bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using Model-Based Systems Engineering for Rig-Level Safety Automation
Authors: Hetherington David 
Published: March 2015

Abstract
“Is the automation making us safer?” This question is coming up with increasing frequency as the industry looks to increasingly levels of automation to solve a host of different technical and business challenges that we are facing. Previous papers have looked into such questions as the appropriate level of automation, mode confusion, and envelope protection approaches. This paper looks at a more basic problem: Are we able to precisely articulate what it is we want the automation to do and rigorously trace these requirements down to their granular point of implementation?
The author is currently working as the consultant to a shipyard that is producing a high-specification jackup rig for operation in the North Sea. This rig contains ten major software systems made by several different suppliers and their subcontractors and divisions. Making sure these major rig systems work properly together in critical situations has traditionally been quite difficult. Detailed requirements are scattered throughout thousands of pages of dozens of different specifications. Accurate manual tracking of these requirements is extremely difficult. This paper reports on the application of Model-Based Systems Engineering techniques common in the aerospace and automotive industries to tighten up the accuracy, traceability, and accountability for the rig-level safety automation design.
Changing the Game from Steel to Aluminum Drill Pipe: Results from Full String Aluminum Alloy Drill Pipe Deployment to Enhance Extended Reach Drilling Performance
Authors: Legarth B.. , Lehner J.. , Okibe H.. , Koinkar V.. , Mammod Z.. 
Published: March 2015

Abstract
An ERD well was drilled with a full string of aluminum drill pipe. Significant reductions in tension, derrick loading and torque and drag were achieved (compared to offset wells drilled with steel drill pipe); an improvement in overall drilling performance was observed (as per the operator's KPIs) and the rig crew handled the aluminum pipe safely and effectively while achieving faster tripping times and reduced connection times.
Aluminum Alloy Drill Pipe (ADP) has typically been used as part of a combination steel/aluminum string to reduce drilling loads in vertical and horizontal wells. To further improve performance and expand the Extended Reach Drilling (ERD) operating envelope, a trial was conducted to run a full drill string consisting of high strength-to-weight ADP to drill a shallow ERD well (with a step out ratio of 2:1), offshore Brunei. The trial also evaluated the overall performance of the ADP including the handling, rig interfaces and new high torque steel tool joints for subsequent deployment in a big bore ERD well. This trial was the second phase of a comprehensive assessment of the potential for ADP to enhance extended reach drilling performance through reduction of tensile and torsional loads and rig/derrick loading. Phase one of the ADP assessment evaluated use of a mixed string (22% ADP of drill string length) with steel drill pipe (SDP), in a 7500m-long, three-dimensional ERD well drilled offshore Brunei in May of 2012.
The phase two well represented the first time that a full string of ADP was used in all hole sections of an ERD well. The trial was designed to quantify the torque & drag reduction potential of the full ADP drill string and to capture operational learnings to optimize future ADP applications.
New Routes to Achieving Well Integrity in Challenging Well Scenarios
Authors: McNicol Jim , Bakken Sverre , Haavardstein Stein 
Published: March 2015

Abstract
In a recent North Sea well, an overburden section with weak zones, faults and a shallow set 13-3/8 in. casing shoe represented a significant challenge to achieving annular integrity during well construction.
The solution was to employ a new flexible, inner-string stage-cementing system and use unconventional circulation paths to achieve two important objectives for the operation. Firstly to build a cement foundation around, and 650 feet above, the 10 in. casing shoe. Secondly to lift cement to just below the 13-3/8 in. casing shoe to isolate weak zones with precise cement placement. Two selective-opening cementing valves were run in the 10 in. casing string above a tag-in shoe, with the upper valve to be opened on the trip in by an inner-string assembly and the lower valve left closed.
A small first stage cement job was performed with an inner-string through a tag-in shoe to take cement up the annulus to cover and isolate any potential weak zones or small faults yet stop short of the lower cementing valve. The lower cementing valve was then shifted open by the inner-string assembly and a second stage cement job circulated through the lower cementing valve up the annulus and into the upper cementing valve, 5, 000 feet higher up, where returns were taken back into the casing. Both cementing valves were shifted closed and permanently locked by the inner-string assembly on the way out; the valves are rated V0, gas-tight to API 11 D1, ISO 14310 and ISO 14998. The entire cementing operation was carried out by an inner-string assembly on a single trip leaving an unrestricted full bore behind.
The paper will discuss in detail the technical challenges of the operation, how they were overcome and the opportunities arising from using gas-tight selective-opening cementing valves.
Field Testing and Applications of a Smart Flow Diverter
Authors: Spreckelmeyer Niko , Regener Thorsten , Clemmensen Carl C. , Eidem Morten , Grindhaug Gaute 
Published: March 2015

