bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tackling the Problem of Ageing Well's Integrity and Rehabilitation in the Arabian Gulf
Authors: Ramasamy Ramesh , Chau Eric , Ibrahim Zainah 
Published: November 2017

Abstract
The Arabian Gulf and the surrounding GCC regions have some of the world's oldest oil and gas fields dating back to the 1930s and 1940s, some of which are still actively producing. From a design perspective, the oil wells in these fields have operated beyond their design lives. However, due to the recent decline in oil prices, there is an ever increasing demand to keep these assets producing for the foreseeable future. It is therefore critical that the asset owners/operators develop a thorough understanding in the health conditions of these aged wells and also to put in place an effective well integrity management system to ensure the longevity of these assets. This paper presents a novel approach towards well integrity management utilising advanced modelling of the well structure coupled with a newly developed non-destructive examination technique to provide the best possible assessment of the health condition of the well system.
An accurate assessment is paramount for operators and assets owners in understanding the health of aged wells in order to continue operate in a safe manner. Traditionally, health assessments are being carried out using original design data and acceptance criteria derived from internationally recognised codes and standards. Whilst providing useful estimation of the condition of these aged wells, these assessments failed to address the actual loading conditions in the well casings. Instead, considerable levels of conservatism/ safety factors are being used, leading to needless underestimation of remaining lives and hence premature remedial works are potentially being carried out at great costs.
A rationalised assessment approach is described herein whereby a set of customised acceptance criteria are being developed based on design data, geotechnical and environmental data, operating history and outcomes from inspection activities. A combination of specialist inspection and re-assessment strategy have also been developed to determine the residual loads within conductor/casings and the corresponding stresses to accurately pin-point current integrity state of these conductors and casings.
The preliminary assessments carried out provides a great insight into the condition of these aged wells, but at a cost of being over-conservative. The criticality prioritisation curves are developed to identify the particular oil well which is being assessed within a certain risk category. The recent development of the specialised inspection tools and methods have reduced these over-conservatisms and thus eliminated the need for premature repairs on effective wells. The entire screening process to identify critical aged wells have also been automated in a computer based scripting for rapid, robust and repeatable use by facility and integrity engineers undertaking overall screening of large number of wells over aged fields.
Digitally Enabled Top Drive
Authors: Holm Anders H. 
Published: November 2017

Abstract
The top drive is designed to provide the highest level of instrumentation to ensure that the operator get total control of the drilling process.
High accuracy sensors and actuators increase drilling efficiency due to better drilling data insight and the ability to respond quickly in a demanding drilling environment that ensures safer drilling operations for the rig crew.
The top drive is suspended from the travelling block using 4 vertical tie rods with an innovative weight on bit (WOB) system. Redundant built-In WOB sensors in all the tie rods provide exceptionally accurate load readings over the entire top drive hoisting range. Accurate WOB measurements is important for the driller to be able to apply the correct downward force needed for the bit to efficiently break rock as well as extend bit lifespan. The top drive’s accurate WOB system decrease the number of time consuming bit runs as the lifespan of each bit is prolonged.
Soft cushioning while doing spin in / spin out pipe connections are controlled using an active tread compensating system in hydraulic cylinders suspended between the travelling block and top drive gearbox. Stroke sensors provide the driller with additional control over actuators and top drive movement which in turn improve operational efficiency and rig safety.
The top drive is powered by two high performance AC motors delivering one of the highest levels of torque and speed. The two 550 HP motors provide 51 000 ft-lb of continuous torque enabling deeper drilling both vertical and horizontal. The motor configuration is designed to be redundant allowing continuous operation at 100% speed and 50% torque if one motor is offline. The redundant individual driven traction AC-motors are crucial to ensure reliability and rig uptime.
Directional Underbalanced Drilling Success With Up to 40% Nitrogen Using Mud-Pulse MWD and Rotary Steerable Technology
Authors: Dolman Lee , Sudron Ken 
Published: November 2017

