bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drill Pipe Cutting at Ultra High Pressure: A Proven Capability for Stuck Pipe Hazards
Authors: Segura John JW 
Published: March 2011

Abstract
From conceptual development to laboratory data this paper will describe the need, development, testing, and results of ultra-high pressure Jet Cutters and Severing Tools for use in environments up to 30ksi for today's deepwater, ultradeep well market. Designing and building of a new, first of its kind test vessel allowed for actual separation of drill string components, at bottom hole pressures, with zero tension applied.
Efficient separation of stuck drill strings with proven results is a must for deepwater wells where depths can reach 35,000 ft and daily rates often exceed USD 1,000,000. Operators want proven results instead of theoretical calculations or critical path experimentation during a stuck pipe hazard event. Historical pipe cutting or severing has been hindered by high bottom hole pressures and internal diameter restrictions for decades. Chemical cutters and Radial Cutting Torches being foremost affected by the effect of hydrostatic pressure on their method of pipe separation, while jet cutters and severing tools explosive charges could overcome more bottom hole pressure. After leaping the 20ksi hurdle we were still limited to 25ksi or less and had unproven products, until now.
Improvements in the initiation timing of explosive cutters and severing tools along with adequate quantities of components in conjunction with laboratory testing proved that jet cutting and severing drill string tubular components, including drill pipe and heavyweight drill pipe, is achievable at pressures up to 30ksi.
Substantial cost and critical path time savings for deep well and deepwater operators can be realized during stuck pipe incidents by utilizing tested technology proven to separate drill string components at bottom hole pressures up to 30ksi. Improved safety features provides for more confident field assembly with reduced risk involved.
Casing Burst Stresses in Particulate-Filled Annuli: Where's the Cement?
Authors: Kalil Issa A. , McSpadden Albert R. 
Published: March 2011

Abstract
For burst design, engineers routinely assume the casing annular space is filled by a fluid equivalent. This assumption ignores mechanical resistance provided by solid cement. Some studies addressed this shortcoming by modeling the cement sheath as a solid with elastic failure criteria. Prior work used cement elastic modulus and Poisson ratio to classify cement as ‘ductile’ (soft) or ‘brittle’ (hard).
In the current study, numerical results from finite element analysis (FEA) indicate that casing burst resistance is increased by the presence of the cement sheath. This study focuses solely on improvement offered by the cement sheath to casing burst resistance and ignores consequences of cement failure on overall well integrity.
Comparisons are provided for casing burst resistance assuming various backup profiles. These include fluid hydrostatics, solid cement matrix (both elastic and plastic response) and cement as ‘loose’ particles. The fluid hydrostatics include: a) mud weight in hole; b) cement slurry density; c) mixed-water density; d) normal pressure (salt-water column); and e) actual pore pressure. Calculations show that these fluid profiles are conservative when used as burst-resistance backup. Original cement slurry density is least conservative.
Since well designers are familiar with fluid profile backup assumptions in casing burst design, recommendations are provided to approximate cement behavior as particles with a fluid profile. This allows ease of calculation and is consistent with current practice. Guidelines are provided to explicitly calculate the enhanced casing burst resistance due to the particulate cement.
Condition Based Maintenance: A New Early Leak Detection System for Mud Pumps
Authors: Kyllingstad Age , Nessjøen Pål Jacob 
Published: March 2011

Abstract
This paper presents a new and patent applied method for detecting and localizing valve leaks in reciprocating mud pumps. The detection method is based on the observed fact that a leak flow through a closed defective valve generates strong and high frequency vibrations in the fluid module housing the valve. These vibrations are picked up by accelerometers and continuously processed and monitored by a computer. A timer signal is used for constructing phase based windows that selectively pick the acceleration signal during the valve closing phases. The vibration strength is then calculated for each valve closing phase and normalized through division by the median value. A leak alarm is triggered if one or more valves have an excessive value.
The presented system, called the Leak Detection System, was originally developed for Hex pumps having six pistons driven by a rotating asymmetric cam. Later on the method was also tested on shaft driven piston pumps, such as triplex pumps and quintuplex pumps. These tests revealed that these pumps require a modified and slightly different method to reliably detecting and localizing valve leaks. The reason is that these pumps have a much higher vibration transfer from the leak source to another valve. This is especially true for quintuplex pumps having only one integrated valve block.
The Leak Detection System basically consists of a proximity sensor, accelerometers and suitable hardware and software for reading and analyzing the sensor signals. The main advantages of the new system are 1) high sensitivity and early leak detection, 2) reliable leak localization, 3) remote diagnosis with no human exposure to the hazardous environment near running pumps, 4) easy retrofit to existing pumps.
The paper includes examples from lab and field tests where the new system has been successfully tested.
Controlling Well Path Trajectory with Rate of Penetration Modulation
Authors: Farley S. R. , Maranuk C. A. , Hronek B. J. , Jasper C. 
Published: March 2011

