bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leakage Through Micro-Annulus Geometries Incorporating Pressure-Driven Elastic Deformation
Authors: Beltrán-Jiménez Katherine , Skadsem Hans Joakim , Gardner Dave , Kragset Steinar , Lourenco de Souza Marcelo Igor 
Published: October 2019

Abstract
The cement between the casings and formation is a critical barrier element for ensuring zonal isolation. Shrinkage during curing and mechanical or thermal loads applied during production can compromise the cement and result in fluid migration paths such as micro-annuli. The fluid pressure inside the micro-annulus will cause elastic deformation of the channel walls. This deformation should be accounted for when developing methodologies for interpreting micro-annulus fluid leakage experiments and the application to real well conditions. Full-size test sections have been constructed with known cement defects and leakage properties to investigate barrier verification technologies. A micro-annulus test cell, instrumented with strain and pressure gauges, has been leakage tested. Leakage rates have been correlated to the micro-annulus size using a model coupling micro-annulus pressure to radial deformation of the cement and casing. The semi-analytical model and the predictions are compared to the experimental data. Within the regime of linear elasticity, the radial deformation of the cell wall is proportional to the pressure in the micro-annulus. During leakage testing, the pressure-driven radial deformation of the cell materials is coupled to the variation of the liquid friction pressure gradient along the axial length of the micro-annulus. The pressure gradient is greatest at the outlet of the micro-annulus. The models presented have been used to improve the interpretation of fluid flow during micro-annulus leakage experiments. An improved understanding of fluid leakage mechanisms through micro-annuli can be applied to field cases such as the interpretation and choice of treatment for sustained casing pressure build-up.
Real-Time Simulation and Motion-Planning for Riser-Based Drilling and Equipment Positioning
Authors: Bizzi Arthur Augusto Coutinho , Fortaleza Eugênio Libório , Yamamoto Márcio 
Published: October 2019

Abstract
A new analytical approach is applied to the riser's equations of motion, aimed at the real-time processing of solutions under hard boundary conditions. Based on this, a mathematical framework is devised, with the objective of supplying practical assistance for challenging riser positioning cases, leading to both live visualizations of the riser displacement during its maneuvering and on-the-fly planning of its desired top-end movement.
The new analytical solution is based on a non-causal analysis using the two-sided Laplace Transform. By transforming a set of approximate PDEs that closely resemble those of the complete riser model, we're able to devise improper transfer functions between any two arbitrary points across the riser. Then, an inverse transformation applied to these transfer functions yields convolutions that may be quickly processed. Nonlinear boundary conditions are dealt with via a proposed iterative method.
Quickly computable simulations for the horizontal displacement along the riser's length are presented, allowing for live, simultaneous estimation of the structure's motion at various cross-sections. Likewise, stress/tension estimates at these points are presented in real time.
Furthermore, various top-end trajectories and motion strategies are derived for scenarios previously unsolved in the literature, involving non-static initial conditions, disturbances and time-variable tensions acting on the bottom-end of the riser. This is done to demonstrate the theory's applicability in dire weather conditions.
Finally, the proposed solution is validated and compared to previous results in modeling and trajectory planning of risers. The speed of the presented approach is attested and properly analyzed.
Corrosion in Multiphase Slug Flow Loop in Deep-Water Oil and Gas Exploitation
Authors: Silva Carlos Alberto , Filho David Rodrigues , Nunes Gislaine Maria , Bassani Gabriel Soares , Almeida Neusvaldo Lira , Panossian Zehbour 
Published: October 2019