Abstract
This paper describes the successful use of mud-pulse Measurement While Drilling (MWD) and Rotary Steerable directional systems (RSS) in an Underbalanced Drilling (UBD) environment utilising up to 40% nitrogen. There are few documented examples of mud-pulse telemetry being successful above 20% gas/nitrogen, and fewer with RSS directional drilling technology. It will be shown that reliable mud-pulse telemetry is now achievable at previously undocumented levels of gas injection that has re-defined the operating envelope for two-phase drilling fluid operations with conventional mud-pulse MWD and advanced RSS directional drilling services and technology.
Evolution of Coiled Tubing Fiber Optic Real-Time Telemetry System in Saudi Arabia Ghawar Field Interventions
Authors: Al-Duaij Ahmad N. , Al-Buali Muhammed H. , Ahmed Danish , Arifin Mohammad , Ayob Adzlan , Sa Rodrigo , Pochetnny Valentin 
Published: November 2017

Abstract
This paper will discuss the coiled tubing (CT) fiber optic real-time telemetry system evolution for varied interventions performed in Saudi Arabia’s Ghawar field. The paper will show the benefits achieved with consistent improvement of the CT fiber optic real-time telemetry system, leading to better understanding of intervention and reservoir in real-time, optimization of treatment, opening new horizons and meeting huge successes.
For years CT with fiber optic real-time telemetry, has been used in Saudi Arabia Ghawar field, whereas the initial version of the CT fiber optic real-time telemetry system consisted of 2-1/8 in BHA, comprising measurements of pressure, temperature, casing collar locator, gamma ray, tension and compression and distributed temperature sensing. Though the successes achieved from this system were remarkable, it was restricted to 2-bpm, had temperature limitations, and was not able to bear shocks and vibrations. As the time passed, interventions became more challenging. In order to meet well intervention objectives, a new tool was developed enabling higher pumping rates up to 8-bpm, and working temperatures of 300 °F. The challenge of bearing high shocks and vibrations was still not met, so a new was further designed to meet that objective. In the field, the new tool proved to be the most superior and advanced one, as the CT fiber optic real-time telemetry system gave high pump rates of 8-bpm, worked at temperatures of 350 °F, has a higher pressure rating, and was used in interventions where high shocks and vibrations were encountered. In addition to the above-mentioned CT fiber optic real-time telemetry system evolution, the system was enable to run the logging tools, leading to the development of a CT dedicated downhole flow measurement tool.
These new tools provided the following advantages: optimize the treatment stages during a particular intervention, help operators gain a better understanding of the well and reservoir response during an intervention, assist in optimization of treatment strategy, and enable pre and post-treatment evaluation in minimum CT runs.
This paper will explain the evolution of the CT fiber optic real-time telemetry system, and the significant impact the system has made to the oil and gas industry. The system enables CT interventions in a concise manner where decisions during a treatment are made using both surface and downhole parameters.
Feasibility of Foam Application in a Giant Mature Field Under Miscible WAG Injection
Authors: Bascialla Guido , Montes Jesús , Romero Pedro , Rodriguez Rosario , Del Moral Jaime 
Published: November 2017

