bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Electrically Trace Heated Blanket: A New Concept for Efficient Subsea Flowline Unplugging
Authors: Marret Antoine , Espinasse Philippe , Parenteau Thomas , Routeau Sylvain 
Published: April 2016

Subsea Flowlines blockage due to hydrate or paraffin plugs, resulting from pour point issues or deposition, is a frequent concern in subsea production requiring expensive remediation methods. The expenditures associated with subsea flowlines unplugging can increase very quickly, especially when considering the associated loss of production as well as the various investigations needed to define the appropriate remediation strategy. Such investigations cover the identification of the plug's nature, its location, the assessment of the appropriate dissociation method as well as the flowline restart strategy.
In some scenarios, the plug dissociation method, like depressurization for hydrate plug and chemical soaking or pigging for paraffin plug, may take a long time ranging from several days to several months. Often, the remediation cannot be performed from the topside facility and will require the mobilization of an external drillship vessel to carry manifold or Xmas tree work over. Ultimately, the plug removal method may fail and therefore lead to flowline abandonment and/or replacement. From these observations, there is room for the development of a more efficient, predictable and reliable method to unplug subsea flowlines. With this regard, the development a new subsea flowline intervention system named Electrically Trace Heated Blanket (ETH Blanket) has been initiated.
The ETH-Blanket is a compact and modular system, with length adaptable typically up to 2km. The system is equipped with trace heating cables relying on Joule's Effect for heat generation to dissociate the plug and distributed temperature sensing (DTS) to monitor the flowline's bore temperature in order to identify the location of the plug, characterize its nature and follow-up the temperature and pressure profiles during plug dissociation. The ETH Blanket can be deployed onto any kind of existing flowlines (flexible or rigid) and in any condition (buried or not) from a Light Construction Vessel. The power required to dissociate the plug is low (typically &lt;1MW) and once the dissociation is completed, the ETH Blanket can be recovered onto the intervention vessel and relocated.
This paper describes into details the ETH-Blanket assembly and its operating principles, its anticipated thermal performances determined using CFD modeling, as well as and its deployment method and spread. To illustrate the ETH-Blanket efficiency, a typical multiple hydrate plugs dissociation operation will be presented and compared to a conventional topside depressurization.
As a conclusion, the on-going fast-track qualification programme for the development of the Electrically Trace Heated Blanket Technology will be presented.
Design Aspects of Pipe-in-Pipe Systems for HP-HT Applications
Authors: Sriskandarajah T. , Ragupathy P. , Rao Venu 
Published: April 2016

The High Pressure and High Temperature (HP–HT) subsea field developments are increasingly using Pipe-In-Pipe (PIP) systems for transportation of production fluids due to superior thermal conductivity performance compared to wet insulated single pipe system. PIP systems can provide the necessary thermal insulation with very low Overall Heat Transfer Coefficient (OHTC) in the order of 0.5 to 1.0 W/m2.K whether installed exposed on the seabed or trenched and buried. An additional inherent feature of PIP systems is that they offer increased protection against third party interaction such as fishing gear and dropped object impact.
PIP system will provide a very long "no touch time" before any intervention (e.g. depresurisation) becomes necessary. This aspect can also be improved by using e.g. hot water circulating and electrical heating in order to overcome difficulties which may arise from prolonged shutdown periods.
The mechanical design of a HP–HT PIP systems is more complex than conventional single pipe system and involves consideration of additional failure modes. This paper gives an overview of the PIP system design, with particular emphasis on in–service buckling and fatigue design. Design considerations for trawl gear impact on lateral buckling and operational aspects of clad and lined pipes for HP–HT and sour service applications are also discussed.
Application of a Novel Cement Spacer with Biodegradable Polymer to Improve Zonal Isolation in HTHP Wells
Authors: Li Li , Alegria Adriana , Doan Angela Anh , Kellum Matthew Grady , Castanedo Rodrigo 
Published: April 2016

Abstract
In deepwater drilling, spacers are widely used between drilling fluids and cement to effectively remove the drilling fluids and improve cement bond. A variety of spacer systems have been applied over the past decades with biodegradable polymers. However, most of these biopolymers are thermally stable only below 200 to 300°F and lose viscosity above their degradation temperature. In this study, a new spacer system for HTHP wells has been developed with a novel biopolymer and lost circulation materials.
The performance of new spacer is compared with a previous spacer system, which has been successfully applied to wells on land and offshore, especially for preventing and remediating lost circulation issues while cementing. The rheological properties of unweighted and weighted spacers (12 to16 ppg) were measured from room temperature up to 400°F with a stabilizer. The new spacer exhibited a superior rheological profile at elevated temperatures. The compatibility tests were conducted between the spacers and various types of drilling fluids and cement slurries. The new spacer improved the compatibility with synthetic/diesel-based drilling fluid and cement with less or no viscosification. The sealing performance of the spacers was determined in a fluid loss cell with 20/40 proppant. The new spacer effectively prevented losses by sealing the proppant under pressure. To date, several land operations have been successfully completed and one case history is discussed in detail.
In summary, the new spacer system is stable at high temperature, improves compatibility with drilling fluid and cement, and maintains good sealing performance. The new spacer is applicable in any types of wells and cementing operations, especially where high-permeability, fragile, unconsolidated and low-fracture-gradient formations are present. The new spacer is biodegradable, forms a seal to minimize filtrate invasion into the formation, effectively reduces cement losses and formation damage from filtrate migration, and enhances hole cleaning prior to cement placement.
Technology Qualification for ADNOC Group Operations in the Arabian Gulf
Authors: El-Gharbawy Sherif , Beydoun Wafik 
Published: April 2016

