bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Successful 4D Seismic Monitoring in Middle-East Carbonate Reservoir Context
Authors: Cailly F. , Al-Romani T. , Hubans C. , Lafram A. , Al Kaabi A. 
Published: November 2018

Abstract
This paper describes 4D interpretation results in a very challenging Middle East carbonate context.
It consists of a 4D pilot (OBC/OBC) over a giant field divided into two phases. For Phase1 the monitor seismic survey has repeated the geometry of the base survey (parallel shooting) to get started in the best possible 4D conditions. For Phase2 the monitor seismic survey design is a modern source spread acquisition for wide azimuth objective. It is clearly different from the base survey design, and so starts with a worse 4D repeatibility.
In this paper, we describe the challenges attached to both phases of this pilot and explain how in the end it has been successfully interpreted.
A focused study is made on a particular 4D anomaly corresponding to an increase of impedance in the reservoir. This is interpreted as the water front movement (due to water injection) during the interval between base and monitor surveys. Petrophysically this is consistent, if water replaces oil in the reservoir then impedance increases. However, 4D interpretation can be ambiguous and other production phenomena can explain impedance increase, so the interpretation must be assessed carefully. This is done through calibration of the interpretation to well data (time evolution of the water cut).
The final interpretation is robust. Other elements not described in the paper could have been added to consolidate the interpretation like the fact that interpreted 4D anomalies (and so water rise-up) stop vertically on a well known impermeable barrier (anhydrite level).
Once the 4D signal is calibrated, unexpected phenomena (i.e. heterogeneities not predicted by the reservoir model) are highlighted as potentially providing added value to reservoir understanding. As a deliverable, 4D anomalies are interpreted as 3D geobodies and a water rise-up top surface is picked. This information will be key to position new wells and to update the reservoir model.
Though 4D seismic techniques are very mature and widely illustrated in clastic reservoir environments, it is still rarely used operationally to monitor carbonate fields. This paper proves the concept that a reliable 4D signal can be extracted over such Middle-East carbonate reservoir.
Relaunch of the IOGP Recommended Practice for Safety in Lifting and Hoisting Operations 2018
Authors: Lawrie Graeme 
Published: November 2018

Abstract
Objectives/Scope: IOGP first published a recommended practice for lifting and hoisting operations in 2006. However, it is clear that lifting and hoisting incidents are still occurring in our industry, so IOGP established an industry task force representing a cross section of operators and service companies to improve and revise the RP to take account of lessons learned over the last 12 years. The Paper will describe the lessons learned and the enhancements to the document.
The Paper will identify through a series of case studies how lifting and hoisting accidents are still occurring and what steps can now be taken to help close these shortcomings.
Methods, Procedures, Process: The Task Force brought together a good cross section of subject matter experts in our industry representing both offshore and onshore activities. The TF met regularly to review fatal accident causes and high potential near miss events to identify deficiencies in the original guidance and to seek to enhance our understanding and knowledge.
Results, Observations, Conclusions: The result is a significant revision to the existing recommended practice. Specific areas for improvement; subsea lifting and dynamic lifting operations (marine conditions). It also looks at best practice associated with lifting over or near live plant. Updated lifting plans, definitions and safety technology.
Novel/Additive Information: The RP is free to all people to download and use, it is not limited to IOGP members. The RP contains many helpful tools that can be implemented at all levels within our industry.
Reduce Emissions and Save Energy by Converting Flared Gases into Fuel Gases
Authors: Bakthavachsalam Venugopal , Abdul Shathar Sevideen 
Published: November 2018

