bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intelligent Completions as a Key Technology in Brazilian Presalt
Authors: Rodrigues D. N. , Minassa L. B. , Nunes R. S. , Costa L. C. P. 
Published: October 2017

Abstract
This paper discusses the increasing importance of intelligent completion technology in presalt developments. The Brazilian oil and gas service industry was challenged when a major oil company decided to implement large-scale intelligent completion technology for exploratory and development campaigns for two important exploration blocks, due to the limited experience and expertise in this region. The technology is considered important for reservoir risk management because of its flexibility. An intelligent completion provides a means to remotely control inflow as necessary by a reservoir management team. This additional functionality maximizes oil production and reduces unwanted water or gas influx. The technology comprises several important multizone systems, such as remotely operated flow control valves, permanent pressure and temperature monitoring, digital infrastructure, and chemical injection valves.
With limited experience and infrastructure available in the region at the time, considerable planning and interface management was necessary to ensure successful execution. The deep water presalt application imposed several challenges and uncertainties related to long-term reliability and flow assurance, such as calcium carbonate scaling, vibration, erosion, corrosion, etc. Additionally, human resources and local technical expertise along with a strong infrastructure had to be developed. Within approximately five years, the industry effort to reduce the learning curve made it possible to deliver intelligent completion technology with a proven track record into the country.
During these intensive preparation years, several key findings were realized. Standardization became important early during the process, which was crucial for accelerating learning. However, as the understanding of the technology evolved, new applications and well designs were implemented. Intelligent completions are currently being considered during all stages of the field life cycle, from extended well testing to the mature field stage, with different benefits expected for each application. With an increasing need to optimize value from the presalt wells, a holistic approach was necessary that integrated recovered data and active control into a digital platform to allow a more informed and strategic decision making process using the intelligent completion technology capability to maximize the reservoirs’ value. Results achieved to date allow a much wider application range, with increasing importance for upcoming deepwater presalt cluster development.
A milestone of 50 wells installed in several fields using this technology was achieved in the Brazilian deepwater presalt with an accelerated learning curve. Many uncertainties existed initially; however, multiple successful installations have proven this technology implementation to be reliable, with small differences in capital expenditures (CAPEX) compared to conventional wells.
Application of the Delta Transient Method to Multi-Rate Tests: A Method for Calculating Individual Layer Permeability and Skin in a Multilayered Reservoir using Production Logging Data
Authors: Guimaraes Ciro S. , Galvao Mauricio S. C. 
Published: October 2017

Abstract
The method proposed in this work calculates the permeability and wellbore skin factor for each individual layer in a multilayered reservoir, fully addressing the superposition principle for the multi-rate test scenario. The method provides an explicit solution for the inverse problem, where the main inputs are downhole pressure data, production logging data and the surface rate schedule, as well as other commonly known parameters.
The Method has a strong operational drive, which consists of demanding only few hours of rig time to acquire the necessary data. The main contribution of this work is to allow the application of the method to multi-rate schedules, providing more flexibility for the data acquisition scheme. Regarding production logging data, only two flow profiles at distinct times are required for full application of the Method. No stationary data are needed.
The calculations for each layer are performed with a set of algebraic equations, which can be easily modeled in any ordinary spreadsheet software. No graph analyses are required.
The resulting skin distribution has a great impact on acid job designing techniques, enabling the assessment of diversion effectiveness across the wellbore, especially on carbonate reservoirs, where acidizing procedures are largely employed. The individual layer permeabilities provide more accurate data for geological modeling, potentially resulting in more reliable production curves and reserves estimates.
As a final step to the Method, once permeability and skin for each layer are obtained, a reasonableness check is provided. The purpose of this check is to guarantee reliability on the resulting outcomes. A successful case study is presented, where it took 9 hours to acquire all necessary data.
New-Generation, Circumferential Ultrasonic Cement-Evaluation Tool for Thick Casings: Case Study in Ultradeepwater Well
Authors: Acosta J. , Barroso M. , Mandal B. , Soares D. , Milankovic A. , Lima L. , Piedade T. 
Published: October 2017

