bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cemented Completions and Through-Tubing Coiled-Tubing Drilling Enable Significant Cost Reduction in Mature Gas Fields
Authors: Ebrahimi Arian 
Published: November 2018

Abstract
A novel well concept to unlock reserves from mature gas fields in Northern Germany has been developed. This concept combines cemented completions with through-tubing coiled-tubing drilling to enable significant cost reductions using ultra slim hole drilling in sour gas bearing, Upper Permian Zechstein dolomite reservoirs.
Once gas reservoirs mature, drilling of conventional infill wells can quickly become economically unattractive. Often this leaves resources untouched and it limits the economic life span of a field. To improve the economics of infill drilling in deep and mature gas fields significant cost reductions are necessary. These cost reductions can be achieved by changing the proven, yet costly, casing scheme to an ultra slim hole well concept. Besides unfavorable economics another challenge while drilling with conventional technology in mature fields can be the reduced inflow performance caused by formation damage. This challenge can be overcome by under- or at-balanced drilling, which is enabled by through-tubing coiled-tubing drilling.
Despite improved efficiencies gained from knowledge by drilling many offset wells, the estimated gas volumes are not sufficient to justify drilling of new wells with the established and conventional well design. Therefore, the operator prepared an advanced ultra slim hole well concept. The casing shoe setting depths remained unchanged, however the hole sizes are reduced significantly. The openhole reservoir section is changed from 5.875-in to 2.5-in and this section is drilled with coiled-tubing and through the installed completion. The size of the completion is selected to be 3.5-in and it is cemented in a 4.125-in hole. In this application, the cemented 3.5-in completion eliminates an entire 7-in liner that would be necessary in the conventional casing scheme. The remainder of the ultra slim hole well is drilled with a 5-in drilling liner, a 7-in intermediate casing and a 9.625-in surface casing. This needs to be compared with the conventional casing scheme comprising of an 18.625-in surface casing, a 13.375-in intermediate casing, a 9.625-in production casing and a 7-in liner. The reduction in cost is estimated to be in the order of 40%.
The presented concept can enable significant cost reductions and by applying this ultra slim hole concept further infill drilling in mature gas fields can become more economically attractive. Moreover, formation damage can be overcome by underbalanced drilling, which is enabled by drilling through-tubing with coiled-tubing. The synergies created by combining cemented completions with coiled-tubing drilling are presented in this paper.
A Method for 3D Saturation Modeling with Drainage and Imbibition Cycles
Authors: Darous Christophe , Raina Ishan 
Published: November 2018

Abstract
Typical saturation height modeling assumes that the migrated hydrocarbon has displaced water under primary drainage until pressure equilibrium controlled by buoyancy, pore throat size, and the position of the free water level (FWL) is reached. When leakage of the caprock or a structural tilting after migration occurs, a shallower position of the new FWL involves an imbibition cycle to represent the initial saturation distribution in a 3D reservoir model.
The methodology starts at the well level by building drainage saturation height functions (SHFs) typically from core capillary pressures (Pc) experiments, in relationship with the reservoir rock typing scheme. The following step involves the construction of the scanning curves that will revert any primary drainage saturation into an imbibition cycle. Then, considering the position of the actual FWL defined from pressure gradients, the position of the paleo-FWL (PFWL) in each well is solved to best match the water saturation profile computed from logs. The resulting PFWL is mapped to implement the saturation height modeling in 3D.
A synthetic case, of tilting after migration is used to illustrate the methodology. The rock typing scheme and the petrophysical properties from logs are coupled with the saturation height modeling defined from Pc core experiments. The typical inconsistencies between the saturation profiles computed from logs and the position of the FWL from pressure gradient that cannot be resolved with drainage SHF are described. The interpretation of the PFWL improves the understanding of the migration episodes and geological events. The implementation of the methodology in a 3D model provides a more accurate hydrocarbon in-place calculation and perspectives for improving recovery and field development strategy.
Methodologies to build 3D saturation height models in drainage consistent with reservoir rock types are common practices. The equations for modeling water saturation by including an imbibition cycle have also already been defined. The developed workflow combines both methodologies to initialize a 3D static saturation model that honors the fluid fill history associated with imbibition and is consistent with petrophysical properties of the reservoirs. The method has been fully coded into commercial software and can be readily implemented to real case studies.
Innovative Field Trial Results of Flangeless Grooved HDPE Liner Application in a Super Gigantic Field for Oil Flow Line Internal Corrosion Management
Authors: Amabipi Abby Kalio , Salem Marwan Hamad , Grandhe Siva Prasada , Gupta Tijender Kumar , Awadh Mohamed Ali , Herbig Nicholas , Schell Jeff , Compton Ted 
Published: November 2018

