems due to sands washout and hole sloughing have been frequently experienced.
In order to avoid considerable formation damage, borehole instability and increase water production, saturated sized salt drilling fluid system has been proposed for two water wells drilling.
Saturated sized salt drilling fluid has been formulated by water saturation with sodium chloride salt following by treatments with modified sized salt of appropriate grade and additions of alkalinity, filtration, viscosity and foaming control agents. The system showed very stable properties throughout operations with tight LPLT filtration, good thin and smooth filter cake and perfect rheological characteristics. Drilling and coring operations in sand and clay formations have been performed with no problems, neither several days of stand-by had any influence on wellbore stability. Electric logs have shown perfect in-gauge hole.
After the section has been drilled and liner with filter screens has been run to bottom, the filter cake was easily removed by displacing and circulating hole with fresh water to dissolve sized salt particles.
When the water wells were put on production, both of them have shown very good production rates in comparison with other water wells drilled in the field and in comparison with estimated production rates for these two wells also. No signs of sand/fines control related issues have been either experienced during more than two years of water production.
A New Model for Matching Fracturing Fluid Flowback Composition
Authors: Gdanski Rick , Weaver Jim , Slabaugh Billy 
Published: December 2007

Abstract
Recovery of fracturing fluid is considered a critical aspect for achieving production performance that meets the expectations of fracture treatment designs. Fluid recovery is often described simply as a percentage of load recovery on a volume basis, without consideration of the composition of the recovered water. Some of this water may in fact be formation water and not original load water at all. Analysis of the ionic composition of the water can determine whether the recovered water is formation water or treatment water. This paper describes a new model that embodies the physics of flow during back-production of a fracturing treatment and incorporates a chemistry "layer" that allows for matching fracturing fluid flowback compositions. The model accommodates formation water having a separate composition from the fracturing fluid. The movements of sodium, potassium, chloride, sulfate, carbohydrate, boron, etc. are modeled during shut-in and production. The compositions of the produced water calculated by the simulator were compared to field production samples.
The process of matching the produced water analyses after the fracturing treatment first required a good match of the produced water rates as a function of both time and the produced gas rates. Reservoir and fracture properties were optimized to match the water production. The ionic composition of the flowback water was then matched by adjusting various parameters that might affect how the water was recovered from the reservoir. The information obtained by adjusting these parameters includes relative permeability curves, capillary pressure curves, and some fracture structure details. Deviations of the model from the observed return profiles indicated areas where the understanding of fluid chemistry and physics of flow might be improved.