Abstract
This paper describes the deployment of a new circumferential ultrasonic tool for cement evaluation used in a thick-casing environment. The operation was performed in a deepwater well, where massive loads often require heavier linear-weight casings with thicknesses greater than 1.0 in.
A new-generation, circumferential, ultrasonic cement-evaluation tool was run in combination with a cement bond-log (CBL) tool to evaluate a primary cementing operation and assure zonal isolation in an ultradeepwater well with 10 3/4-in. casing set in the 14 3/4-in. hole section. Casings with thicknesses greater than 1.0 in. are outside the operating range of current circumferential ultrasonic tools. The improvement features, main specifications, and measurement physics comparing the new tool with previous-generation technology are presented.
The operation was performed in a well containing two sizes of 10 3/4-in. casing in the same casing string. Both 85.3 lbm/ft (0.8-in. thick) and 109.0 lbm/ft (1.0-in. thick) casing sections were present and evaluated in the same pass. The sonic/circumferential ultrasonic combination was able to effectively evaluate the quality of the primary cementing operation behind both casing weights, as well as positively detect the top of cement (TOC). The combination of the ultrasonic tool with traditional bond-log technology provides independent and complementary measurements of cement bond quality. This presented the operator with the ability to radially analyze the zonal isolation using an image map and to identify cement quality issues, such as channeling and the presence of microannuli. In addition, the casing integrity was evaluated in the same pass using the ultrasonic tool.
The new ultrasonic tool makes it possible to achieve confirmation of well integrity in complex, deepwater environments, clearly identifying zones ranging from free pipe to fully cemented conditions, including radial mapping. Improvements in the measurement physics enables the analysis of the annulus in cases of heavy, thick-walled tubulars, as well as in the presence of heavier drilling fluids.
Planning and Execution of Pigging Procedure for Gas Pipeline
Authors: Carvalho Matheus Henrique Pestana de , Rotava Eloi 
Published: October 2017

Abstract
Multisize pipelines are widely used in offshore oil and gas production system; however, the inspection and cleaning process for these pipelines usually are more complex. The pigs used in Santos basin, such as porcupine pigs for inspection and varipigs for cleanning, require some restricions, like maximum pig speed to guarantee a good cleaning effectiveness and, mainly, to guarantee the pig structural integrity.
The main purpose of this work is to evaluate the simulation effectiveness to estimate pig total travel time and pig speed profile, therefore assuring the pig integrity during the pigging process in a gas network with many platforms interconnected. The analysys will compare total travel time and structural integrity of pigs after they arrive in final destination, given the lack of a velocity profile information in these procedures.
Riserless Open-Water Abandonment Module: Allowing Open-Water Tubing Pulling in a Safe and Environmentally Contained Manner
Authors: Batista João H. G. , Carr David J. 
Published: October 2017

Abstract
The increasing demand to plug & abandon (P&A) subsea wells has reinforced the need to identify true opportunities to reduce the costs of subsea abandonment.
The existing method in typical P&A programs of switching from a light well intervention vessel (LWIV or dedicated intervention semi-submersible) after lower abandonment, to a drilling rig with subsea BOP and drilling riser to perform upper abandonment activities is uneconomical, due the loss of efficiency and increase of total operational time.
In 2016, a project to develop an 18 ¾" large bore Riserless Open-Water Abandonment Module (ROAM) was launched to enhance well abandonment capacity from a well intervention vessel, by allowing tubing to be pulled in open water in a safe and environmentally contained manner. The ROAM is run in combination with a high pressure Intervention Riser System (IRS)
As ROAM has circulation capability and is self-contained, once the tubing hanger is unseated, residual fluids and debris can be flowed back through circulation hoses and the IRS intervention riser system to the LWIV, guaranteeing minimal leakage to the environment during tubing pulling operations.
ROAM also allows operator to check integrity of the cement bond behind the casing through a logging run after production tubing removal. According to the results, operator can decide to move on with upper cement plug placement and conclude the P&A or safely leave the well and prepare the remedial operation. The full bore access afforded by ROAM opens up multiple options for ‘abandonment in situ’ operations to be performed.
In order to keep the well safe in the event of the vessel losing its position (through drift-off or drive-off), ROAM has dual 10,000 psi rated shear-seal rams, an emergency quick disconnect (EQD) system and a stand-alone intervention work over control System (IWOCS), as well as a 10,000 ram to isolate annulus/circulation side.
ROAM, combined with existing riser-based (IRS) and riser less intervention systems (Subsea Intervention Lubricator or SIL), will extend the capability of well intervention vessels to perform a full P&A without jeopardizing well control and environmental protection.
The paper will give a detailed description of the design, capabilities and operational premises considered in ROAM development and also demonstrate how the system is deployed and operated to guarantee a safe, efficient and cost-effective operation. The paper will also detail all the executed qualifications and performed tests, as well as the update about manufacturing and field-tests.
Evaluation of the Discrete Latin Hypercube with Geostatistical Realizations Sampling for History Matching Under Uncertainties for the Norne Benchmark Case
Authors: Ferreira Carla J. , Davolio Alessandra , Schiozer Denis J. 
Published: October 2017