Abstract
Energy management and fuel conservation are crucial for controlling emissions and enhancing profitability of today’s oil and gas industries. Many organization are pursuing flaring and emission reduction initiative as part of their energy management system thereby minimizing operating cost and liberation of harmful greenhouse gases to the environment.
This paper presents a flaring and emission reduction initiative implemented at ADNOC Gas Processing natural gas liquids (NGL) fractionation plants in Ruwais. The design limitations on spent gas piping system leading to loss of valuable of fuel gas resources were recovered by enhancing the capability of the system.
Following is the list of actions completed to implement the initiative:Feasibility study for utilization of flared spent regeneration gases as fuel gases for boilersUpgradation of spent gas piping for sour serviceApplying an innovative non-linear fuel blending controller
The successful implementation of the initiative by in-house team resulted in an impressive flaring reduction of 60% and a reduction of CO2 emissions of 62,700 Tons/annum.
The Concept of Right Modelling, Toward a More Effective Usage of the Static Modelling Tool
Authors: Lazar Raffik 
Published: November 2018

Abstract
The reservoir modelling task occupies most of the reservoir modeller daily routine. The key challenge faced by the reservoir modeller has shifted from the ability to build A reservoir model to building THE right reservoir model. The concept of right modelling responds to the challenge of building more predictive reservoir model by using a structured methodology to use the static modelling tool in a more efficient fashion. Complexities are introduced in the model only when required and supported by hard data. A set of guidelines, covering the overall workflow, are established for the principal reservoir modelling tasks. By following the guidelines, the reservoir modeller can handpick the best modelling strategy to ensure that the reservoir is modelled at the right level. Following the right modelling concept minimizes the risks of under modelling (not tackling the technical need in a robust way) or over modelling (losing the technical relevance by being too narrow) the reservoir.
Reservoir Management Solutions Through Innovative Seismic Modeling
Authors: Goraya Yassar , Al-Neaimi Ahmed Khalifa , Al-Felasi Ali , Van Kleef Franciscus Johannes , Al-Dhafari Bader , Akram Fazeel , Ashraf Muhammad , Khemissa Hocine 
Published: November 2018

Abstract

Objectives/Scope
Today, the major challenge in reservoir monitoring is difficulty of building high-resolution reservoir model. Reservoir modeling can only be truly effective in increasing oil and gas recovery and providing input to recovery programs if it is able to incorporate 3D problems with innovative techniques of structural characterization,synthesizing seismic attributes, well information and Seismic Inversion.
Fit for purpose seismic PSDM processing, advanced level seismic attributes generation,seismic inversion, high quality sonic and density log acquisition and correction was the main objective to integrate petrophysics, rock physics, facies classification and geophysics.
Case studies supported, how an integrated novel approach could be useful to determine the relationship between seismic structural and reservoir characterization attributes and reservoir properties to improve the reservoir management.
Debottlenecking of an LNG Plant to Capture Gas with Higher Nitrogen Content
Authors: Halil Kirpici Onur , Salmeen Abdulla Haitham , Abdulkareim Al-Ameiry Ahmed , Kuntadi Agung Margono , Kumar Das Anjan 
Published: November 2018

Abstract
Liquefied Natural Gas (LNG) has been a significant contributor to the global energy market. This is emphasized with continuous demand from industrial and population growth. ADNOC LNG has stepped up efforts to enhance its asset reliability and utilize every opportunity with utmost attention to HSE, bolstering its role as a key gas operating company. ADNOC LNG runs 3 facilities, in which three operating trains are LNG producers.
Over several years, the company has conducted tests and studies with assistance of global engineering service companies and vendors. The rationale was envisaged in 2011 to check for possibilities of debottlenecking LNG Train-3. The aim of the conducted studies was to exceed the design LNG production capacities of 384 ton/hr and 390 ton/hr in summer and winter respectively. The study objective was to establish the limit for production rate considering all operating parameters at post 2009 overhaul, bottleneck process findings, Integrity & Reliability issues and safety elements. The scope of this two phase study was detailed in a "Management of Change" approval for process plants for the purposes of this paper, in which the next auxiliaries’ adequacy step based its analysis.
Following a structured process (study, classify, prioritize, debottleneck, test, assess); the conducted studies surfaced a number constraints that limited LNG production. Recommendations were implemented to surpass the identified constraints. In short, this entailed minor modifications including replacement of 2 valves for better controllability, 1 set of PSV’s and structural reinforcement/monitoring.
Ultimately in 2015, ADNOC LNG achieved a new rated Train-3 LNG production capacity of 394 ton/hr and 408 ton/hr in summer and winter respectively. This gain of 10 ton/hr has yielded additional returns and the accomplishment has paved the way for safe increased production with a satisfactory margin to operate within.
How is the Dynamic of Drillstring Going Under Internal & External Countercurrent-Axial Flows?
Authors: Liu Yongsheng , Gao Deli , Tan Leichuan , Li He , Cai Zhixiang 
Published: November 2018