Abstract

Objectives
The ADNOC super gigantic onshore field suffered many cases of loss of containment in oil flow lines due to internal corrosion. The loss of containment caused by internal corrosion and need to determine specifications and accurate future flow line integrity management plan, led to a field trial application of Grooved and Flangeless HDPE Liner technology in 3.0km Schedule 80 API 5L Gr. B 6"flow line to eliminate this problem in the super gigantic ADNOC Onshore Field.

Methods
The field trial was initiated in June 2011 and installed in April 2012. The HDPE lined flow line was monitored for 5 years between April 2012 and December 2017. This paper presents the detailed extrusion of the HDPE material, installation, thorough monitoring program, results and integrity challenges of the technology validation in 3.5km and 3.0km pipe lines. A rolling machine reduced the OD of HDPE liner by 7% before drawing into the flow line by a pulling machine, the HDPE OD expands back to full size in the flow line. The trial was monitored closely with intensive program. An optimization process was followed (frequent monitoring of test spool vent, sample analysis, possible re-injection of any flow line vent pressure) assisted by thorough testing and analysis at the Borouge Innovation Center (BIC).

Results
This paper describes the successful 5 years field application of HDPE Liner as a cost efficient innovative method that eliminates oil flow line internal corrosion and ensures that Asset value is maximized. The results show that there is no chemical degradation after 5 years of use in oil well, few scratches were found that did not propagate into cracks. The outcome of this technology is a major breakthrough of a cost efficient technology for Company oil flow line internal corrosion management. Field validation of this technology had a positive impact on operator's flow line integrity management, giving more options for proactive flow line internal corrosion management and resulting in total cost reduction and improved HSE performance. Additionally, results from 6 spool sections of the tried oil flow line allows for extending the cost effective HDPE Liner technology to oil flow lines with less risk associated. This technology eliminates internal corrosion threats with huge Opex savings in chemical treatment programs as no chemical treatment is required.

Novel
This paper explains the value added to the company and the feasibility of using grooved/ PERT liners for high temperature and high GOR oil flow lines for maximum benefits. Finally, the paper advances knowledge in the clear impact on the internal corrosion management process that guarantee proper flow line design strategy that prevents uncontrolled release of hydrocarbons (oil) and loss of containment caused by leaks due to internal corrosion.
An Integrated Multidisciplinary Approach in the First Extended Reach Horizontal Well in an Undeveloped Reservoir: A Case History, Offshore Abu Dhabi
Authors: Al Hassani Sultan , Altameemi Ibrahim , Khan Owais , Ahmed Shafiq , Serry Amr , Fares Wael , Essam Ramy , Aki Ahmet 
Published: November 2018