Abstract
This work describes a methodology that evaluates the Discrete Latin Hypercube with Geostatistical Realizations (DLHG) sample size for complex models in the history matching under uncertainties process with application to the Norne Benchmark Case. The sample size affects the time demanded and results accuracy in a history matching process because a small sample size can yield inaccurate risk quantification and a high sample size can demand excessive time to reach good results. Both factors should be evaluated in order to improve the project's efficiency and to obtain reliable results. Such evaluation gains greater importance in complex reservoir models because the number of tests to determine the reservoir scenarios that match dynamic data can be high due to the level of complexity. The methodology presented in this work is divided in three steps. First, we evaluate the ability of DLHG to produce output cumulative distribution functions (CDF) that replicate a more exhaustive sampling technique (Monte Carlo) using the Kolmogorov-Smirnov test. The output is the misfit between observed and simulated production rates; then, we compare the influence and correlation matrices obtained with DLHG and Monte Carlo samples. The influence matrix shows the impact of the uncertainty variation on the outputs and the correlation matrix measures the strength of the dependence between the uncertainty attributes and outputs. Finally, we perform the stability test. The methodology was applied to the Norne benchmark case; a field located in the Norwegian Sea. The main characteristics of the methodology are: (1) it uses a statistical technique to compare the output CDFs from the reference and DLHG samples and (2) it evaluates the ability of the DLHG sample to identify the reservoir attributes that affect the history match results. We evaluated DLHG sample sizes of 20, 50, 100 and 200, and considered a MC sample size of 5,000 to the Norne benchmark case. The DLHG CDFs for the 100 sample size was able to accurately replicate the corresponding MC CDFs, however it did not replicated the behavior of the influence and correlation matrices. The DLHG sample size of 200 was able to reproduce the CDFs outputs, the influence and correlation matrices and it was considered stable. The study showed that even if the sample size is able to represent the CDFs outputs from a reference solution, the influence and correlation matrices should be evaluated. The methodology presented can be incorporated into usual history match routines.
New Technologies for Enhanced Production in Deepwater and Long Subsea Tiebacks
Authors: Hanssen Birger Velle , Hagland Arill Smaaland 
Published: October 2017

AbstractNew technologies that contribute to enhanced production in ultralong tiebacks have recently been developed. These new developments include higher differential pressure in multiphase pumps and compressors, mechanical designs for high pressures and temperatures, and power systems suited for ultralong tiebacks.When developing new, cost-efficient boosting technology for long subsea tiebacks and deep water, a system approach is important. This includes power systems, installation methods, maintenance, reliability, and condition monitoring. The new technologies described have been developed based on operational experience and physical theory combined with practical experiments and validation, both scaled and full size. The importance of developing simple and reliable solutions in facilities that enables comprehensive experimenting and testing is also explained. Today’s oil and gas price level also requires cost-efficient solutions, and the paper explains how this can be obtained through standardization and modularization.The first pump systems that are able to provide a more-than 200-bar differential pressure are already developed, qualified, and put in operation. A game-changing multiphase gas compressor technology that provides differential pressure up to 55 bar has also been built, tested, and verified. In parallel with these developments, subsea power systems have been further developed so that they can be used for step-outs longer than 200 km. Recently, a multiphase pumping station designed for 2,500-m water depth and 15,000-psi design pressure was installed and set in operation in the Gulf of Mexico. All of this contributes to enhanced production and lower field developments costs in subsea environments and provides a platform for further technology developments that can potentially make extremely remote subsea field developments economically attractive.This paper presents new technology related to multiphase pumping and compression and a system approach that can make production from remote and deepwater subsea fields more capital efficient.
Monitoring Flexible Risers with Optical Sensors – Operational Experience and Future Perspectives
Authors: Santiago B. M. , Morikawa S. R. , Carrara W. , Kravetz A. , Martins J. A. 
Published: October 2017

Most of the subsea production systems in Brazil are developed using flexible pipes, including pre-salt fields and their challenging scenarios in ultra deepwater, with CO2 and H2S contaminants, high internal pressure and severe metocean conditions. The integrity management of these flexible pipes plays a major role in maximizing the availability of the production systems while minimizing both safety and environmental risks. One of the key areas for the integrity management is the riser top section, where high tensions and curvatures result in high stresses and may lead to fatigue issues in the tensile armors.
In order to better assess the integrity of the tensile armor at the top section of flexible risers Petrobras has developed a monitoring technique known as MODA (Monitoring based on Optical fiber attached Directly on Armor wires). As the name implies, this technique uses optical sensors — strain gauges based on Fiber Bragg Grating (FBG) technology — attached to each wire of the outer tensile armor. The strain measurements provided by these sensors make it possible to identify broken wires and detect events associated with wire ruptures.
Many components and steps are required to transform the wire strain measurements in integrity data. The main components are the riser end-fitting, adhesives, FBG sensors, submersible optical connectors, optical distribution panels, FBG interrogators and server computers. The main steps are the strain sensor bonding procedure, infrastructure commissioning, equipment installation, data acquisition, data processing and data analysis. The coordination of interfaces between different players involved in each of these steps is crucial for a successful implementation of the MODA.
This paper will discuss Petrobras operational experience with of the MODA and its challenges, lessons learned and future perspectives.
Challenges of Drilling Operations in Extreme Deepwater
Authors: Capeto Jorge , Stahl Matt , Bhalla Kenneth , Kluk Daniel 
Published: October 2017

