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A blowout preventer (BOP) is one of the major pressure control safety devices used in the drilling of hydrocarbon wells. Hence, improving BOP reliability and reducing nonproductive time has been always a concern to ensure safe and efficient operations. In the last years, multiple analytics tools have been developed by the Oil and Gas (O&G) industry to monitor the health of BOP components using the control system data. However, the ability of those tools to predict critical failures and establish a predictive maintenance strategy was constrained by the limited number of sensors and the inability to transmit higher fidelity data. First, this paper describes the state of the art of the BOP analytics, data transmission and instrumentation technology and points out its limitations. Different solutions are then proposed to leverage the IoT technology as a driver to enhance BOP predictive analytics capabilities.
During loss of well control events, fracture initiation occurring during the post-blowout capping stage following uncontrolled discharge, can lead to reservoir fluids broaching to the seafloor. A classic example is Union Oil's 1969 oil spill in Santa Barbara channel, where fracture initiation at various locations caused thousands of gallons per hour to broach in the ocean floor over a period of a month before it could be controlled (Mullineaux, 1970; Easton, 1972). The impacts on California's oil industry are still felt strongly today. Disasters as such could be prevented if the effects of the post-blowout loss of well control stages (uncontrolled discharge and capping) are incorporated into the shut-n procedures and the wellbore architecture. Analytical models are used to simulate the loads on the wellbore in the different stages during loss of control and predict capping pressure buildup during the shut-in to indicate fracture initiation during the capping stage. Using these models, critical capping pressure and subsequently critical discharge flowrates is calculated for a well below which fracture initiation would occur. A hypothetical case study with typical deepwater Gulf of Mexico parameters is performed demonstrating the likelihood of fracture initiation during different discharge flowrates, discharge periods and shut-in methods (abrupt/"hard" or multistage/"soft").
In this study, the highly sensing chemo-thermo-piezoresistive smart cement behavior as a function of temperature and pressure with a water-to-cement ratio of 0.38 was investigated. Series of quality control, curing, compression and high-pressure high-temperature (HPHT) lab experiments were performed to evaluate the smart cement behavior with pressure and temperature variations. Vipulanandan p-q curing model was used to predict the changes in resistivity with curing time. The piezoresistivity strain of smart cement after 1 day of curing under 140 °F was 207% which is much higher than the regular cement failure strain of 0.2%. The Vipulanandan p-q piezoresistivity model also predicted the experimental results successfully. Observed fluid loss and gas leak after 30 minutes of testing was recorded. The measured fluid loss was predicted using the Vipulanandan fluid loss model and compared to the API static fluid loss model. Smart cement detected and sensed gas leak throughout the fluid loss test. During the gas leak through the piezoresistive smart cement slurry, the resistivity change was positive which could be used as an indicator for immediate gas migration. During the gas leak in the smart cement slurry, the resistivity increase was about 36% at pressure gradient of 1,800 psi/ft for 70 °F curing. Vipulanandan fluid flow model, generalized Darcy's Law, predicted the non-linear responses of gas leak velocity (discharge per unit area) to the applied pressure gradient. Additionally, the electrical resistivity changes predicted the gas leak velocity in the smart cement at different curing temperatures.
Looking at martensitic stainless steels (MSS) NACE MR0175 / ISO 15156 lists six tables with different H2S acceptance levels. Generic Table A.18 lists several MSS with a maximum allowable partial pressure H2S of 0.1 bar whilst equipment specific Table A.23 (Wellhead and tree components and valve and choke components) shows no restrictions when it comes to partial pressure H2S.
To substantiate the applicability of Table A.23, a study was performed to evaluate environmentally-assisted cracking resistance of cast alloy CA6NM (UNS J91540) in highly sour environments (Level VII) and the implications of the findings on the usage of CA6NM as pressure containing valve bodies in wellheads.
After that a ballot (no. 2013-03) was written to clarify the scope of Table A.23 and limit the use of cast alloy CA6NM (UNS J91540) based on applied in situ stress. An additional note was incorporated for UNS J91540; “Low-carbon, martensitic stainless steel J91540; the maximum design tensile stress shall not exceed 2/3 specified minimum yield strength or 345 MPa (50 ksi) whichever is less.”
The paper includes a historic perspective of NACE MR0175, results of NACE level VII tests, the ballot process including an FEA study to simulate stress distribution in valves for wellhead equipment.
In this paper the use of valves for wellhead equipment in accordance with NACE MR0175 / ISO1 15156 is described. What are the pitfalls and what is of importance when selecting materials for valves, both in general as well as more in particular related to martensitic stainless steel? Especially for pressure containing parts such as the valve body.
For a good understanding of this paper it is important to remember that the very first NACE MR0175, published in 1975, was titled “Materials for valves for resistance to sulfide stress cracking in production and pipeline service”. The standard covered material requirements applicable to materials used for equipment covered by API specifications 6A and 6D and were not intended to include design requirements.
