bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquefaction Technology Considerations for Floating LNG
Authors: Tierling Shane , Attaway Doug 
Published: October 2017

Abstract
Floating LNG (FLNG) technologies are being deployed to monetize mid-sized offshore gas reservoirs, avoiding constructing a sub-sea gas pipeline to a land based LNG facility and export jetty. A previous OTC-Brasil paper (OTC-26158 Gas Pretreatment Considerations for Floating LNG) has discussed marinization and pre-treatment options available for FLNG, and an OTC paper (OTC-27940 Liquefaction Technologies and Mechanical Drive Considerations for Floating LNG) has discussed space, weight, and safety consideration in liquefaction technology selection. This paper is a continuation, focusing on the thermodynamic and efficiency considerations of the liquefaction technology options. For those not familiar with the previous work, there is some discussion of the marinization and safety drivers within the focus topic.
Offshore liquefaction technologies are often novel and many lack offshore references. The available offshore liquefaction technologies will be presented by Licensor and Technology name. Because of the diversity of liquefaction technologies, and to remain Licensor agnostic, the technologies are grouped by refrigeration method, with Nitrogen expander and SMR (Single Mixed Refrigerant) groupings of technologies examined with an emphasis on overall liquefaction efficiency, efficiency focus areas and design flexibility. DMR (Dual Mixed Refrigerant) is compared with the other two technology groupings.
The paper provides an overview of the FLNG state of the art in liquefaction.
Low-Cost, Rigless, Nonintervention Well Testing
Authors: Engel Diogo , Margotto Romulo , Azevedo Vinicios 
Published: October 2017

Abstract
Well testing is a proven method for reservoir characterization, which is important for well-completion design, future development strategies, stimulation needs, and determining the commercial feasibility of the reservoir. This paper presents a surface data-acquisition system and its applications for rigless well-testing operations.
Drill-stem testing (DST), which is classified as a temporary completion of a well, typically involves a large and complex operation. A key activity during DSTs is collecting downhole pressure and temperature data using gauges at the bottom of the well that monitor pressure changes throughout the operation. Particularly crucial are the shut-in and initial build up, which provide insight into major reservoir properties. While shutting in the well at the bottom reduces the effects of wellbore storage, providing the most accurate downhole measurements, it also requires a rig and numerous personnel to prepare the well and run in hole (RIH) the test string. A rigless DST operation using a surface closure and surface data-acquisition system has been used in several wells to optimize data acquisition recovery as a non-invasive alternative to running downhole pressure gauges for pressure-transient well testing.
The effectiveness of the data-acquisition system provides advantages and accountability by avoiding the cost and risk of running equipment downhole and monitoring tests in real-time at surface.
The surface gauges acquire high-resolution pressure data at the wellhead during flowing and shut-in, which are then converted to bottomhole conditions using proprietary models. Because this technique is nonintrusive, it can be used to test wells in which downhole gauges are impractical or cost prohibitive, such as highly deviated, horizontal wells with tubing restrictions, sour-gas, high-pressure wells with high bottomhole temperatures, and low-cost evaluations. For mediumto high-permeability formations, a three-day test is typically sufficient to calculate basic near-bore and reservoir properties, including skin, permeability, and initial pressure. Longer tests that track pressure changes to reservoir boundaries can also be used to calculate the reservoir size.
The data-acquisition system has proven its efficacy after enabling a low-noise response and low-pressure changes resulting from temperature effects. Based on data provided by the data-acquisition system, the operator designed a well-testing campaign and achieved results typical of those expected using a conventional approach.
Direct Pore-Level Examination of Hydraulic Electric Analogy in Porous Media
Authors: Goudarzi Banafsheh , Mohammadmoradi Peyman , Kantzas Apostolos 
Published: October 2017

Abstract
Taking advantage of the analogy between hydraulic and electrical flows to facilitate the prediction of porous media characteristics is a longstanding practice in petroleum engineering. The relationship between hydraulic and electrical properties is widely used in well-logs interpretation and characterization of transport properties of porous media relying on the strong correlation between electric and hydraulic flow conductance. However, due to the lack of direct investigations, the similarity among their pathways/tortuosities is still unclear. It is a challenging and almost impractical task to identify the streamlines experimentally. Here a series of direct finite element numerical simulations are conducted within pore-level microstructures to extract and compare the streamlines of both electric and fluid flow currents and examine the accuracy of the analogy by predicting the petrophysical characteristics of the case studies. The fluid flow and electric transports are simulated through pore-level digital rocks of synthetic unconsolidated sand packs representing the Athabasca oil sands deposit as the second largest oil reserve in the world. The formation factor, porosity, and absolute permeability of the media under consideration are predicted, and consequently, the streamlines of both electric and hydraulic currents are extracted and compared in terms of length, shape, and pathways. According to the results, the fluid flow pathways pose differently and are longer than the homogeneous electric current streamlines. The ratio between the hydraulic and electric tortuosities follows a polynomial trendline, and a local extremum occurs at the porosity of eighteen percent. Pedotransfer functions for tortuosities, dimensionless permeability, and formation factor are proposed underpinning the rigorous relationships between transport processes in rocks.
New Technologies for Cost Effective Offshore Compression Stations
Authors: Falomi S. , Iurisci G. , Matina D. , Bigi M. , Bisio V. 
Published: October 2017