Abstract
The undeveloped sublayers of the prolific offshore Arab reservoir were recently targeted for appraisal drilling, aligning with the ever-increasing efforts to expand production and book new reserves. The first extended reach horizontal well was drilled in this field to evaluate the economic potential of four different reservoir sublayers. Reservoir characterization and the evaluation of lateral permeability changes were the primary objectives for these low permeability layers. Maximizing reservoir contact while maintaining minimum borehole tortuosity presented substantial geosteering challenges. Another challenge is that the bottomhole assembly (BHA) must be free from radioactive chemical sources.
A well placement workflow was developed that honors the structural geological setting, based on the existing field knowledge and offset petrophysical data. The optimized BHA consists of a point-the-bit rotary steerable system (RSS) and logging-while-drilling (LWD) sensors. These LWD sensors include high-resolution microresistivity imaging, laterolog resistivity, azimuthal multipole acoustic, nuclear magnetic resonance (NMR), ultrasonic calliper, and near-bit azimuthal gamma ray sensors.
High-resolution microresistivity imaging and the near-bit azimuthal gamma ray sensor were used to geosteer in the thin reservoir subunits and to facilitate fracture identification. NMR was used to help remain in sweet zones in real time and to provide pore size distribution, based on T1 measurements for permeability evaluation. Acoustic and high-resolution image data were used to derive empirical permeabilities.
The 8,000-ft horizontal section was successfully geosteered with 100% reservoir contact, tapping into four thin reservoir sublayers. Real-time high-resolution microresistivity images, dip picks, and near-bit azimuthal gamma ray data helped to maintain the wellbore attitude parallel to the stratigraphy within each sublayer; they also facilitated a smooth transition from one sublayer to the next with minimum borehole tortuosity, aided by the point-the-bit RSS and at-bit inclination measurements.
Fracture evaluation from high-resolution images, NMR, acoustic, and image-based permeabilities are integrated with production log results to enable a better understanding of the field, to benchmark flow unit identification in these undeveloped reservoirs, and to optimize future geosteering and petrophysical data acquisition requirements.
The traditional reactive geosteering concept is challenged by placing the 8,000-ft extended reach section in four different sublayers that are as thin as 3 ft true stratigraphic thickness (TST) without penetrating any boundaries.
The multidisciplinary approach helped to assess the economic potential of these undeveloped layers within the local reservoir sector and to formulate plans for a future field development program.
Mitigating Wellbore Stability Risks through Geomechanical Solutions
Authors: Hamid Osman , Al Qahtani Adel , Alamer Sarah , El Sherbeny Wael 
Published: November 2018

Abstract
Geomechanical modeling is a key driver in attaining optimum wellbore stability while drilling horizontal wells in the orientation of the minimum horizontal stress (Shmin).
Although geomechanical modeling remarkably helped to obtain best estimates on minimum required mud weights for ensuring stable wellbore, these models still have uncertainties along the horizontal wellbores. Multiple factors contribute to wellbore instability such as lateral changes in rock mechanical and strength properties, formation pressure, and localized digenetic effects. An improved geomechanical workflow has been developed to manage uncertainties and enhance operational efficiency.
The proposed methodology is composed of calibrated geomechanical models for wellbore stability assessment that to be applied for upcoming planned wells during drilling operations. A number of key parameters were identified to build customizable geomechanical solutions and deliver stable wells. These key parameters include occurrence and sequence of strong/weak formation intervals and risk of differential sticking across depleted intervals. Each plan well requires a solution that includes computation of minimum required mud weight, formulation of mud system to handle multiple failure mechanisms, design of Logging-While-Drilling (LWD) Bottom Hole Assembly (BHA), and real-time geomechanical monitoring.
Upon implementation of this methodology, the horizontal well was drilled successfully in a controlled manner. In this paper, an experience is highlighted to demonstrate the effectiveness of customized geomechanical solutions. It discusses the implementation of geomechanics at a specific sub-surface condition to attain the best result. In this study, there was a high risk for wellbore instability while drilling through highly stressed formation in minimum stress direction.
The task was approached in a systematic way with a core objective of ensuring practical implementation of geomechanics findings, and follow the recommendations to mitigate wellbore stability related issues. There were two options that were been evaluated in this paper to prevent and mitigate wellbore stability, the first one is to low mud weights together with wellbore surveillance using real-time technolog, the second on is to use higher mud weights using sealing polymer and proper mud system formulation to avoid differential sticking.
What's the Difference Between Lean Construction and an Operations Science Approach to Project Delivery?
Authors: Shenoy Ramachandra 
Published: November 2018

