bluuebunny/crossref_metadata_2025_split huggingface dataset:
Twisting Slip and Rotation of UAE Fault System
Authors: Obaid Khalid , Noufal Abdelwahab , Mahgoub Mohamed 
Published: November 2017

Abstract
Abu Dhabi fields are influenced by strike-slip and their damage zones as a main tectonic regime. A damage zone is the deformed volume of rocks around a fault surface that results from the initiation, propagation, interaction, and build-up of slip along fault segments. These damages zones impacted the distribution of the traps, migration pathways and increasing the drilling risks. Slippage and rotation along the fault segments in Abu Dhabi fields increases the damage zones widths around the fault segments. This paper presents a detailed description of the kinematics and dynamics of rotated damage zones in the strike-slip faults of Abu Dhabi fields.
The factors that are controlling the damage zones around faults are mainly the rock type, relation between bedding and fault plane and stress tensors. This paper, however, focuses on the structures within the damage zones as they are influencing the trapping mechanism, the drilling hazards and how the rotation increases these. In addition, the structures formed at the fault tips are also considered, especially for the initiation and propagation of the fractures. Field examples and outcrop analogues of damage zones around strike-slip faults are presented. This study is integration between seismic, cores, logs, and outcrops.
During the Late Cretaceous the kinematics of Abu Dhabi fault system changed to transtensional and accommodated a major component of left-lateral strike-slip motion with a SE-NW compressional component. The final phase occurred by the Miocene time, where the stress tensor is changed to NE-SW compression, which rotated the blocks. During this deformation, the blocks were dissected into a series of large-scale blocks bounded by NW-trending left-lateral strike-slip faults which merge into a NE–SW fault system that forms the main structures in Abu Dhabi. Field studies on the mountains exposures data from the fault bound subsurface blocks indicate 10°–15° of post-Early Miocene anticlockwise rotation with substantial latitudinal motion.
The decrease/increase of stresses along the fault segments in the overlapping/linkage zones and at the fault tips under differential confining pressures affecting the rocks behavior and understanding of these will greatly avoid drilling dry holes and reduce the drilling risks.
Seismic Characteristics, Identification and Comparison of Strike Slip Fault Systems in Onshore/Shallow Marine Fields in Abu Dhabi, UAE
Authors: Aamir Muhammad , Ahmad Mula Nur , Noufal Dr. Abdelwahab 
Published: November 2017

Abstract
In Abu Dhabi fields, strike slip faults can be originated from deep seated basement and/or reactivated salt related faults in a wrench tectonic regime. This paper outlines the identification of strike slip faults using 3D seismic imaging and describes the characteristics, orientations, spacing of the fault zones and the characterization of fault corridors through horizontal wells. Finally comparing similarities and contrast in the faults systems between different fields at the seismic scale.
The structural development and deformation mechanics associated with the Late Cretaceous tectonic phase represent the key factors of hydrocarbon accumulation in Abu Dhabi, where strike slip fault system that forms structural traps with several discoveries have been made.
3D seismic analysis has been performed on multiple 3D seismic cubes, and structure sensitive seismic attributes at different stratigraphic levels has been derived to better understand structural characterization and the geometry of Strike Slip systems. The main NW-SE fault system consists of a complex series of sub-parallel faults that connect via transfers, relay ramps or accommodation zones. Seismic images shows that these zones are associated with micro faults, fractures and folded closures resulting from the development of positive and negative flower structure.
These deep-seated faulting generally drives strike-slip tectonics happened when basement faults are reactivated a zone of rotational bulk strain develops in the overburden. The strain is accommodated by a variety of en-échelon structures including Riedel shears, normal and thrusts faults and folds. However, in deep seated detached salt related tectonics, a symmetric, conjugate pair of strike-slip faults will develop accommodating rotational bulk strain
Long Term Downhole Wet-connector Technology for Separate Injection Well - A Case Study in Changqing Oil Field
Authors: Yang L. , Mu L. , Lu H. , Huang W. , Yao B. , Ju Y. , Wang J. , Yu J. , Hu G. , Wang Z. , Wang S. , Wang W. , Zhang S. , Lu X. , Sui L. 
Published: November 2017

Abstract
Drill pipe conveying wet-connector horizontal well logging technology is a more mature logging technology. It could be used in all kinds of well loggings, even in highly-deviated wells and horizontalwell, as its downhole joint is connected to the bottom of the drill, using cables to carry heavier and the joint under pump. The two joint complete electrical and mechanical connections, located in themud, cannot meet the need of field test, since it generally lasts less than 15 days. Therefore, longterm downhole Wet-connector technology for separate injection well is proposed, basing on wet-connector horizontal well test technology. This technology mainly consists of the lower docking and upper docking. Specifically, the lower joint is connected to the top of tool string after completion. The upper one joins up on the lower joint by cables from wellhead with help of gravity. Five flow holes of20mm diameter are assembly designed on the lower joint which unlocking mechanism stress is 1.2-2 t approximately. It achieves long-term stability, communications and power supply after docking and normal water injection consequently.
Changqing oil field application results show that the wet-connector has several advantages such ashigh success rate, repeatable docking and maintenance. Its various technical indexes could meet the requirements of power, communication and wells backwashing. This proposed technique is an effective method of dynamical real-time monitor and downhole control for seperate injection well in low permeable oilfield.
Early Gas Leak Detection EGLD
Authors: Baque Marc 
Published: November 2017