Abstract
The need to minimize the total cost of ownership for offshore plants requires the development of technologies focused on both reducing equipment footprint and weight (capital expenses) and increasing performance, reliability and availability (operational expenses).
The OEM has been working on those features through the development of different products: ▪Maximize reliability/availability by removing most critical items (such as mechanical dry gas seals) with an integrated motocompressor design;▪Minimize the overall equipment (reduced footprint combined with improved reliability) through:High head and high-speed stages (High Pressure Ratio Compressor);Liquid tolerant compressor;Integrated auxiliaries.
The reduction of installed equipment is first obtained through combination of newly developed high head and high-speed compressor stages, which allow to increase the pressure ratio that can be performed in a single compressor casing, minimizing the total number of compressor casings required for a certain duty.
Secondly, these stages can also be combined with a compressor design which is liquid tolerant, thus allowing higher resistance to the liquid carry over from upstream scrubbers and eventually decreasing the scrubber size (or in some instances its removal). It should be noted that this technology is not only limited to flange to flange centrifugal compressor, but the overall auxiliary system (including dry gas seals’ system).
Finally, the OEM has been working on the integration of auxiliary systems: the possibility to reduce number of compressor casings, leading to possibility to handle most of services in a single body, and the reduction of required lubrication oil, allows integration of lube oil console within the compressor baseplate. This design has been proved for reinjection services up to 50 MW and for floating LNG compressors up to 70 MW.
The present paper will thus describe the design and validation strategy of the proposed technologies, showing how they can positively impact the total cost of ownership of compressor stations.
First Openhole Intelligent Well Completion in Brazilian Pre-Salt
Authors: Schnitzler E. , Gonçalez L. F. , Ascaneo W. M. , Gonçalves F. F. , Almeida R. S. , Marques M. 
Published: October 2017

Abstract
This paper describes a new Intelligent Well Completion (IWC) configuration used in Brazilian pre-salt fields. It also presents the first application of this new design and the future benefits expected. The conventional IWC design used in Brazilian pre-salt areas comprises cased hole wells. The casing perforation is performed before installing the completion, which does not provide a separation between upper and lower completion. The production string is installed in a single run from its lower part to the tubing hanger and does not include a disconnection element to allow the upper completion retrieval. The new design adds a separated lower completion that can temporarily isolate the formation during the upper completion installation and heavy workover operations.
In the development of the new openhole IWC design some features have been considered critical: maximum flow area, minimum complexity, CAPEX reduction, improved well safety, flexibility with single zone completion configuration and compatibility with workover. The introduction of a lower completion system added some complexity to the wells, at the same time as it provides reservoir isolation during upper completion installation. Other benefits observed are the decrease of the wellbore size required to drill into the reservoir as an openhole completion is to be installed instead of a case hole. In instance, the use of one of the casings is not required anymore. The proposed alternative was initially applied in one well for qualification and was capable of delivering a dual zone completion where initially an openhole single zone completion was planned. The use IWC in this well was an important feature for reservoir management due to the significant difference between the injectivity of the zones completed. The new design proved to be a success in this initial application.
The new solution developed has set a new completion philosophy for pre-sal wells. Other benefits of using a lower completion in IWC is the ability of quickly isolating the reservoir, what is especially important when major fluid losses are expected during drilling and completion phases. One of the major benefits of this approach is the possibility of installing the lower completion using Managed Pressure Drilling (MPD) techniques.
Cost, Efficiency, and Environmental Considerations of Medium Voltage Electric Heating Technology
Authors: Molnar Christopher 
Published: October 2017