Abstract
Project Management aims to address the myriad technical, human, organizational and managerial issues encountered during project execution [1]. Over the past two decades, different variants have emerged, including Lean Project Management, Agile Project Management, Scrum, Theory of Constraints and Extreme Project Management, to name a few. Lean Construction [2,36,54] utilizes concepts originally from Lean manufacturing and applies them specifically to the delivery of projects in the construction sector.
Despite the proliferation of different "flavors" of project management, major capital project outcomes in construction and in other industries remain poor [3 – 5]. Industry practitioners face a confusing array of differing methodologies, each claiming to address poor project performance. Project Production Management (PPM), based on operations science principles well-established in industrial engineering, addresses the gap between today's poor project performance and what is possible, thereby differentiating PPM from other methodologies.
Here, we focus on a comparison between PPM and Lean Construction. We trace the historical evolution of Lean Construction from its roots in Lean manufacturing, highlighting the operations science foundation underlying both Lean and PPM. Lean Construction covers aspects of project governance, organization of project stakeholders and the work activities of the organization. In contrast, PPM focuses on the organization and control of project work activities. PPM's deeper focus on the execution of work activities results in quantitative, predictive outcomes, validated by practice, that address poor project execution performance.
Advanced Logging-While-Drilling Cased Hole Sonic for Real-Time Cement Evaluation and Formation Slowness - Case Studies from West Africa
Authors: Murray Doug , Ghia Gabriele , Pouty Miguel , Blanckaert Thibault , Turner Michael , Balou Efficience 
Published: November 2018

Abstract
The acquisition of high-quality logging-while-drilling (LWD) cased-hole borehole sonic data in real-time (RT) and in memory (RM) dramatically improves drilling efficiency. RT sonic waveform amplitudes and slowness-time-coherency (STC) measurements enable qualitative cement evaluation either while running in hole (RIH) or when pulling-out (POOH). Operators can make appropriate decisions on cement quality to either continue drilling or perform remedial work. Data acquisition is transparent to drilling operations, removing wireline logging that can contribute to additional time and cost.
Furthermore, with RM data a quantitative cement evaluation can be performed, and when environment conditions are adequate, formation compressional slownesses through casing can be computed.
The advent of the latest LWD sonic acquisition technology and related processing techniques has significantly reduced the challenge of cased hole LWD sonic acquisition. More powerful sonic transmitters, improved receivers, altered transmitter-receiver spacings, and fundamental changes in tool design have meaningfully improved the acoustic signal-to-noise ratio. An improved understanding of LWD cased-hole borehole acoustic modes, the ability to transmit acoustic energies at more optimal frequencies, and the capability to simultaneously acquire cement evaluation information have all contributed to improved LWD cased-hole sonic logs.
Cementing is essential to well integrity, it supports casing and provides zonal isolation. Historically, quantitative cement evaluation has been acquired via wireline (WL) tools, the most common being the cement bond log (CBL), a principle based on the amplitude of casing arrivals. LWD sonics have historically been used for top of cement (TOC) logging, which shows cement presence or absence behind casing and is a quantitative cement evaluation. Contrary to WL CBL tools, LWD tools have a steel collar that permits acoustic propagation. As such with LWD tools it has been difficult to separate casing signals from those in the tool collar (Kinoshita, 2013). In poorly bonded conditions, the casing amplitude is much larger than the collar arrival. In well-bonded conditions, the casing signal is weak and can be less than the collar arrival.
From multiple cased wells in Deep Water Offshore West Africa, this paper demonstrates the application and results for the latest LWD sonic tool and processing techniques for the following; RT TOC evaluation while RIH before drilling out the casing shoeQuantitative cement evaluation from tool memory waveform dataFormation compressional slowness through casingApproximately US$450,000 saving compared to wireline runs
Integration of Penta-Combo LWD Measurements for Petrophysical and Geomechanical Feasibility
Authors: Elabsy Islam , AlTurkey Shaikha , Alhazzaa Shaimaa , Dutta Abhijit , Belhouchet Mohamed , Abba Abdessalem 
Published: November 2018