Abstract
The majority of footage drilled directionally is achieved by using bent-housing, positive displacement motors. This established technology uses oriented drilling intervals to maintain well trajectory. These intervals can be difficult and time consuming in many drilling environments; however, the economic advantages of this system often preclude the use of more capable rotary steerable assemblies. Operators have long needed a system that fills the widening gap between the two technologies.
A new system of wellbore directional control has been developed that uses continuous string rotation above a positive displacement motor and bent sub. Path deviation is achieved by brief variations in the rate of penetration (ROP) that occur once during each rotation of the bent sub. Bit advance is increased during each rotation causing the bit to drill faster in the targeted direction. This directed variation in ROP allows manipulation of hole trajectory while the bent housing and drillstring are continuously rotating. Steering is accomplished by managing pressure fluctuations within the drillstring, creating slight oscillations in the flow rate through the mud motor. These controlled fluctuations in flow rate allow variations in drilling parameters to steer the well in any targeted azimuth.
The goal of this system is to eliminate all oriented drilling in applications up to 3 degree per 100 feet by employing a low risk, low cost method that maximizes ROP and hole cleaning. At the Gas Technology Institute (GTI) Catoosa Test Facility in Oklahoma, drilling tests yielded successful well trajectory manipulation, delivering up to 3 degree per 100 feet of controlled directional performance in both 6 ⅛" and 8 ½" hole diameters. Because a standard bent housing assembly was used, oriented drilling was always available as needed. This allowed a redundancy in directional control (oriented or rotary), widening the operational scope and technical capability of the system.
Drilling Highly Depleted Formations with Engineered Particle Non-Aqueous Fluids (EP-NAF): South China Sea
Authors: Niznik Michael R. , Lawrence Adela , Zeilinger Sabine 
Published: March 2011

Abstract
A new fluid system (EP-NAF) has been utilized in the Malay Basin of the South China Sea to drill through highly depleted sands with a non-aqueous fluid at elevated densities. The fluid contains sized particles to both bridge and prop open fractures as they occur during actual drilling operations. Formation integrity is gained immediately and does not require additional critical path rig time.
The design of the EP-NAF fluid commenced by first determining the formation integrity of the drawndown sands. The required fluid density plus equivalent circulating density (ECD) expected indicated a high potential for lost circulation as the fracture gradient was anticipated to be exceeded. A research team was engaged to determine the required fracture width to build 1.0 to 1.5 ppg of formation integrity in the sands; a particle size distribution was then engineered for the specific application.
The sized particles were procured and delivered to the site. Training was conducted in the office and at the rig to educate all parties in the concept and procedural requirements. The drawndown sands were successfully drilled to section total depth (TD) with EP-NAF on several wells.
Exploration Drilling Campaigns - Optimized Drilling Performance using Drilling Consortium Management
Authors: Ribesen Bjørn Thore , Horvei Kjell Arild , Magnussen Tove , Saasen Arild , Veiberg Tormod 
Published: March 2011

Abstract
Currently there are many smaller operators drilling on the Norwegian continental shelf. It is not an optimal use of resources to staff a complete drilling department in-house in all of these companies. For others, the drilling activity requires that wells are drilled in a discontinuous manner. Therefore, the drilling process can easily be costly and inefficient.
The current paper describes in detail, based on a three year field experience, how an operator, a well management company and an integrated service provider efficiently run a drilling campaign. During this campaign five different operators have used this management system to efficiently drill exploration wells. The drilling rig Bredford Dolphin was hired by a consortium of operators. All the planning of the drilling operations and the follow up during the entire operation were conducted by a well management team. The same provider of integrated services has been used throughout the whole campaign, giving the drilling operations a high priority.
Exploration drilling involves several work demanding processes including rig hire and management, well planning and reporting, operations, logistics and setup of emergency preparedness organisation. Use of an independent well management team handling such items continuously without removing the operators responsibility, was very efficient. This core team also included the integrated service provider to remove any logistical hindrances.
As will be shown in the paper, this combination of companies using a rig continuously throughout the campaign has produced several of the best exploration well drilling operations on the Norwegian continental shelf. This is illustrated by presentation of the Det norske's benchmarking data from these operations.
Field Experience with an Active Stick-Slip Prevention System
Authors: Nessjøen Pål Jacob , Kyllingstad Åge , D'Ambrosio Piero , Fonseca Isaac S. , Garcia Alexis , Levy Bruno 
Published: March 2011