The Exploration and Production industry faces increasing challenges as a result of a volatile market outlook and declining short-term returns. The fluctuating demand for energy, when coupled with declining production from older reservoirs and stricter standards for sustainable operations, require more efficient recovery from existing assets. The Abu Dhabi National Oil Company (ADNOC) and our Group of Operating Companies (OPCOs) have focused attention on New Technology Development and Qualification, acknowledging that, in the coming years, innovation will be paramount to realizing our strategic production targets.
To qualify new technologies for deployment in field operations, we have historically relied on disparate processes in each of our operating companies. Alternatively, our operating companies have relied on their respective International Shareholder processes which had been developed and tested for environments that may be dissimilar to that of the Arabian Gulf. Our increasing reliance on innovation has called for the development of our own, bespoke standard processes for the maturity and qualification of new technologies. Key to the adoption of a new process was to communicate the benefits of centralization to, and obtain early buy-in from, our operating companies. Our approach to the design of the new process has been to accommodate the established practices of the operating companies and then to capture and integrate the best and most relevant elements of the International Shareholders' processes to our operating environment.
Our work has led to the development of the ADNOC Group standard process for the qualification of new technologies. The process uses NASA's Technology Readiness Level (TRL) tool as a backbone structure in its development. Strategically positioned Stage Gates with Key Performance Parameters are utilized to assess the maturity and inherent risk associated with each new technology as it is allowed to advance from one stage of development to the next with better performance. We are integrating the new process into our research and development project contracts with partner universities so as to positively influence the maturity of our new technologies and hence enhance the chance of success of our technology development efforts by bridging the gap between the stage gates. The standard process has been pilot tested throughout 2015, with full deployment targeted for Q2 2016.
The new technology qualification process benefits from the collective experiences of our operating companies, their International Shareholders and qualified service companies. The process was developed to be specific to the local environment and most responsive to the relevant technical challenges of each of our OPCOs. It allows only technologies with managed risk and improved performance to reach Operations.
Field Test for Real Time Monitoring of Piezoresistive Smart Cement to Verify the Cementing Operations
Authors: Vipulanandan C. , Ali M. , Basirat B. , Reddy A. , Amin N. , Mohammed A. , Dighe S. , Farzam H. 
Published: April 2016

Abstract
In this study, a field well was installed and cemented using the smart cement mixture with enhanced piezoresistive properties. The field well was designed, built, and used to demonstrate the concept of real time monitoring of the flow of drilling mud and smart cement and hardening of the cement in place. The well was installed in soft swelling clay soils to investigate the sensitivity of the smart oil well cement. A new method has been developed to measure the electrical resistivity of the materials using the two probe method. Using the new concept, it has been proven that the resistivity dominated the behavior of drilling fluid and smart cement. LCR meters (measures the inductance (L), capacitance (C) and resistance (R)) were used at 300 kHz frequency to measure the changes in resistance. The well instrumentation was outside the casing with 120 probes, 18 strain gages and 9 thermocouples. The strain gages and thermocouples were used to compare the sensitivity of these instruments to the two probe resistance measure in-situ in the cement. The electric probes used to measure the resistance were placed vertically at 15 levels and each level had eight horizontal probes.
Change in the resistance of hardening cement was continuously monitored since the installation of the field well for over 100 days. Also, a method to predict the changes in electrical resistance of the hardening cement outside the casing (Electrical Resistance Model - ERM) with time has been developed. The ERM predicted the changes in the electrical resistances of the hardening cement outside the cemented casing very well. In addition, the pressure testing showed the piezoresistive response of the hardened smart cement and a piezoresistive model has been developed to predict the pressure in the casing from the change in resistivity in the smart cement.
Reduction of Energy Consumption When Using a Grab for Deep-Sea Mining Operations
Authors: Kuiper Roel J. , Chen Xiuhan , Frumau Jan C. L. , Miedema Sape A. 
Published: April 2016

