bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast and Accurate Screening and Evaluation of Halite Scale Inhibitors by Two Novel Static Bottle Testing Methods
Authors: Ruan Gedeng , Kan Amy T. , Dai Zhaoyi , Yan Fei , Zhang Fangfu , Bhandari Narayan , Alsaiari Hamad A. , Liu Ya , Zhang Zhang , Lu Yi-Tsung , Deng Guannan , Tomson Mason B. 
Published: March 2017

Abstract
Halite (NaCl) scale is a non-conventional scale, which happens due to the temperature or pressure drop, or water evaporation at extremely high TDS environment (TDS up to 350,000 mg/L), such as deepwater field, shale formations, gas and gas condenstate fields. Compared to other conventional mineral scales, like barite or calcite, there is no standardized experimental procedure to screen and evaluate halite scale inhibitors. Because of the extremely high solubility of NaCl, it is very challenging but important to accurately control and calculate the halite saturation index (SI) or saturation ratio (SR) experimentally and theoretically. The Brine Chemistry Consortium has been continuously working on the development and optimization of the thermodynamic model, ScaleSoftPitzer (SSP), for the the prediction of the solubility and scaling risks of various minerals in mixed electrolytes over a wide range of temperature and pressure based on Pitzer theory. Recently the new SSP2017 version which can predict the halite SI within SI error of 0.01 from 25 to 90 °C with up to 1.0 m Ca2+ (~35,000 mg/L). In this study, two static bottle testing methods have been developed by taking the advantage of the powerful calculation ability of SSP2017 to fast and accurately screen and evaluate the inhibition efficiency of different chemicals. The Method One is a temperature-driven and monitoring method and the Method Two is a brine-mixing method of mixing a naturally saturated NaCl solution, a highly concentrated chloride salt solution and an inhibitor solution. By using these two novel methods, over 40 different chemicals are screened and evaluated, including small molecules and polymers in the category of polyacrylate, polyaspartate, polysulfonate, carboxylate sulfonate copolymer, phosphonate polymer, etc. From the experimental results, five carboxylate sulfonate copolymers (Inh #H14, #H23, #H26, #H30, #H40) have better inhibition efficiency. The synergistic effect of Inh #H40 and Fe(CN)64– is also investigated, and 130 mg/L of Inh #H40 and 20 mg/L of Fe(CN)64– can effectively inhibit the halite scale at simulated field condition of SI = 0.09 (SR = 1.23, TDS ~ 353,800 mg/L) and 0.6 m Ca2+ at 70 °C. In summary, two fast and accurate methods have been developed for the screening and evaluation of halite scale inhibitors, and with the usage of effective halite scale inhibitors, the costs of halite scale control can be significantly reduced both in freshwater usage for dilution and high-salinity produced water treatment.
Micro-Sonde Well Logging System
Authors: Gardner D. , Hjelstuen M. , Fallet T. R. , Fallet Truls , Kragset S. , Lohne H. P. , Husby K. , Hamou F. R. , Stamnes Ø. , Belle B. 
Published: March 2017

Abstract
The micro-sonde well logging system utilizes miniaturized data logging devices, which are released at the bottom of a well and record downhole parameters whilst being transported by fluid flow to surface.
The μSonde capsules are designed to be small enough to pass restrictions without obstructing the flow path. Each sonde is activated when launched and thereafter records sensor measurements to a memory. Typical measurements include pressure, temperature, motion and fluid electrical properties. Upon reaching surface, wireless communication transfers the recorded data for analysis.
For production wells a magazine carrying μSondes is deployed to the bottom of the well and thereafter, based on predetermined well conditions and/or time intervals, the sondes are released. For drilling operations, the μSonde storage magazine is deployed together with the bottom hole assembly. The sondes are constructed from low density materials such that their effective density can be matched to the well fluid.
Applications and design requirements for the μSonde well logging system have been investigated for drilling operations and production well surveys.
The development of the micro-sonde (μSonde) well logging system is supported by the Research Council of Norway' Petromaks 2 Ground breaking technology research program.
The CHAOS-X Model and Uncertainty Values for Magnetic Directional Surveying
Authors: Herland E. V. , Finlay C. C. , Olsen N. , Edvardsen I. , Nordgård-Hansen E. , Laundal K. M. , Waag T. I. 
Published: March 2017

