bluuebunny/crossref_metadata_2025_split huggingface dataset:
Well Control in Carbonate Zone – Total Loss and Kick in Gas Reservoir
Authors: Mahry Arvandi , Suryadi Dedi , Sufiadi Eri , Hadinata Dwie , Wahyudi Yudantoro 
Published: April 2016

Abstract
North Senoro Gas Field is located onshore at Sulawesi Island, operated by JOB PERTAMINA – Medco E&P Tomori Sulawesi. The aim of North Senoro Project Development is to produce gas from limestone reservoir (Mentawa reef) which has unique characteristic formation that total loss hazard wasn't found at the adjacent well. One of effort to solve the problems is bullheading. In this paper, it will explain how bullheading might become a sufficient method for controling pressure during stripping operation while curing loss circulation problem. Well control situation in sandstone and carbonate formation has different characteristic. In carbonate, well control issue is mostly come by total loss which caused the mud hydrostatic pressure was less in the wellbore. Curing loss circulation was the first major to control pressure on the well. Also on sandstone formation, has more compact if hasn't fault or fracture on there.
The well control issue happened in 8-1/2? hole section; the situation occurred when suddenly got total loss in the bore hole. It was followed by the increasing number of background gas from the cutting. Shut in well, got record of SICP is 1700 psi and SIDP is 0 psi. The operations continued with circulate gas out through choke simultaneously with original mud and LCM to try plugged the loss zone and filled up the hole. The result was same with no indication of curing the loss problem. Decided to circulate on the two side, through annulus and inside drill string, while circulate mud and LCM through drill pipe got plugged. The engineer team made some analysis then created few scenarios, such as severing BHA, perforate drill pipe to make communication with annulus, continued pumping mud and LCM via annulus (bullheading), or stripping operation. With all assumptions and condition, the stripping operation while bullheading became the best choice to POOH BHA and running OE to cure loss circulation with BDOP/BDOC, then continue with circulate out gas/kick. Finally, with 2 spot BDOC and the last BDOC was modified using LCM to mitigate micro fracture in cement, loss circulation solved then following circulate out gas by driller method.
For total loss and kick issue, the important thing that we have to assure is pressure gradient and availability of water and LCM material. Setting casing shoe at the high rating pressure will give us much possibility to select the way of curing loss circulation and kick. RIH OE pipe and spot BDOP & BDOC through OE pipe became success story to curing the loss for next well. Finally, the safety for crew, environment and production target is achieved with this option at North Senoro Gas Field.
3000 m Water Depth Flexible Pipe Configuration Portfolio
Authors: Vidigal da Silva J. , Damiens A. 
Published: April 2016

Since several years, Technip flexible pipe technology has been successfully used in water depths down to 2500 m and a test campaign was completed in 2010, proving its suitability down to 3000 m Water Depth (WD). However, hitherto no complete engineering studies had been conducted in realistic project environment for such WD. The aim of this paper is to deliver optimized flexible pipe configurations using conventional or alternative optimized technologies to reach 3000 m WD.
This engineering study has been conducted on realistic project specifications, representative of the Brazilian Offshore Region, adjusted to 3000 m WD with the objective to cover conventional applications such as Oil Production, Gas Injection, and Gas Export. The process was o challenge and push further the engineering and technology to a very detailed level, using these case studies to highlight the benefits of the most cutting-edge technologies. In particular the development of Carbon Fiber Armours (CFA) with high strength/weight ratio, high fatigue performance and corrosion free has opened new frontiers for Ultra Deep Water (UDW) with optimized riser configurations.
The result is a portfolio of advanced flexible pipe configurations for a set of applications in a water depth of 3000 m, derived either from conventional configurations, such as Lazy Wave and Free-Hanging, or alternative concepts such as Free Standing Flexible Riser. One of the main conclusions of this engineering study is that the use of Carbon Fiber Armours permits more simple configurations when compared to conventional ones, which has a positive impact on interference issues, simplifies the installation process, by removing the need for buoyancy modules, and finally leads to a global CAPEX reduction. Additionally, the use of the high inertia pressure armour wires, called "PSI", enables considering higher diameters in this water depth by optimizing the weight of the flexible pipe structures.
This portfolio aims at anticipating the petroleum industry needs with diversified flexible pipe configurations as well as identifying and adressing the design challenges to address Ultra Deep Water developments.
Direct Electrical Heating of a Flexible Pipe
Authors: Holst T. , Larsen T. , Straarup A. , Glejbol K. , Olsen K. S. 
Published: April 2016