Abstract
Advanced levels of depletion cause unexpected reduced pore pressures and thus reduced reservoir fracture gradients, presenting considerable drilling challenges in the Burgan Field in Kuwait. This can lead to matrix damage due to mud losses and result in borehole collapse due to the relative increase of effective stress concentration in the vicinity of the borehole. The area of the study showed high levels of non-productive time (NPT) as well as increased costs due to the drilling of unplanned sidetracks in highly deviated wells. LWD Penta-combo measurements including azimuthal sonic and formation pressure have been utilized to model fracture gradient and borehole collapse gradient in real-time, and proved effective at reducing risks and rig time by allowing proactive management of these challenges.
Borehole collapse in offset wells was analyzed to predict and simulate the wellbore stability of a planned well via a pre-drill geomechanics model prior to drilling the well. The well was planned with a high deviation of 56° and oil based mud. The salinity of the water phase was recognized as an essential factor in assessing wellbore stability risk with respect to shale-dependent time failure.
The integration of real-time LWD sonic and density data with formation pressure testing data in the geomechanics model for the first time in the 12 ¼-in. section showed excellent correlation and confirmed different levels of depletion in the reservoir. Uncertainty in the modeled fracture gradient was significantly reduced and effectively eliminated with the inclusion of real-time formation pore pressure testing data. This successful combination of modeled pore-pressure curves from the real-time LWD sonic data with the real-time formation pressure test data acquired while drilling in the same run is a first in Kuwait. A total of 15 pressure points were sampled in real time while drilling, allowing for proactive mud window optimization and borehole stability geomechanical analysis.
This real-time wellbore stability technique based on advanced LWD azimuthal acoustic technology in conjunction with real-time formation pressure testing while drilling has been developed with a unique process and workflow allowing the operator to drill the well with no significant wellbore stability issues and with the optimized shape of the borehole for a safe casing run. In addition, NPT was reduced to 0 hours and overall days per well were reduced significantly.
Delivering and Sustaining Step Changes in Drilling Performance Through a Physics-Based Digital Workflow Application
Authors: Davis J. Ryan , McClain Eric E. , Al Sawafi Jamal , Al Maskari Iman 
Published: November 2018

Abstract
In 2015, the operator deployed a global initiative that focused on using physics-based principles to optimize various aspects of the well construction process. The initial rollout emphasized optimization of on-bottom drilling time utilizing mechanical specific energy (MSE), and this was successful in generating step changes in performance. The success of this initiative, and the internal and external marketing of that success, laid the foundation for the physics-based digital workflow developed in the operator's international business unit in Oman during the second quarter of 2017.
The drilling teams launched a proof of concept in Oman in July 2017 to test the workflow. Throughout the proof of concept, the workflow was digitized, and it evolved into a robust web-based application to serve as the framework to facilitate consistent, repeatable, and scalable execution of the physics-based workflow. The purpose of this paper is to illustrate the benefits of utilizing a physics-based workflow as well as to describe the innovative approach the operator used to execute the physics-based workflow. The workflow overview, proof of concept results, challenges, and future opportunities are discussed in detail.
During the proof of concept, which lasted from July 2017 through August 2018, field personnel from eleven drilling rigs submitted over 4,000 entries into the digital workflow application. Office-based personnel then launched 32 design projects, addressing more than 200 of the issues identified. Of those 32 projects, 17 were completed within the specified period. In one particular field, the drilling team achieved a 20% reduction in well cost and a 27% reduction in drilling days on location by using this digital workflow. Overall, both drilling teams in Oman experienced tremendous performance gains throughout the proof of concept, with one team achieving a 72% increase in footage drilled per day, and the other achieving as much as 32%. The success of the proof of concept led to the operator's decision to deploy this web-based application and digital workflow globally in the second half of 2018.