In the second edition, published in 1978, the scope was broadened to include more than just valves. It was called “Sulfide stress cracking resistant metallic material for oil field equipment”. This version was more general and talked about metallic material requirements for resistance to SSC.
The marine and offshore industries face uncertainty in oil prices as well as concerns over climate change and energy transition. These are challenges but also opportunities as the industry moves from a culture seeking evolutionary concepts to a culture seeking efficiency through innovation. Safety and efficiency are key to supporting future progress and such goals are achieved through optimization of hull forms, load paths and material efficiency. On the structural discipline, advanced methodologies exist to cover the key concepts of shape optimization through concept models of hull form, definition of loads and load paths, modeling of randomness and uncertainty, customization of structural reliability through Structural Reliability Analysis (SRA), decision making metrics, robustness & resiliency and computational multi- criteria multi-objective optimization. This paper proposes to integrate such concepts into a conceptual framework to develop resilient offshore structures. The concepts described have wider application to several types of structures on land, marine and offshore-based.
As the OSH profession continues to evolve, a major concern remains: the number of workplace fatalities and serious injury events each year. As incident rates have declined over the years, fatality rates have not significantly changed; they have plateaued and risen slightly. Recent data from Bureau of Labor Statistics (BLS, 2017) indicate 5,190 workers died from an occupational injury in 2016. This number increased by 7% over 2015 and is the highest count since 2008.
In the authors’ view, the persistence of serious injuries and fatalities suggests that many organizations have flaws within their management systems in the way they plan, organize, implement, execute, monitor, communicate and improve. One way that OSH professionals can help organizations improve their management systems is through more effective analyses of incidents.
An incident is an unplanned, unwanted event that results in injury or damage (an accident) or an event that could have resulted in harm or loss (a near-hit). All incidents should be investigated, regardless of the extent of injury or property damage. In the authors’ experience, most organizations perform some degree of investigation and analyses for incidents resulting in injury, damage or those with significant severity potential. However, the driving forces for conducting incident investigations and analyses can vary for organizations ranging from the need to file insurance claims; complete regulatory compliance records; track lagging indicators; or meet contract requirements from customers. All of these are important, but they do not represent the real purpose of incident causal analysis.
NACE MR0175/ISO 15156 has now been out in its entirety since December 2003. What have we, the global materials and corrosion community that uses this standard, learned from the use of it over the last almost 15 years? What have been some of the biggest problems that we have had to face? What are our biggest achievements? What are the recent changes to the standard and what remains to be done? These questions are answered in this paper.
This standard is now undergoing a critical review to determine how it should change to meet the future needs of the Oil & Gas Industry better. Where are we headed with NACE MR0175/ISO 15156? The results of our collective initial efforts are presented.
The global materials and corrosion community is now 20 years into the process of an NACE/ISO Standard on Materials for use in H2S containing environments in oil and gas production. The standard describes requirements and recommendations for the selection and qualification of metallic materials for service in equipment used in oil and gas production in H2S containing environments. The ISO 15156 standard was published in parts where Part 1 – General principles for selection of cracking-resistant materials was initially published in 2001 with Part 2 – Cracking-resistant carbon and low-alloy steels and the use of cast irons and Part 3 – Cracking-resistant CRAs (corrosion resistant alloys) and other alloys were initially published in March and December respectively in 2003.1,2,3,
The origins of the combined NACE MR0175/ISO 15156 lie mostly in NACE MR0175 (2002 revision cited here) but with heavy influence from the work of the European Federation of Corrosion that culminated in EFC Publication 16 Guidelines on materials requirements for carbon and low alloy steels for H2S-containing environments in oil and gas production and Publication 17 Corrosion Resistant Alloys for Oil and Gas Production: Guidelines on General Requirements and Test Methods for H2S Service 4,5,6 A proposal to create a joint ISO/NACE standard originated in 1995 with an initial work group meeting that occurred during Corrosion 1996. The Task Group project leaders were Derek Milliams and Bob Tuttle. In conjunction with this effort, we (NACE) worked on a transition MR0175 standard that would act as a bridge to the n new ISO format standard. This was the 2003 revision of MR0175.7 The author served as Chairman of NACE’s STG 32 and Chairman of NACE’s TG 299 during this transition period from NACE MR0175 to the NACE MR0175/ISO 15156; he is the current outgoing Chairman of the NACE MR0175/ISO 15156 Maintenance Panel.