Abstract
A dynamic model of drillstring under internal and external countercurrent-axial flows is presented, and the stability of drillstring under different drilling parameters is analyzed. Results are compared to previously published simplified models (e.g., fluid-free models, influx models, outflow models). The dynamic governing partial differential equation (PDE) of drillstring is established under internal and external countercurrent-axial flows by means of the differential element method. The equation taking into account the mechanical force, the fluid pressure, the buoyancy force, the inertial force, the gyroscopic force, and the Coriolis force. PDE equation can be converted into the ODE equations by using the Differential quadrature method (DQM) and combining the boundary conditions under different working situation of drillstring. The vibration response to submerged drillstring under different parameter αc, which represents the annular clearance, is studied by plotting the stability diagram. The results were compared with the reference model established by the former researcher. Two cases, cantilever beam model and hinged-hinged boundary conditions, were discussed and found that increases the value of αc that means the annular gap increases, the outflow velocity should be decreasing, thus the effect of fluid induced vibration would be decreasing. As for cantilever case, the stability region will change obviously with the change of parameter αc, but for Hinged-Hinged case, parameter αc has little influence on the stability region. The novelty of the new dynamic model of drillstring is lying in considering the internal and external countercurrent-axial flows effect for the first time. The numerical results can be implemented in drilling engineering to predict drillstring vibration and guide drillstring design.
Innovative Geophysical Hazard Survey for Jack-Up Rig Approach and Operating in Hazardous Area of Shallow Seabed Due to Gas Pockets or Entrapped Gas and Tower Integrity Update and Conclusion. A Case Study
Authors: Goraya Yassar , Nair Rajeev Nair , AL-Neaimi Ahmed Khalifa , AL-Felasi Ali , Kleef Franciscus Johannes , Al-Dhafari Bader , El-Sayed Mohamed Abdul-Khalek , Akram Fazeel , AL-Hosani Ibrahim Ali 
Published: November 2018

Abstract
During a routine tower maintenance visit, gas bubbles were observed at sea bed. The challenge now was to identify the source of the gas leak and identify areas where gas had accumulated. The observed gas seep, escaped from the seabed to the water column and was in the vicinity of the TWR-2 platform as confirmed during a diving survey. A geophysical survey was initiated to understand if gas had accumulated in the subsurface and whether it was safe to approach the site with a rig to kill the well.
A Comprehensive Reservoir Quality Characterization for Fractured Basements in India
Authors: Hati Samhita , Chawla Hemlata , Ghosh Arnab , Guru Udit , Ray B. B. , Guru Rakesh , Pattanaik Sambit 
Published: November 2018

