bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduction of CAPEX for Offshore Platforms in Shallow Water Depth with Uncertain Reservoir Capacity by Adopting a Two-Phase Installation Approach
Authors: Chatterjee Prabir Kumar 
Published: November 2018

Abstract
Fixed Offshore Platforms (FOP) in shallow water depths for wellhead-cum-production operations are frequently installed by float-over deck technique to reduce offshore tie-in and commissioning time. Generally, float-over deck installation method is justified for a medium to reasonably large topside involving many equipment (related to process, electrical, instrumentation, utilities and HSE) and piping that can be pre-commissioned onshore to a large extent before sail-off. A high CAPEX for construction and installation of such platforms may be justified for a proven field in which reserve may last for several years with 8 or more numbers of drilled wells. However, when the reservoir volume and pressure is uncertain, the investment risk is too high to make a commercial decision for a medium to large sized offshore platform.
Whatever be the installation technique, structural design of an FOP is greatly influenced by the topsides requirements in terms of space and weights of various equipment/facilities to be supported and the construction/installation methods to be adopted. In the present study, structural design of an offshore wellhead-cum-production platform in 26m water depth is carried out considering a conventional but two-phase installation approach for the structure as well as the topside facilities. This approach for an oil production platform is suggested to reduce the high initial CAPEX when the expected success of drilling outcome is uncertain. The first phase will consist of only essential facilities such as power generation/supply unit, equipment for well testing, separation of water & gas from oil, heating unit in case of high viscosity crude and critical safety related equipment before sending the crude to onshore through pipeline. In case of successful drilling outcome and proven reserve, the offshore platform can be further extended (Phase-2) by installing remaining facilities such as installation of low pressure system, sand handling unit, artificial lift equipment, produced water treatment plant.
A comparison of structural weight and cost has been made between the proposed platform and an actual float-over platform of similar deck space. The advantages of the proposed design are (i) significant reduction of investment risk by lowering the initial cost and (ii) significant reduction of the overall structural weight resulting in cost saving for structural material and fabrication.
In spite of two-phase installation approach, the cost of conventional installation will be less than the float-over installation due to the requirement of smaller capacity crane vessel and less marine spread. Based on the results, it is found that a two-phase installation approach may govern the design for certain fields due to low initial cost and reduced overall cost of medium sized FOP's.
The Dichotomy of Lost Circulation Material – Is Their Application in Prolific and Troublesome Formations Mitigating Losses or Progressing as a Habitual Practice?
Authors: Bijjani Patrick , Anez Marcos , Luyster Mark , Tresco Kim , White Craig , Dobson Jay W. 
Published: November 2018

Abstract
A review of lost circulation plans, contingencies, recaps, and methods used to primarily prevent losses in the upper-hole sections drilled in the offshore region of the Arabian Gulf was compiled in an effort to ascertain which lost circulation treatments and/or combinations were historically effective or ineffective for regaining circulation especially after total losses, whereby total planned depth was achieved with little to nil non-productive time (NPT) as related to drilling fluids. This evaluation highlighted numerous inconsistencies and excessive time committed to combating losses whereby the critical path was marginalized. While these wells comprised sole objectives, their upper-hole sections were drilled through known troublesome formations often with the same result. It was surmised that the type of lost circulation material (LCM), combinations of LCM, and frequency of use contributed little to no benefit in particular circumstances. Subsequently, this review was undertaken to ascertain if time could be saved with more prudent utilization and/or tactics when utilizing LCM to combat losses.
A well-known application of LCM is its usage as background solids to mitigate fluid loss in troublesome wellbore sections primarily due to the relatively inexpensive cost, availability, ease of use, and compatibility with the drilling fluid. LCM are supplied in a myriad of sizes, types, textures, and applied in varying concentrations and combinations. This review details numerous LCM types and combinations in addition to various pills. While attempts were successful in stopping losses in the upper-hole sections, success was sometimes temporary as subsequent drilling operations would, in some cases, realize losses greater than the established trigger rate.
The ensuing discussion includes a synopsis of challenging vugular and/or fractured carbonate formations in the UAE and Copper Ridge Formation in the US, a review of common and some uncommon LCM, the field results, and finally, lessons learned and strategies are propositioned. The selected LCM are contrasted with their application in formations of the upper-hole sections versus various loss scenarios and results.
Heavy Lift Performance of Seven Champion Under Wave Conditions
Authors: Luong Tuyen , Kurundwade Santosh , Trisnawan Wahyudin 
Published: November 2018

