bluuebunny/crossref_metadata_2025_split huggingface dataset:
Continuous Circulation During Drilling Utilizing a Drillstring Integrated Valve—The Continuous Circulation Valve
Authors: Torsvoll A. , Horsrud P. , Reimers N. 
Published: December 2007

Abstract
A Continuous Circulation Valve, CCV, was developed for enabling drilling in depleted reservoirs in the Norwegian sector of the North Sea. By utilizing a system to obtain circulation throughout the whole drilling operation, the down hole pressure will remain constant even during drill pipe connections. By balancing this down hole pressure between a maximum pore pressure and a minimum fracture pressure, drilling can be performed properly even through narrow drilling windows.
The valve is a two position three way ball valve. It is possible to circulate through the valve from the top drive down the drill string or through a side port and down the drill string. Such a valve must be installed at the top of each drill pipe stand before the continuous circulation operation starts. When a connection is to be performed, a hose must be connected to the side inlet of the valve, the flow from the mud pumps will then be switched from the top inlet to the side inlet and top drive can then be disconnected and a new stand installed. To continue drilling, the operation is reversed. The valve is designed to withstand HPHT pressures including gas filled casings, bull heading and maximum pressure during standard drilling operation.
A prototype of the valve has been produced and operation tested on the full scale research drilling rig "Ullrigg" in Stavanger, Norway. The current paper presents in detail the advantages gained by using the CCV in a drilling operation. The paper gives a thorough description of the valve and its performance. The "Ullrigg" test of the prototype is described in detail.
Safety is Not No. 1; It's a Core Value
Authors: Schwall G. , Nealis P. 
Published: December 2007

Abstract
Over the past 2-1/2 years, ConocoPhillips has undertaken a challenge to establish safety as a core value in its drilling and completion operations in the ArkLaTex region with positive results in safety and operations. By working together with our contractors, decreases in trailing indicators (e.g. recordables) have been realized along with increases in leading indicators (e.g. JSAs performed/reviewed, BBS participation, unplanned event reporting). The paper details a journey (still in progress) starting with safety leadership training and the establishment of a regional safety leadership team comprised of senior operations managers and business owners dedicated to making a change. The paper also details a host of initiatives including visibility, contractor management, focused HSE campaigns, stand-downs, incentive programs and joint efforts with production. While this is not a roadmap to HSE improvement, it can be used as a compass to set and maintain direction.
Advancements in 3D Drillstring Mechanics: From the Bit to the Topdrive
Authors: Menand S. , Sellami H. , Tijani M. , Stab O. , Dupuis D. , Simon C. 
Published: December 2007

Abstract
The well trajectories becoming more and more complex (Extended Reach Drilling, Horizontal or Multilateral Drilling, Ultra-Deep Drilling, 3D wells….), the associated drillstring composition being unconventional and the material being used to its operating limit, the necessity to have a tool that predicts realistically forces, bending moment and contact loads along the wellbore is essential. To simulate the mechanical behavior of the drillstring, the industry generally uses a stiff-string model for the bottom bole assembly (BHA) to predict drilling trajectories, and a soft-string model for the entire drillstring to calculate torque and drag.
The conventional soft-string model gives a good approximation of forces and contact loads in the drillstring for very smooth well trajectories, but is inappropriate when the trajectory becomes tortuous (micro or macro-tortuosity) or complex, as the drillstring no longer contacts the low side of the borehole.
An advanced numerical method has been applied to address the 3D mechanical problem of a complete drillstring moving and freely rotating inside a wellbore: computation of the unknown contacts between the drillstring and the wellbore. As this new model does not use the time consuming finite element analysis, it can be used in real-time drilling operation at the rig to monitor torque and drag. For the first time, it is even possible to perform simultaneously a torque and drag, buckling and directional analysis while drilling.
The power of a 3D visualization of the drillstring deformed inside the wellbore enables to localize easily contact loads on any drillstring component, from the drilling bit (including side force at the bit and tilt) to the top drive or rotary table (hook load and rotary torque at surface), facilitating drilling problems analysis.
This paper will describe the fundamentals of the model developed and shows the differences between the conventional soft-string model and the advanced stiff-string model in terms of tension, torque and contact points between the drillstring and the wellbore, for many actual wells. With the help of the 3D visualization software, this paper will show the cases where the drill pipe contacts the high side of the borehole, or goes up to the right or the left side of the borehole depending on the right or left turn rate of the well trajectory. This new model should improve significantly the torque-drag and buckling calculations and the understanding of the drillstring contributions to overall drilling performance.
Torque Reduction Techniques in ERD Wells
Authors: Schamp J. H. , Estes B. L. , Keller S. R. 
Published: December 2007

