In recent past, most of Brazil's oil production was generated from siliciclastic reservoirs in scenarios of deep and ultra-deep water of the Campos Basin, being much effort focused on developing technologies to guarantee production optimization. Despite the great experience acquired by Petrobras in evaluating dynamic behavior of deepwater fields, new production scenarios of heavy oil reservoirs are even more challenging due to their high oil viscosity that generates emulsion stability.Jubarte field (siliciclastic turbidite reservoir) development features 15 heavy oil producing wells tied to P-57 floating production storage and offloading (FPSO) vessel. Each well is equipped with a 1500HP electrical submersible pump (ESP) installed in a caisson located 210 meters away from the wellhead in water depths varying from 1260 to 1360m. Over the last 3 years, since Jubarte first oil, the maturity curve of the wells has revealed a scenario where ESP has been recognized as a critical component of the subsea production system to sustain well production. Normally adopted in projects to anticipate production during the early years, ESPs in Jubarte field have been presenting an outstanding performance, overcoming oil viscosity limitations or unpredictable multiphase flow regime with strong emulsion formation (both tied to injection of viscosity reducers and the advent of natural free water from the reservoir).Operating ESPs installed at the seabed poses challenges in many aspects. Understanding the flow pattern (to ensure effective startup and run in optimal conditions), pump and caisson fluid dynamic behavior (to allow the pump ride through some observed inflow discontinuities) are two essential issues.This work aims to introduce the phenomenon of flow intermittency experienced during the operation of ESPs installed in vertical caissons in Jubarte field. It also demonstrates the engineering approach and the main proposed solutions to overcome the problem of well instability. The advantages obtained through the injection of demulsifier upstream the ESP are finally presented as a key element to promote stability, allowing ESP to run properly with significant gains in production rate.

Technology Focus The tragic blowout of Macondo has triggered many technical and managerial developments in the field of well integrity since its occurrence in April 2010. Acting as a catalyzer since then, this event has demanded from all industry players a huge amount of effort to mitigate the risk of well-integrity problems. Originally, these efforts were aimed at deepwater drilling in the Gulf of Mexico, but, with time, they were disseminated throughout the oil industry, where well integrity is a must. Undoubtedly, significant progress has been made in enhancing safety during all phases of the well life cycle, mainly in the areas of well-control equipment and reliability, subsea well control and containment, documentation, training and competency assurance, and well-integrity management systems and processes. Here, I address important headway made in two areas in which I have been deeply involved during my professional career, mainly after Macondo: well-integrity documentation and well-control training and competency assurance. One of the first actions in response to the blowout was the formation of four joint-industry taskforces. Two of them provided recommendations on operating procedures and equipment that resulted in the revision of some American Petroleum Institute standards and the development of new ones. Some other standardization organizations also have been making contributions, elaborating and revising well-integrity-related standards (such as NORSOK D-010 and ISO 16530-2). Many operator companies (including mine) and drilling contractors have been reviewing and updating their well-integrity procedures and practices, especially those related to deepwater operations. Concerning well-control training and competency assurance, following the recommendation of Report 476 of the International Association of Oil and Gas Producers, the certifying bodies executed changes in the contents of the courses to stress important subjects such as barrier management, risk management, well influx detection, and immediate response and to adapt the training to well operation, rig category, and responsibility of the people involved with all types of operations. Thus, the crew members are now trained and assessed better according to their roles on the rigs. More class hours are now dedicated to simulator exercises. Arguably, this move is making the well-control- certification systems more reliable and more standardized among all training institutions. JPT Recommended additional reading at OnePetro: www.onepetro.org. SPE 175523 Searching for Well-Integrity Issues—Automated Generation of Annulus- Pressure Trends by Remco Donders, Total E&P UK, et al. OTC 25256 Enhancing Well Control Through Managed-Pressure Drilling by Oscar Gabaldon, Blade Energy Partners, et al. SPE/IADC 173822 Field Trial of Well- Control Solutions With a Dual-Gradient Drilling System by John H. Cohen, Enhanced Drilling, et al.

Technology Focus Statistics on well-integrity incidents are difficult to find in the literature. There are some examples of kick and blowout events, but normally they are scarce and focus on the number of incidents and their root causes. There is, however, one example of statistics that has been inspiring me throughout the years when I prepare my lectures on how we can drill, complete, and produce wells safely. It is one that is presented in the excellent textbook on high-pressure/high-temperature wells published by Aberdeen Drilling Schools that shows human factors related to offshore blowouts. On the basis of those statistics, I divided these factors into four groups: (1) inattention to operations (25%) and inadequate supervision/work supervision (20%); (2) improper maintenance of equipment (20%) and improper installation/inspection of equipment (2%); (3) inadequate documentation (2%) and improper method or procedure (11%); and (4) improper planning (12%). No direct human error involved was stated for the remaining 8%. Here, I will show how these factors can be addressed to make a well-integrity system efficient. The first group represents 45% of the human factors related to offshore blowouts. One efficient way to address it is through training and assurance of personnel competence. A well-integrity system implemented by any company of the oil industry can be robust only if it strongly considers this aspect. Regrettably, this topic only barely appears in the literature and conferences on the topic of well integrity. Recently, the International Oil and Gas Producers Association presented appropriate recommendations for technical enhancements to well-control training, examination, and certification that can be extended to other activities related to well integrity. The second group encompasses well-equipment-related issues. An adequate well-integrity system should have the necessary safety barriers in place, understood, tested, verified, and maintained. It should also have proper contingencies in case of failure of these primary barriers. The third group refers to documentation. Currently, there is a strong movement toward elaborating or revising regulations related to well integrity by entities such as the American Petroleum Institute and the International Organization for Standardization. Creation of new or improvement of existing design and operational procedures that result in safer operations throughout a well’s life cycle is mandatory for an effective well-integrity system. It is also important that any well-integrity anomaly be documented, analyzed, and transmitted to all involved parties. The last group refers to planning. Many well failures are a result of poor well design and operation planning. A strong well-integrity system should rely deeply on approaches such as risk assessment, management of changes, action plans, and design basis. JPT Recommended additional reading at OnePetro: www.onepetro.org. SPE/IADC 163417 Detection of Kicks Prompted by Losses and Direct- Measurement Well-Control Method Through Networked Drillstring With Along-String Pressure Evaluation by Daan Veeningen, NOV IntelliServ SPE/IADC 163445 Feasibility Study of Applying Intelligent Drillpipe in Early Detection of Gas Influx During Conventional Drilling by Karimi Vajargah, The University of Tulsa, et al. SPE/IADC 163438 Analysis of Potential Bridging Scenarios During Blowout Events by S.M. Wilson, Apache, et al.