Abstract
In liner drilling operations, the annular velocity of the drilling fluid drops significantly when it transits from the narrow cross section of the openhole-liner annulus into the increased annular volume between the casing and the drillpipe. The reduced annular velocity above the liner can cause critical hole cleaning problems that can jeopardize the entire drilling operation and, therefore, must be managed. To effectively mitigate this problem, a major operator and service company jointly developed and tested a smart flow diverter that can be positioned in the drillstring directly above the liner running tool.
The flow diverter (FLD) is designed as a standalone tool that can be placed anywhere in the drillstring and is independent of the measurement-while-drilling (MWD) service-supplier. It can be used in different applications, e.g. under-reaming operations and liners without tieback, where enhanced, continuous hole cleaning is required. The fluid bypass of the flow diverter is simply activated either by drillstring rotation and flow or by a flow pattern signal if string rotation is not possible. These surface manipulations are recognized and interpreted by the flow diverter sensors and electronics. The concept enables an unlimited amount of activations and both activation principles can be incorporated into standard connection procedures, thereby eliminating nonproductive time (NPT).
The FLD went through extensive testing and was run in steerable drilling liner and in other applications. The paper presents the features and activation principle of the technology, its benefits and field experience in combination with steerable drilling liner (SDL) technology and how the utilization of the technology in an underreamer application resulted in an optimized bottomhole assembly (BHA) design preventing previously experienced formation washouts.
Downhole Automation Using Spline, Catenary, and Clothoid Curves Based On Minimum Wellpath Energy
Authors: Yi Ping , Samuel Robello 
Published: March 2015

Abstract
To design a correction wellpath with minimum energy to return a deviated path to the planned well trajectory, an experimental downhole drilling automation is set up and applied. The criterion used to select the best curve between the deviated point and target point is the minimum well profile energy model. This criterion considers curvature and torsion together, which supplies an advanced qualification of wellbore quality. In the consideration of reducing wellbore fiction, unconventional curves are coupled in the wellpath design. Catenary, spline, and clothoid curves supply curvature bridging in transition zones as they make the wellpath smooth. Several survey points are set to check the coordinates for bit moving. The balanced average method, minimum curvature method, and natural curve method are used to build the well trajectory. Finally, this research compares the results of nine optimization models by using different unconventional curves and calculation trajectory methods.
Use of Real-Time Downhole Data Helps Mitigate Operational Risks in Challenging Deepwater Bypass Operation
Authors: Chouquette Peter , Seiler Nancy 
Published: March 2015

Abstract
As technology advances so does the ability to drill deeper and more complex 3D wells. The costs associated with these wells have also increased significantly. In an effort to minimize non-productive time (NPT), one key learning is that utilizing surface parameters alone for decision making is unreliable. To perform many operations, access to real-time downhole parameters can be the difference between a successful or failed operation.
Historically, pre-drill modeling and surface parameters were used for decision making during operations; current technology now allows access to real-time downhole parameters to improve the quality of the information. Understanding real-time downhole parameters can lead to more informed decision making, minimize operational risk, increase operational efficiency and eliminate unnecessary capital expenditures.
This paper describes recent activity in a deepwater subsalt development well involving a very difficult bypass in the 10 3/4 inch × 9 7/8 inch production casing in which a wellbore intervention method that records and makes use of real-time downhole parameters is utilized.
This paper will discuss different stages of the bypass operation where real-time downhole parameters; such as, torque, weight, RPM and bending moment were utilized in making real-time operational decisions. During an operation where the real-time downhole parameters were disregarded an unsuccessful operation resulted.
The stages of the bypass operation to be discussed include:
Drilling:
Fishing operation with a box tap assembly. Fishing operation with a fixed lug retrieval tool (aka Churchhill Key). Clean-out run where the tortuosity/geometry of the hole was analyzed, resulting in the modification of the whipstock BHA and the orientation and setting of the whipstock. Milling a window in the 10-3/4” x 9-7/8” production casing.
Completion:
Compression testing in the 10-3/4” x 9-7/8” x 7-3/4” production casing with water-based mud and ZnBr fluid to optimize completion BHA's.
As drilling, completion and wellbore intervention operations continue to present technical and economic challenges for deepwater operators, using real-time downhole parameters in combination with surface parameters will improve operational results. This paper will demonstrate the use of a drilling mechanics Smart Intervention system and service that helped improve the overall success of a bypass operation.
New Automated MPD System Provides a Step Change in Performance with a Streamline Equipment Footprint
Authors: Couturier Y. , Dow B. , Hardt J. , Leonard T. , Milligan B. , Thow P. 
Published: March 2015