Abstract
The necessity to reduce cost in handling fluids requires a high flow rates with an inherent risk for turbulence influencing the corrosion process of the involved equipment. These conditions occur especially in offshore environments, as oil and gas production, and in chemical processes and energy production industries. There are several ways to discuss corrosion control associated to multiphase-flow- induced corrosion. One possibility is the mechanistic approach and the other makes use of professionals' practical experiences. A pre-requisite for any effective control practices in multiphase flow induced corrosion is a basic understanding of the involved flow mechanisms. This work presents the study of the influence of slug multiphase flow on API 5L X80 carbon steel pipe corrosion in an environment that simulates oil wells. As a simulated environment, an 80 %water-cut mixture, comprised of 20 % light oil (10 cP) or heavy oil (150 cP) plus 15 % of sodium chloride and 80 % of deionized water, was used. The tests were performed at 40 oC under a different CO2 and H2S partial pressure balanced by N2 to reach a total pressure of 2.5 bar. The tests were conducted in a multiphase simulating loop. All test parameters were monitored to guarantee a slug flow pattern. The conceptual design of the loop allowed the simultaneous evaluation of the influence of the horizontal (0°) and inclined (45°) position of the flow to verify the influence of hydrodynamic effects on the weight loss. The conducted laboratory test results allow the establishment of empirical correlations between the corrosion rate and specific exposure conditions. These correlations may be used in corrosion prediction softwares, which can help an engineer to design and to monitor life expectancies of industrial pipes. Studies conducted in autoclaves and in glass cells produce results which, despite here being useful on the understanding of corrosion mechanisms, are not able to produce multiphase-flow regime results like those related to the conditions of pipelines in oil and gas exploitations. A smaller scale corrosion loop provides a suitable environment for better reproducing hydrodynamic effects on the corrosion of pipe walls. In tests performed in the presence of only CO2, concavities on the carbon steel surface were observed. This was attributed to the flow regime, which allowed the formation of a higher disperse-bubble volume and of an emulsion, either by the formation of an oil-in-water emulsion or a water-in-oil emulsion. However, the increase in CO2 partial pressure promoted, in all tested conditions, an increase of the weight loss rate. Thus, the work allowed scoring basic mechanisms of multiphase-flow-induced corrosion which intensifies the damages of carbon steel pipes in environments containing CO2 and H2S, in different concentrations and in controlled conditions of pressure and temperature.
Recent Updates on Smart Water EOR in Limestone
Authors: Strand Skule , Puntervold Tina 
Published: October 2019

Abstract
Experimental data confirm that the EOR-effects observed during Smart Water flooding can be explained by wettability alteration toward more water-wet conditions. Detailed knowledge about the important crude oil – brine – rock parameters affecting reservoir wetting, fluid flow and wettability alteration in oil reservoirs is needed when Smart Water EOR potential for reservoirs should be predicted.
Both field observations and laboratory experiments confirm that seawater behaves as a Smart Water in limestone reservoirs, significantly improving the oil recovery. Laboratory core experiments have been performed to evaluate the effects of polar components present in crude oil on core wettability during core restoration. Spontaneous imbibition and viscous flooding oil recovery tests have been performed on the restored cores to evaluate the effect of initial core wettability on ultimate oil recoveries. The results have been compared with oil recovery tests that include wettability alteration induced by Smart Water.
The experimental results confirmed that adsorption of polar components in crude oil dictates the core wettability established during the core restoration, and strongly water-wet outcrop cores became mixed-wet. The amount of oil that the core was exposed to affected the degree of water wetness, and therefore the crude oil amount needs to be accounted for in core restoration procedures.
Oil recovery experiments showed that the ultimate oil recovery increased with increasing water wetness in the cores, confirming that increased positive capillary forces, resulting from wettability alteration, significantly affected fluid flow in porous media, improving oil recovery. The results are in line with the proposed chemical Smart water EOR model valid for both carbonate and sandstone. Wettability alteration toward more water-wet conditions induces increased capillary forces and improved microscopic sweep efficiency. Ultimate oil recovery in was significantly influenced by the core wettability, increasing with water wetness, confirming that capillary forces is an important recovery parameter. Only small changes in core wetting have significant effects on ultimate recoveries, confirming that laboratory core restoration procedures need to be optimized when recovery potentials for reservoirs should be estimated.
Application of the Convective-Dispersive Equation to Estimate Field Scale Dispersivity based on a Field Scale Numerical Model and Tracer Production Data
Authors: Cavalcante Filho Jose Sergio De Araujo , Pizarro Jorge Oscar De Sant'Anna 
Published: October 2019

Abstract
The displacement of a given fluid by another in a porous media can occur either in miscible or immiscible conditions. An immiscible displacement happens, for instance, when water displaces oil in a reservoir. It can also occur when the displacing fluid is a gas, if the interfacial tension with the oil is high enough. These processes are usually described by the fractional flow theory, which assumes isothermal flow of two immiscible and incompressible fluids in an one-dimensional, homogeneous porous media; dissipative effects, such as capillary pressure, compressibility and thermal conductivity, are neglected. Miscible floods, on the other hand, can take place in gas-oil displacements when the interfacial tension approaches zero. Common dissipative effects are fingering and dispersion, the former related to mobility ratio magnitudes and the later related to diffusion and velocity contrast commonly caused by the presence of heterogeneities. In miscible displacements through porous media, dispersion is described as the result of diffusion, local velocity gradients, streamlines dimensions in heterogeneous regions, and mechanical mixing into pores. The present work discuss these concepts and relate them to data from an actual deep offshore field. Estimates of field dispersivity by history matching tracer production profiles are based on the analytical solution for the convection-diffusion equation. Gas tracers injected and produced from wells located in the field area were evaluated assuming miscible displacement. The estimated dispersivity allowed the evaluation of mixing/spreading zones. The solution for intermittent tracer injection was used to history match tracer production data. Results shows the scale dependence of the dispersivity, which depends upon the distance and degree of heterogeneity between wells. The field scale dispersivity obtained by history match was coherent with numerical dispersion observed in a field scale numerical model. They were also compared against literature data (laboratory and field scale) in a log-log plot denoting a good agreement of present data with literature.
Development of Deepwater Fields in South America – Available Technologies and Innovative Initiatives
Authors: Aggarwal Rajiv , Carneiro Daniel 
Published: October 2019