Abstract
This study develops a numerical hydrodynamic model in time domain to simulate an offshore heavy lift installation of a topside by using the crane of a heavy lift vessel (HLV) – Seven Champion. The main purposes of this model are to understand the behavior of the vessel during the lifting installation, to determine operation weather windows and to optimize the installation procedure. A 3D hydrodynamic diffraction model of the vessel, lifting crane and topside with rigging system are simulated together as an integrated model in time domain by using MOSES software to study interaction between vessel motions and pendulum effects of the lifting system. Dynamic hook loads (DAF) are recorded and compared with established design criteria to ensure safety lifting operation and the numerical results are also compared with real offshore records during real heavy lift conditions. The studies show that the analysis results strongly depend on chosen mesh size and time step. Using an appropriate mesh size and time step and convergence study are important to ensure appropriate analysis results in time domain simulation. Various parameters of environmental conditions including wave heading angle – β, peak period - Tp and significant wave height Hs are investigated to define weather matrices and find out limiting operation windows. The obtained DAF can be used to compare with allowable DAF values to determine the weather window limit for the offshore lift operation. These studies showed that environmental conditions strongly affect HLV's lifting performance especially wave headings and peak periods. The simulation by using a numerical hydrodynamic model gives better prediction of HLV performance under heavy lift condition and comparison between numerical results and real offshore records help to give more confidence in design practice. From the analysis results, offshore contractors and client can develop optimal design solutions and good operation plan and schedule which are key points for safe and successful executing of an offshore heavy lift.
Gas Well Performance Analysis with Downhole Gas Compression
Authors: Montoya Cesar , AlAdawy Ahmed , Malkawi Ameen , Lastra Melo Rafael 
Published: November 2018

Abstract
Downhole gas compression is an artificial lift means that aims to increase production, maximize recovery and delay onset of liquid loading from gas wells. Being a technology not widely implemented yet, its application, benefits, operating window and limitations are not deeply managed by the oil & gas industry community.
The compressor boosts gas flow rates by increasing the pressure drawdown in the well proportionally to inlet pressure reduction. The required pressure ratio needs to meet the discharge pressure requirements to overcome well head pressure, column weight and pressure losses across the tubing, but the larger pressure ratio is the higher outlet temperature will be, which may become a limiting factor due to completion, compressor and process specs. Fluid velocity also varies across different casing sections, carrying with changes in liquid volume fraction (LVF) and flow regimes. In general, compressors are known to be low efficient handling liquids, therefore a close investigation on the LVF and flow patterns at inlet conditions must be very well understood for downhole applications.
Well modeling and sensitivity analysis will be used in this paper to illustrate in detail the well performance representation with downhole gas application along with a comparative analysis with surface gas compression to evaluate potential gains. Results and observations about these parameters, along with methodologies to calculate inlet/outlet conditions will also be described in this paper, adding to the existing literature a new holistic approach for analyzing gas well performance operated with downhole compressors.
Measurements of the Inorganic Scale Buildup Rate on Downhole Completion Equipment – Debris Barrier Screens
Authors: Morrow Timothy , Al-Daghar Tariq , Troshko Andrey , Schell Caroline , Keller Michael , Shirazi Siamack , Roberts Kenneth 
Published: November 2018

Abstract
The long-term development plan for a giant oil field offshore Abu Dhabi calls for new extended reach wells drilled from artificial islands. The existing wells in this field have historically suffered from inorganic sulfate-based scale deposition in the production tubing which is mitigated by periodic scale inhibition squeeze treatments. The new extended reach wells will have more sophisticated lower completions, including limited-entry liners (LELs) and inflow control devices (ICDs) with external debris barriers. It is currently planned to mitigate inorganic scale in these wells with periodic coiled tubing or bullhead scale inhibition squeeze treatments, which are anticipated to be more challenging and costly due to the extended reach. It is unknown as to whether these types of completion equipment are susceptible to scale deposition or how much scale deposition can be tolerated before well productivity is impacted.
Knowledge of the rate of scale buildup on ICDs and LELs versus the volume of water produced through the devices is an important factor for choosing the optimum frequency for scale inhibition squeeze treatments to mitigate scale in these completions while keeping operational costs down. A two-phase laboratory study is currently underway to assess the susceptibility of ICDs to scale deposition. The first phase of the study will focus on the potential for strontium sulfate scale deposition on the debris barrier upstream of the ICD.
This paper reports the experimental design and results of laboratory scale deposition experiments on a series of debris barrier test coupons with the goal of estimating the rate of scale buildup on the full-size ICD debris barriers, and the volume of scaling brine that can be produced through the ICD debris barrier (in the absence of any scale inhibitor chemical) without risking significant plugging.
Simulation and Testing of an Isolator Tool for High-Frequency Torsional Oscillation
Authors: Heinisch Dennis , Kulke Vincent , Peters Volker , Hohl Andreas , Schepelmann Cord , Reckmann Hanno , Ostermeyer Georg-Peter 
Published: November 2018