Abstract
World class ERD wells are being used in the Russian Far East to develop an offshore reservoir from an onshore location. These wells have reaches of 9-11 km. While drilling the initial wells into the reservoir, high torque was experienced even while using a nonaqueous drilling fluid (NAF). The torque was sufficiently high that concerns arose about the feasibility of being able to drill longer wells later in the development. Consequently, finding techniques to reduce drilling torque became a major focus for the drilling phase of the project.
A systematic R&D process was initiated to look for solutions to the torque problem. The scope of the investigations included consideration of different drilling fluid base oils, solid/liquid lubricants, and mechanical means to reduce torque. Small-scale screening lubricity testing was performed in a controlled laboratory environment to identify potential lubricant candidates. Full-size laboratory testing was then performed on the leading products. Various mechanical means to reduce torque were also evaluated. Finally, field trials were performed using solid and liquid lubricants and different types of mechanical torque-reduction tools.
Solid lubricants caused plugging problems with BHA components and their use was discontinued. Liquid lubricants achieved torque reductions of 5-15%, which was sufficient to drill the longest throw wells. The mechanical tools when added to the drill string showed the greatest reductions in torque, but were very expensive.
Since the liquid lubricants represented a significant addition to the cost of the wells, other means of reducing torque were investigated. Eventually, it was discovered that the use of 4,500 m of range II drill pipe instead of range III caused a reduction in the torque. This is believed to be related to the larger tube body-casing contact area of the range III pipe joints compared to the range II pipe joints. Further evidence that the large contact area between the casing and the range III drill pipe was causing both excessive wear and torque was provided when drill pipe inspections revealed an alarming increase in rejections due to excessive tube wear near the middle of many joints.
Ongoing investigations are attempting to find mechanical solutions to the drill pipe-casing contact problem. New orders of drill pipe could be range II pipe, but the existing large inventory of range III drill pipe needs to be protected from excessive wear, while at the same time reducing the drilling torque. Several types of drill pipe stand-off bands are under investigation and may represent a viable solution to both problems.
Removing Oil and Grease from Produced Water Using Microbubble Flotation Technique: From Theory to Field Practice
Authors: Hayatdavoudi A. 
Published: December 2007

Abstract
The paper addresses the issue of using micro-bubble flotation technique for cleaning produced water such that the output (effluent) water meets or exceeds the US EPA or country-specific standards. The joint cooperation between academia and the service industry and shared field and theoretical studies have revealed the following results: (1) micro bubbles, using acetylene (C2H2) gas medium, at 55 psi backpressure on a patented Dissolved Gas Flotation pump and constant temperature, can remove 97% of the Oil and Grease from water, (2) a theoretical scaling law has been devised for estimating the potential solubility of gas in water, for example CH4 and C2H2, where Henry's Law might not be linear due to complex bubble hydrodynamics, pump pulsation, the rise of a multitude of bubble sizes in the fluid column, distribution and number of bubbles, partial pressure and concentration (molality) of the main gas and the leaked air impurities in the recycling system, and other variables, (3) the mechanism controlling the removal efficiency of the flotation cell is related to the number and the uniformity of micro bubbles rather than their size only-the sizes range from an average of 5 to 200 microns at sampling points, (4) at sampling points, the bubble count and the gas-filled bubbles as a percent of the unit bulk volume are nonlinear periodic functions of the operating pressure of the flotation cell, and (5) there exists an optimal operating pressure of the patented Dissolved Gas Flotation pump system such that the flotation cell gives the best results and this optimal pressure can be easily adjusted by field personnel to achieve the most efficient removal of Oil and Grease from water.
Based on these results, one may conclude that a seemingly complex mix of gas chemistry and bubble thermo-hydrodynamic properties can offer a simple, efficient, and environmentally friendly technique for cleaning the produced water.
A New Stochastic Bubble Population Model For Foam In Porous Media
Authors: Zitha P. L. J. 
Published: December 2007

Abstract
Foam has been widely used as a mobility control agent for Improved Oil Recover (IOR), gas blocking and acid diversion during matrix stimulation. The prediction of foam performance relies on macroscopic modeling. Foam modeling approaches include fractional flow theories and population balance models.
Traditionally, fractional foam models assume implicitly that foam is incompressible and do not account directly for the evolution of bubble population. The population balance models, instead, rely on the idea that foam mobility depends on bubble density and are more comprehensive. Yet, population balance models did not gain full acceptance thus far, because of their perceived complexity, with parameters that are hard to obtain experimentally.
This paper presents an improved foam model based on a simpler but realistic foam rheology and stochastic bubble generation ideas. Physical ideas in agreement with pictures emerging from recent foam studies using X-ray computed tomography form the basis for the new model. First, we provide the conservation equations for foam motion in porous media. Then we present their analytical treatment considering several cases that are likely to exist in the laboratory and in the field. We present an analysis of quasi-incompressible foam, reconciling for the first time the population balance and fractional flow ideas. We demonstrate why fingering is likely to occur during liquid injection following foam. Then we provide a solution for the coupling of liquid drainage through foam and viscous fingering.
The Effect of Stress Relief Features on HWDP and Drill Collars: Are SRFs Necessary, and When are they Most Beneficial?
Authors: Gokhale S. , Ellis S. , Lee K. 
Published: December 2007