Abstract
Offshore production facilities utilize a variety of process heating equipment to start production and operate efficiently. Applications include glycol reboiling, oil and gas conditioning, knock-out drum heating, molecular sieve regeneration, sea or potable water, and fuel/lube oil maintenance. Fuel-fired solutions for these applications present many challenges in regards to start-up time, operating efficiency, safety, and environmental impacts. A new technology regarding medium voltage (MV) electric heating elements and MV thyristor control technology exists as a solution for high powered process heating applications in the oil & gas and petrochemical industry.
Medium voltage electric heating technology is capable of controlling process streams to +/-1°C for very large power output and can operate on voltages up to 7,200 Volts. Medium voltage electric heating technology opens the door for new solutions to eliminate local emissions, improve on operational efficiency, and allow for greater process flexibility through the use of clean, efficient, emissions-free electric heating.
The purpose of this paper is two-fold. First, the paper provides a summary to industry experts regarding the latest design methods and test results regarding second-generation MV heating systems. It will be important to gather questions and recommendations for additional research and development of such systems from the conference and apply them to future work.
Second, this paper also highlights several case studies regarding the reduction in installation and operational costs, as well as the positive impact on footprint, weight, and safety for an offshore facility. Lab data, original analysis, and third party testing results will be presented as a means of educating the audience and to provide a model for industry standards regarding this new technology.
Finally, medium voltage electric heating technology opens the door for completely new solutions in downhole, subsea and offshore heating, especially with regard to hydrate prevention and flow assurance.
Advanced Control for Gas-Lift Well Optimization
Authors: Campos Mario C M M , Lima Marcelo L , Teixeira Alex F , Moreira Cristiano A. , Stender Alberto S , Von Meien Oscar F. , Quaresma Bernardo 
Published: October 2017

Abstract
The search for improvements in the production efficiency is one of the main challenges for the production engineers responsible for an asset, mainly at moments of low prices and very strict regulations for safety, environment and quality of products. Another point is that offshore plants are becoming more complex, so advanced control systems can support the operators and play an important role to improve stability and profitability.
This paper will present an advanced control algorithm for gas-lift optimization of offshore wells that aims to increase oil production. It will also show and discuss some results of the implementations of this real time advanced control system in two offshore platforms, emphasizing the economic gains and critical points to maintain this controller running with a good performance.
Soil Modelling Calibration Using Measured Data
Authors: Venero Germain , Muniz Leandro , Diezel Alexandre , Gomes Victor , Fachini Rafael 
Published: October 2017

Abstract
This paper presents the procedure for the calibration of a soil model represented by P-Y curves in the global finite element model of a drilling riser system using onboard measured data.
In the case of lack of real data or data uncertainty regarding the soil properties of one specific well location, the soil model can be calibrated using measured data during the drilling campaign.
The calibration procedure improves the accuracy on the prediction of the wellhead bending moment and stresses along the conductor pipe based on global riser analyses performed during the operation to assure the integrity of the well structure and thus, safe operations.
Planned Shutdown Time Optimization Using Lean Six Sigma
Authors: Matos F. L. , Pereira T. D. , Bonini C. H. K. , Carocha D. M. 
Published: October 2017

Abstract
Reducing planned shutdown duration (turnaround time) has been one of the biggest challenges in the offshore business. Ensuring operation efficiency while also considering safety, environment and quality issues is a complex activity that involves planning and strategies to mitigate risks and wastes. The main objective of this paper is to demonstrate how Lean Six Sigma (L6S) tools allied to good practices can guide the management of these activities, minimizing downtime and reducing Lost Production Opportunity (LPO). After the scope of work is defined, a Kaizen event was held to walk through the current process (organized in a Gantt Chart) in order to find improvement opportunities. Some Lean Six Sigma methods used were: simultaneous activities matrix, to find clashes between projects; Critical Path Analysis; 5S tagging and positioning the materials near the job location; applying the 8 wastes and Single Minute Exchange of Die (SMED) analysis to separate internal to external activities and converting possible internal to external activities; streamlining/rationalizing internal activities; Failure Mode Effect Analysis (FMEA) to provide the contingency plan on the critical path; and daily progress report using an S-curve. All these methods helped to ensure maximum efficiency of the operation, mitigating risks and wastes on the planned shutdowns. Using the proposed methodology, three successful planned shutdowns were accomplished between 2015 and 2016. The first one was the largest in complexity and duration, embracing 50 projects among vessel internal inspections, software upgrades and multiple piping replacements; the shutdown duration was reduced from 26 to 24 days, with a return of 70k bbls. The duration of the second one was reduced from 5 to 4 days, saving around 50k bbls. The last one was a partial shutdown, with more restrictions to resources on board due the live plant. The shutdown duration was reduced from 14 to 4 days, returning around 60k bbls to the company. The proposed methodology shows how the L6S tools allied with good management practices can systematically optimize all planned shutdown processes, eliminating wastes and delivering results.
Epoxy Resin Helps Restore Well Integrity in Offshore Well: Case History
Authors: Vicente Perez Miguel , Melo Jardyson , Blanc Romulo , Roncete Andre , Jones Paul 
Published: October 2017