Abstract
During downhole drilling, severe vibration loads can occur that affect the reliability and durability of tools in bottom-hole assemblies (BHA). These high-frequency torsional oscillations (HFTO) can cause premature damage to tools or their subcomponents. This paper presents dynamic simulations, prototype testing, and field test results of a BHA component that isolates the upper part of the BHA from HFTO. This isolation increases the performance and reliability of BHA components through reduction of the vibration load.
The paper provides a brief summary of the theoretical background for predicting the critical torsional eigenfrequencies, mode shapes, and susceptibility of BHA design to HFTO. Finite-element (FE) models were used to simulate the effect and efficiency of the isolation. The isolator tool was tested in a full-scale laboratory test setup that emulated the critical mode shapes to analyze the torsional dynamics and the expected isolation effect. A BHA with the isolator tool positioned between a rotary steerable system (RSS) and measurement while drilling (MWD) tools was excited in the critical HFTO mode shapes with an electrodynamic shaker. Vibration response was measured using triaxial accelerometers.
Later, the tool was tested in the field in a BHA configured to log the vibration below and above the tool at sufficiently high sample rates to validate the isolation effect of the tool.
The laboratory results showed the isolating effect between BHA components above and below the isolator tool, in particular for the critical HFTO-frequencies and mode shapes as predicted by the finite-element simulation. The torsional deflection shapes from testing using distributed triaxial accelerometers showed a high correlation with the predicted mode shapes from the FE model.
The measurements from the field test also identified the isolation effect between the BHA sections. The measurement data showed that as predicted only the lower part of the BHA below the isolator tool oscillated at non-critical torsional eigenfrequency.
The isolator tool reduced torsional vibrations and improved tool reliability, tool lifetime and service delivery, especially while drilling in formations that are susceptible to excite HFTO.
A Case Study on Open-Hole Logging While Tripping LWT Through Drill Pipes, as a New Technology for Risk Mitigation and Cost Optimization in Abu Dhabi Onshore Fields
Authors: Singh Maniesh , Al Benali Khaleefa , Sallam Yassin , Sajeel Kashif , ElWazeer Fathy , A. Chaker Hicham , Propper Maarten 
Published: November 2018

Abstract
The ability to measure formation petro physical properties thru drillpipe has always been a challenge. It requires unconventional approaches to remove the effects of metal and borehole fluids on both the transmitted and received logging signals. This paper will present a proven technology executed in more than 1,000 wells all over the world and a first two successful trail case study from ADNOC Onshore wells in the Middle East.
The main objective is to acquire triple combo data (resistivity, density, neutron, gamma ray, spectral gamma ray & caliper) using the LWT conveyance and acquisition technology where there is a high risk of downhole triple combo Logging While Drilling (LWD) and or wireline (WL) tools getting stuck and the risk of losing radioactive sources.
The new patent pending technique was executed by using a slim downhole measurement tools inside specially designed drill collars invisible to the measurement sensors. LWT collars can be used for drilling and reaming as with normal drill collars. Propagation resistivity and neutron measurements are mostly like conventional techniques in tools physics. Density and nuclear caliper are measured by modelling the responses of three detectors short, medium and long distance away from the cesium source.
The measured LWT log data has been validated through back to back comparisons with WL & LWD) logs showing almost one to one correlation considering the effects of mud invasion due to lapsed time between runs, different wellbore condition and different depth of investigations.
Measured caliper, resistivity, density, neutron from LWT showed respectable match with WL or LWD tool. The differences in log responses are explained by differences in tool physics, logging speeds and environmental conditions. Similarly, the computed porosity from LWT tool comparison with WL and LWT porosity has almost the same statistics. The Quality LWT data was acquired in both wells at virtually zero LIH risk and minimum extra drilling rig time.
Introducing the new LWT technique to measure accurate Open Hole formation evaluation data from inside the drill-string is a cost-effective solution in various challenging scenarios, Exploratory/ Appraisal/ Development risky & challenging wells with unknown reservoir pressures or unsystematic depletion scenarios, complex downhole in-situ stress regimes, challenging tectonically faulted or fractured areas & unstable shales and many more, posing challenge to drill stable holes and a threat to LWD/ WL radioactive tool stuck.Unplanned deviated 8-1/2’ hole section geo-steered by MWD-GR, where at last minute triple combo is desired.
Impact of Natural Fractures in Reservoir Modelling and Characterization. Case Study in UAE
Authors: Mandl Johannes , Mills Carey , Obaidli Eissa Al , Basioni Mahmoud , Ali Khalfan Al , Blooshi Ahmed Al , Belova Natela , Arroyo Elkin 
Published: November 2018

