bluuebunny/crossref_metadata_2025_split huggingface dataset:
Near Field Developments with an Upgraded Brown-Field Platform Rig: Sharing the Learning from a Three-Well Extended Reach Drilling (ERD) Program
Authors: Mota Miguel O. , King Gregory W. , O'Donnell William D. , Hewit Kerr , Dumont Paul A. 
Published: March 2012

Abstract
This paper will summarize the concept selection, concept definition, and modifications for a two-stage upgrade of a 35-yr old platform rig on a production platform to extend the drilling radius from 15 to 25 kft (Cutt 2007), the maximum working pressure (MWP) from 5 to 10 ksi, and how combined projects enabled the development of new fields which could not support subsea infrastructure.
The paper will highlight the lessons learned at each stage of the upgrade and the drilling programs, focusing on how the legacy limitations of the original rig design and inherited constraints of 200% well slot utilization were mitigated to enable the drilling of a next generation of wells. The upgrade of the rig in two separate projects allowed the lessons learned from the first extended reach drilling (ERD) upgrade (Cutt 2007) to be applied to the second 10-ksi upgrade. This approach also allowed different approaches to be taken to achieve improved results.
The drilling of redrilled wells on an old platform through depleted reservoirs constrained many aspects of well design; most specifically, casing sizes and maximum mud weights through intervals of reactive shale and depleted sands (Bennett et al, 1998). The company has global experience in new field developments with world class ERD wells (Elks et al, 2002; Walker 2008; Armstrong et al, 2011; McDermott et al, 2005; Viktorin et al, 2006; Elsborg et al, 2005; Woodfine et al, 2011) and the different approaches for new wells and redrilled wells will be compared.
The paper will show how the challenges of ERD operations to 25 kft in a 6-in. hole size were overcome and will comprehensively address how some risk mitigations introduced new risks, with specific emphasis on managing an operation where the extreme requirements did not allow any fallback contingencies in the event of a problem.
Scaled Tortuosity Index: Quantification of Borehole Undulations in terms of Hole Curvature, Clearance and Pipe Stiffness
Authors: Brands S. , Lowdon R. 
Published: March 2012

Abstract
Wellbore tortuosity is a potential source of friction, which can lead to problems while running casing and completions. Describing a smooth trajectory qualitatively as one with the least amount of bends is easy. However, quantitative tortuosity indices based on survey trajectory data alone have shortcomings that make comparisons and interpretation very difficult:
Their computational results depend on the survey interval (averaging effect). While 90-ft surveys hide important wellpath features, short spacing surveys might yield alarmingly high tortuosity, which does not reflect the curvature of the pipe in the borehole. Varying stiffness of the pipe and clearance between the pipe and borehole can have different levels of negative consequences with the same survey data. Stiffness and clearance have a direct impact on physical bending moments and sideforces, which drive frictional losses when moving pipe in an out of a borehole. The scale of the wellbore undulations relative to the clearances is relevant to be able to distinguish relatively benign undulations from tortuosity that limits wellbore construction.
In formulating a scaled tortuosity index we have taken into account that actual hole curvature is not the curvature of the pipe in that hole, which is governed by stiffness and clearance. The main driver for the index is the bending moment profile along the pipe as it is positioned in the wellbore. The proposed index describes the total amount of required elastic energy (originating from these bending moments) to bend all the components in the string in all the required configurations to move it to total depth. The index is linked to nominal hole and casing sizes, (i.e. 7in casing in 8.5in hole) to make it applicable and comparable. Hence this concept is different from the existing dimensionless wellbore energy index.
Newbuild Construction Cycles - An Evolving Paradigm
Authors: Hope Iain , Livingston Scott , Ogg Jeremy 
Published: March 2012