Abstract
The Earth's magnetic field provides a unique natural source of orientation information that is particularly useful for subsurface magnetic measurement-while-drilling (MWD) navigation. In order to utilize the MWD magnetic field measurements for calculating the orientation of the bottom hole assembly (BHA), an accurate geomagnetic reference model is needed for comparison. In this paper we present the CHAOS-X model, a new geomagnetic reference model that provides global vector field estimates of Earth's magnetic field, with high resolution in both space and time, for precision magnetic directional surveying applications.
The model is derived from more than one million satellite and ground-based observatory magnetic measurements and consists of modules representing internal sources (in the Earth's core and crust), mag-netospheric sources, and ionospheric sources. Compared with previous reference models, the CHAOS-X model is particularly designed for better characterization of the time variations in the geomagnetic field. In this paper, we describe the model and present benchmark comparisons with magnetic observatory data to establish the uncertainty values required in models of wellbore positional errors in magnetic directional surveying applications.
The discrepancy between geomagnetic measurements and reference models are typically dominated by spatial variations caused by local geology. In applications requiring high accuracy, these variations can be taken into account by using a dedicated local model. In such cases, when the errors associated with local geology is small, our results show that the CHAOS-X reference model may yield a significant improvement compared with existing reference models. This result holds both when the model is used predictively and retrospectively. We also argue that using a model with an accurate description of the time variations improves recent magnetic surveys while drilling, since the description of the rapid time variations can be updated near real-time.
Pneumatic Conveying of Model Drill Cuttings - Pilot Scale Experiments and Simulations
Authors: Malagalage A. , Ratnayake C. , Ariyaratne W. K. , Melaaen Morten C. , Aas Nina 
Published: March 2017

Abstract
The offshore drilling operations generate huge volume of drill cuttings. Rig site transfer of cuttings can be a challenge both if pneumatic conveyors or screw conveyors are used. Especially, wet powder is a challenge since the particles become too sticky for easy handling or too dry for acting like a slurry. This paper presents the preliminary results of a scientific investigation aimed to study transport properties and storage criterion of dry and partially-moist solids drill cuttings. Model materials have been tested in pilot scale pneumatic conveying rigs and CFD simulation on particle conveying has been performed in parallel. The pilot scale tests have been conducted for the sand particles in the size range of 0.1 – 3 mm diameter under the air flow rate of 13-23 ms-1 The simulations were carried out using multiphase particle-in-cell method (MP-PIC) for dry particles that are having particle size distribution in the range of 0.3-3 mm diameter. Pressure drop in a horizontal section is studied and it was observed that at a minimum pressure drop and a minimum specific power requirement is reached when decreasing the superficial air velocity. This region can be considered as the economical region for operation. For the considerd particle size this region was obtained at the air velocity of 16-19 ms-1 for a horizontal pipe section with 81.2 mm diameter.
In the simulations, the predicted pressure drops in 15-22 ms-1 velocity range are in good agreement with experimental results. The combination of pilot scale pneumatic conveying tests and simulations of dry drill cuttings provide a platform to evaluate and predict pneumatic conveying parameters for partially-moist drill cuttings.
Extended-Reach Open-Hole Gravel Pack Completion under Multiple Complexities
Authors: Aggarwal Vishal , Gupta Vaibhav , Narayan Shashank , Horatio-da-Costa Shado Olushola 
Published: March 2017

Abstract
This paper aims to discuss completion of deepwater open-hole gas wells that were completed using an alternate paths system (APS) and a state-of-the-art viscoelastic surfactant (VES) carrier fluid. The wells presented multiple design and operational complexities such as high bottomhole temperature, narrow fracturing window, extended horizontal laterals, and unstable shale zones. Operational and design steps considered to overcome these complexities are discussed, making this literature a resource that maps obstacles and presents viable solutions faced in any similar operation. These complexities combined with deepwater operational requirementsand economics made cost of failure unacceptable.
Two 8.5-in. openhole depleted gas wells upto bottomhole temperature of 230 °F were completed with gravel pack treatments using a VES carrier fluid to counter sand settling, minimize friction pressures, and optimize fluid viscosity. The operations pumped 200% excess proppant compared to design volume to ensure complete packs downhole, countering any thief zones or open-hole washout regions. Returns were taken through the BOPvia mud line to avoiding high fluid friction in the choke line. In one case, the riser was displaced with lighter base oil to reduce the bottomhole pressures.
Using the alternate path system and VES carrier fluid proved to be highly successful in these wells, as compared to the pre-drilled liners and standalone screens used previously in the same field. Complete packswere obtained within narrow fracture gradient windows inall cases. After reversing out the slurry, a filter cake dissolver treatment was also performed to decrease the flow initiation pressure for the well. Case studies have been presented elaborating completions plan and execution of open hole gravel pack treatment for two 8.5-in wells.
This literature is a case study elaborating operational procedures that have proved to be successful in performing open-hole gravel packs under complex constraints. This paper serves as a reference, highlighting obstacles faced and presenting viable solutions for any similar operation.
Comparing Reservoir Fluid Models to PVT Laboratory Measurements
Authors: Meisingset Knut Kristian , Yang Tao 
Published: March 2017