Abstract
Stick-slip oscillations are self-sustained and periodic twist and torque oscillations of a rotating drill string, characterized by large and harmful variations of the downhole rotation speed. This paper is a field evaluation of an active stick-slip prevention system.
The evaluated system is active with smart control of the top drive, meaning the top drive speed is varied in a way that dampens stick-slip oscillations. It is software based, in many cases it requires no extra instrumentation and can be implemented on virtually any types and brands of top drives.
The paper includes field test results, both from ordinary tests with surface data on top drive speed and torque, and from special tests including downhole measurements. The field data verified existence of the expected 2nd mode stick-slip in longer strings and proved that the system is able to reduce the downhole speed variations. Therefore a general conclusion is that the active stick-slip prevention system significantly lowers the critical rotation speed below which stick-slip oscillations persist. Simultaneous surface and downhole measurements indicate that the reduction of stick-slip oscillations improved drilling performance and the rate of penetration (ROP).
The positive field test results are good news to the drilling industry that has struggled for a long time with harmful stick- slip oscillations, causing premature tool failures, excessive bit wear and poor drilling rate. Installation and use of an active stick-slip prevention system is therefore a very cost effective solution to a long outstanding problem.
Development of an Innovative Model-Based Stick/Slip Control System
Authors: Rudat Jens , Dashevskiy Dmitriy 
Published: March 2011

Abstract
Stick/slip is a severe type of torsional drillstring oscillation that affects the efficiency of the drilling process and can cause bit damage as well as drillstring failure. Different approaches to mitigate stick/slip oscillations are used in the field, ranging from procedures for optimizing drilling parameters, to passive downhole damping devices, and active surface controllers. To improve performance, some of these systems use mathematical models of the rotary system. Since the drilling process is subject to permanent changes, model-based control systems can only perform adequately when constantly updated with the actual conditions. To date, surface data has been used for this, but some key drilling process characteristics can only be identified with downhole data.
This paper presents an innovative model-based stick/slip control system. It is based on a model of the drilling process that predicts the intensity of downhole vibration with respect to drilling parameters. Using downhole measurements, the model is adapted to the actual drilling process and employed to find optimal drilling parameters. To overcome the limited bandwidth of the typically used mud-pulse telemetry systems, models are identified downhole in the dynamics measurement tool.
The paper presents field tests performed to evaluate the stick/slip control system and the investigation of how model parameters can be identified from measurements as well as how well the identified models represent the drilling process. Results show that this model can be used to predict the intensity of torsional oscillations and determine optimal drilling parameter values.
The presented stick/slip control system can provide quantitative recommendations on changing drilling control parameters to mitigate stick/slip and can be used in an automated mode by directly connecting to the rig control system for monitoring drilling conditions and adjusting drilling parameters. Proper handling of downhole vibrations can significantly increase reliability.
Passive Inflow Control Devices and Swellable Packers Control Water Production in Fractured Carbonate Reservoir: A Comparison with Slotted Liner Completions
Authors: Youl Kim Sam , Harkomoyo _ , Suhana Widayat , Regulacion Rhandy , Jorgensen Thomas 
Published: March 2011

Abstract
Many applications for Inflow Control Devices (ICDs) are designed to delay water breakthrough in new wells and for remediating wells shut-in because of water encroachment. The ICDs for carbonate reservoirs typically are combined with wire-wrapped screen (WWS) strainers on 13-ft basepipe. Many wells also have been compartmentalized with swellable packers. Passive inflow control technology has been used extensively in horizontal wells in the Norwegian section of the North Sea and in the Middle East for approximately a decade. This paper discusses first usage of a new tube-type ICD combined with swellable packers to control water in fractured carbonate reservoirs in Asia. Traditionally, horizontal wells in the Poleng field in East Java, Indonesia were completed with slotted liners and struggled with early water breakthrough and high water-cut production. Since highly productive fractures are thought to be the main conduit for water, and slotted liners do not provide control for fluid inflow to the wellbore, resolving high water cut has challenged offshore production significantly.
To combat these challenges, a new completion strategy using ICDs and swellable packers for both delaying and minimizing water breakthrough has been developed.
Production performance of 5 horizontal wells completed with the ICD/swellable packer concept will be compared to production of 8 wells completed traditionally. This project marks several world firsts in tube-type ICD technology with its first installation in Indonesia.
Achievements and Lessons Learned from a 4-Year Experience of Extended Reach Drilling in offshore Dagang Oilfield, Bohai Basin, China
Authors: Cheng Rongchao , Wang Haige , Zou Lingzhan , Zhou Mingxin , Sha Dong , Liu Chuandu 
Published: March 2011

