bluuebunny/crossref_metadata_2025_split huggingface dataset:
Getting to Grips with Human Factors in Drilling Operations
Authors: Thorogood J.L. , Lauche K. , Crichton M. , Pollard I. , Hviid L.B. , Verweijen B. 
Published: March 2015

Abstract
Since the events on Montara in late 2009 and Macondo in 2010, the exploration and production industry has undergone a substantial change in culture and regulation. However, investigations still tend to focus on technological and managerial deficiencies rather than probing deeper into the causes of human error. Nonetheless, facilitated by organisations such as International Oil and Gas Producers Association (OGP), there is a growing desire to understand human and organisational factors that influence potential process safety incidents during drilling and completion operations.
A workshop was held in London in October 2014 to define and clarify the underlying ideas about human factors related to the drilling community. The objectives of the workshop were:
Introducing the concepts behind human factors and key definitions Highlighting the effects of human factors in drilling operations Operationalising human factors and the impact of the introduction of new technology Implementing training and assessment of non-technical skills Taking human factors into the mainstream of drilling operations
Attendees at the workshop discussed the principles underlying the psychological concepts of human factors, such as non-technical skills, cognitive bias, weak signals and chronic unease, as well as socio-technical systems and the impact of automation. Examples of how the influences of human factors may be recognised in routine drilling operations and how biases affect decision-making were examined. Practical applications of human factors techniques were described, along with methods currently being implemented to train and assess non-technical skills. The workshop culminated in a debate about how to operationalise human factors in drilling operations.
The main points to emerge from the presentations and ensuing discussions are summarised and references are provided for further reading. Practical tools and insights that can be applied in day-to-day operations are also presented.
In conclusion, workshop presenters and attendees, whilst acknowledging the importance of human factors on drilling operations, also recognised the challenges yet to be overcome in implementing human factors principles in the workplace. However, there are some positive signs of growing acceptance and influences. By facilitating open dialogue about human factors in drilling the goal is to encourage progress towards human factors integration being the norm rather than the exception.
Bit Trip Optimizer: Just in Time Bit Trip Decision Model
Authors: Kuesters A. , Wingate J. 
Published: March 2015

Abstract
This paper presents a model which aids the decision making process to determine the optimum point to trip out of hole to change a dulled drill bit.
Drill bit interaction with abrasive rock and impact damage due to vibrations causes the state of wear or damage to cutters to increase. This results in a slower rate of penetration (ROP) than with a new bit with sharp cutters. The operator faces the question whether or not to take the time to pull the bit out of hole and change it for a new one. A delayed or a premature decision of when to pull the bit can add to the overall project cost.
In the past the decision has been made using either the operator's experience or a simple cost model projecting a single bit run into the future. The model presented in this paper optimizes the bit strategy for an entire well with multiple bit runs to obtain the most economical choice of bits and bit trip strategy. The model can be used during planning, in real time implementation and for post well performance analysis. In particular, during real time and post run evaluation the model can be used for performance benchmarking of ROP by comparing an expected rate of progress with the actual field data.
This paper further presents a case study highlighting the value of each of the features of the model including potential time and cost savings. It shows that running the model real time can reduce well costs significantly in hard rock areas. The deployment of the model is not limited to any specific application and can save costs on any well where the operator has a requirement for multiple bit runs and a good understanding of drilling performance through numerous geological intervals.
Durable Bit Coating Reduces Shale Balling in Field Tests and Contributes to Longer Runs
Authors: Radford S.R. , Patel S.G. , Dee K.C. 
Published: March 2015

Abstract
Shale agglomeration or balling onto PDC bits is a problem in the oil drilling industry, reducing drilling speed and requiring costly bit trips to clean or change the bits. A new polymer-based bit coating was developed and introduced, which is proving to be very effective at reducing shale bit balling and is significantly more durable than previous polymer bit coatings.
This paper documents a previous coating from the same service company was superior in balling resistance compared to non-polymer coatings, such as metal or electrically charged coatings, and doubling the rate of penetration (ROP) in a Malaysia application. A new coating, and the subject of this paper, was developed and proven to be as effective but significantly more durable. The development of this new coating, its set of requirements and its intensive testing process are presented.
The authors document the history of utilizing different types of bit coatings to reduce formation balling and present limited comparisons between coatings. A set of field tests is presented wherein the new coating was applied to twenty of 233 bits run in similar wells and formations in Prudhoe Bay, Alaska by a major oil and gas exploration company. In all cases, the bits were 4 1/8-in “ream-while-drilling” eccentric bits run on coiled tubing, which, by nature restricts the flow and bit cleaning, thus increasing the probability of short runs and bit balling. Results, however, showed that the bits with the new coating stayed in the hole longer and maintained much of the coating coverage while drilling an average of 73% further than the similar uncoated bits which exhibited shale balling and ceased drilling.
Comparison analysis is made between the coated and uncoated bits in this case study, utilizing several parameters and perspectives. Cost savings are estimated and the future developments of this technology presented. Examples are summarized of drilling with PDC bits, with and without this new coating in shale balling-prone areas from other regions of the world.
Experiences, Challenges, and Common Recommendations from Performing HAZOP Studies to Identify Potential Hazards Associated to Surface Gas and Mud Handling Systems During Drilling Operations
Authors: Rubiano Carolina , Sullivan Paul , Gil Frederic , Tench Jordon 
Published: March 2015

