bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of the CO2 Solubility in Deep Eutectic Solvents: A Comparative Study between PC-SAFT and Cubic Equations of State
Authors: Animasahun Olamide H. , Khan Muhammad N. , Peters Cor J. 
Published: November 2017

Abstract
For industrial post-combustion CO2 capture processes, deep eutectic solvents (DESs) have been identified as a viable replacement for the conventional amine-based counterpart. DESs are cheap to prepare and they are more environmental friendly, also in comparison with ionic liquids (ILs).
Although, several DESs have been tested for their CO2 absorption capacity, still there are a lot of DESs that are yet to be studied. This work focused on developing and comparing thermodynamic models (equation of states) for predicting vapor/liquid equilibria (VLE) of CO2/DES systems. With this approach, all the available DESs can be tested while limiting cost and time.
Peng-Robinson (PR), Soave-Redlich-Kwong (SRK) and Perturbed-Chain SAFT (PC-SAFT) equations of state were employed to predict the vapor/liquid equilibria of 75 different CO2/DES systems over a range of temperature and pressure conditions, comprising in total 562 data points. The algorithm was evaluated by first estimating the pure component properties of the DESs, followed by the model predictions, which turned out to be in close agreement with experimental measurements.
The results show that all the three EoS performed to a very high degree of accuracy. For eighty-one percent of the systems evaluated, both the Peng-Robinson and Soave-Redlich-Kwong EoS were able to predict the VLE with average deviation of less than 5% from the experimental data. Perturbed-Chain SAFT EoS predicts seventy-two percent of the systems with deviations of less than 5% from the literature values. It was also revealed that for some systems with CO2 composition less than 0.5% and at temperature below 293.15 K, the prediction capability of PC-SAFT reduced drastically.
Tensioned String Anodes for Cathodic Protection of Offshore Platforms
Authors: Tremolada Simone 
Published: November 2017

Abstract

Objectives/Scope
The retrofit of cathodic protection systems of offshore platform is crucial for the extension of existing oil and gas fields life in the present economic scenario of oil low pricing.
Tensioned string anodes is a reliable way to afford this problem in a fast and efficient way with CAPEX savings.

Methods, Procedures, Process
A real case of retrofit of 4 platforms in offshore West Africa is presented with focus on technical and economical aspects.
The technical review will cover the analysis of anodes and cables residual life after 18 years in operation in seawater as well as design and installation procedures.
The economical analysis is aimed to compare the costs for galvanic vs. impressed current cathodic protection for the retrofit of oil rigs CP systems in shallow and deep water in order to allow easier ROI analysis.

Results, Observations, Conclusions
The experiences gathered with different mixed metal oxide anodic structures provide the offshore oil and gas industry with valuable options for retrofits on platforms where cathodic protection systems need to be replaced or installed.
The reported case represents a significant experience of cathodic protection retrofitting of offshore platforms using the impressed current technique.
The Tensioned Anode String assembly allows for a versatile and flexible design, with installation costs quite competitive with respect to galvanic anodes system in water depth greater than 80m.
The 18+8 years of performance with the Tensioned Anode Strings, installed in 1987 and replaced in 2005, demonstrates the robustness of the system and the durability of all the components.
The laboratory investigations on the anodes recovered after 18 years of continuous service confirm the performance of the mixed metal oxide activated titanium anodes in sea water in line with the results extrapolated from accelerated life tests performed in the laboratories.

Novel/Additive Information
A complete review of state of the art technologies for impressed current cathodic protection systems for offshore platforms will complete the paper with highlights on the new progresses on installation in the Mediterranean Sea and offshore Brazil
Minimizing Production Losses through Effective Failure Analysis and Mitigation
Authors: Liu Zhenhai 
Published: November 2017

Abstract
Equipment failures, malfunction of protection devices, human errors, process upsets, etc. are the common causes for unplanned shutdowns. These unplanned trip events can lead to substantial production opportunity losses and impact company's profit. The requirements of outstanding performance forces companies to take effective measures in reducing plant downtime frequency and its consequential costs.
ADGAS operates three LNG trains and five gas treating plants on a remote Island. Due to its harsh operating environment, equipment aging, frequent change of feed gas conditions, etc., maintaining a reliable and stable operation has been very challenging. Since 1997 the accumulated production losses caused by unplanned shutdowns has reached few hundred million dollars. Among these losses, unplanned trips due to instrument and control failures have contributed to more than 20% of total production losses. Theses failures also resulted in increased flaring. Thus minimizing unscheduled plant downtime and improving the reliability of instrument devices is imperative both economically and environmentally.
This paper describes a three-track approach which implementation has led to 66% reduction on the number of unplanned trips caused by instrument failures.
Analysis of Wireless Data Transmission for the Site Survey of Telemetry Systems Projects
Authors: Aouadj M. , Sellami D. , Naceri F. , Aissi S. 
Published: November 2017