Abstract
Since the last newbuild cycle of the late 90’s, the deepwater construction paradigm has evolved significantly, altering the way the key participants in the process interact. The shipyard and drilling contractor are all still instrumental in getting a deepwater rig built, but the relationships governing execution, particularly project management, has changed. Due to the nature of rig building contracts, the role of the drilling contractor is now more removed from the hub of the project management process. This presents a challenge for the drilling contractor, who receives a complex vessel, having had minimal input into its design from an operational needs perspective.
Current trends and lessons learned from the recent newbuild trend will be discussed, specifically focusing on the handover of turnkey rigs to drilling contractors. Recommendations founded in recent field performance feedback will be made with reference to key behaviors and operating plans and these strategies will assist drilling contractors with defining key roles and responsibilities in their new environment.
The solutions offered will include specific examples and practices which have led to successful shipyard deliveries in the past, and how these lessons can be applied forward in constructing tomorrow’s newbuilds. The paper will focus on where the new risks can be identified while providing methods for a drilling contractor to apply their valuable knowledge and experience, the object being to ensure the most efficient way of providing these new highly complex rigs to meet the needs of both the drilling contractor and drilling customer. Specifically, industry workforce, automation and its complexity, newbuild package quality, worldwide equipment sourcing, and the merits of turnkey builder furnished equipment (BFE) contract management versus owner furnished equipment (OFE) will be examined.
Improved Stability of Invert Emulsion Fluids
Authors: Zanten Ryan Van , Miller Jeff J. , Baker Chris 
Published: March 2012

Abstract
Clay-free invert emulsion fluids (IEF) can offer reduced potential for barite sag, improved rate of penetration, low equivalent circulating density and substantial decreases in surge/swab pressures. The unique properties of these fluids are achieved by omitting organophilic clay used to stabilize emulsions in conventional IEFs, and instead relying upon robust emulsifiers, colloidal solids and shear. Clay-free IEFs are generally built using a “seed” fluid that has been exposed to high shear levels by travelling through the bit. High shear helps form an extremely stable emulsion, allowing the seed mud to help stabilize fresh built fluid at the liquid mud plant. Occasionally a fluid may need to be built without using seed mud. Unless properly mixed, these fluids may exhibit lower stability, leading to top oil separation and barite sag.
This paper details an extensive investigation into the effects that emulsifier concentration, addition of colloidal fines and shear have on the stability of laboratory, mixing plant, and field-tested invert emulsion drilling fluids. Fluid stability is intricately linked to emulsion stability, which is directly related to the shear history of the whole fluid, the viscosity of the external phase, the emulsifier type and colloidal solids loading. Optimizing these properties can lead to more stable fluids that exhibit stronger gels and lower sag tendencies. Therefore, a mud built “from scratch” should be exposed to high shear, contain the appropriate amount of emulsifier and if possible, contain a small loading of colloidal fines. A series of field cases demonstrates how these modifications have led to improved fluids that remain stable from initial mix to delivery at the wellsite and commencement of drilling.
Slotted Liner for Continuously Acid Jetting Stimulation
Authors: Kofoed Sara Sparre , Marketz Franz , Krabbenhøft Jørgen 
Published: March 2012

Abstract
Appraisal and development of thin chalk reservoirs in the Danish Sector of the North Sea requires wells providing maximum reservoir contact and completions designs so that wells can be stimulated to maximize well productivity. Completion liners for pin-point matrix acid stimulations of long horizontal wellbore sections have been designed, manufactured and tested. The objective of the work was to identify a liner design with maximum inflow area but sufficient strength to withstand installation loads as is required if rotating the liner to target depth.
This paper describes the results from finite element analyses of different slotted and some pre-drilled liner designs. Staggered patterns were selected following recommendation from manufacturers. Based on the results from the finite element analysis designs was chosen. Liner joints were manufactured and tested to verify the designs. Both slotted and pre-drill liner designs were verified.
High-Angle Gyro-While-Drilling Technology Delivers An Economical Solution To Accurate Wellbore Placement And Collision Avoidance In High-Density Multilateral Pad Drilling In The Canadian Oil Sands
Authors: Brown Kevin M. , Beattie Keith A. , Kohut Cory 
Published: March 2012