Technology Focus I am honored to be the first JPT Editorial Committee member to write the introduction of January’s Technology Focus section under a new title: Well Integrity. With this alteration, this section broadens its scope, not only focusing on topics related to well control but also now covering all safety aspects concerning the construction, maintenance, and abandonment of wells. The importance of well integrity has been recognized by the oil industry for a long time, and great effort has been made to improve the design and operational procedures during the well design and construction processes and throughout the entire well life cycle. Despite these efforts, many well integrity related problems still occur. This indicates that investing in well integrity is a strategic approach to minimize design and operational risks that may jeopardize personnel safety, the environment, and the operator’s image, reputation, and assets. Last November, I had the opportunity to be the chairperson of an Applied Technology Workshop (ATW) in Salvador, Brazil. This ATW was the third of the Global Integrated Workshop Series on Well Integrity and focused on deepwater issues. The quality and appropriateness of the presentations were remarkable, as were the discussions following the presentations. In the area of well construction, the challenges of drilling in near-salt rubble zones were presented in relation to well integrity (lost circulation and wellbore instability) and the use of high-performance water-based drilling fluids as an alternative to synthetic oil-based fluids considering the borehole instability. It is important to note that borehole instability issues are also considered part of the well integrity domain. Concerning producing wells, the most important aspects discussed were the importance of managing annulus pressure during production, the use of solid expandable liners in recompletions in mature fields, and solutions for casing leaks. The importance of safety barrier assurance was stressed. Zonal isolation by cementing was an important point when considering the integrity of the well during and after its abandonment. Revisions or elaborations of new standards were presented with emphasis on American Petroleum Institute RP 96, NORSOK D-010, and a new International Organization for Standardization standard on well integrity production operations. The most important aspects regarding deepwater well integrity were reliability of subsea blowout preventers, evaluation of the probability of uncontrolled leakage in subsea producing wells, a nonintrusive device for monitoring B-annulus pressure in subsea wells, and cementing of shallow hazard zones. Recommended additional reading at OnePetro: www.onepetro.org. SPE/IADC 151381 Dynamic Modeling of Gas Distribution in the Wellbore During Kick Situations by H.F. Spoerker, OMV Exploration/Production, et al. SPE 146231 Casing- and Screen-Failure Analysis in Highly Compacting Sandstone Fields by Kenji Furui, ConocoPhillips, et al. SPE/IADC 151181 Use of Liner Drilling Technology as a Mitigation to Loss Intervals and Hole Instability: A Case Study in Mississippi Canyon by Steven M. Rosenberg, Weatherford, et al.

Technology Focus One of the more important aspects of well integrity during drilling operations is early kick detection. When an unintentional flow of the formation fluid into the wellbore occurs during conventional drilling operations, it must be detected promptly and the flow must be stopped, normally by closing the well. The early detection is crucial in minimizing the influx size. When the amount of formation fluid inside the well is large, especially if it is gas, the pressure inside the well will be higher during the subsequent well-control operations. This can lead to an increase in time to control the well or even to a worse situation: the loss of control. Another concern may be the amount of formation fluid to be handled at surface. Deepwater, high-pressure/high-temperature, and slimhole drilling are situations where early kick detection is mandatory. The early kick detection is accomplished with a rig equipped with the appropriate kick-detection sensors and alarms and with a rig crew trained in quickly recognizing a kick and in the shut-in procedures. However, there are situations where early kick detection becomes more problematic—for example, when operating on a floating rig because of its motions, when using non-aqueous drilling fluids because of gas solubility, or during connections. Recently, new technologies and research have been applied or developed to improve the kick-detection systems and to overcome some of the difficulties. To cite just a few examples, Development of automated kick-detection systems (one of the papers summarized here addresses kick detection during connections) Kick detection just above the bit using logging-while-drilling information Kick detection using wired drillstring Research on the effect on kick detection of gas solubility in nonaqueous drilling fluids (mineral oil, paraffin, ester, and olefins) The use of managed-pressure-drilling systems (one of the papers recommended for additional reading comments on the advantage of this technology in reducing the kick size) Recommended additional reading at OnePetro: www.onepetro.org. SPE/IADC 173153 A Barrier-Analysis Approach to Well-Control Techniques by D. Fraser, Argonne National Laboratory, et al. SPE 180047 Impact of New and Ultrahigh-Density Kill Fluids on Challenging Well-Kill Operations by T. Rinde, Acona Flow Technology, et al. SPE 180053 A Numerical Study of Gas-Kick Migration Velocities and Uncertainty by K.K. Fjelde, University of Stavanger, et al.