With the Storm Packer Root Cause Analysis complete, the probable RCs will be known. The next step is to confirm causation of the failure. In Failure Simulation (FS) the goal is to confirm cause and effect. When more than one probable RC has been identified, the FS will consist of multiple simulation tasks. How extensive will the Storm Packer’s FS program be?[Read more…]
Equipment Risk and Reliability in Downhole Applications
The equipment used in oil and gas wells is designed to operate for long periods of time at very high absolute pressures and temperatures, frequently in highly corrosive environments, and with little opportunity for visual surveillance of equipment condition. The reliability of these products directly affects the economics of operating these wells, the environment, and the safety of the communities in which the wells are located. This series of five articles explores the risk and reliability associated with the downhole tools used in oil and gas well applications and provides recommendations for engineers on how to include reliability thought and practice in design.
The information collected in the Storm Packer (SP) failure (Information) will establish:
- The timeline of events – which activity(s) preceded each significant event?
- 3rd party impacts (process, products).
- Product readiness at the time of installation.
- Product suitability for the application.
- Crew competency.
In failure analysis, the collection of information is a tedious but necessary step that determines success in the root cause analysis (RCA), simulation, and mitigation phases. In Article 2, the SME identified five areas of possible root causes for the SP failure, further explained in Table 1.[Read more…]
Analysis of the Storm Packer (SP) failure in Article 1 will be complicated. Some stakeholders will assume that the SP was defective, some will assume the drilling crew made mistakes, and others will assume that wellbore conditions predisposed the SP to fail. Any of these may explain the failure of the first SP, but only rigorous due diligence will uncover the root cause(s). What should be investigated, and what will be the roadmap for the analysis? [Read more…]
The floating drilling rig, operating in 6,000 ft. of water, pitched in rough seas 300 miles away from shore as the outer bands of the hurricane’s winds buffeted the drilling location. Per procedure, the crew installed the Storm Packer (SP) in the well to isolate its open wellbore from the ocean before the storm roared across the location – but it failed its pressure test. The crew then installed the back-up SP which passed the pressure test. The well was finally secured, and the 25,000-ton drilling rig was moved out of the hurricane’s path. Because the first SP failed, a 12-hour process took 30 hours to complete, while wind speed and wave heights increased.
The Critical Equipment Series has covered design and design risk reduction. A Laboratory Test Program (LTP) is the final step in validating the equipment design after updating it with all improvements determined through design risk reduction and related activities.
Refer to Article 7 for the expansion joint project. This project had progressed – perhaps beyond lab testing – before it was realized that the design could not meet ASME LRFD criteria. LRFD was considered necessary for reliability. The engineering manager had to consider a redesign.
Missing the LRFD may be the result of not conducting a design failure modes and effects analysis (dFMEA). FMEA is a risk discovery process. Discovering design risks early in the project improves reliability and increases profitability by avoiding redesign and schedule delays. [Read more…]
A high-pressure packer for use in 9 5/8”, thick-walled, P-110 casing is being developed for a well barrier application. It is based on a legacy configuration. Is it a candidate for simulation?
Your engineering team tells you the new deep-water product is ready for field trials because it has passed an API validation test in the lab. But as the OEM engineering manager overseeing product development, how do you know that passing just the validation test is sufficient? [Read more…]
The new deepwater expansion joint design meets company requirements for factors of safety but cannot comply with ASME Section VIII load factors. How does the OEM engineering manager proceed?[Read more…]
You are an engineering manager overseeing product development. For the new offshore product developed by your team, you want to know:
- If the final design margins comply with company standards
- If the thin-wall components are susceptible to Bauschinger Effect
- Which load factors were used for the ASME section 8 analysis.
High temperature stress analysis of metallic components must account for an inevitable decrease in room temperature minimum yield strength (Sy). Linear-elastic stress analysis is the norm for nearly all downhole metallic components and accurate results depend upon the use of reliable temperature deration factors. [Read more…]
The materials used in new equipment can pose a design risk. But what makes a material a design risk? And how is de-risking achieved for metallic and nonmetallic materials?
To satisfy design requirements for loading, corrosion resistance, and manufacturability, materials properties must be controlled. Design risk is high when material properties are not controlled and materials are not selected using best practices. And as stated in Equipment Risk, material stability is also necessary for long service life, meaning that mechanical and physical property response to elevated temperature and corrosive media is predictable or reasonably estimated. Thus, controls for material properties and selection are the basis of de-risking. [Read more…]
Your staff has a concept for a deepwater completion product. They say it is the solution offshore operators need. The concept contains many new components and seems risky. How mature is the technology?
Conducting a Technology Readiness Assessment (TRA) answers these questions. A TRA assesses the maturity of the technology in a product and assigns it a Technology Readiness Level, or TRL. The higher the TRL, the more mature the technology, and the lower the risk. [Read more…]
Critical is defined as “a situation or problem having the potential to become disastrous”. A system of physical well barriers is used in offshore wells to mitigate against a disastrous event. The United States Bureau of Safety and Environmental Enforcement (BSEE) refers to Category 1 and 2 well barriers. A failure of a barrier can lead to a blowout or fluids spill into the ocean, either of which is high severity. Thus, it is customary in the upstream energy industry to refer to well barriers as “critical equipment”. [Read more…]