Abstract
While developing an offshore well in Brazil, the integrity of a well under construction became compromised resulting from channel communication after cementing the production liner. Leaks in producing wells can cause formation damage, loss of production, and increase tubular corrosion. This paper discusses the application of a new resin for a casing-leakage problem caused by a channel after the primary cementing operation.
Conventional cements and slurries are commonly used to repair this challenge; however, these solutions are limited, at best. Depending on the channel size, well integrity can be restored with cement, but only if the channel is large enough to allow a sufficient volume of slurry to enter. The new epoxy resin exhibits exceptional resistance to contamination, including oil-based and water-based fluids, tailored mechanical properties, very-low yield point, as well availability of solids-free designs, making the resin an ideal candidate for a wide range of remedial operations throughout the life of the well.
When the challenge is outside the capabilities of either conventional solution (Portland cement/microfine cement), another method is necessary to squeeze off the leak. Recent developments have shown that resins are an excellent alternative for these types of challenges. A new resin design has overcome this limitation and is helping ensure wellbore integrity, thereby contributing to environmental sustainability and social responsibility, while acting as an annular barricade against water and gas leaks. The liner-hanger leak was repaired in one attempt using the new epoxy resin and squeeze techniques. Well integrity was restored, and the operator was able to perform the completion operation without any signs of leakage.
The new epoxy resin has become the primary solution and offers three primary benefits for restoring wellbore-integrity applications, including solids-free liquid with high-penetration capabilities and tailored mechanical properties to withstand a variety of wellbore challenges and enable customization and optimization for specific pumping operations.
Evaluation of Hybrid EOR as Polymer-Assisted Carbonated Waterflood in Calcite Cemented Sandstone Reservoir
Authors: Lee Ji Ho , Kim Guan Woo , Lee Kun Sang 
Published: October 2017

Abstract
Hybrid enhanced oil recovery (EOR) as polymer-assisted carbonated waterflood (PCWF) improves mobilities of both aqueous and oleic phases. The process introduces synergetic effect modifying reservoir wettability and fluids’ viscosity. These effects are the results of polymer rheology, geochemical reactions, and interphase transport of CO2 in crude oil/brine/mineral system. In this study, its performance is compared to waterflood, polymer flood, and carbonated waterflood. Firstly, polymer injection of PCWF raises the viscosity of aqueous solution over 4 cp despite of chemical and mechanical degradations. Secondly, PCWF contributes to considerable calcite dissolution increasing molality of Ca2+ by 400%. It triples equivalent fraction of Ca2+ and the reservoir is modified toward more water-wet condition. Lastly, PCWF allows CO2 to be transferred from aqueous solution to oleic phase. This transport reduces oil viscosity with 8% while pressurized system by polymer injection viscofies oil. As a result, PCWF recovers additional oil with 14.5%, 9.5%, and 2% over waterflood, polymer flood, and carbonated waterflood after 1.5 pore volume injection. Despite of the synergetic effects, PCWF requires operating cost to consume polymer and CO2. To improve oil production and economic efficiency of PCWF, robust optimization with multiple heterogeneous permeable fields is performed. Optimum injection designs of PCWF increases net present value with 36% over waterflood.
First 03 Zone Intelligent Completion in the Brazilian Pre-Salt: Design Considerations, Challenges, and Lessons Learned
Authors: Del Vecchio Filipe , Maciel Potiani , Salom Francisco , Chagas José , Ortiz Antonio 
Published: October 2017

Since the first Intelligent Completion installed 20 years ago, the systems have become more and more complex in order to enable the results in terms of productivity and optimization, allowing real time monitoring and management of each zone in the well in an independent way. Accompanying the search for higher efficiency of the system is reliability assurance, one of the most important themes for the oil industry. Producers and injectors wells have been completed with the ultimate technology to achieve the best performance for each zone, allowing management optimization of the reservoirs, improving the reliability of the systems, reducing costs with workovers, therefore improving the return on investment over the life of the field. Currently, Intelligent Completion can be found widely in production areas around the world, from mature land to ultra-deepwater wells like those in the Brazilian Pre-Salt. Each scenario has its challenges, for example the Carbonates of the Pre-Salt.
Presented in this paper are the complexities and the challenges to plan and install the first Intelligent Completion in a subsea well with three producing zones in the Brazilian Pre-Salt, performed in 2015. A selective completion in three zones, comprised of feed-through packers, permanent downhole gauges in all zones, chemical injection mandrels, inflow control valves with adjustable choke, mechanical sliding sleeves and Flat Packs with hydraulic and electric lines. In addition, a downhole safety valve, Tubing Hanger (TH) with eight hydraulic penetrations and one electric, in a water depth of 2200 m. Planning and detailing were the main drivers of this big project