Abstract
The long-term continuous exploitation makes it increasingly difficult to maintain sustainable hydrocarbon production onshore in Dagang Oilfield. The shelf sea area of Bohai Basin with an average water depth of about 2.5m is identified as the main take-over battlefield, which needs to be developed by extended reach drilling (ERD) due to the lower loading capability of subsea thick silt and the inaccessibility of drilling rigs onshore or offshore. This is one of the major ERD campaigns implemented independently onshore in China.
Favorable achievements have been obtained during the 4-year ERD play. Four extended-reach horizontal wells with the horizontal displacements larger than 4000m have been successfully completed by integrated application of pseudo-catenary trajectory design, casing floating running technology, compound drilling method, real-time ECD monitoring, highly inhibitive drilling fluid, optimized hole cleaning operation and enhanced drag/torque reduction technology. The maximum horizontal displacement to vertical depth ratio reaches 3.92. Many other ERD records have also been made in China onshore, building basic foundations for much larger-scale of application of ERD in Bohai Basin. Meanwhile, many new challenges have also emerged, such as the wellbore instability in highly deviated intervals, inappropriate design and optimization of PDC bit, instable bottom hole assembly (BHA), difficult control on well trajectory for the long angle-holding section, etc. This calls for technical innovations to address problems associated with previous ERD activities.
This paper focuses on the technical achievements as well as the lessons learned from the ERD play in recent years, with its purpose to explain where we are and what to do next for further research and development of ERD technology in China. Helpful case histories and recommendations will also be presented.
Dynamic Aspects Governing Cement Plug Placement in Deepwater Wells
Authors: Aranha P. E. , Miranda C. R. , Magalhães J. V. , Campos G. , Martins A. L. , Braghini A. , Naccache M. F. 
Published: March 2011

Abstract
Plug cementing is still considered to be a critical operation and cases of failure eventually happen. Large annular gap and eccentricity, typical of these operations, are factors which may promote unstable flows resulting in cement slurry contamination. Deepwater conditions enhance chances of free fall, and consequently, low displacement velocities can occur in the annulus.
This article presents a parametric study in the role of rheological properties of fluids (drilling fluid, spacers and cements slurries), string rotation, flow rates (including freefall effects) in the displacement quality of cement plugs. Analyses are based on 2 different simulation tools. Conventional cement pumping softwares define flow rate profiles at annulus entrance, accounting for free fall effects and CFD to simulate the interface propagation and contamination levels.
The main issues addressed by the simulations are:
What are the maximum yield stresses which guarantee that non stagnation regions while circulating the drilling fluid? How to optimize density and rheology hierarchy which minimizes contamination and avoids channeling? What is the role of string rotation on the displacement efficiency?
The compilation of simulation results in useful guidelines and procedures for displacing cement plugs in vertical, inclined and horizontal offshore wells.
Anatomy of the "Best In Class Well": How Operators Have Organised the Benchmarking of their Well Construction and Abandonment Performance
Authors: Rushmore Peter 
Published: March 2011

Abstract
The use of comparative performance data by operators to drive well construction performance improvement is a powerful and proven technique. Offset well data is also used by operators for a range of other applications.
Twelve operators came together in 1989 to organise the sharing of drilling offset data between themselves, in order to remedy the deficiencies experienced in obtaining this data from other sources. This has grown into a global programme with data shared on over 38,000 wells provided by over 200 operating companies in 80 countries (Appendix 1 and 2). As well as the initial drilling study, data are also shared in studies looking at the completions and well abandonment phases.
Every super-major, most of the large and mid-sized international operators, many independents and a number of national oil companies participate in one or more of these studies. It is the aim of the participating operators to grow the programme to ultimately collect data on all hydrocarbon wells constructed globally.
This paper describes why operators have chosen to share comparative performance data amongst themselves, the way in which this is organised and the data itself. It examines the analysis and normalisation tools employed as well as the quality controls in place to ensure data integrity. Operators use the data for benchmarking and other applications, all focused on improving planning and operational performance.