Abstract
Manual choke control has been the staple of many Managed Pressure Drilling (MPD) operations. To be successful manual choke control requires close communication and cooperation with between the driller and the choke operator. Responding to contingency scenarios, such as rig pump failure, is highly dependent upon the situational awareness of the choke operator and the speed at which they can respond. The consistency and repeatability of manual methods is therefore only as good as the choke operator's skill, experience and how well the choke operator and driller work together.
Automated choke control increases the consistency and repeatability of control, as well as the ability to respond to contingency scenarios with little or no operator intervention. However, automation tends to increase the complexity of the equipment needed and changes the competencies required from personnel. Achieving a fit for purpose degree of automation that balances the delivery required to successfully drill the well without adding any more complexity than is absolutely necessary is therefore a challenge.
This paper describes a new automated MPD system that was developed with the goal of providing increased performance while minimizing any additional complexity. The new system had to be capable of providing pressure trapping, to be able to manage multi-step pressure/flow pump ramp schedules, and yet had to have a similar physical footprint to and work with existing equipment. The technology was evaluated in terms of ability to control, setup time, ease of use, and ability to perform the scope of work required.
The system represents a step change in performance compared to manual MPD and yet maintains a streamline equipment footprint.
Analysis of the Impact of Wellbore Tortuosity on Well Construction Using Scaled Tortuosity Index and High-Resolution Continuous Surveys
Authors: Lowdon Ross , Brands Sjoerd , Alexander Gregg 
Published: March 2015

Abstract
The increasing complexity of wells currently being drilled has led to considerable innovation in the oil and gas industry. The advent of rotary steerable systems has improved average rate of penetration (ROP), borehole quality, and, therefore, well construction times. In addition, the improvement in well placement technologies, such as deep resistivity measurements, has enables greater geological certainty in well placement. However, there is a trend towards increased trajectory complexity due to geosteering, which has led to the possibility of higher unplanned tortuosity. This will have an impact on the well construction as problems related to torque-and-drag can be expected to increase. These problems include increased casing and completion running times and possibly other types of problems, such as reduced wireline or logging-while-drilling (LWD) log quality and cementing problems. The improvement in continuous surveying techniques, which provide high-resolution surveys while drilling, enables a greater insight into the true trajectory of a wellbore and provides a more realistic input trajectory for torque-and-drag modeling.
A study comparing wells with different drive mechanisms highlighted the difference between standard 30-m (90-ft) surveys and high-resolution surveys built from standard and continuous survey measurements in the context of torque-and-drag modeling. An analysis was conducted of the wellbore tortuosity described by high-frequency continuous survey using finite-element drillstring modeling. Identifying the impact of various drive mechanisms provided insight into the level of tortuosity that may be expected on typical horizontal geosteered wells, buildup sections, and tangent sections. Findings from this study were combined with those from previous papers published on tortuosity to deliver results based on multiple wells. Recommendations stemming from this work include torque-and-drag requirements and improvements to drilling practices that will enable an improved ability to drill for completion.
The Macondo Inflow Test Decision: Implications for Well Control and Non-technical Skills Training
Authors: Thorogood John L 
Published: March 2015

Abstract
Information in published reports is used for this paper to review the events leading up to the Macondo loss of well control. Avoiding as far as possible the trap of hindsight, it offers an alternative interpretation based on ambiguities inherent in the data to suggest how the resulting decision could have appeared logical given the series of cues with which the crew was presented. The implications of these findings on initiatives currently underway in the industry relating to enhanced well control and crew training are considered.
A brief background is provided to some of the key psychological concepts related to the incident, including risk aversion as well as other biases that can influence teams in a similar situation. How hindsight bias can affect subsequent interpretations of the event is also discussed. By describing a scenario in which data are open to misinterpretation, it becomes evident how an incorrect conclusion can be reached with the ensuing decision leading to an unexpected outcome. Comparisons are made with accounts of other well control incidents available in the public domain as a cross-check on whether similar influences could have played a part elsewhere.
Analysis of Macondo and other similar incidents highlights the general rule that when there is ambiguous information and the potential for multiple interpretations, a natural tendency is to choose the least threatening scenario. Once an explanation is accepted, decision makers tend to hold onto it and discount information that undermines it until the situation evolves to a point where the evidence to the contrary cannot be ignored.
It is concluded that unless crews and supervisors are trained to be vigilant for potential ambiguities as part of their day to day activity, i.e. instilling a sense of chronic unease, it is unlikely that they will be capable of recognising, and pre-empting, an unusual but rare situation when it happens. Furthermore, future incident investigations should go beyond technical or managerial explanations of incidents to include an in-depth consideration of the human factors aspects as, at present, causes of incidents are simply put down to “human error” without sufficiently enquiring what might have triggered the error in the first place.
Cement Displacement and Pressure Control Using Magneto-Rheological Fluids
Authors: Nair Sriramya D. , Wu Qian , Cowan Mike , van Oort Eric 
Published: March 2015