Abstract
The benefit of stress relief features (SRF's) on heavy weight drill pipe (HWDP) has often been questioned. Much more may be at stake than the cost of adding stress relief features and the impact cutting stress relief grooves has on connection refacing and recuts. The fatigue benefits provided by SRF's may prevent a costly failure and will provide improved service life.
The fatigue performance of HWDP and drill collars (DC's) cut with and without pin stress relief grooves and API boreback boxes was evaluated using Finite Element Analysis (FEA) and a strain life prediction model. Both 3 1/2 inch (NC38) and 6 5/8 inch (6 5/8 FH) HWDP were modeled in various hole curvatures and while buckled in straight hole sections of various hole diameters. Similarly, 4 3/4 inch (NC38) and 8 inch (6 5/8 REG) drill collars were evaluated.
Although typical ‘small’ and ‘large’ HWDP and drill collar sizes were analyzed, the trends and results observed are thought to apply across the size spectrum.
The results of the analyses show that stress relief features improve fatigue life significantly and should be included on all HWDP and drill collar components with NC38 and larger connection types. Additionally, heavy weight drill pipe is proven more fatigue resistant than comparably sized drill collar alternatives because most of the bending in HWDP occurs in the tube instead of the connection. Conversely, in drill collars significant bending occurs in the highly stressed connection. When possible and practicle, replacing drill collars with heavy weight drill pipe (eliminating tapered drill collar strings) is recommended. The fatigue benefit of stress relief features on HWDP and drill collars decreases as dogleg severity increases or as the hole size in which the components are buckled increases. Nevertheless, the stress relief features still provide a significant improvement in fatigue life (relative to HWDP and drill collars without stress relief features in the same hole) while drilling across severe doglegs or when buckled in holes with large radial clearances.
Unlocking Two-Cone-Bit Potential: Technology, People, and Planning Make It Possible and the Lessons Learned
Authors: Centala P. , Burley M. , Burnett T. , Ford R. , Sinesi J. 
Published: December 2007

Abstract
Many, perhaps most, who drill oil wells, know something about two-cone bits. These bits, for example, received the first cone bit patent nearly 100 years ago, yet, they have been popular in certain drilling environments within the last 20 years or less. Designers have always recognized great advantages in two-cone bits, but concerns with vibration, directional responsiveness, drilling straight holes, mechanical reliability, and hole cleaning lead to their displacement by three-cone bits. Unfortunately, two-cone bits have not, fully lived up to their potential.
People have changed, and this has triggered changes in research philosophy. This together with technology advances in complex mathematical modeling, simulations and drilling processes has encouraged bit manufacturers to re-visit some older designs and learn to harness the potential inherent in those designs without their ill effects. This evolution has encouraged numerous step changes in drill bit technology. Could new people, new engineering and new manufacturing tools and tolerances, and a new sophistication at the rig finally unlock the potential of two-cone bits?
To date, numerous runs with a modern two-cone bit design have taken place in Texas, Louisiana and internationally. Some of these runs are reported in this paper, detailing lessons learned and successes from the new two-cone bit that have been shared by the operators. Offset bits were one basis for performance evaluation and offset comparisons are also reported. In a direct offset well, a single modern two-cone bit drilled an interval, for which four offset bits were required (estimated savings: $342,000). Operator evaluations, performance outlines, information on reliability, bit vibration, directional responsiveness, deviation free performance, and hydraulic aspects of bottom hole cleaning, free of bit-balling, in several types of applications are included.
The process and technology involved in designing the two-cone bits are identified in this paper. The lessons learned in planning between highly experienced drilling operators and bit company personnel toward overcoming paradigms and apprehensions in developing test plans for the improved technology are also discussed.
Lessons Learned From Treating 500,000 Tons of Oil-Based Drill Cuttings on Five Continents
Authors: Pierce D. , Gaddis C. , Wood B. 
Published: December 2007