Abstract
To prove that PVT input to reservoir models is representative, the comparison between the modeling of PVT data and relevant PVT laboratory measurements should preferably be as direct as possible.
A black oil reservoir simulation model can be described as a compositional model with only two hydrocarbon components (‘oil’ and ‘gas’). The reservoir fluid is represented by a set of tables, defining oil and gas viscosity and formation volume factor as a function of pressure, temperature and composition.
Examples on quality assurance of fluid modeling by direct comparison of PVT input for black oil and compositional reservoir simulation with PVT laboratory measurements are shown in the present paper, including results from Differential Gas Liberation (DGL) for reservoir oil and Constant Volume Depletion (CVD) for reservoir gas.
Challenges with regard to black-oil modeling of depth gradients are also discussed.
Sustained Intervention Campaigns Over a 10-Year Period with Riserless Light Well Intervention Vessels Enables North Sea Operator to Improve Operational Efficiency and Increase Recovery from its Subsea Fields
Authors: Varne T. , Jorgensen E. , Gjertsen J. , Osugo L. , Friedberg R. , Halvorsen E. C. 
Published: March 2017

Abstract
This paper describes the approach, experience and results achieved by a North Sea operator (the Operator) when using purpose-built riserless light well intervention (RLWI) vessels to perform continuous well intervention operations on its subsea fields over the last 10 years. Using RLWI vessels on a continuous basis, the Operator has been able to; achieve a high intervention intensity on its subsea wells (345% increase—from 11 wells in 2006 to 49 wells in 2016), lower the intervention cost per well and improve field recovery factors. The contributory factors to these successes that are covered in this paper are: –Continuous improvements in efficiency during all stages of the intervention operation. This has resulted in the capacity to perform more interventions and hence a lower intervention cost per well. Specifically, over the last 10 years, there has been a 60% decrease in the average number of days to perform an operation.–Improved reservoir management, as a result of regular data acquisition of production and saturation monitoring logs.–Introduction of new technologies and the improved robustness of powered mechanical intervention systems. This has enabled more complex intervention work scopes, such as milling and manipulation of completion components, which would previously have required a modular offshore drilling unit (MODU).
The next target, is to reach water depths deeper than 1500 m. Some of the main challenges and equipment upgrades required to work at these depths are discussed.
A Novel Approach to New Field Development - Application of Reservoir Mapping Technology to the Ivar Aasen Field Development for Maximizing Field Performance and Improving Reservoir Characterization
Authors: Jøssund Tor-Ole , Elfenbein Carsten , Johansen Yngve Bolstad , Drange Ingrid Sætre , Olsborg Lodve Hugo , Skorve Torstein , Kvilaas Geir-Frode , Christoffersen Kjell , Mastad Sigbjørn , Stubsjøen Marte , Wang Haifeng , Denichou Jean-Michel , Charef-Khodja Hakima 
Published: March 2017

Abstract
The Ivar Aasen field was discovered in 2008 and consists of two main groups of reservoirs – the Jurassic and Triassic reservoir zones. The reservoir architecture is complicated by their different depositional settings and by syn- and post-sedimentary faulting. Developing a new field of such complexity is a challenging task that demands a novel approach to optimize well placement and improve reservoir characterization.
Reservoir mapping while drilling (RMWD) technology has recently been introduced to the industry, providing an array of deep, directional measurements that are converted to a resistivity map of the formation out to approximately 30 m above and below the borehole. The reservoir mapping results are available for the operator to make geosteering decisions during drilling, to optimize the completion design with inflow control devices after TD, and to update the post-well reservoir model for planning the next wells. This process helps the operator maximize the benefits from the already drilled well on the yet-to-drill wells. The sequence of the wells to be drilled can be logically arranged to leverage the maximum value from the information that reservoir mapping provides.
The drilling campaign on the Ivar Aasen field started in summer 2015 and the RMWD technology was used while drilling all the production wells. It revealed that the actual reservoir structure was even more complex than originally expected, and enabled the operator to pursue the best well path to maximize field production potential. This was achieved by using the data to actively geosteer, estimate reservoir producibility (through permeability-thickness calculation) in real-time to decide on TD, and by sidetracking to new targets revealed by the mapping. This new approach can also be applied to infill campaigns on existing fields. In this paper, one of the producer wells are reviewed in details to illustrate the process and demonstrate the results.
Drilling Fluid Rheology Under High Pressure High Temperature Conditions and its Impact on the Rate of Penetration
Authors: Sukhoboka Olha 
Published: March 2017