Abstract
Competent cementing to achieve lasting zonal isolation is a crucial requirement during well construction. Key to achieving a good cementation is proper displacement of drilling fluid out of annular spaces and placement of the cement in them. The viscosity contrast between drilling fluid, spacer(s) and cement as well as centralization of the casing in the wellbore are important variables affecting displacement efficiency. For instance, when the casing is not well-centralized in the wellbore, fluids flow more easily and faster through the wider annular gap, while displacement lags behind and may be incomplete in the narrower gap. Such non-uniform displacement and/or incomplete cement placement can lead to unreliable zonal isolation, which in turn may compromise the productive life of the well.
In this paper, a new cementing technique is presented wherein the rheological properties and the flow direction of the cement slurry can be controlled in real-time to achieve more uniform displacements, even when casing is not optimally centralized. This new technique is based on the principles of magneto-rheology, where an external magnetic field is applied to a cement slurry carrying magnetic particles. In the presence of the magnetic field, the viscoelastic properties of such a modified slurry change instantaneously to cause a stiffening behavior characterized by yield point values that are increased by several orders of magnitude. By varying the intensity and the direction of the magnetic field as well as the dosage of magnetic particles, the flow properties of the slurry can be altered and the flow can be beneficially directed as desired.
The magneto-rheological behavior presents other benefits as well. The instantaneous stiffening effect when a magnetic field is switched on can be exploited to generate temporary top-, bottom- or straddle packers for pressure control, and the specific sensitivity of the magnetic slurry to an external field may be exploited for sensing the quality and integrity of cement sheath over the life of the well. Voids, gaps or cracks in the cemented annulus cause disturbances of magnetic field lines that may be picked up by suitable detectors.
Novel Filter Cake Breaker Design and Successful Use for OHGP Carrier Fluid
Authors: Bulgachev R. , Duran W. , Harpley G. , Hurst G. , Lee R. , Twynam A. , Thay T. , Sookoo A. 
Published: March 2015

Abstract
The Serrette and Savonette gas fields offshore Trinidad will be developed through use of open hole gravel pack (OHGP) completions. This completion type was chosen as the preferred completion technique for sand control for these fields. Due to a wide range of expected fluids densities required, the fluids design considered both monovalent and divalent brine as the base fluid for water-based reservoir drill-in fluid (RDF), completion brine and gravel pack carrier fluid (GPCF). Low pore pressures in the field did not allow applying high drawdowns during backflow of the wells, therefore chemical breaker technology was recommended by the Operator to be included in the fluids package to assist with filter cake removal and wells clean-up. The large pore throats of the formation necessitated the use of a high concentration of coarse sized particles in the RDF for bridging which caused a considerable decrease in retained permeability and potentially plugging of gravel and screen from assurance laboratory testing. High overbalances used during drilling potentially would exascerbate any near wellbore damage from the use of water based fluids.
Most of the commercially available filter cake breakers are compatible only with monovalent brines and the acid precursors in use could not guarantee the low corrosion requirements required, nor result in ideal rheological properties expected from the GPCF over time since Hydroxy-ethyl-cellulose (HEC) was selected as the viscosifier to transport and deposit the gravel.
GPCF with incorporated breaker, composed of a novel chelant compatible with divalent brines and a buffer, was chosen as a solution for the Serrette project. The system was modified for successful use on the Savonette Field. Screening tests were performed by the supplier to obtain an optimized formulation that would satisfy GPCF requirements and logistics. The final formulations were tested and approved at the operator's fluids laboratory. Several wells have been completed using the procedure and products. All have achieved outstanding production rates. The flow initiation pressures measured during wells start-up were noted to be less than those historically seen in the field.
The GPCF with incorporated breaker is believed to have assisted with filter cake removal and well clean-up and also contributed to the fact that the gas requirements from the project have been met. The paper will focus on the development of fluids package for successful implementation in the field to deliver the wells and planned gas production.