Abstract
A giant mature light oil field under miscible WAG injection is a potential candidate for foam application to control gas mobility and reduce field gas – oil ratio (GOR). We conducted a feasibility study which comprised live oil corefloods at reservoir conditions and compositional numerical simulation coupled with a foam formulation. The objectives of this study were to identify critical variables and potential detrimental factors for the process implementation; and evaluate the GOR decrease due to foam application.
This feasibility study comprises an evaluation of the effect of foam on a field scale through numerical simulation, and the study of foam creation under reservoir conditions through coreflood experiments. We used a compositional simulator with an empirical foam implementation to predict the effect of foam in a mechanistic sector model of a high production area of the field. Simulation results show that foam is able to reduce field GOR by reducing the mobility of injected gas in high permeability layers. It became clear that the incremental oil production is strongly dependent on gas production limits; thus, foam application has to be coupled with overall field optimization.
Due to challenging field conditions for foam application, we performed an extended laboratory study. Static mixing experiments allowed surfactant compatibility limits in mixtures of formation and injection brines to be defined. In addition, a series of corefloods showed that foam can be successfully generated with a commercial alpha-olefin-sulfonate surfactant under reservoir pressure and temperature in presence of live reservoir oil, rich hydrocarbon gas and injection brine.
To our knowledge this is the first published feasibility study of foam application in a mature miscible WAG project including compositional simulation and live oil corefloods with rich hydrocarbon gas injection under reservoir conditions.
Base-Line Logging Before Commencement of the EOR Project to Enhance the Chances for Success
Authors: Al-Qenaie A. , Chetri H. B. , Tiwari S. , Al-Twaitan T. M. , AlAbdullah M. B. , Ranjan P. , Aslanyan I. , Prosvirkin S. 
Published: November 2017

Abstract
Successful EOR project management in mature fields depends on proactive planning that includes reservoir characterization and determination of the engineering design parameters. Base-Line logging performed in the pilot EOR pattern before implementation of an EOR project will make possible an early detection of any potential problems and weaknesses to avoid costly subsequent repairs or alterations. The objective of this paper is to demonstrate the results and value of Reservoir-Oriented Base-Line Logging carried out in Sabriyah Field, Kuwait, before ASP injection. The Base-Line logging is focused on the flows behind pipe and any anomalies that might have impact on the project.
Seven new vertical wells were drilled in a selected area within an existing waterflood pattern, to monitor the viability of pilot polymer injection in the field. An integrated suite consisting of reservoir evaluation tools, High Precision Temperature (HPT) and Spectral Noise Logging (SNL) tools, and metal losses evaluation tool (EmPulse), were run on slickline under shut-in conditions. Temperature is sensitive to any lateral flows and possible behind-casing cross-flows between permeable zones. Spectral noise logging can distinguish between noises caused by fluid flows through well completion elements and the reservoir. The idea was to record the wellbore and reservoir initial conditions before any mechanical or reservoir effects begin to influence the EOR performance. Analysis of subsequent Time-Lapse logging would be easier with this base-line information on hand.
The five wells were drilled in a 5-spot pattern in the selected area, with two additional logging well and a sampling well for continuous monitoring. The objective was to check for possible communication of the target reservoir with underlying and overlying formations to prevent off-target chemicals injection, and get a baseline for metal thickness of each barrier. At the same time, it was vitally important to trace the cold injection water propagation in the target reservoir before the EOR started.
Experimental Investigation of the Effects of Rotational Speed and Weight on Bit on Drillstring Vibrations, Torque and Rate of Penetration
Authors: Bavadiya Vimlesh A. , Alsaihati Zeeneb , Ahmed Ramadan , Gustafson Kyle 
Published: November 2017