Abstract
Recent developments for deep-sea mining have shown multiple scenarios of gaining mineral deposits of Seafloor Massive Sulfides (SMS). One of the problems for these scenarios is the overall large energy consumption of processing rock material which are a technological challenge and are increasing production costs. This paper compares two methods for deep-sea rock excavation on their energy consumption, based on rudimentary calculations.
The best known scenario for gaining mineral deposits from the seabed is to excavate rock materials with a crown or drum cutter and pump the fluidized crushed materials to the vessel at the surface. This process requires high cutting forces deep-sea due to the hyperbaric effect at large water depths, when cutting with full cavitation. This high energy consuming process therefore requires a considerable amount of subsea installed power.
An alternative scenario is to use a hydraulic grab for excavating mineral deposits and not crush all the materials entirely subsea. Using a grab would be very beneficial in rough terrains and unstable seafloor conditions, compared to track-driven vehicles typically used for crown or drum cutters. Also specific cutting forces are much lower when using a grab, because it is not cutting at full cavitation in hyperbaric conditions. However the main advantage is to keep most of the rock intact which allows the material to be crushed at the surface. Mechanically uplifting large pieces of rock therefore could have the advantage that most of the required power can be installed at the surface, rather than subsea for the traditionally proposed hydraulic pumping systems. The rock can then be further crushed under atmospheric pressure at the surface, avoiding the hyperbaric effect. The combination of using a grab and further crushing at atmospheric conditions is more energy efficient and therefore requires substantially less installed subsea power.
Using rudimentary calculations, a great reduction of energy consumption is found for using a grab compared to typically used crown or drum cutters. Substantially less subsea installed power is required for excavating the mineral deposits with a grab. Although additional crushing needs to be done at the surface, the overall required installed power for using a grab still can be much less than fully subsea excavating and crushing.
Smart Production Monitoring & Management Information Systems
Authors: DeVries Stan 
Published: April 2016

Abstract
While oil and gas operations have used a variety of software systems, especially during the early years of "digital oilfield", very few produced sustainable "smart" work. This industry is arguably in a new wave of the digital oilfield, with a renewed focus on transformed work and the software systems which are necessary to enable this transformation. While perspectives vary, there appears to be a growing consensus that "smart" operation is essential, and it is sufficiently different from "reacting better" or installations of operations centers with insufficient transformation of work and collaboration.
This paper will present a perspective on "smart" operation, and the value and approach of systems which enable and sustain this change. One example of current implementation will be presented, along with perspectives on newer technologies such as Cloud and Internet of Things as they can be applied to oil & gas operations.
Introducing a new Recommended Practice for Fit for Purpose Well Abandonment
Authors: Buchmiller David , Jahre-Nilsen Per , Sætre Stian , Allen Eric 
Published: April 2016

Abstract
Globally, operators and regulators are pushing to ensure wells are abandoned successfully and securely. DNV GL is introducing a new, risk-based Recommended Practice (RP) for performing and qualifying well abandonments, entitled DNVGL-RP-E103 "Risk-based abandonment of offshore wells." The RP lays out a process to assess and control subsurface pressures and prevent the free flow of pore fluids between formations and to the seafloor. The ultimate objective of the RP is to protect the environment and ensure safety standards are upheld.
Most of the current regulations use prescriptive requirements for well abandonment design and the necessary plugging operations. As an alternative to the established ‘one-size-fits-all’ approaches, the DNV GL RP analyzes the abandonment requirements for each well and field using a quantitative method that takes account of sub-surface uncertainties. This approach is founded on best industry risk management techniques. Using these techniques, well-specific acceptance criteria for the environment and safety are established, setting the abandonment requirements for each well.
Up until now, offshore wells have been plugged generically and not according to well-specific requirements. Results from case studies have identified solutions ensuring long lasting integrity, robust well abandonment designs and tremendous cost savings potential by using fit for purpose abandonment methodology. Environmental protection and safety considerations are maintained when using the DNV GL RP, while saving operators considerable rig time and overall cost. Differing flow potentials in the reservoir and overburden formations have been studied quantitatively, leading to the development of the DNVGL-RP-E103. The fit for purpose method uses environmental mapping, quantitative risk calculations and well seepage models to evaluate each well and evaluate the suitability of the final abandonment design. By combining disciplinary expertise, the RP sets a new standard for well plug and abandonment (P&A).
Roll Performance of an LNGC with Partially-Filled Spherical Tanks
Authors: Zhao Wenhua , Efthymiou Mike , Wille Sjoerd , McPhail Finlay 
Published: April 2016

Abstract

Objective/Scope
Roll performance of an LNG carrier (LNGC) plays a critical role in side-by-side offloading. Liquid cargo motions can couple with the global motions of an LNGC, affecting the roll response and affecting the operational window for side-by-side offloading. In this study, a series of model tests has been conducted in a wave basin, and the roll characteristics of the LNGC are studied with liquid cargo in spherical tanks.