Abstract
This paper highlights the challenges to drilling risers and running equipment for offshore drilling operations from dynamically positioned mobile offshore drilling units (MODUs) in extreme water depths. Whereas nearly all exploratory drilling has occurred in water depths shallower than 3,000-m, Total recently set the water depth record with its Raya-1 well (3,400-m water depth, offshore Uruguay) using the Maersk Valiant drillship. Petrobras has also set a new Brazilian record for exploratory drilling by reaching a water depth of nearly 3,000-m. The 3-BRSA-1296-SES well was drilled to a water depth of 2,988-m the Moita Bonita area, located in the Sergipe Alagoas basin off northeastern Brazil. Several operators have leases that extend into significantly deeper water depths. This paper discusses approaches and criteria to evaluate the suitability these systems for operations in such depths.
As drilling water depths increase, candidate MODUs may require additional and/or upgraded subsea and running equipment to perform drilling operations. Some of the main concerns faced at these sites by the existing riser systems include but are not limited to: riser deployment and retrieval○challenges to handling and lift capacity caused by running weight and axial dynamic response,○diverter housing contactrerating / requalification of subsea BOP equipment (particularly control components);utilization of the riser system's rated capacity,riser recoil following planned or emergency riser disconnect,connected operability,collapse pressure rating,storm hangoff of the riser and LMRP,fatigue due to vortex-induced-vibration or wave loads.
In such depths, longer and heavier riser equipment, rig motions, submerged weight to mass ratio, hydrostatic pressure, mud flow, stiffness, drag, waves, and current all play important roles on riser system integrity, from the wellhead to rig equipment. In addition, many of these wells are located in remote frontiers and are typically characterized by difficult logistics and harsh environment. These factors exacerbate the complexity and potential risk of already challenging operations.
This paper provides general guidelines to evaluate and understand the performance and limitations of existing drilling riser systems on MODUs in moderate and harsh conditions in extreme water depths. The paper will discuss evaluation methods, typical findings and potential mitigations for these issues.
Application of TMCP Material for Large Diameter Pipelines under Sour Service Conditions
Authors: Schruff C. , Kalwa C. , Hillenbrand H. G. 
Published: October 2017

Abstract
Due to the progressive exploitation of natural gas fields pipeline designers facing more and more challenging demands to ensure durable and safe operation conditions for their products. Besides a reliable application in arctic areas, in the deep sea or in seismically active regions the HIC resistance for H2S containing fluids is a key requirement which has to be fulfilled. Here, sophisticated pipe material and tailormade solutions for specific projects have to be developed.
Over the last decades EUROPIPE is looking back on a successful history in the delivery of sour service material based on TMCP plates. This paper gives an overview about EUROPIPE´s development activities and the contribution in actual pipeline projects to fortify the confidence in the use of TMCP material:
In the beginning adequate steel making practices for sour service material are presented. Afterwards the requirements for sour service steels and the benefits of TM rolling with accelerated cooling are introduced. Furthermore it is explained how the design concerning material grades and corrosion testing has developed in the past. An outlook on further developments will be given as well.
During a controlled TM rolling process the precipitation stages, grain refinement and microstructure of line pipe material can be adjusted to meet requirements which are needed for later operation. Accelerated cooling ensures a homogeneous material and restricts carbon redistribution and banded microstructures. These effects lead to a reduction of HIC and SSC initiation sites due to inhomogeneity. Nevertheless recent operator experience has questioned the general suitability of TMCP rolled products for sour service. From the pipe manufacturers position lean alloy designs below material grade X60 are considered unsuitable due to the resulting heavy wall thicknesses and the higher deformation rates in processing plates to pipe. On the other hand the developments towards even higher grades are influenced by discussions concerning an increased carbon content and local hard spots. The presented information will show that the use of grade X65 is technically justified and the recent research activities towards the implementation of higher grades shall be further considered and developed.
Due to given results pipeline operators and manufacturers are encouraged to maintain their fruitful cooperation in the development of high quality-products even for application under severe sour service conditions.