Abstract
Drillstring vibrations namely axial, lateral and torsional vibrations are the primary reason for downhole tool failure and reduction in rate of penetration (ROP). Factors like bit design, bottom hole assembly, bit-rock interaction, rotational speed, wellbore hydraulics, weight on bit (WOB) and drillstring-borehole interaction affect vibrations, out of which only rotational speed and WOB can be changed in real-time to minimize vibrations. It has been a topic of interest to understand and model downhole vibrations, minimize them and find an optimum range of drilling parameters to increase the drilling efficiency.
This article presents the results of experimental studies conducted on a fully automated drilling rig to examine the effects of drilling parameters on drillstring vibrations, torque and rate of penetration. The study is different in terms of the high-speed range and the use of axial vibration transmitter to measure the vibration severity as per ISO standards. Experiments were performed on two different rock samples with varying strength. Perfect hole cleaning with negligible fluid flow effect was assumed. Each experiment was run for an average of six minutes collecting an average of 120 data points which were then averaged out for analysis. Parametric study was carried out to analyze the impacts of bit strength to rock strength ratio, bit constant and intrinsic specific energy on torque using existing model. As the drillstring was stiff and small, torsional oscillations were not observed and only lateral and axial vibrations were studied. Effect of drilling parameters and vibration on ROP was studied only on soft rock sample as ROP on hard rock was too small to be recorded
Once the input parameters for the analytic model were methodically selected they show good agreement with the experimental data. The results of the parametric study revealed that estimation of torque relies heavily on the bit constant. Axial vibrations increased when rotational speed was near to the natural frequency of the drillstring which resulted in increase of ROP. Type of formation affected the magnitude of lateral and axial vibrations. Reducing both rotational speed and WOB helps to minimize lateral vibrations in hard formations while reducing rotational speed can effectively reduce axial vibrations.
Step Change in Deepwater Drilling Performance Through Optimisation Saves Operator 3.5 Rig Days, West Africa
Authors: Trulsvik Nils , Grant Lauren , Alexander Gregg , Alvarado Robert , Diffendaffer Waco , MacLeod Lindsey , Tetley Nicholas 
Published: November 2017

Abstract
An operator was planning to drill a 12¼-in. vertical borehole through highly interbedded shale and sandstone off the coast of Equatorial Guinea in deepwater West Africa. Offset data predicted bands of highly abrasive sandstone with unconfined compressive strength of up to 30,000 psi, which had resulted in multiple bit/bottomhole assembly (BHA) trips and associated nonproductive time (NPT). A new approach was required to find the optimal bit design that would drill the section in a single run whilst ensuring full compatibility with the planned BHA.
Offset wells were utilising heavy-set bits to offer greater abrasion resistance. The initiation of wear flats with such heavy-set bits had a detrimental effect on rate of penetration (ROP), particularly in the more-competent sandstone, and required high weight on bit (WOB) to drill ahead. This introduced harmful downhole drilling dynamics, which further accelerated any bit damage, leading to costly bit trips.
A time-based holistic modeling suite was used to capture the entire drilling system and push the boundaries of bit design to deliver optimal performance without sacrificing durability. A lighter-set drill bit was designed and validated using the modeling system to maximise dynamic stability over the benchmark. The new bit design and improved stability coupled with the latest cutter technology allowed the cutters to be kept sharp to deliver improved ROP and section length.
The 12¼-in. bit drilled 1,140.2 m—24% further than planned—in one run at an average ROP of 38.4 m/h. The bent-motor BHA maintained verticality throughout the section without any significant shock or vibration, and the bit was pulled out in good dull condition. The combination of new bit design and optimal BHA and operating parameters enabled the operator to complete the 12¼-in. section 3.5 days ahead of schedule, resulting in cost savings of USD 3.5 million.
Implementing holistic drilling system design and optimisation methodologies that consider not only the bit, but the entire BHA, drillstring, trajectory, and rock, can deliver proven performance in the most challenging environments.
Preventing Process Safety Repeat Incidents Driving better performance through embedded PS Incident learning
Authors: Sipkema Anthony W , Ahmed Arshad S , Salmani Mohamed AA 
Published: November 2017