Abstract
One of prerequisite of any detection system is to get preliminary data from the risk analysis to estimate the safety, the socioeconomic and environmental impacts of a loss of containment. From this prerequisite it will be possible to consider a strategy for an early detection of a loss of containment, and to choose a particular method or technology.
Under this aspect, a leak detection system permits to set up a means of risk management: the earlier the leak is detected, the faster the pipeline operator can deploy countermeasures of the emergency plan.
Methods of early detection belong, broadly speaking, to two main families: "direct" methods based on the detection or the "direct" observation of the fluid after the containment loss;"indirect" or "deductive" which use the evolution of the measured pipeline operating data to deduct the probability of the loss of containment.
Fiber optic is considered as one of the most promising "direct" leak detection technologies. The fiber core normally used for telecommunication purposes can be converted as a sensor with the principle of light backscattering within the fiber.
Distributed temperature or acoustic profiles can be obtained with the analysis in real time of the light backscattered when sending a light pulse in the fiber.
Electromagnetic Corrosion Logs, Insights from Yard Test
Authors: Macki Ali Al , Salmi Albashir Al , Duggan Timothy , Delgado Eduardo , Kechichian Jackie , Busaidi Hamood Al , Azri Nasser Al 
Published: November 2017

Abstract
Well integrity is one of the highest operational risks for E&P companies across the industry. As such, well integrity concerns are high priority for operational excellence. Electromagnetic Corrosion Logs have been more frequently acquired as Cased-hole logging services enabling the quantification of multi-barrier well integrity. Due to ease of data acquisition through logging operations and the ability to model remaining metal thickness per-barrier from acquired surveys, demand for Electromagnetic Corrosion Logs has been sharply growing across the industry. Electromagnetic Corrosion Logs can compliment conventional integrity tests and can be used for well integrity compliance where business-critical decisions are accordingly made.
Electromagnetic corrosion logs are run more frequently across assets to investigate time-lapse per-barrier integrity status for multi-barrier systems (multiple concentric tubulars). Degradation in barrier integrity in operating wells present integrity risks. Harsh operating environments during production/injection, sour environments, life-time wear and tear, and shallow aquifers all affect wellbore integrity in the form of internal and external metal loss. Electromagnetic Corrosion Logs are currently reported to be capable of quantifying total remaining metal per-casing (separately) up to three barriers.
In 2016, a yard test was conducted in Oman to assess the limitations of different Electromagnetic corrosion tools. The test consisted of multi-barrier concentric oil-field tubulars of different sizing and set-up. Four tubular set-ups (simulating routine well completions) were constructed with man-made "corrosion" features to assess raw, processed and interpreted Electromagnetic Corrosion logs. The man-made features included defects of various shapes and configurations distributed axially and longitudinally as well as machined thickness-loss areas with precise thresholds. Multiple service providers with different tools and configurations were requested to acquire corrosion logs through the yard test "completions."
This paper investigates Electromagnetic Corrosion Log technology. It illustrates the physics, practice, and applied technology scope of Electromagnetic Corrosion Logs gathered from the yard test and multiple surveys in Petroleum Development of Oman (PDO). The outcome is improved awareness of operational windows, tool resolution and sensitivities, detection capability, data QC and analysis, processing, and modeled thickness outputs. Some discussion is made around the limitation of Electromagnetic Corrosion Logs and the uncertainty in thickness estimation, and recommendations for this technology's scope for application.
Optimal Equivalent Liquid Rate ELR in Managed Pressure Drilling
Authors: Huang Xiaoqian Christina , Samuel Robello , Morales Gabriela , Parak Mahdi 
Published: November 2017