Abstract
This paper summarizes a number of the challenges encountered and the common findings in HAZard and OPerability (HAZOP) studies related to the surface gas and mud handling systems on drillships, jackups, semi-submersibles, and land rigs. These HAZOP studies are conducted by experienced multi-disciplined teams that combine the operations, engineering, and process safety personnel from both the oil company and the drilling contractor.
Pressure Transmission in Gelled Drilling Fluids
Authors: Oliveira G. M. , Franco A. T. , Negrão C. O. , Vadinal R. B. , Lomba B. S. , Fonseca T. U. , Martins A.L. 
Published: March 2015

Abstract
In deep water environments, the operational window has become narrower and narrower resulting that pressure control within the well needs more accuracy. Pressure differences between the choke line and the stand pipe in a close well operation, usually ignored in the past, may now be a determining factor on the specification of the fluid weight to control a kick. Additionally, pressure changes in the choke line that delay and undermine the transmission to the kill line and to the stand pipe have been receiving much more attention nowadays. The current work proposes a mathematical model to explain the pressure differences, delays and attenuations observed in closed well operations. The model is based on the conservation equations of mass and momentum, deals the problem as transient and compressible and the fluid motion is admitted to be one-dimensional. The drilling fluid is modeled either by the Bingham or the Power law equation. It can be anticipated that the problem is intrinsically transient and cannot be treated by a steady-state model. In addition to that, a pressure difference between two pipe ends, generated by a step change at one pipe end, can either be permanent, in case of a Bingham fluid, or reduced very smoothly, in case of a Power law fluid.
ROP Enhancement in Shales Through Osmotic Processes
Authors: van Oort Eric , Ahmad Muneeb , Spencer Reed , Legacy Nick 
Published: March 2015

Abstract
70%–80% of all formations drilled globally are identified as shales, i.e. argillaceous rocks that contain significant amounts of clays. In addition, the US Energy Information Administration conservatively estimates that 26% of recoverable oil and gas resources of the United States alone are contained in shale formations (EIA Annual Energy Outlook, 2014). Accordingly, there has been an increasing focus on efficient drilling of tight shaly formations, as encountered for instance in long horizontal laterals of unconventional wells. Improvements in PDC bit design and low friction cutter technology need to be mentioned in particular, which have made PDCs the bits of choice in all but the hardest formations.
The question now arises where the next step change in rate-of-penetration (ROP) improvement for PDC bits is going to come from. The answer lies in optimizing the intricate relationship between bit, intact and failed rock, and the drilling fluid. When shales are drilled with PDC cutters, a built-up “detritus” edge of failed rock will temporarily adhere to the cutter and prevent it from cutting new rock effectively. Disrupting this detritus may significantly reduce friction at the bit and improve PDC cutting efficiency. This appeared to be the case when high salinity formate muds were tested in the Deep Trek downhole drilling investigation reported on in 2007–2008. The merits of high salinity formate muds, which significantly out- drilled even oil-based mud at high densities during Deep Trek, were duly noted but never fully explained.
In this paper, it is proposed that the mechanism responsible for the Deep Trek ROP results with formate mud is chemical osmosis, which effectively draws water from the drilled shale and generates a lubricating layer between the cutter and the shale that disrupts the detritus and allows the bit to be cleaned more effectively through the hydraulic nozzle flow, thereby enhancing ROP. Support for the proposed mechanism is provided by an extensive set of laboratory tests, ranging from simple hot-rolling tests that measure accretion tendencies of shale on steel, to realistic drilling tests on full-scale equipment and actual PDC bits under downhole conditions. The results show unequivocally that high salinity muds yield consistently lower accretion tendency and 50–60% higher ROP in shales, and that the underlying mechanism appears to be chemical osmosis. Moreover, positive results of field trials conducted in Canada, where application of formate fluids allowed oil/synthetic mud drill rates to be significantly exceeded, further support the hypothesis of the merits of chemical osmosis for ROP enhancement. The osmosis phenomenon is well-known for borehole stabilization in oil/synthetic-based muds and high salinity water-based muds, but has never before been deliberately deployed for ROP enhancement in shales.
Managing Marine Geohazard Risks over the Full Business Cycle
Authors: Hill Andrew W. , Wood Gareth A. 
Published: March 2015