Abstract
The offshore Field-A Gas Development Project is an integral part of the Abu Dhabi Deep Gas Project targeting untapped hydrocarbon reserves with priority given to gas reservoirs to satisfy an increasing gas demand and sustain economic growth of Abu Dhabi Emirate.
Well test data from Field-A Khuff Formation cannot be modeled solely using a matrix based porosity system and requires the presence of fracture network to give a "mixed" porosity system to explain the observed flow test results. To assess this a subsurface study was initiated to incorporate fractures within the matrix porosity based 3D reservoir model and to examine different methods of populating fracture distributions across the geologic model. The ultimate aim of this work was to more accurately predict gas rates to better understand and mitigate rate uncertainties across a range of development scenarios.
Ultrasound Tomography Based Two-Phase Composition Measurement
Authors: Ahmad Talha J. , Li Weichang , Adams Robert , Deffenbaugh Max , Arsalan Muhammad 
Published: November 2018

Abstract
Reliable flow measurement at the surface is critical for production optimization and reservoir management. Commercial water-cut and three phase flow meters have limitations in accuracy over the range of multiphase flow conditions. They require frequent calibration, and have high capital and operational cost. This paper describes an ultrasonic tomography based measurement of water hold-up, and presents preliminary flow loop and field test results. This ultrasonic system has the potential to overcome certain limitations of existing metering solutions.
Advanced Spectral Modeling of Noise Log Data: The Key for a Comprehensive Downhole Dynamic Characterization
Authors: Rocco François , Pirrone Marco , Galli Giuseppe , Moriggi Sara 
Published: November 2018

Abstract
This paper discusses the enhanced use of noise logging aimed at characterizing the dynamics of complex reservoirs and addressing wellbore integrity issues. The methodology makes use of a fit-for-purpose quantitative spectral analysis of noise log measurements and can provide direct and fast information about well completion integrity, post-stimulation job efficiency, fluid flow path in the near wellbore region, reservoir porosity characteristics and flow-units identification.
The approach is presented by means of a study performed on several wells intercepting different heterogeneous reservoirs and characterized by complex completions and, sometimes, by intensive stimulation jobs. In details, a high-resolution noise pattern modeling in a wide frequency range is performed to discriminate the character of the recorded flow noise in terms of mesopores, macropores, fractures, behind-casing channels and completion elements (including active valves and leaking packers). In favorable scenarios, the noise power amplitude is also used to understand the contribution of active reservoir units.
It is proven that providing a quantitative noise pattern classification is fundamental to recognize unusual poor cement placement issues, not detectable by standard sonic and ultrasonic cement logs and to discriminate between leaking and sealing packers. Moreover, in case of acid and/or acid fracturing treatments in carbonate reservoirs, the methodology can identify the generated wormholes/fractures and quantitatively evaluate the efficiency of the stimulation jobs by means of noise power analysis in the related frequency range. In addition, a dedicated spectral noise modeling is also used in order to identify flow-unit contributions in multi-layer scenarios and the type of porosity providing the flow. The reliability of the workflow comes after a successful comparison with the available standard production logging interpretations. The integration of this approach with standard workflows completes the reservoir characterization providing additional dynamic outcomes.
The key role played by the enhanced modeling of spectral noise log data demonstrates the versatility of the methodology. Although the added values of this logging technique are already known, the quantitative use of noise power amplitude in selected frequency ranges is relatively new and can shed light on this topic for future advanced applications.
Tipping the Scale in LNG Plant Design: Considerations for Train Size, Driver Selection, and Adopting Digitalization
Authors: Guccione Danielle , Russell Matthew 
Published: November 2018

Abstract
In recent years, there has been a great deal of discussion surrounding the topic of mid-scale vs. large-scale liquefaction trains in LNG export facilities. While in some select cases, mid-scale trains (0.5 – 2 million tonnes per year (typ)) may offer commercial, executional, and financial advantages, the decision is not a simple matter of one-size-fits-all, as large trains (&gt;3 million tpy) offer economies of scale, among other benefits. As this paper will explain, choosing a solution that delivers the most value over the life of a facility is contingent on the operator's specific objectives and circumstances. Ultimately, train size and liquefaction licensor selection have only a marginal impact on project capital costs as long as the total facility achieves a minimum of 8 million tpy (Russell, 2018).
The paper will offer objective cases for building both mid- and large-scale trains and outline key areas for project stakeholders to consider when making an informed decision regarding capacity and liquefaction licensor. It will also discuss important considerations for optimizing LNG plant design, such as mechanical driver selection, modularization, and the incorporation of digital technologies. The paper will conclude by discussing the importance of adopting a holistic strategy that integrates the entire gas value chain when attempting to drive out costs, minimize risk, and maximize overall project economics.