Abstract
One of the most important factors when designing an aerated-fluid drilling operation is the volume of injected gas and liquid necessary for the downhole mud motor to achieve managed pressure drilling (MPD) conditions.
This paper discusses a new method for calculating the equivalent liquid rate (ELR) of the gas/liquid mixture. ELR can be equally treated as the liquid volume to measure mud motor performance and can also be used to refine the permissible MPD operational window.
During aerated-fluid drilling, gas/liquid are mixed to form one complex flow regime along the wellbore. To model its flow rheology and mechanisms, both foam and multiphase flow models are used. ELR is calculated by using the surface gas injection rate (GIR)/liquid injection rate (LIR), drillstring configuration, wellbore trajectory, and wellbore geothermal allocation. This calculation also considers tool joint effects and formation influx from downhole and parasite string injection.
This paper also describes the impact of ELR to form the MPD operational window by considering GIR/LIR, minimum/maximum ELR, bottomhole pressure (BHP), and annulus flow velocity. Sensitivity analysis is performed for various combinations of GIRs/LIRs. Similar ELR value trending is observed in foam and multiphase flow models for both vertical and deviated wells. Increasing ELR is not always the goal because BHP should be controlled within reasonable ranges during MPD. To ensure operational constraints at the bottom hole, a set of ELRs is calculated from a few combinations of surface GIRs/LIRs. Refined by the target BHP and the desirable hole cleaning capability, the permissible managed drilling operation window can be achieved and visualized.
Drilling engineers can calibrate surface GIRs/LIRs to achieve maximum mud motor performance. Conversely, with the fixed GIRs/LIRs, to maintain the desirable BHP and hole cleaning, drilling engineers can select the proper mud motors for use.
The calculated ELR in this method is not only variable for evaluating mud motor performance, but it is also novel to combine it with other important operational factors to help manage downhole pressure and meet hole cleaning requirements.
Optimization of the Operation Time Required for Data Gathering Requirement in Extended-Reach Drilling Well by the Use of Open Hole Tractor in the United Arab Emirates
Authors: Toki Takahiro , Benygzer Mhammed , Wahedi Khalid Ahmed , Anurag Atul Kumar , Singh Rudrap Pratap , Sayed Mohamed I , Ruzhnikov Alexey , Cocagne Michael Jason 
Published: November 2017

Abstract
Gathering of wireline data in Extended Reach Drilling (ERD) wells is still not a standard process, complicated even more by inclination and step out. This paper presents a case study of recording logs conveyed using an open hole tractor in a highly deviated section. The challenge was made more difficult because Water Based Mud (WBM) was required to allow the full suite of planned logs. The operation time that can be saved is up to four days.
The 8.5 in. pilot hole was designed based on the target and the sidetrack points for the mother hole. The inclination of the pilot hole was 63° and the wireline accessibility simulation based on offset friction factor showed that the open hole was not 100% accessible with Wireline Conveyed Logging (WCL) string. Therefore, an open hole tractor was selected to reach the required point. To minimize the risks for the logging operation, a six blade Polycrystalline Diamond Compact (PDC) bit, Rotary Steerable System (RSS) and Logging While Drilling (LWD) were used in the pilot hole to make a smooth trajectory and confirm wellbore conditions.
The logging operations were conducted smoothly and safely. It was observed that the actual results matched very well simulations, and the open hole tractor was required to convey the tools to the Total Depth (TD). The total tractoring length was 16,000 ft over the four runs, and there were no issues observed during the tractoring which confirms that the steps taken while drilling the section were correct and approximately four days of operation were saved by means of the open hole tractor as compared to Pipe-Conveyed Logging (PCL) operation. In addition, the mother hole length also was minimized to get proper sidetrack point from the optimized pilot hole trajectory and the potential total saving time would be more than seven days.
This paper also describes the optimization of well trajectories for pilot hole and mother hole and the gap related to planning from drilling and logging points of view, with aim to ensure 100% data gathering. The use of an open hole tractor for long interval in highly deviated well is the first time in the United Arab Emirates (UAE) and WBM conditions are non-standard operations which require significant amount of preparation during execution.
Improved Recovery of Carbonate Reservoir by Optimizing Acidizing Strategy; Coupled Wellbore, Reservoir, and Geomechanical Analysis
Authors: Safari Reza , Smith Clayton , Fragachan Francisco 
Published: November 2017