Abstract
This paper aim is to propose a radio transmission analysing method for the site survey of telemetry systems (e.g., SCADA: Supervisory Control And Data Acquisition), these systems are usually used to supervise remote process installations in large oil and gas fields. This method is presented over a software design and development which includes all radio propagation data and calculations, needed during the technical site survey phase of a telemetry system project execution. The approach is applied for the acquisition, control and online modeling of an oil collection pipeline network using a SCADA system.
The designed software we named "SCADA Radio Transmission," is to perform the radio propagation analysis. By introducing data (topographic coordinates, obstacles heights and characteristics data of the transmission equipment) it allows calculation of towers heights that ensure good radio clearance (Fresnel Zone), plot of the radio transmission link and to visulize results of the radio link budget. Complete calculations equations of this software are provided with detailed radio propagation analysis sample results of the studied oil collection pipeline network, to permit more comprehension for readers. The designed software role is to:
– determine the correct height of the towers by inserting the topographical data of the field, thus providing a radio clearance of the Fresnel first ellipsoid; – Draw up, for the established link, a link budget including the received signal power as well as the margin against the reception threshold; – In addition, this software allows the adjustment of the pylons heights in order to rectify any diffraction, due to bad visibility hop.
A case study application of this software is presented for the data acquisition, control and online modeling of an oil collection pipeline network at Hassi Messaoud oilfield.
Investigation of Dissolution Effects on Dolomite Porous Media under Carbonated Water Injection CWI
Authors: Nunez R. , Vaz R. G. , Koroishi E. T. , Vargas J. A. , Trevisan O. V. 
Published: November 2017

Abstract
To investigate the effects of carbonated water injection (CWI) on dolomite porous media, a set of two coreflooding experiments were performed on outcrop samples. The results allowed the identification of the effects of dissolution on porosity and permeability on outcrop dolomite samples. Experiments were carried out at 70 °C, injection pressures of 8500 and 7500 psi, and a constant injection flow rate of 2 cm3/min. The experimental setup was assembled and commissioned arranging two coreholders connected in series, each one containing a rock sample, to improve result acquisition. The injected fluid was carbonated water made from synthetic sea water (salinity of 38 kppm) saturated with 21.5% of total solubility in CO2 X-ray Computed Tomography (CT) provided image acquisition allowing the evaluation of porosity evolution throughout the tests.
Experiments showed a tendency for porosity increase for the sample in the first coreholder, possibly associated with rock dissolution. The spatial porosity profile from the CT scan for the first coreholder showed porosity variation in the first centimeters of the rock sample inlet. In the second coreholder, porosity remained unchanged during the entire test, indicating that the dissolution effect promoted by carbonated water injection was most notable in the first sample when compared with the second.
The amount of dissolved moles afforded the behavior regarding dissolution phenomena. Permeability behavior was analyzed through the pressure drop values from the sample for the entire experiment, registered by pressure transducers installed in each coreholder. Results showed consistent permeability behavior for the first coreholder samples, despite the tendency of the porosity to increase. The samples placed in the second coreholder presented lower permeability because minerals dissolved in the first sample were transported to the second sample and likely precipitated and so related to the porous media blockage.
Reduce the Costs of Ignorance through Retention of Critical Knowledge
Authors: Spek Rob van , Kelleher Michael 
Published: November 2017

Abstract
Common sense says that learning from experiences, both successes and failures and the ability to re-use lessons identified will lead to the continuous improvement of performance (Swieringa 1992, van der Spek & Kingma 1999, Weick 2011). An organisation's effectiveness and resilience can be leveraged by organizing three core learning processes in a smart and sustainable way: Learning from successes and failures, on individual, team or company level;Learning from each other, both from co-located colleagues as well as colleagues that might be located at a further distance through geography, organizational structure or discipline;Learning from ‘outside-in’, from partners, suppliers, customers and even competitors.
However, in many companies, these learning processes might not function properly anymore and need attention and support. This may be caused by many reasons, such as: Competing rather than collaborating divisions;Differences in culture, pressure of the daily challenges;Lack of communication tools and places to meet;Poor discipline;Counter-productive incentives within the company;Overload of data and information in disconnected silos.
These barriers create various symptoms (van der Spek & Spijkervet 1997): Non-productive time of assets due to unexpected failures or sub-optimal operations;Duplication of mistakes because earlier ones were not recorded or analysed;Re-invention of the wheel because people are not aware of activities, projects in the past or their outcomes;Good ideas and best practices are not shared which raises overall costs;Loss of critical knowledge due to retirement and mobility of work force;1 or 2 key employees hold crucial knowledge creating continuity risks;Slow innovation which results in delayed product development or missed opportunities;Frustrated employees because it takes too long to find validated content or the right experts.
Revitalized Three-Dimensional Design Method Improves Tubular Design
Authors: Aasen Jan A. , Ostvold Tor D. , Aadnoy Bernt S. 
Published: November 2017