This paper describes a new direct electrical heating method which offers unique flow assurance opportunities in flexible pipe systems. The method effectively expands the operational envelope of flexible unbonded pipes by offering prevention/removal of hydrate plugs, mitigation of vax precipitation and allowing for the transportation of viscous fluids over longer distances by distributed heating along the entire pipe length. Furthermore, the direct heating system can be applied continuously or intermittent as required by operation, e.g. after prolonged shut down periods.
The direct electrical heating solution for flexible pipe takes advantage of the electrical insulation properties of the polymeric pressure sheath in a flexible pipe. The system is effectively operated as a coaxial cable, where electrical current is passed through the carcass and returned via the tensile armor layers. Normally, the electrical resistance of the carcass is significantly above that of the tensile armor resulting in heat being primarily generated in the innermost carcass layer and in direct contact with the bore fluid. Thus, the presented system is a highly effective heating solution of the transported fluid which minimizes heat loss to the ambient structure. Furthermore, it is also highly beneficial that the existing type-approved pipe structure can be used without any modifications.
A full-scale demonstration of the new heating concept is presented here, where a 125 m long flexible pipe with a 12 in. bore diameter was placed in a water tank and subsequently heated electrically. Optical fibers for distributed temperature measurements were integrated in the pipe structure to monitor and regulate the bore temperature in a feedback loop with the power system.
In-Situ Production Profiling for Recovery Optimization via Fiber-Optic Monitoring
Authors: Chen Kyle , Lee Erik , Duncan Roger , Howard Jesse , Denney Tommy 
Published: April 2016

Abstract
Lower Tertiary reservoirs are characterized by high temperature and pressure, but low drive energy due to compaction and cementation. Primary recovery factors are expected to be low and enhanced recovery through waterflood is an anticipated recovery strategy.
Design and implementation are constantly changing throughout the life of a field with the desire to converge to an optimal solution as data is gathered and models are refined. Accurate input of production and injection allocation history reduces the need to rely on assumptions and generates more productive designs, faster. Lower Tertiary fields can see particular benefit due to the fact that there are a relatively large number of geologic unknowns, uncertain injector/producer connectivity, and relatively high vertical heterogeneity.
Highly heterogeneous vertical geology and poor communication suggest the need for high spatial resolution measurements. Wireline spinner surveys require mobilization and intervention costs that limit their utility in deep water applications. However, fiber-optic surveillance has the potential to provide the necessary information. Permanently installed fiber-optic systems can enable equivalent surveys to be conducted with in-situ equipment, on-demand, for the life of the asset. This will have a substantial impact on the cost to obtain data, significantly improve measurement frequency, and reduce the time required to implement changes that improve recovery rates. Even small relative changes in the recovery rate can translate into substantially improved project economics. Optimizing the enhanced recovery process with fiber-optic surveillance provides this opportunity. A wide range of fiber optic sensing applications have been evaluated and employed throughout the oil and gas industry. In this paper, an overview of fiber optic sensing applications will be discussed and their use in Lower Tertiary reservoirs will be evaluated.
Monotonic and Cyclic p-y Curves for Clay Based on Soil Performance Observed in Laboratory Element Tests
Authors: Zhang Youhu , Andersen Knut H , Klinkvort Rasmus T. , Jostad Hans Petter , Sivasithamparam Nallathamby , Boylan Noel P. , Langford Thomas 
Published: April 2016

This paper presents a numerical framework for monotonic and cyclic p-y curves for piles in clay, based on soil performance observed in laboratory element tests. A framework of constructing monotonic p-y curves from the stress-strain response measured in direct simple shear (DSS) tests is firstly introduced. The framework is developed from a parametric finite element study. An extension of the framework for analysing cyclic loading is then described, with the use of the cyclic accumulation procedure established at NGI in the last few decades. Finite element analyses are performed for a pile element subjected to various cyclic load parcels in order to validate the extension, using a soil model that follows the cyclic contour diagrams. The procedure to apply the proposed framework for calculating the overall pile response under monotonic and cyclic loading within a conventional beam-column type analysis is then described.
The proposed framework offers a rational approach for the p-y response of a pile element under monotonic and cyclic loading, with the possibility to consider the site specific pile-soil interface roughness, soil properties as well as the cyclic loading conditions. Finally, an example case using a program (NGI-PILE) that implements the proposed procedure is presented and validated against finite element analysis.
The currently proposed framework has potential applications for design of a range of offshore structures, including offshore well conductors, anchor piles and pile foundations supporting jacket structures.
Liner Hanger Rating Methodologies Validated with Physical Testing
Authors: Payne Curtis W. , Warneke Jacob S. , Kaculi Jim T. 
Published: April 2016