Abstract
The aim of this paper is to investigate the temperature and pressure dependent rheology of drilling fluids, and show its effect on the rate of penetration. A better understanding of the mechanisms that affect the rate of penetration is necessary because the high costs of the high pressure high temperature wells often make the field development economically inefficient.
To achieve the goal of the study, laboratory experiments on temperature and pressure dependent rheology of various drilling fluid samples were conducted. The experiments show that temperature has a more significant effect on the drilling fluid viscosity than pressure. In addition, computer modelling of the rate of penetation was done. As a result of the modelling, it was observed that the temperature does not have a significant effect on the rate of penetration.
Influence of Construction and Deterioration on Platform Well Life Extension
Authors: Saleh Hassan , Rimmer Alex 
Published: March 2017

Abstract
One of the most common challenges faced by well operators worldwide is extending the lifetime of their aging platform wells. The initial well construction, operational loading and time-dependent deterioration of a well through field life are all key factors that need to be understood to establish the remaining capacity of a well. However, often these factors are not fully understood and consequently costly decisions to repair or abandon wells can be made unnecessarily, or in some cases critical wells or operations on wells are not identified, risking structural collapse of a well. To address these issues, this paper describes the factors that influence the integrity of the well, and presents advances in the approaches to understand and evaluate the condition of a well and hence better evaluate remaining capacity. Methods, Procedures, Process: Typically, corrosion of the casings is taken as the key parameter to establish a well's remaining capacity. However, as demonstrated in this paper through an analytical evaluation, the axial loading in the well is another key parameter that needs to be understood. A range of factors affect the well axial loads based on well construction and deterioration is considered, including: Weight of casing hung off wellhead during installationLevel of axial support provided by casing shoeCement levelsChanges to well configurationChanges to well service (Producer to Injector)Changes to operating temperatures and pressures through field lifeCorrosion and other deterioration of the conductor and casings
This information can, however, be difficult to obtain due to incomplete or inaccurate construction records or difficulties in taking direct measurements or inspecting a well. This paper demonstrates the influence of each of these variables on the capacity of the well, how the uncertainty in these variables affects this assessment, and consequently the overall uncertainties in establishing the remaining capacity of a well. Results, Observations, Conclusions: Having established the limitations and uncertainties of an analytical evaluation and the need to establish well axial loads, the paper also proposes a method to characterise the axial loads in a well, including a proposed technique for in-field measurement as an input to establishing a well's on going fitness for service alongside corrosion measurements. Novel/Additive Information: Overall, the paper presents an improved approach to establishing the suitability of a well for life extension based on an improved understanding of the influence of well loads, with widespread application to aging platforms in the North Sea and globally.
Multilevel Force-Balanced Cutting Structure Layout Helped Solve PDC Bit Dullness Issues Resulting from Geosteering in Thin Reservoirs
Authors: El-Gayar Mahmoud , Ali Tarek Samy , Talaf Mansour Abu 
Published: March 2017

Abstract
Thin reservoirs of a few feet in thickness present challenges to well placement. The challenges generally involve remaining within the reservoir boundaries and undergoing as few exits as possible. Geosteering is typically used to optimize wellbore placement in the productive reservoir to maximize hydrocarbon production. The challenge posed by the subject reservoir in this study was a combination of the thinness of the reservoir and the highly resistive environments of the boundary, including formation heterogeneity and low porosity anhydrite formations.
Steering in this challenging environment using a rotary steerable system (RSS) resulted in premature cutting structure damage of the polycrystalline diamond compact (PDC) bits. This damage led to a significant increase in nonproductive time (NPT) resulting from tripping out of the hole for bit changes. A customized PDC bit design was necessary for the drilling operation to address the dull conditions, maintain a competitive rate of penetration (ROP), provide smooth borehole quality, and maintain low vibration levels. A new PDC bit was designed using patented multilevel force balancing technology: a new theory of PDC cutter layout in force-balanced groups. By carefully selecting the order of cutter layout groups, an even distribution of the cutting structure forces was obtained, thus reducing the imbalance forces induced as the bit entered transit lithologies.
This PDC bit design and the implementation of the integrated engineering software used to analyze offset well data, drilling parameters, bit walk tendency, and rock mechanics significantly affected the horizontal section drilling performance. A single new bit design was used to drill three laterals from shoe to total depth (TD) while achieving a new field ROP record. The bit was pulled out of hole (POOH) twice in green dull condition. The successful implementation of the multilevel force-balancing technology improved overall bit stability, reduced vibration levels, and increased the horizontal section drilling efficiency.
This paper demonstrates the successful implementation of an innovative PDC cutting structure layout using computer-aided design (CAD) and computer-aided manufacturing (CAM) software for bit design and optimization. The PDC bit design software incorporates a steering mechanism, bit/formation interaction model, and advanced rock mechanics modeling software to help predict bottomhole drilling mechanics, thus helping to create an optimized engineering solution for enhanced drilling efficiency.