Abstract
Until the offshore industry stepped off the continental shelf, the main marine geohazard risk addressed from geophysical data was the presence of shallow gas. Presence had been described using a number of non-standard approaches for its potential presence – distinct from the actual risk it presented to operations. In the 1990 “UKOOA Guidelines for the Conduct of Marine Rig Site Surveys,” a standardised nomenclature was suggested that was largely taken up as a standard by the industry.
At around this point in time, the industry had begun a move off the shelf and into deep water and, with this, a number of new geohazard issues started to present themselves (e.g. shallow water flow, chemosynthetic communities, hydrates and slope instability) for which the industry had no standard approach to assess the risk such hazards presented or to reliably define their presence.
Today the industry is faced with entry into frontier areas, with little prior published understanding, potentially complex slope and deep-water settings, and where the sources of geohazard risk to drilling and developments may be multiple, over printed, and inter-related.
In such settings, early effort in the exploration and production cycle is required to allow appropriate data to be gathered and assessed in appropriate time for drilling and facilities engineers either to avoid identified hazards, or mitigate their presence through appropriate engineering design.
In order to address these issues, BP has adopted a methodology to manage geohazard risks over the “Life of Licence,” starting with assessments of fundamental geohazard complexity and manageability on entry to a frontier area, at the basin or fairway scale, and thence defining an ongoing work programme to support continued refinement in understanding through to and including the abandonment phase.
This includes:
Suggested specific risking criteria for the presence of individual geohazard elements at a well location such that engineers can clearly, and consistently, understand potential hazard presence, Early definition of required data acquisition needs and integrated studies for field development to adopt appropriate risk mitigation methods in engineering design, Through the Operate phase of a field and on to eventual abandonment a system to address lessons and changes are noted with documents regularly updated ahead of additional drilling, field development, or abandonment activities.
The paper will present, and illustrate, the rationale adopted by BP showing examples of outputs produced along the process path, to demonstrate how the approach is delivered in practice.
A Dynamic Dual Gradient Model and its Use for Training Prior to DGD Operations in Norway and GoM
Authors: Svendsen Morten , Bjørkevoll Knut S. , Rommetveit Rolv , Aghito Manuel , Frøyen Johnny , Ødegård Sven Inge , Molde Dag Ove 
Published: March 2015

Abstract
A very realistic training simulator for dual gradient drilling has been developed, and then utilized for training. Realism in the responses that trainees see is ensured by embedding advanced real time downhole mathematical models, which are set up with the planned configuration for each upcoming well.
Dual Gradient Drilling (DGD) capabilities have been developed into an already proven dynamic hydraulic and temperature model. The flexibility of the model allows incorporating additional pumps in the flow, as in Dual Gradient Systems. The model includes dynamic 2-D temperature calculations, covering the radial area affecting the well. To create the Dual Gradient functionality a subsea pump module was developed, including the mud return line. To assure that the simulator behaves realistically extensive work was done, including implementation and verification of the U-tubing effects in the system. The model has been implemented into a virtual reality training simulator which also includes a full 3D topside drilling environment and 3D downhole visualization model.
This unique DGD training simulator has been utilized for training the drilling teams (both drilling team and DGD operational team). First training for operations utilizing the Controlled Mud Level (CML) system in Norway was developed around the training simulator. Then a further development was done prior to DGD operations in GoM, integrating a quick closing annular as well as booster line functionality. The training course was created around the Dual Gradient procedures, including the contingencies procedures with a focus on the communication between the different parties in the DGD operation.
The paper presents the model basis and how this is implemented into an advanced virtual reality training simulator which enable accurate modelling of the upcoming well. Furthermore, the training process of the drilling crews will be presented including lessons learned.
New Quantitative, Analytical Approach Provides Rapid Identification and Diagnosis of Dysfunctional Bit Performance
Authors: Rahmani Reza , Smith John Rogers 
Published: March 2015