Abstract
The ANSI/API Technical Report 5C3 was updated with addendum Annex M in October 2015 (informative). This is a significant step forward, since the effect of internal pressure on collapse is now calculated on the basis of Lubinski (1975) theory instead of using an inaccurate approximation. This theory is utilized in the present study to demonstrate three-dimensional model with API design formulas expressed as a circle instead of the conventional ellipse. The presented three-dimensional method is easy to use and the main user group is drilling and well engineers working in the field or in well tubular design.
Industry practice is to use the effective axial tension (buoyed force) for buckling calculations, while for yielding and collapse analysis the actual axial force is used. In this study we use the effective tension for yielding and collapse calculations, thus employing a stress reference datum that is in agreement with buckling equilibrium and buoyancy. Using the effective tension, a yield circle is produced instead of the conventional yield ellipse. The circle is easy to use and a full set of design equations including buckling stresses are developed in this study.
Effective force is equivalent to oilfield definitions such as fictitious force, buckling force, stability force and buoyed force. Note that for some of these terms compression is defined positive. A comprehensive set of equations for yielding and collapse are presented in this study, where the theory includes bending stresses from helical buckling and wellbore curvature. Tension is defined positive herein while compression is negative.
First Successful Single-Trip Hole-Enlargement-While-Drilling and Rathole Elimination Operation in Indonesia Using Integrated Borehole Assembly Design and Modeling
Authors: Noviasta Bonar , Awaliyah Siti , Sonny Shannon , Pratama Kevin , Hasibuan Frengky 
Published: November 2017

Abstract
Well A, drilled by KN, an oil & gas operator in Indonesia, is a deepwater vertical exploration well located offshore Bali. The high cost of a deepwater operation demanded all drilling components to be as efficient as possible. One of the optimizations performed was a single-trip hole-enlargement-while-drilling (HEWD) and rathole elimination (RHE) operation, in which drilling the pilot hole, opening the hole, and eliminating the rathole were all executed in one run.
The key component of the single-trip HEWD and RHE was the on-demand hydraulically actuated reamer, an underreamer with advanced technology by which activation based on flow index is used instead of a conventional ball-drop system; this enables the tool to be positioned below measurement- and logging-while-drilling (MLWD) tools, closer to the bit. This advanced technology, however, required extensive preplanning activities, especially for bottomhole assembly (BHA) vibration and hydraulics modeling. Multiple BHA alternatives were evaluated using simulation based on finite element analysis (FEA) in terms of stability, and the most stable BHA was selected. In regard to hydraulics, sufficient pressure drop below the reamer and rotary steerable system (RSS) tool needed to be achieved to ensure the full cutter-block opening capability, as well as the RSS functionality.
The integrated BHA design and modeling successfully delivered an excellent single-trip HEWD and RHE operation in two different hole sections. The 12 1/4-in × 14 1/2-in BHA used an RSS to drill a 1,400-ft interval in HEWD mode and eliminated 157 ft of rathole using the on-demand reamer. The 10 5/8-in × 12 1/4-in BHA drilled 1,418 ft with HEWD and eliminated 182 ft of rathole. A savings of 57 operating hours (equal to USD 1,425,000) was realized as a result of eliminating a dedicated RHE run. The 11 3/4-in liner and 9 5/8-in casing were smoothly run to bottom, indicating a good hole quality produced by a stable HEWD and RHE system.
Case Study - Failure Caused by Mercury Embrittlement in MCHE Main Cryogenic Heat Exchanger in a LNG Plant
Authors: Zeeshan Anwar , Manikandan A. 
Published: November 2017