Abstract
One of the sources of damage in stimulated carbonate rock is the loss of near wellbore formation compressive strength which may results in casing collapse under extreme conditions. Field studies have shown that the failure of acidized rock may cause damage and thereby negatively impact production. In this work, an integrated analysis workflow is presented to simulate acid placement in carbonate reservoirs and model stimulated rock behavior during the productive lifetime of the well. The workflow is utilized to design a unique approach to horizontal wellbore acidizing and optimize the strategy to maximize hydrocarbon recovery.
The presented workflow is based on the interaction between the distributions of reactive fluid along a wellbore, a two scale continuum model to simulate porosity evolution during stimulation, and stimulated rock performance during production time. The model first simulates stimulation fluid movement in the wellbore and couples it with transient reservoir flow. The primary analysis provides the distribution of reactive fluid along the well. The rock dissolution at each section of reservoir is then analyzed by continuum two-scale model (pore-scale and Darcy scale). This analysis presents porosity evolution at different locations along the well and at different radial distance from the wellbore center. Then, the developed geomechanical engine simulates the weakened rock under the in-situ stresses and bottom-hole pressure and predicts any possible compressional or shear failure. The effect of rock failure is then considered on the production prediction.
The workflow is best used to analyze and optimize acid stimulation for a horizontal well. The analysis results show that the induced wormholes are stable and open since reservoir depletion increases the effective mean stress. At the elevated mean effective stress, wormholes or pores start to collapse and the failure extended away from near wellbore region and neutralized the stimulation effects. Since in the acid treated zone the rock is softened, the stress concentration around the wellbore might extended more into the reservoir. Analyzing this phenomenon showed that at a certain level of lowered stress concentration extension, in other words at certain strength and volume of acid, the wormhole can be stable and open during expected production time. Furthermore, the coupled analysis also demonstrates that at specific environment, the wormholes penetrated further into the rock, longer than possible
induced failure. The workflow can be used to determine how weak or strong the acid should be at specific environmental condition to have longer life for the induced wormholes and hence extra hydrocarbon recovery.
Flow Assurance during Gas Hydrate Production: Hydrate Regeneration Behavior and Blockage Risk Analysis in Wellbore
Authors: Deng Zhiming , Wang Zhiyuan , Zhao Yang , Guo Yanli , Zhang Jianbo , Sun Baojiang 
Published: November 2017

Abstract
Natural gas hydrate is a potential resource to meet the ever-increasing energy demand. Yet wellbore/pipeline blockage due to hydrate regeneration poses serious safety hazards during gas hydrate production. In order to estimate and effectively manage the blockage risk, we studied the hydrate regeneration behavior in wellbore during hydrate production. A method is developed to predict where gas hydrates regenerate (i.e. the hydrate regeneration region, HRGR) in the wellbore. The HRGRs with different production methods were studied. The results indicate that hydrates regenerate in wellbore. The hydrates can deposit onto the wall of the production tubing and form a growing solid layer, which narrows the tubing and even reults in complete blockage. The simulation work indicates that there tends to be a rather large HRGR in the production tubing regardless what production methods are adopted. The blockage risk is usually much higher in the region where a higher subcooling is encountered. This region is the high blockage risk region (HBRR). For the depressurization method, the HRGR shrinks as the depressurization amplitude increases. Accordingly, the HBRR and most vulnerable site become shallower. Therefore, the blockage risk is reduced. Similar trend is found as the thermal/chemical injection methods are used. However, for thermal injection and chemical injection, there are no significant change in the HBRRs and the most vulnerable sites. Only an unnoticeable slight upward trend is found for the thermal injection cases.
Reducing the Impact of Experience Gap and Increasing Service Delivery by Automating the Coiled Tubing Intervention
Authors: Aitken Bill , Micheli Rodrigo , Ramsey Tim , Dobkins Ken 
Published: November 2017

Abstract
The current coiled tubing (CT) industry as know is changing as a major service experience shift is being experienced; the generational crew-change is ongoing; the net result is a reliance on a smaller pool of qualified personnel. From a historical root-cause analysis across a variety of industries, we can contribute the human factor to more than 50% of Health, Safety and Environmental (HSE) and service delivery incidents. The solution presented in this paper highlights mitigating this potential risk by introducing several degrees of automation into CT interventions.
The foundation of the human-centered automation approach revolves around a software suite that incorporates pre-job modelling, real-time operational feedback, and active control of surface equipment during CT interventions. This approach updates operational parameters, to enhance safety and efficiency, and to increase the certainty of success.
This paper describes the process of bringing together the pre-job simulation with well intervention operating limits and real-time data acquisition, resulting in an automated programmable logic controllers (PLC) driven intervention that can intervene if/when deviations from job design occur. Five case histories are reviewed, and the benefits confirmed during field operations are presented. These findings outline the versatility of the automated system, resulting in the predictability of successful operations for operators.
Creation of a New Light Weight Grating
Authors: Tan Bugs Yeow 
Published: November 2017

Abstract

LIGHT WEIGHT AND ANTI SLIP GRATING PANEL
The invention of the light weight and anti-slip grating panel is an improved product that has significant advantages over common steel grating. Beside the many features found on the new grating, there are four major outstanding advantages over common steel grating. 1) The unique design of the new grating that is lighter by approximately 35% in weight. This is made possible with the creation of a hollow load bearing bar. The new grating being lighter in weight could also potentially reduce the overall weight of the main building structure. 2) Even though the load bearing bar is hollow but the overall integrity of the new grating panel is stronger. The new design can take approximately 12% more loads. 3) It takes a lot lesser raw material to manufacture the new grating panel. Thus, the finish product is priced competitively. This cost benefit will assist the consumer greatly in the overall project cost management. 4) The embossed rings found on the new grating provide a true anti-slip function. This safety feature aims to reduce the number of accident that occurs at workplace especially on oily working surface and stair treads.