Abstract
Cenovus Energy initiated an aggressive infill drilling program early in 2011 in its Pelican Lake polymer/water flood project in northeast Alberta. By mid-year, the company had drilled 52 injection and producing wells, and drilling is scheduled to continue at the same pace through year-end.
Pelican Lake employs a two-phase drilling program from 18-well pads: batch-drilling the intermediate hole sections to approximately 425m MD at 70° of inclination; using follow-up rigs to drill the horizontal sections of over 2,000m in the Wabiskaw formation. Wellbore collisions in the intermediate phase and landing the wells accurately prior to horizontal drilling are critical concerns. Highly accurate gyroscopic surveying techniques are required throughout the project considering the close well spacing and congestion of existing wells.
Early in 2011, the company tested a new gyro-while-drilling (GWD) system, capable of accurate performance up to 70° of inclination versus the 20° to 40° of previous models. If successful, the higher operational range would facilitate collision avoidance and accurate well placement in one operation with real-time data, potentially enhancing both the economics and the feasibility of the drilling program.
Since accurate well placement was so critical—some well passes would be as close as 4 meters—the company developed a plan to evaluate the new tool: first, by surveying previously surveyed wells and comparing the results; and, second, by running back-up gyro surveys on wireline during drilling. GWD performance exceeded expectations, both in the initial tests and in the drilling operations—to the extent that the back-up surveys were eliminated, with the GWD data accepted as the definitive wellbore survey.
This paper will provide the results of the initial tests and analyze GWD performance during drilling with statistics compiled from 36 wells. The savings from eliminating the back-up surveys will be presented along with other benefits and observations.
Colorado Drill Cuttings Injection Pilot Results
Authors: Kunze Kenneth R. , Romero Edgar E. , Duck Steven 
Published: March 2012

Abstract
From December 2007 through April 2011, the operator conducted a two-phase drill cuttings injection pilot at the Piceance Field in Western Colorado in an effort to reduce the environmental footprint of drilling operations. This was the first subsurface injection of drill cuttings in Colorado and utilized a lost circulation zone in the Wasatch G formation as the injection interval.
The first phase of the pilot was to assess the technical feasibility and formation response to injection. During this phase, water-based mud and drill cuttings from four wells were injected into a fifth well that was temporarily suspended at the intermediate casing and perforated in the Wasatch G formation. Over 40,000 bbl of fluid were injected under vacuum conditions with confirmed confinement to the target zone.
Based on the injection results, the pilot progressed to a second phase to assess the logistical requirements of transporting cuttings from multiple drilling locations to a central processing and injection site. The injection well selected had experienced lost returns in the Wasatch G when originally drilled and was completed as a dedicated injector. The pilot processed cuttings from three active rigs, and demonstrated capacity to process cuttings from over six rigs.
The operator proved injection as a technically feasible option for drilling waste disposal during full-field development at Piceance.
Drillstring Dynamics Simulation Optimizes Multilateral Casing Exit Windows
Authors: Guidry Christopher W. , Thomas Reena 
Published: March 2012