Abstract
As oil and gas exploration and development forays into unconventional plays, more specifically, basement exploration, its characterization and understanding have become very important. The present study aims at understanding the reservoir quality in terms of complex mineralogy and lithology variations, porosity, fracture properties and distribution near and away from the borehole using an integrated approach with the help of elemental spectroscopy, borehole acoustic imager, borehole micro-resistivity imager, nuclear magnetic resonance and borehole acoustic reflection survey.
A comprehensive petrophysical characterization of different mineralo-facies of basement was carried out using elemental spectroscopy, formation micro-resistivity imager, borehole acoustic imager and combinable magnetic resonance along with basic open-hole data. Two distinct rock groups were identified – silica rich, iron poor zones having open fractures with good fracture density, porosity and aperture and silica poor, iron rich zones with no open fractures, poor fracture density, porosity and apertures. The zones with open fractures were the prime zones identified for further testing and completion. However, the near well bore analysis could not explain the oil flow from one zone having open fractures, whereas another similar zone showed no flow.
Borehole Acoustic Reflection Survey processing was attempted to understand how extent of fractures beyond the borehole wall contributed to productivity from a well. The presence of laterally continuous fracture network at an interval that coincides with the depths from which the well is flowing, in turn validated from production log data, explained fluid flow from basement. Furthermore, the absence of such network can cause no flow even though near well-bore possible open fractures are present.
Present study established the fact that, identification of potential open fractured zones in basement is a lead for reservoir zone delineation, however, a lateral extent of such basement reservoir facies is the key for successful basement hydrocarbon exploration.
Force Balance Analysis and Efficient Measures to Improve Vertical Sweep Efficiency in Oil-Wet Carbonate Reservoirs
Authors: Namba Takao , Nakashima Toshinori , Yonebayashi Hideharu , Hiraiwa Takeshi 
Published: November 2018

Abstract
Many carbonate reservoirs in Middle East under water or gas injection exhibit poor or limited vertical sweep efficiency due to channeling of the injected fluid through high permeability streaks (high-k streaks) and/or gravity segregation. In this paper, causes of the limited sweep efficiency and its possible mitigation measures are discussed through conceptual reservoir simulation and the force balance (FB) analyses of their results. The analyses are based on convention-diffusion-gravity (CDG) formulation, and applied to five-spot waterflood, line drive waterflood and line drive gas flood schemes to provide insights to improve reservoir development strategy.
In waterflood either in five-spot or line drive scheme, the injected water moves fast in a high-k streak in oil-wet reservoirs where the effect of convection decreases rapidly and the diffusion has no or limited contribution to diverting the water from the high-k streak to neighboring layers, leading to early water breakthrough and poor sweep efficiency. Gravity force works to slump the water into the high-k streak, thus accelerates water breakthrough especially in case the high-k streak is located at the bottom of the reservoir. For such reservoirs, the practical mitigation strategy will be to delay the decline of the convection effect. Mobility control is the effective mitigation measure in this regard. In-depth conformance control is another mitigation measure in line with this strategy. If the blocking is implemented sufficiently away from the wellbore and with sufficient blockage width, it can make similar level of positive impact on waterflood performance as that expected by mobility control with minimal impairment of injectivity.
In gas flood under unfavorable mobility ratio, gravity override is the key risk even in homogeneous reservoirs. Gas breakthrough is further accelerated in case the high-k streak is located in the upper part of the reservoir. In such reservoirs, the principal mitigation strategy will be to reduce the relative effect of gravity force in addition to increasing the gas front saturation. Enhancement of the viscosity of the injectant will realize both, thus lead to significant improvement of vertical sweep and oil recovery. On the other hand, in-depth conformance control will have positive but limited impact on gas flood performances.
Considering the study results mentioned above and the state-of-the-art of the related technologies, mobility control is considered to be the principal solutions to the poor vertical sweep both for waterflood and gas flood, and in-depth conformance control can be another cost effective solution for waterflood in the oil-wet carbonate reservoirs associated with high-k streaks.
Neutral Grounding of Dissimilar Generators in Offshore Power Systems
Authors: Pragasam Sathishkumar 
Published: November 2018

Abstract
Designing neutral grounding systems for Generators require careful consideration of various aspects, which are mainly related to the Generators themselves and, also with respect to other aspects of the overall system design. More importantly, when the Generators to be operated in parallel have dissimilar design, the neutral grounding design must address a whole array of issues and technical requirements. While there are solutions to mitigate these issues, some of them are not appropriate for offshore installations.
When Water Turns to Oil: Low Resistivity Pay Characterization through Integrated Open-Hole/Cased-Hole Log Interpretation
Authors: Raimondi Cominesi Nicola , Guglielmelli Andrea , Rotelli Fabiana , Putignano Natale , Roscini Paolo , Pirrone Marco , Galli Giuseppe , Vinci Fabio , Rametta Dario , Raniolo Stefano 
Published: November 2018