Abstract
Oil and Gas companies, now more than ever, need to prioritize the prevention of process safety incidents. Finding root causes and learnings are not only cost-effective means of preventing repeat events from taking place, but also good business. Avoiding a costly incident (that would impact lives, money and the environment) is by far the most effective and controllable cost saving measure in the current volatile business climate.
Experience in PDO demonstrates that merely learning from incidents (LFI’s) is not enough to prevent repeat events from occurring. Only when these learnings are applied and embedded by staff on projects and in operations can they ensure that improvements occur.
The assurance that an LFI has been embedded (and truly learned) in the corporate systems is achieved through: Clear reporting requirements for AI-PS eventsMulti-disciplinary team investigations - lead by senior managersValidation of learnings and root causes by directorsCascading of key learnings via the online AI-PS Databook (with the ability to push and pull content)Corporate level assurance of actions embedded in new projects and work practices
A cornerstone in this learning journey was the retention of knowledge from our AI-PS investigations and senior management discussions and decisions. PDO developed a comprehensive online AI-PS Databook which contains all significant AI-PS incidents and their LFIs learnings from PDO’s own investigations, as well as regional and international incidents. Utilizing the SharePoint technology platform, the Databook helps provide in-depth access & search functionality to over 175 significant PDO Process Safety incident investigations (i.e. Tier-1 and HiPo) spanning back to 2000. It also contains over 3000 Shell LFI’s for further reference. Engineers, operators and indeed anyone in the business with a PDO email account could now access a fully assured learnings database to improve process safety delivery of their projects and activities.
Preventing Explosions and Sudden Breakdowns of Oil Filled Power Transformers by Packed Advance Oil Testing
Authors: Abou Ali Khaled Atef , Alrais Mohammed 
Published: November 2017

Abstract
Power transformer is critical electrical equipment in any electrical network, which is used for power transmission and distribution. Power transformer is static electrical equipment that can live for relatively long ages (25 years average) therefore it should be manufactured from high quality material and accurate design which will be costly (based on its size) and will take long for manufacturing and it is not shelf item. ADGAS electrical network has around 80 power transformers that supplies different voltage levels from 415 V to 33 KV. Although transformers are reliable equipment but there are three challenges for maintenance and operations teams that they can face with transformers. First, transformer cannot be dismantled easily to monitor its internal components and be proactive for any abnormality so it is hidden system. Second, even with reliable equipment there is possibility of faults and the consequences of transformer failure are massive as the consequences can be power loss, power redundancy loss, recovery time is significant, costly and has potential of explosion. Third, replacement decision is challenging as if the decision is only time based as the common practice (25 years) there is no guarantee that the transformer will fail before that period due to manufcuatirng issues/operational abnormalities/lack of maintenance, etc. Meanwhile; if transformers had proper operation and maintenance, then transformer can live much more than 25 years so replacement decision will be not efficient from cost wise. Therefore ADGAS electrical team is developing applying the best practices of transformer condition monitoring analysis and trending which will significantly enhance the safety, reliability and availability of electrical transformers. Applying condition monitoring will maintain the safety culture of ADNOC and meets with ADNOC four pillars as it will be described in details. The paper will start with simple definition for power transformer, discussing the potential hazards of transformers with accidents case studies. Then the paper will illustrate the existing solutions of controlling the hazards which is protection system and replacing old transformers. Then condition monitoring tools and results will be discussed thoughly and then the paper will conclude the project and shows its advantage and its role in applying ADNOC four pillars.
Optimizing Water Disposal: Case Study of an Integrated Multi-Disciplinary Project in the Jasmine Oil Field
Authors: Trekarnjanavong T. , Last N. , Edwards M. , Wasanapradit T. 
Published: November 2017

Abstract
The multiple challenges associated with a large scale offshore water disposal project are set out in this paper, which goes on to describe how these challenges have been overcome using an integrated multi-disciplinary approach that optimizes disposal well performance, while at the same time significantly reducing the OPEX associated with produced water handling. The difficulties associated with maintaining injectivity in the disposal wells have been overcome through a combination of strategies, including targeting alternative aquifer intervals, which lie above existing oil-producing zones, modifying the completion design, improving the water treatment process and implementing topside modifications. A comprehensive surveillance program has also been implemented to ensure that well and flowline integrity is maintained, and to understand the distribution of injection between the aquifers.
A key outcome of this project has been to scale back the requirement for high pressure water disposal (HPWD). The resulting low pressure water disposal (LPWD) strategy has achieved a cost saving of approximately $0.5 per barrel of oil produced which is highly significant in the prevailing low oil price environment.