Abstract
Currently there are no industry standards specific to the design of liner hangers that provide guidance for determining equipment capacity. The demand for increased pressures, temperatures, and load capacities within stringent space constraints has added complexity to liner hanger design. As wall thickness decreases, capacities are more sensitive to geometrical features and imperfections such as slots, grooves, ovality, and end effects. Classical engineering calculations become increasingly inaccurate as liner hanger geometries become more complex, driving a demand for more precise methods of design verification and validation. Advanced 3-D finite element analysis (FEA) with elastic and elastic-plastic analysis and non-linear geometrical behavior is being used to more accurately quantify stress levels and identify sources of instability in complex liner hanger geometries. The addition of axial slots to a cylindrical pressure vessel result in localized bending stresses which are often overlooked when using only classical engineering calculations for cylindrical members. FEA captures these bending effects, resulting in more accurate ratings. Additionally, external pressure failures due to instability are difficult to capture with classical engineering calculations. Unlike hand calculations, 3-D FEA allows the user to accurately detect instability in liner hanger bodies with complex geometries and end effects. Although 3-D FEA is more accurate than classical engineering calculations, it is imperative that the inputs and assumptions that go into the model accurately represent the physical conditions of the validation test and end use. Internal and external pressure tests have been conducted and the information obtained was used to validate the FEA verification methods. By using a combination of verification analysis with advanced FEA and test validation, an accurate and proven rating methodology for liner hanger systems has been developed. Details about the calculations, FEA, testing, safety margins, and a proposed methodology for rating liner hangers are presented.
Permanent Chemical Tracers Piloted for Inflow Monitoring in Cemented Production Liner
Authors: Oftedal Gaute , Recordon Marion , Loddervik Christer , Nyhavn Fridtjof 
Published: April 2016

Abstract
This is the world's first field trial where inflow tracers have been permanently integrated into a cased, cemented and then perforated production liner; previous inflow tracer deployments have been into non-cemented lower completions. This field trial took place for an oil production-well in the Vigdis field located in the North Sea. The objectives for the tracer deployment for the field trial were: To demonstrate a tracer deployment method not causing complications during Run-in-hole or cementing, while allowing tracer marking of produced oil and water.To demonstrate inflow tracer monitoring specifically for cemented linersTo improve the understanding of inflow and reservoir dynamics specifically for this well and the Vigdis field
Inflow tracers are unique tracer chemicals suspended in a plastic material, designed to release by liquid contact. These were deployed in a metal chamber at the outside of the production liner, to protect from the cementing operations. The liner joints containing the tracers were then spaced out at strategic locations across different reservoir intervals, and the production liner was cemented in place. After perforating, the tracers were exposed to flow, allowing surface sampling and later analysis of each unique tracer. Inflow along the wellbore was then determined through the use of sophisticated tracer transport models.
To ensure the success of this first field trial, the following items were specifically explored: Care was taken to build the customized metal chamber with a smaller outer diameter than the couplings used for the 7inch liner, and to fill this with low solid oil-based mud. The integrity of the tracer systems and the deployment method were proven by:?No complications were observed during Run-in-Hole (RIH) or cementing?All tracers were detected with strong signals in liquid samples,Tracer transport models were applied to the tracer signals and related production data, enabling:?Identification of the location of early water inflow?Defining which of two reservoir layers held the highest pressure?Verifying contribution from the toe during cleanup
Applied Geostatistical Reservoir Characterization in R: Review and Implementation of Rock Facies Classification and Prediction Algorithms-Part I
Authors: Al-Mudhafar Watheq J. 
Published: April 2016