Offshore industry has about three decades of experience with the development and deployment of floating and subsea technologies in deep (&gt; 500 m) and ultra-deep (&gt; 1,500 m) waters. Most of the ultra-deep water experience has been gained from fields in the Gulf of Mexico, Brazil, and West of Africa. Significant exploration and development activities undergoing in deep and ultra-deep waters of more than eight South American countries require low cost solutions to enable their development.
This Panel will present and discuss the innovative initiatives undertaken by the industry for further development of solutions and technologies for deepwater production facilities (floating and subsea units, risers, umbilicals, flowlines and pipelines) to reduce their capital and operating costs. The innovative initiatives range from variations in the design and execution plans to qualification of specific new technologies. The digitalization of these facilities is also providing means to further reduce capital and operating costs and enhance productivity, safety, and reduce environmental impact. In addition, the potential value from renewable energy to subsea and field operations is being evaluated.
These initiatives are in various stages of development and some are being implemented in deepwater fields in Brazil and Guyana. Several of these innovative technology initiatives will go from Technology Readiness Level (TRL) 5 to 7 in South American fields after operating for more than 3 years.
Artificial Intelligence-Based Screening of Enhanced Oil Recovery Materials for Reservoir-Specific Applications
Authors: Giro Ronaldo , Lima Filho Silas Pereira , Neumann Barros Ferreira Rodrigo , Engel Michael , Steiner Mathias Bernhard 
Published: October 2019

Abstract
The global average Recovery Factor (RF) in oil fields is only about 20-40%. A possible reason for such a low RF might be that Enhanced Oil Recovery (EOR) techniques are not yet broadly applied. This could be for economic reasons, concerns regarding the effectiveness of EOR and potential damage to the reservoir, or the lack of reservoir-specific recommendations.
In this contribution, we introduce a methodology that selects EOR materials for specific reservoir conditions by using Artificial Intelligence (AI) methods. We investigate the consistency of the screening results with the results obtained by state-of-the-art techniques that are used to identify EOR methods only, i.e., without EOR material specificity.
Our method correlates physical and chemical representations of injection fluids, including EOR materials, with reservoir-specific information on lithology, porosity, permeability, as well as oil, water and salt conditions. We have used machine learning on the combined data set in order to provide recommendation for EOR cocktail for injection fluids. Reservoir specific data input on rock, oil, and water conditions available in well logs is transformed by the AI model into a reservoir-specific recommendation of EOR candidate materials for optimized EOR effectiveness. The screening criteria are ranked based on EOR effectiveness and the similarity of key reservoir parameters at pore scale.
Methodologically, a Naïve Bayes Classifier with 10-fold cross-validation over the full training data set classified all instances with an accuracy of up to 90%. In order to compare with the EOR method screening criteria typically used in the industry, we have created a test data set containing instances based on averaged parameter values for representing each EOR method. In this case, our method is capable of classifying the test data set with nearly 100% accuracy. Our methodology allows to produce recommendations for EOR cocktails, including concentrations of their chemical components, for specific reservoir conditions that are readily available through well logs.
Digital Technologies Used in Constructability Design for Surface Installations
Authors: Simas G Torres Milton , Augusto F Rodrigues Breno , Rocha do Nascimento Alexandre 
Published: October 2019

Abstract
During basic design development for new FPSO projects in Brazilian pre-salt exploration, digital technologies were employed, in order to achieve constructability design requirements, construction and commissioning specification checks. Due to its benefit cost, schedule, quality, and overall project objectives and deep influence in platform safety and operability, in a process explained in Figure 1.
Those digital technologies, such as the use of databases, computer aided engineering (CAE), analysis tools, 3D simulations and consistency check, were identified in constructability reviews and were developed to achieve the best constructability procedures and solve construction inconsistencies between several involved disciplines in posterior detailed design, procurement and commissioning phases. This manuscript aims to present the use of digital technologies to support constructability analysis in offshore oil & gas production facility – surface installations - projects of Petrobras.
Floating Deepwater Production Integrity Challenges and Solutions
Authors: Paris Mario Jorge , Constantinis Danny Alexander 
Published: October 2019