Abstract
Zubair is a giant oil field located in the South of Iraq. The production started in 1951 and current oil production is around 450 kbopd achieved through 150 wells completed in two main formations: Mishrif (carbonate) and 3rd Pay (sandstone). The scope of this paper is to show how an integrated methodology based on core analysis, open-hole and cased-hole logs unlocked the underneath potential of a sand layer (L1) with an anomalous resistivity.
Multiple wells, indeed, show resistivity curves in the L1 interval with surprising low values with respect to the average of other levels of the same sandstone reservoir. Therefore, fit-for-purpose open-hole (OH) and cased-hole (CH) log acquisitions have been integrated with information from cores and dynamic data (i.e. production logging) in order to better understand the phenomena behind the low resistivity scenario. As a consequence, several perforation extensions have been performed with L1 as the main target, providing an overall improvement of hydrocarbon deliverability without any increase in water production.
In details, routine and special core analyses in L1 samples delineate the typical setting of a fine-grained low resistivity pay sandstone, able to host a large quantity of irreducible water. However, such behavior is not always present among L1 cores. Therefore, a methodology aimed at characterizing this sandstone behavior was mandatory. Nuclear magnetic resonance logging, commonly used to identify low resistivity pays, was not a suitable option due to bad-hole problems. Hence, an approach based on a detailed integration of OH resistivity and CH pulsed neutron logging (PNL) is used to recognize and characterize such low resistivity pay. This method mainly relies on the fact that formation water is very conductive and strongly affects the resistivity, while its effects on PNL measurements are not so pronounced. Such intuition is confirmed by multi-rate PLT interpretations that dynamically describe the L1 sandstone with fair productivity index and high reservoir pressure, together with a significant dry production contribution. In conclusion, a clear geological trend of L1 resistivity behavior is revealed and associated to the decreasing cementation of the matrix and its coarsening in the same direction.
The integrated OH/CH methodology allows characterizing low resistivity intervals as pay zones. Such achievement represents an important milestone for the perforation strategy of new and existing wells in Zubair. As a natural consequence, the overall field production has been enhanced by widely applying the new technique without any increase in water-cut.
A Holistic Approach Utilizing Simple, Reliable and Cost-Effective Axial Friction Reduction System in Improving the Drilling Efficiency and Cost Optimization in the Directional Sections
Authors: Abdelhaq Zeina , Fei Ji , Wu Jiandong , Yan Miao , Yufeng Chen 
Published: November 2018

Abstract
The introduction and standardization of the use of an axial friction reduction tool by a service company in they Halfaya field for a national oil company has resulted in a significant improvement in drilling efficiency and reduction in operating costs.
The directional application in the Halfaya field in the start of the campaign was challenging for the operator and directional companies. Challenges in terms of high torque, poor tool face control resulting in multiple trips, damaged bottomhole assembly (BHA), and the inability to reach planned total depth (TD) forced the operator to call for alternative high-end technologies. Those technologies, although wellperforming, presented various operational challenges and did not represent a cost-effective solution to the operator.
The introduction of a simple axial friction reduction tool combined with a positive displacement motor assembly showed an immediate and clear improvement to the torque and drag issues and was comparable to the higher end alternative technologies that were not cost effective.
This paper presents how this tool became an essential part of the BHA with an average of 30% improvement on the overall performance. Apart from enhanced drilling efficiency, another major factor contributing to this achievement was at least a 50% reduction in the number of trips required to change the BHA components, resulting in a highly cost-efficient solution. This technology was successful across all well designs.
A holistic and optimization-based approach focusing on tool placement using a special algorithm was conducted in the field for both the buildup and the lateral sections. The performance of the tool was consistent and gradually improved to becoming the standard with motor assemblies completing sections in one run.
By introducing the axial friction reduction tool, there has been more than 100 runs to date over the course of the Halfaya field development that have lead to a massive cost saving for the operator.