Abstract
Many multivariate statistical learning algorithms are used for rock facies classification. These algorithms are done through several commercial software packages with limitations in terms of availability and computation time consuming. In this paper, we introduce a simplified reservoir characterization workflow through seven multivariate statistical analysis algorithms of rock facies classification modelling, prediction, and validation with high-quality results visualization. That workflow was done through R, the most powerful open-source statistical computing language.
R codes were prepared for seven Facies classification algorithms, which are either supervised learning or regression based. The algorithm are Nave Bayes Classifier (NBC), Logistic Boosting Regression (LogitBoost), Linear Discriminant Analysis (LDA), Multinomial Logistic Regression (MLR), Tree-Based Classification Models (RPART), and Kernel Support Vector Machine (KSVM). These algorithms were modeled rock facies given core and well log attributes for a well in sandstone reservoir in West Africa. The predicted discrete and posterior facies distributions could be used to build the spatial facies distribution and trend modelling, respectively.
To predict the discrete and posterior probability for the clustered Facies, seven algorithms were modeled in R given core and well log attributes. Naive Bayes Classifier and Linear Discriminant Analysis adopted Bayes rule to compute the facies discrete and conditional posterior probabilities. The LogitBoost classification is based on weighted vote of weak classifiers that are sequentially added to the model to minimize the residual loss. The MLR is used to predict the facies probabilities given each independent variable by constructing a weighted linear predictor function. TBM are a recursive partitioning methods that build Classification and Regression s for predicting continuous facies probabilities. Two nonlinear classification algorithms that are efficiently achieved accurate facies modelling and prediction: Kernel Support Vector Machine and Probabilistic Neural Networks. KSVM recognizes the discrete facies based on maximizing the margin around the separating hyperplane and the decision function is fully specified by a subset of the supporting vectors. The accurate models could be adopted to predict facies distribution at other wells in the reservoir for geospatial modelling.
The comparison between these seven-classification algorithms was done through confusion table, transition probability matrix and total percent correct (TPC) of the predicted facies that reflect the classification accuracy. It was noticeable that LogitBoost, KSVM is the most accurate models by achieving the highest TPC as they incorporate nonlinear modelling. Conversely, the lowest TPC was by LDA as linear classifier and NBC as Bayesian one. However, the in-between approaches are MLR and TBM.
High Strength Tapes Layer Design and Qualification, Reinforcement Solution Against Armor Buckling of Flexible Pipe
Authors: Gasc S. , Lambert A. , Do A. T. , Félix-Henry A. 
Published: April 2016

AbstractUnbonded flexible pipelines for deep water field applications are subject to elevated hydrostatic constraints; bore pressure being dropped brings high compressive stresses due to reverse end cap effect. If the external sheath is unsealed, the axial compression loads transmitted to the tensile armors induce their radial expansion, which can lead to their buckling. Specific layers shall be added in order to maintain armors in place: anti-buckling tapes. These layers, designed with high performance fibers, have been introduced in the early 1990's when the use of flexible pipe has grown in deep water.Various failure modes are expected and observed depending on the fiber characteristics, tape construction, tensile armors properties and annulus environment. For each pipe design, an optimum has to be found between the anti-buckling tapes loads and the compressive stress in the armor layers in order to ensure sufficient safety margins against both tapes breakage and different buckling modes of the armors.Anti-buckling tape interaction with the tensile armors and annulus environment main influencing parameters will be explained in the light of full scale tests performed on flexible pipes in hyperbaric tank. Specific laboratory devices have also been developed to be representative of the operating behavior of both armors and high strength tapes.In parallel, this paper will present qualification tests performed in compliance with the requirements of 2014 editions of API standards 17J and 17B.The tests showing tape resistance and flexible pipe behavior have enabled to establish a robust design rule. This process is being scrutinized by an Independent Verification Agent and aims at leading to Type Approval Certification according to the latest edition of API 17J.
Application of CFD for Computing VIM of Floating Structures
Authors: Kara M. C. , Kaufmann J. , Gordon R. , Sharma P. P. , Lu J. Y. 
Published: April 2016

Abstract
Under certain current conditions (e.g., the Loop Current in the Gulf of Mexico), floating structures such as semi-submersibles, spars, and TLPs may experience significant vortex-induced motion (VIM). VIM is one of the key drivers of fatigue damage for risers and moorings. It is essential that fatigue from VIM is properly accounted for in design and operation of the structure.
A CFD study was performed using OpenFOAM™ on a model scale, deep draft, "Paired-Column" semi-submersible to estimate the VIM response. The CFD results are compared to model test data. The study concluded that the calculated VIM responses obtained using OpenFOAM™ is comparable to those from model tests. Therefore, if used properly, the CFD approach can be a cost effective and reliable alternative to model testing, which is costly and schedule constrained making it impractical in the early phase of a project.
The paper also describes a set of sensitivity studies based on a fixed, single square column of the semi-submersible which was undertaken to: (i.) better understand the differences in the flow characteristics at model and full scale and (ii.) identify meshing requirements for future calculations.