Abstract
Traditional casing exit technology includes tool strings comprised of mills with cutting structures for traversing anchored whipstocks to create elliptically shaped windows. Successful casing exit operations involve generating windows sufficiently long for easy passage of subsequently run directional drilling bottomhole assemblies (BHAs) and creating full-gauge ratholes that deviate from the exited casing. Paramount to generating a long window is maintaining sufficient restraining forces on the bottom-most mill to keep the mill tracking the full ramp length and thereby preventing an early whipstock ramp departure by the mill.
This paper describes an innovative casing exit milling BHA and the method by which its design and predicted performance were optimized using in-house-created drillstring dynamics finite element analysis (FEA) software. This analytical tool helped in designing the milling BHA so that its operational bending stresses were reduced and its fatigue life was increased. Purposefully designed shapes and placements of the BHA’s bladed cutting sections provided a favorable distribution of restraining forces, thus enabling an optimal-length casing exit window.
The resultant BHA design is such that the upper-most mill can traverse against the entire ramp, and then preferably deviate away from the ramp to avoid undesirable re-entry into the previously exited wellbore. Analytical results have shown that contact forces endured by the mills during window milling have been optimized, thereby supporting efforts to improve BHA component fatigue life.
As directional drilling assemblies continue to be made longer and stiffer, there is an increased significance of using simulation tools to design milling BHAs. These newly designed BHAs will continue to be enhanced to maximize window length for improved ingress and egress of the rotary steerable drilling BHAs. Extensive analysis, qualification testing, and field trials were performed on these systems. Case histories describing operational results will be shared and discussed during the presentation.
Innovative PDC Cutter Technology Leads to Step Out Performance Improvements in Diverse Applications in Shale Plays
Authors: Scott Dan , Meiners Matt , Isbell Matt 
Published: March 2012

Abstract
Since the commercial introduction of the PDC cutter in 1976 the cutter technology and impact on the drill bit market has changed dramatically. There have been many milestones along the way as other vendors entered the market and as the bit companies continued improving bit designs and applications understanding. (1) This service company pioneered application specific and position specific cutter technology features in the 1990s. PDC cutters were also substantially improved with the introduction of a patented layered diamond table technology and polished surface finish. (2,3,4,5,6) In the last decade detailed analysis and understanding of cutter behavior and failure mechanisms, drilling mechanics, bit stability, new drive systems, focused design and application review teams (DART) and innovative manufacturing processes have lead to a steep increase in the conversion of traditional roller cone hard rock markets to PDC bits. From approximately 25% of the market in 2000, the PDC bits now occupy approximately 70%. This paper will highlight the latest improvements in PDC performance including supporting case studies throughout North America.
Automated Closed-loop Drilling with ROP Optimization Algorithm Significantly Reduces Drilling Time and Improves Downhole Tool Reliability
Authors: Chapman Clinton D. , Flores Jose Luis , De Leon Perez Roberto , Yu Han 
Published: March 2012

Abstract
The use of an ROP Optimization algorithm within an automated closed loop process has dramatically increased ROP in its first deployments in Iraq, Algeria, and Mexico. Additionally, an unexpected reduction in downhole tool failures was observed resulting in a notable decrease in non-productive time. Importantly, the closed-loop automation, where the algorithm is allowed to send commands directly to the rig control system, shows yet another step change in ROP improvement compared to the algorithm that just presents recommendations to the driller.
This paper briefly describes the optimization algorithm and then focuses on the system architecture used to integrate the algorithm with the rig control system. Similar to the SPE DSA-TS Comms Team architecture, the deployed architecture enables the algorithm to receive real-time data from the rig control system and drilling acquisition system to provide a complete data set to the ROP Optimization algorithm. The algorithm constrained by a set of operational limits dynamically computes RPM and WOB commands and sends these to a SCADA system which converts the generic commands into rig specific commands for each rig type used. The driller controls the use of the system via an "Automation Console" provided by the SCADA system and located adjacent to the driller’s console. The driller is able to engage or disengage from the system. Failsafe conditions are also incorporated into the automation system.
Results showing the improved ROP and downhole reliability compared to field averages across various hole sizes and trajectory profiles are given. These results consistently demonstrate the effectiveness of a closed-loop automation system to improve ROP and tool reliability.
Interaction of selected anthocyanins with erythrocytes and liposome membranes
Authors: Bonarska-Kujawa Dorota , Pruchnik Hanna , Kleszczyńska Halina 
Published: March 2012