ABSTRACT Robustness is an important concept in different fields of science and technology including mathematical modeling, software development, statistical and probabilistic investigation / interpretation, design and assessment of systems, products and procedures. Robustness is the property of a system that enables it to accommodate perturbations and variability without disproportional loss of functionality and in an efficient manner. Engineers face the challenge of designing structures that are capable of efficiently accommodating a reasonable level of perturbation and variability. This paper reviews the efforts to introduce robustness into the design of offshore structures and gives suggestions for future development. INTRODUCTION - A DISCUSSION ON ROBUSTNESS In simple terms, a robust system does not easily break. For example, during college my father gave me an HP calculator, Figure 1. Thirty-five years and many bumps later, it still works as new. Another inspiration is Voyager 1, Figure 1, the only human-made object in interstellar space, which has been flying for 40 years and still communicating with Earth. On November 28, 2017, NASA was able to use a set of four backup thrusters, dormant since 1980, to reorient the spacecraft, which is 11.7 billion miles from Earth. Figure 1 - Robust Systems - an HP Calculator and Voyager 1 Proceedings of the 23 rd Offshore Symposium, February 14 th 2018, Houston, Texas Texas Section of the Society of Naval Architects and Marine Engineers Robustness applies to different fields of science and technology including mathematical modeling, software development, statistical or probabilistic investigation, design of systems, products and procedures.
After years of low oil prices, the focus is on adding a lot of value for a little cost. SPE’s technical directors are talking about adding value to everything from a petroleum engineering degree to a wellbore.
A failure to do so can mean a degree that does not prepare a student to con-tribute after graduation, or a well whose production fades early.
Those working as petroleum engineers have a generation’s worth of challenges to address due to the push into unconventional development. Those results will determine how much value can be coaxed from these ultra-tight rocks.
For those designing projects that will get built, it pays to think small. A standardized, modular design can deliver value at a cost that is lower, and more likely to come in within the budget.
Doing more with less in drilling means there are fewer drilling rigs in the world, and the job of many engineers still working will be to identify the best available technology to continue to reduce the number of rigs required.
Leaders need to be aware of the value that can be destroyed by mistakes made by humans interacting with complex systems.
And SPE needs to identify and support successful efforts to address health, safety, and environmental challenges, to help spread good ideas and show the difficult challenges the industry can and does address. The value of those efforts is often hard to measure, but it can be big.
Ramona Graves, Academia
The value of a petroleum engineering degree varies widely, depending on where it was earned. In many universities in the developing world, where hiring local workers is essential, the petroleum engineering graduates are far from ready to begin contributing, said Ramona Graves, the director representing academia.
Jeff Moss, Drilling
Drilling engineers are looking ahead to more years of managing jarring change. Jeff Moss, technical director for drilling, said the rapid increase in drilling productivity in recent years is a prelude to more of the same as drilling engineers sift through a flood of digitally controlled offerings promising even greater efficiency.
Hisham Saadawi, Production and Facilities
It is not the time to be thinking big in oil and gas facilities. Hisham Saadawi, technical director for production and facilities, said the focus has shifted from megaprojects to smaller projects where the investment management challenges and risks are all lower. Often companies are “looking at existing facilities to maximize return on the investment made,” he said.
Tom Blasingame, Reservoir
Reservoir engineers have a lot of promises to fulfill. “We were promised big data would save us. That more simulation would save us. And we were promised that we could understand flow regimes at scales we have not been using for the past 100 years,” said Tom Blasingame, technical director for reservoir.
Jennifer Miskimins, Completions
A keyword for completion engineers is interactions. For Jennifer Miskimins, technical director for completions, those range from production-altering pressure surges from well to well during fracturing to collaborations with drillers and reservoir engineers to build more productive wells.
Johana Dunlop, Health, Safety, and Environment
Recognition of industry success is on the growing list of things to do for the new technical director for health, safety, and environment (HSE), Johana Dunlop.
J.C. Cunha, Management and Information
Offshore drilling involves “an amazing set of equipment and high technology … run by human beings.” That sort of human interaction with complex systems has been on the mind of J.C. Cunha, whose term as technical director for management and information ended this fall. He is thinking more needs to be done to “reduce human error in complex systems.”
CSB’s report on the Deepwater Horizon incident contains several unusual comments pertaining to operations risk management that may have long-term effects on the practice of safety. CSB is a well-regarded governmental agency. This article calls attention of OSH professionals to these comments.
The agency’s final report on the explosion and fire that occurred April 20, 2010, at the Macondo Deepwater Horizon rig in the Gulf of Mexico was issued April 12, 2016. The incident resulted in 11 fatalities, 17 injuries and extensive environmental damage. CSB’s comments may be signals indicating that, over time, organizations should revise their accountability levels and the content of their operations risk management systems that aim to protect people, property and the environment.
The report’s executive summary sets forth CSB’s responsibility: “CSB is an independent federal agency charged with investigating industrial chemical accidents. Its mission is to independently investigate significant chemical incidents and hazards and to effectively advocate for implementing its recommendations to protect workers, the public and the environment” (CSB, 2016a, p. 11).
While CSB investigates and reports on chemical incidents, safety professionals should consider as generic the sections of its report on the Macondo event addressed by this article.
According to the executive summary, “BP was the main operator/lease holder responsible for the well design and Transocean was the drilling contractor that owned and operated the Deepwater Horizon drilling rig” (CSB, 2016a, p. 6).