Abstract
This paper provides case histories for new methods facilitated by Hull Inspection Techniques & Strategy (HITS) Joint Industry Projects (JIP) including: i) Diverless inspections of hull and mooring systems; and ii) Robotic inspection of cargo oil tanks and pressure vessels. Also, will describe how non-contact thickness measurements by synchronous lasers and big data statistical analysis for inspection scopes are being trialled in the year of 2019 on operating assets. Further innovations around non-intrusive and robotic methods for inspection of electrical systems and pressure vessels, described with case histories supported by business cases, showing how these latest innovations meet the $50-barrel oil industry price target.
The Remarkable Growth of Integrated Subsea Projects from 2016 to 2019
Authors: Labbé David F.L. , Jan Karim , Xavier Marcelo , Tadeu Carlos , Vilchez Marcial 
Published: October 2019

Abstract

Objectives/Scope
The international offshore oil and gas industry started numerous efficiency initiatives in 2014 and 2015 as a response to the global down-turn in field development activity. Additionally new and innovative ways of doing business were conceived and investigated. One of these was integrating the work scopes involved in subsea production and processing systems construction together with associated pipeline and controls infrastructure.

Methods, Procedures, Process
The mechanisms by which integrating the subsea hardware and offshore delivery scopes yields value have been studied and compared with traditional approaches of segmenting the various elements.
Previously executed projects, it was discovered, would have been delivered with different results and imporved cost performance within an integrated structure.
Similarly prospective projects costed and priced using a traditionally segmented approach showed a higher cost and schedule compared with those designed from the early stages of the project by an integrated design team of equipment and installation specialists.
These effects were observed on projects of different sizes and in various geographical regions. (This paper will provide anonymous examples of these cases to provide context).
Our industry currently has more than 15 integrated projects underway and offshore oil and gas operators are starting publicly share their experiences of this new way of working.
The result is that potential field development projects are integrating traditionally segmented subsea scopes earlier in the economic lifecycle of the project. (This paper will illustrate this trend).
As the project execution phase progresses different systems and mechanisms are used to ensure that the value is captured and an acceptable project risk profile is maintained.

Results, Observations, Conclusions
The market for integrated subsea project delivery has grown from 8% of the market in 2015 to 35% or more in 2018 and seems unlikely to diminish in 2019.

Novel/Additive Information
Integrated subsea delivery has emerged as an enabler of different project outcomes for international oil and gas companies and is setting new standards for efficiency in our industry.
Corporate Strategy to Tackle Offshore Drilling Discharge Regulation
Authors: Marinho Leonardo De Souza , Alo Cristiano Pamphili , Loureiro Sebastiao De Andrade , De Oliveira Thiago Judson Lima , Martins Andre Leibsohn 
Published: October 2019

Abstract
This paper provides an overview of the main efforts that are being endeavored by Petrobras in order to contribute for developing a Brazilian regulation for use and discharge of drilling fluids and cuttings from offshore oil and gas operation, based on operational safety, well integrity and environmental aspects.
In early 2018, the Brazilian Environmental Agency launched a Normative Instruction (IN 01/2018) addressing some new conditions for use and discharge of fluids and cuttings from offshore drilling rigs. This regulation is based on the EPA rules, although some relevant points deviate from it, such as the prohibition for discharging drilling fluids and cuttings associated with hydrocarbon reservoir sections. Additionally, this regulation mentions a potential zero discharge by 2022. Due to the challenges for meeting these new requirements and some uncertainty about the real environmental benefits, Petrobras has been developing fundamental and applied studies, research development and protocols in this area.
Petrobras settled an innovative governance model to deal with the new regulation, its consequences and interfaces. It works as a multidisciplinary committee coordinated by an executive manager. It involves a law support for environmental issues and four work fronts, such as (1) linking between internal and external organization (2) guarantee of providing the required infrastructure (3) economical and operational impacts (4) technologies (research, development, studies and protocols) dedicated for related matters. Concerning the forth front, seven important initiatives were initially addressed and cover topics such as operational safety, well integrity – including offshore wells dedicated to cuttings disposal, laboratory protocols and environmental issues. Some relevant studies are those concerning LCA (life cycle analysis), options for avoiding landfill as final cutting disposal onshore and the quantification of oil compounds in drilling fluids and cuttings from the pay zone well section.
The lack of knowledge about the whole impact for onshore destination as drilling waste management strategy, the improvements that still have to be established in order to achieve better operational practices and the comprehension of the input of oil from drilling discharges are the main drivers of this paper. The results help to clarify cloudy topics and, consequently, contribute to create a new basis for building or revisiting some aspects of the present regulation.