Abstract
This is a case study explaining the failure of an inlet nozzle to a Main Cryogenic Heat Exchanger (MCHE) used in a LNG plant, causing the refrigeration compressors to be in shutdown for 6 weeks. This resulted in loss of LNG production. The failure analysis of the nozzle indicated the cause of failure was Mercury embrittlement that is made of Aluminum, which caused flange leakage.
Main Cryogenic Heat Exchanger (MCHE) is made of aluminum and part of refrigeration process in a LNG plant MR (mixed refrigerant) loop. The Mercury embrittlement is a form of liquid metal embrittlement (LME) and a complex metal fracture mechanism that occurs without any warning indications. Mercury embrittlement, being a significant problem in LNG Plants using aluminum MCHE, have led to number of major plant incidents worldwide. Mercury is always present in natural gas feed stocks, sometimes in quantities sufficient to cause severe attack and failure of Aluminum heat exchanger.
To avoid Mercury embrittlement failure in aluminum heat exchanger tight limits have been placed on allowable mercury levels in natural gas passing through Aluminum heat exchanger. The natural gas is pretreated with mercury removal units before entering the refrigeration units in a typical LNG plant. Root cause of this failure is identified as the failure of mercury removal units to remove the mercury efficiently. In this case study,
Different type of mechanisms has been highlighted by which the mercury degrades the aluminum heat exchanger that includes LME, Amalgamation and Amalgam Corrosion. The importance of mercury removal units in LNG plants is emphasized. Different types of mercury removal technology are explored and discussed.
This case study Introduce the newly developed high activity mercury removal absorbents that allows greater flexibility in the design of LNG plants. These absorbents allow for smaller beds, which coupled with new reactor designs improve savings in compression costs. It is now possible to locate the mercury removal units upstream of the main gas processing plant and thus avoid mercury emissions and contamination of any co-produced Natural Gas Liquids (NGL) in a LNG plant.
ADMA Rigless Intervention Campaign: Breathing New Life in to Old Wells
Authors: McNeilly K. , El-Sayed M. A. , Al-Blooshi J. , Al-Qubaisi S. 
Published: November 2017

Abstract
The ADMA Rigless Intervention "Cheap Oil" Campaign is an on-going initiative begun in 2015 to drive ADMA-OPCO to execute cost effective rigless wellwork interventions to maximize recovery, extend the economic life of the super-giant offshore field, and breathe new life in old wells. The scope of the project included an extensive well review to identify rigless opportunities, creation of a Wellwork Hopper to rank ideas based on economics, design and support of intervention execution, and development of Wellwork Tracking System to measure post-job value.
During this campaign, a novel rigless intervention technique was generated and applied to four inactive wells in ADMA resulting in the successfully reactivation of 6,000 bopd total from the wells. The technique utilizes methods and equipment never used in ADMA before. When combined together, these new methods and equipment have the potential to unlock significant value within the ADMA Inactive String well stock.
As of Jul-2017, the total campaign has successfully completed 70+ interventions adding 30+ mbod oil instantaneous gain and 40+ mbwd water injection instantaneous gain using new wellwork techniques and technologies.
Large WAZ Broadband Seismic Data: From Acquisition to Evaluation
Authors: Al-Abri S. S. , Riyami J. , Kiyumi R. , Haupt E. , Shaibani M. 
Published: November 2017

Abstract
In 2012, the PDO Geophysical Operations team started to acquire the largest 3D seismic survey to be acquired in Oman, with a total area of 8000km2. Here we will present geophysical workflow for that survey, including 3,000 km2 of the Umm As Samim sabkha. Before the acquisition of this survey, the area had limited 3D seismic coverage due to its highly complex and logistically difficult environment. To ensure the survey would be acquired safely; extensive scouting was put in place, bulldozers were used to construct graded tracks across the buckled sabkha crust outside which the workforce was not allowed to walk. Furthermore there was a continuous measurement of the water level below the sabkha and there were contingency plans in place in case the sabkha got flooded.
The 8000km2 area was split into 4 blocks overlapping with an acquisition geometry of 25x250m receiver grid and 25x100m shot grid. The acquisition recorded up to 30km inline offset and 6km cross-line offset and sweeping from 1.5 to 86 Hz. To expedite the seismic for interpretation, the processing started a couple of weeks after the first shot, and it was done in 4 phases. The first phase consisted of signal processing and pre-stack time migration of the first two blocks. This was followed up by pre-stack depth migration of the first two blocks in the second phase. In phase 3, the phase 1 processing was reperated for blocks 3 and 4 and finally in phase 4 all blocks were merged and depth migrated to give seamless volume. The processing of the data was executed in phases to speed up the evaluation of the data for exploration purposes. The integrated team has allowed an optimum processing of the data. The survey took 29 months to acquire with a detailed pre acquisition planning to mitigate potential HSSE risks in the area such as Umm As Samim sabkha and hydrocarbon field facilities. In order to minimize the acquisition gaps in the wet sabkha, light vibrators were used. Due to the massive size of the survey, data quality over the area was different and this led to a change in the workflow from one block to the other. This has lead to re-work to ensure a seamless merge could be accomplished over the whole area. Superior data quality compared to legacy data led to a number of wells being planned or changed position due to the improved imaging. Phase three and four led to an increased confidence on evaluation of prospects (both volumetric and risking) and reducing HSSE risk. As part of the deliverables, acoustic impedance volumes have been generated; these volumes will help the interpreters to more accurately pick events as well as having a first view on the reservoir quality of identified prospects. This project is a result of close cooperation and synergy in delivery between Exploration and Production.