Methods/Procedures
Scale model tests were conducted with an LNG carrier-like model under waves in an artificial wave basin, whereby the model was positioned in the centre area of the wave basin through four horizontally arranged spring lines. The time series of the vessel motions and the internal liquid cargo motions were measured. To quantify the liquid cargo effect, several sets of tests were performed for which the tanks were empty, but the vessel properties modified to a ‘frozen’ approximation. Decay tests were conducted with the model oscillating freely in calm water, excitation by a given initial heel angle.

Results/Conclusions
Spectral analyses have been conducted to obtain the response amplitude operators (RAO) from the test results. Based on the obtained RAOs, short-term spectral analyses were conducted to understand the most probable maximum roll response in side-by-side offloading sea states. For the first time, the effects of cargo motion have been clarified for LNGCs with partially-filled spherical tanks. The findings reveal that the operational window may not be estimated robustly using a simplified method which ignores the liquid cargo and considers only the ballast condition. Based on the results in five different loading conditions, the most responsive loading condition is examined for spherical cargo tanks. It is suggested that intermediate load conditions with explicit inclusion of the effects of cargo motions to be utilised in side-by-side operability studies to robustly ascertain offloading availability. To facilitate potential numerical simulations, suggestions on selection of linear or nonlinear roll damping coefficients are provided as well. In conclusion, this study provides a better understanding of roll performance of an LNGC with liquid cargo motion in spherical tanks.

Novel information
The hydrodynamic performance of a ship with partially-filled spherical tanks has been clarified, for the first time. The findings in this study provide a foundation for improved numerical modelling with relevancy for side-by-side offloading operations, one of the key challenges associated with FLNG facilities.
Value Improving Practice (VIPs) for Optimization of a Marginal Oil Field Development in ONWJ Indonesia
Authors: Gani Arliansyah Abdul , Aryawan Wasis Dwi , Girindra Yuyung S. 
Published: April 2016

Abstract
An oil and gas company in West Java Indonesia operates an oil field located on the Offshore North West Java (ONWJ) block. For maintaining production rate for oil and gas, its marginal oil field will be developed in the near future in order to meet management policy for national oil and gas demand. However, global oil prices have fallen sharply over the past year, leading to significant revenue shortfalls in the company, and having it sharply cut investments in exploration and production. The current production concept used contribute surface facility cost is high and it is not comparable with the reserve to be developed. The approach will be applied for ONWJ marginal field development is to cluster some fields in an integrated and developed in a sequential manner utilizing floating structure to support production.
This paper describes the selection of floating structure technology using Analytical Hierarchy Process (AHP) method. This paper also presents an effective management tool Fuction Analysis System Technique (FAST) to be used as the rationale and integrated methodology for working through Value Improving Practices (VIPs) to improve fuction or cost floating structure system. Benefits of this approach are discussed including cost savings and future development flexibility.
The cluster and sequential development approach with the utilization of floating structure described in the paper provide management with alternatives to current operation concept for ONWJ marginal field development.
To Buckle or Not to Buckle - Best Practices for HP/HT Pipelines Lateral Buckling Design in Shallow Water
Authors: Hakim M. Abdel , Azouz A. , Awda H. 
Published: April 2016

Abstract
Mitigation of lateral buckling is one of the key design challenges for HP/HT subsea pipelines. Case studies of lateral buckling designs in shallow water developments are used to examine the merits and shortcomings of the different mitigation techniques. The case studies include both Greenfield and Brownfield developments as well as existing pipelines in operation. The assessment covers the design methodology, design challenges and methodology adopted to overcome those challenges as well as interaction with other pipeline design activities. Key factors such as technical feasibility, constructability and cost-effectiveness of the different mitigation techniques are considered.
The different lateral buckling mitigation techniques described are generally applicable to subsea pipelines in shallow water developments. The methods can be classified into two main approaches. The first is to prevent buckling and the second is to allow buckling to occur in a controlled manner. Hence, a key decision for the designer is whether to aim for buckle prevention or buckle control i.e. to buckle or not to buckle.
The assessment of the different techniques used for lateral buckling demonstrates that there is no ‘one size fits all’ solution. Unlike deep water applications where buckle prevention might be technically unfeasible or prohibitively expensive, the prevalence of shallow water in the Arabian Gulf region makes both buckle prevention and buckle control generally feasible and cost effective solution. However, each mitigation approach has its own pros and cons as well as limitations on its applicability and therefore the mitigation approach should be determined on a case by case basis based on comprehensive techno-economic assessment. Hence, understanding the merits and shortcomings of the different approaches is considered instrumental for proper selection of lateral buckling mitigation technique.
This paper provides guidance to the designer for the selection of mitigation approach through consolidation of the understanding of the merits and shortcomings of typical lateral buckling mitigation techniques in shallow water applications.