AbstractAnthocyanins are one of the main flavonoid groups. They are responsible for, e.g., the color of plants and have antioxidant features and a wide spectrum of medical activity. The subject of the study was the following compounds that belong to the anthocyanins and which can be found, e.g., in strawberries and chokeberries: callistephin chloride (pelargonidin-3-O-glucoside chloride) and ideain chloride (cyanidin-3-O-galactoside chloride). The aim of the study was to determine the compounds’ antioxidant activity towards the erythrocyte membrane and changes incurred by the tested anthocyanins in the lipid phase of the erythrocyte membrane, in liposomes composed of erythrocyte lipids and in DPPC, DPPC/cholesterol and egg lecithin liposomes. In particular, we studied the effect of the two selected anthocyanins on red blood cell morphology, on packing order in the lipid hydrophilic phase, on fluidity of the hydrophobic phase, as well as on the temperature of phase transition in DPPC and DPPC/cholesterol liposomes. Fluorimetry with the Laurdan and Prodan probes indicated increased packing density in the hydrophilic phase of the membrane in the presence of anthocyanins. Using the fluorescence probes DPH and TMA-DPH, no effect was noted inside the hydrophobic phase of the membrane, as the lipid bilayer fluidity was not modified. The compounds slightly lowered the phase transition temperature of phosphatidylcholine liposomes. The study has shown that both anthocyanins are incorporated into the outer region of the erythrocyte membrane, affecting its shape and lipid packing order, which is reflected in the increasing number of echinocytes. The investigation proved that the compounds penetrate only the outer part of the external lipid layer of liposomes composed of erythrocyte lipids, DPPC, DPPC/cholesterol and egg lecithin lipids, changing its packing order. Fluorimetry studies with DPH-PA proved that the tested anthocyanins are very effective antioxidants. The antioxidant activity of the compounds was comparable with the activity of Trolox®.
High-definition fiber tracking for assessment of neurological deficit in a case of traumatic brain injury: finding, visualizing, and interpreting small sites of damage
Authors: Shin Samuel S. , Verstynen Timothy , Pathak Sudhir , Jarbo Kevin , Hricik Allison J. , Maserati Megan , Beers Sue R. , Puccio Ava M. , Boada Fernando E. , Okonkwo David O. , Schneider Walter 
Published: March 2012

For patients with traumatic brain injury (TBI), current clinical imaging methods generally do not provide highly detailed information about the location of axonal injury, severity of injury, or expected recovery. In a case of severe TBI, the authors applied a novel high-definition fiber tracking (HDFT) to directly visualize and quantify the degree of axonal fiber damage and predict functional deficits due to traumatic axonal injury and loss of cortical projections.
This 32-year-old man sustained a severe TBI. Computed tomography and MRI revealed an area of hemorrhage in the basal ganglia with mass effect, but no specific information on the location of axonal injury could be obtained from these studies. Examinations of the patient at Week 3 and Week 8 after TBI revealed motor weaknesses of the left extremities. Four months postinjury, 257-direction diffusion spectrum imaging and HDFT analysis was performed to evaluate the degree of axonal damage in the motor pathway and quantify asymmetries in the left and right axonal pathways. High-definition fiber tracking was used to follow corticospinal and corona radiata pathways from the cortical surface to the midbrain and quantify projections from motor areas. Axonal damage was then localized by assessing the number of descending fibers at the level of the cortex, internal capsule, and midbrain. The motor deficit apparent in the clinical examinations correlated with the axonal losses visualized using HDFT. Fiber loss estimates at 4 months postinjury accurately predicted the nature of the motor deficits (severe, focal left-hand weakness) when other standard clinical imaging modalities did not. A repeat scan at 10 months postinjury, when edema and hemorrhage had receded, replicated the fiber loss.
Using HDFT, the authors accurately identified the presence and location of damage to the underlying white matter in this patient with TBI. Detailed information of injury provided by this novel technique holds future potential for precise neuroimaging assessment of TBI.