Abstract
As Yogi Berra is fond of saying, "it ain't over till it's over". During any oil-based mud drill cuttings treatment project, the task is not complete until the solids are clean and permanently disposed, the oil is clean and reused, and the water is clean and recycled or discharged. The project is over when the wastes pass the auspices of the local environmental rules and are no longer an environmental risk.
Thermally desorbing the liquids from the drilled solids is the easiest part of the job. It's the little things that really make the difference between a successful project and a total failure. This is true not only for the treatment company, but also for the oil company that is generating the cuttings. In most cases for these projects to benefit all, they must be approached as a partnership between the waste generator, the treatment company and the environmental agency. Anything else can lead to problems.
Our experience covers five continents and the successful treatment of more than 500,000 tons of oil-based drill cuttings. We will share data concerning many of our projects. Some problems will tend to be light hearted while others will be more complicated. Problems have arisen due to inadequate planning while others have been born due to an interpretation of the regulations. This paper will cover topics including transporting and storing oil-base drill cuttings, the need to pre-treat for a consistent homogeneous feed, re-hydrating the dried solids and separating the liquids into useable oil and dischargeable water. All of these pre and post treatment activities have a great deal to do with the success of a project.
Understanding the complete job and having an agreement between the treatment company, the oil company and the regulatory agencies prior to beginning the project is essential. Even when you have done your homework, unexpected problems arise. We will share some of our problems and how they were overcome, thereby decreasing the environmental risks as well as the financial risks associated with oil contaminated cuttings.
An Innovative Ultradeepwater Subsea Blowout Preventer (SSBOP) Control System Using Shape Memory Alloy Actuators
Authors: Song G. , Hu Z. , Sun K. , Ma N. , Economides M. J. , Samuel R. , Ehlig-Economides C. A. 
Published: December 2007

Abstract
API RP16E1 mandates that minimum acceptable Blowout Preventer (BOP) control system response times are 60 seconds or less for an annular preventer and 45 seconds or less for a ram type preventer. Norsok standard2 response time for closing rams when located at seabed is 30 seconds, or 45 seconds for annuli greater than 20 inches. As drilling moves to deep water, conventional BOP actuation technologies based on full or partial hydraulics (hydraulic, electrohydraulic or multiplex electrohydraulic systems) are unable to meet this standard because of the long hydraulic fluid communication path between the offshore platform and the BOP stack on the sea floor.
This paper presents an innovative undersea Blowout Preventer (BOP) using Shape Memory Alloy. The goal of this project is to develop innovative fast-response BOPs using only Nickel Titanium (Nitinol) Shape Memory Alloy (SMA) as the actuator. Nitinol SMA has a long fatigue life and high corrosion resistance. As a solid-state actuator, it is capable of up to 5% strain recovery or 72,500 psi restoration stress with many cycles. It can be actuated by electrical heating, thereby replacing hydraulic actuation and hydraulic lines with electric cable. With significantly fewer components, the SMA system will dramatically reduce total cost and will increase operation reliability. The new device could easily be retrofitted to existing conventional subsea control system so that other methods can also be used as a backup. Most important, the innovative all-electric BOP will provide much faster response than its hydraulic counterpart and will improve safety for subsea drilling.
To demonstrate the feasibility of such a device, a proof-of-concept prototype of a BOP with SMA actuation has been designed, fabricated, and tested at University of Houston. The BOP actuator uses strands of SMA wires to achieve large force and large displacement in a remarkably small space. Experimental results demonstrate that the BOP can be activated and fully closed in less than 15 seconds. The concept of this innovative device is illustrated, and detailed comparisons of the response time for hydraulic and Nitinol SMA actuations are included. This preliminary research reveals the potential of smart material technology in subsea drilling systems.
Next-Generation Multisensor Seismic-While-Drilling Technology
Authors: Cornish B. , Deady R. 
Published: December 2007

Abstract
Seismic While Drilling (SWD) technology provides a means to properly locate a well path with respect to depth and seismic travel time in order that the driller can effectively guide the bit toward a seismically-defined target. SWD can also facilitate drilling decisions such as setting coring and casing points, avoiding drilling hazards, and identifying overpressure-zones .
Accurate and reliable SWD tools must address at least two main issues: sensor coupling/fidelity, and precision timing. These issues must be addressed within the framework of the drilling environment, whose rigors impose significant constraints on the design and mounting of the seismic sensors and on the accuracy of the clock.
A next-generation SWD tool has been developed that addresses coupling issues through the deployment of multiple, multi-axis sensors, including ruggedized geophones, seismic accelerometers, and hydrophones, in combination with a novel, highly accurate clock and contingent surface systems. This paper investigates the performance of the new tool design and presents the results of field tests and operations in which seismic data were acquired using multiple sensors and types of sensors in various types of formations and in deviated boreholes. The data acquired while drilling are compared to baseline commercial wireline VSP measurements in order to verify that the system provides accuracy comparable to that of a standard commercial wireline.