Abstract
A complete analytical model for the penetration rate performance of polycrystalline diamond compact (PDC) bits has been developed to support a more rapid identification of drilling dysfunctions and allow more accurate efficiency calculations. The model predicts both rate of penetration (ROP) and torque based on the rock properties, pressure environment, PDC cutter and bit geometry, applied weight on bit (WOB), and rotary speed. The model has been used to identify and diagnose bit balling in full scale pressurized laboratory tests, as well as excessive drillstring torque and drag in the field.
Evidence of global bit balling and cutter balling was found in full-scale drilling tests in Catoosa and Mancos shales using both water base and oil base drilling fluids. Reduction in ROP with increasing WOB was confirmed as a symptom of severe balling, but typically time is required to identify the trend, at which point it is often too late, as severe bit balling is generally irreversible. The model was applied to identify global balling before the onset of irreversible global balling, using specific force ratio signatures. The symptoms were similar in both mud types and were observed to be completely reversible by a applying a timely adjustment of drilling parameters.
A sample application of the model to a southern U.S. shale play has been presented where both surface and downhole drilling measurements were used to evaluate the model. Overall, the model's predictions are in agreement with field data, as the model clearly identifies the occurrence of a dysfunction from change in formation properties and depth. The data also confirms that surface torque can be significantly different from downhole torque, though surface WOB is much closer to downhole WOB.
The proposed model can be used as a diagnostic tool for real-time monitoring of drilling efficiency to identify and diagnose dysfunctions. Because the prediction is based on applied WOB, which can be accurately measured in real time even from surface data, identification is faster than with torque-based equations such as mechanical specific energy (MSE). This provides the opportunity for the rapid mitigation of drilling dysfunctions and reduced ROP.
Well Cost Estimation and Control - Advanced Methodologies for Effective Well Cost Management
Authors: de Wardt John P , Peterson Susan K 
Published: March 2015

Abstract
Managers crave greater confidence in well construction costs, from the inception of a cost estimate for investment decisions, through cost estimation for budgeting, to cost tracking and control during well construction, and finally, for validity of performance tracking and benchmarking. Shortfalls in well cost estimation and control are due to three main sources: lack of defined processes, lack of discipline, and reliance on outdated or poor methodologies. This technical paper describes advanced methodologies for effective well cost management and documents their benefits to decision-makers and the industry. These include processes from the construction industry for cost tracking / control, best practices for estimating using probabilistic methods and leading to a process that can be applied for any well complexity utilizing modern methodologies. The technical content contributes directly to improved decision making by managers for investment in wells, improved planning for better decision making on choices for well design and drilling / completion operations including applications of various technologies, improved control of costs, and improved confidence that performance tracking and benchmarking are based on valid measures.
Assuring the Effectiveness of Well Engineering Operations Through a Company-Wide Internal Audit Process
Authors: Colt Alexandru , Thorogood John , Wirth Stefan 
Published: March 2015

Abstract
The effectiveness and impact of internal audit procedures implemented within an Operator’'s Well Engineering organization is described and how it ensures quality and integrity of the performance in the company’'s operating units. The work is based on four years of internal operations audit data where the results of operations audits have been analysed to identify trends in the levels of compliance and the quality of the technical work carried out in the different operations group.
It is explained how compliance with policies, procedures and standards is set and monitored within the Company and also show the effect of internal audit activities on performance. One of the outcomes of the audit process is the continuous refinement of the audit tools themselves. The audit results also highlight the need to review and refine the well delivery process itself and show correlation between audit results and operational performance. The results provide useful metrics and give an indication of the state of the health of the well engineering organisation.
Multiple Relief Well Planning for an HPHT Blowout in Southern Mexico
Authors: Varela Rodrigo , Iturrizaga Freddy , Patino Diego , Atencio Nixklafe , Romero Daniel , Buitrago Oscar , Pineda Javier 
Published: March 2015

Abstract
Following a catastrophic blowout incident onshore Southern Mexico on the Terra-123 well during due to an uncontrolled leak on the side valve of the wellhead, along with the loss of a barrier in the well, surface capping control operations and planning activities for three relief wells (RW) were initiated to intercept the target well (TW). This paper describes the planning and design process for the three RWs. The main objectives were set to intercept the target well and then killing it safely and efficiently.
The tasks performed for the relief operations included complete project management, well engineering, well bore positioning, communication protocols, hazard analysis and risk control (HARC), casing design, and hydraulic killing simulations.
Wellbore positioning was one of the main challenges due to the gross errors in survey data and local procedures, for this advanced geomagnetic referencing techniques were employed to identify the TW's position and design the RW's survey program. Active ranging techniques for well interception and detection were discarded due to salt interference; therefore, passive ranging and acoustic ranging (BARS: Borehole Acoustic Reflection Survey) techniques were selected as the best alternatives. Additional measurements while drilling (MWD) surface tests were performed to ensure the detection of the target casing. As part of the hydraulic communication design, tubing-conveyed perforating (TCP) was planned as the communication method.
All the RW trajectories were designed to accomplish the kill operation as standalone wells, meaning that the other two RWs are not needed if one is successful. A new casing design criterion to ensure low-risk scenarios during the interception and hydraulic communications was considered. Directional requirements based in the survey accuracy to determine the 3D relative positioning of the target well and RW were defined.