Independent third party asset-condition inspections are a generally accepted method to meet internal quality and regulatory requirements during normal between-well operations or rig intake projects. Sometimes a decision is made to minimize or even skip these inspections based on prior operational results or a good report from the last operator of the rig. This can be referred to as a “proven-in-use” decision.
While there may be a history of proven-in-use decisions working, they all to often provide a false sense of security and comfort with the perceived safety and risk issues on the rig moving forward. A proven-in-use decision does not assure the next set of operational safety and performance requirements will be met unless the prior operation was identical to the next operation.
To illustrate this, consider the example of two groups in the oil industry that are well aware of the shortcomings of relying on proven-in-use as a method for mitigating risk and ensuring safety: commercial divers and pilots. Both of these groups rely on the methodical use of comprehensive project-specific planning and inspection checklists to ensure their equipment is set up correctly and will work properly on next use. It is generally understood that assuming your next dive or flight will be successful because the prior one was similar and successful is a recipe for disaster. All too many accidents are a direct result of shortcuts taken in planning for the next dive or flight because “it worked for the last guy that tried it”.
Similarly, while a rig may have performed satisfactorily for the last operator, that does not mean it will perform the same for your campaign, since you will likely have different operational procedures, drilling plans, and geographic locations. This is made even more important by the nature of the typical machinery on the rig. Any given piece of equipment or machinery has two very important aspects:
- The physical electro-mechanical state of the equipment/machine
- The ability to operate that machine through an integrated control software and sensor actuator array.
Most proven-in-use decisions are based on the perceived satisfactory condition of the electro-mechanical aspects of the equipment or machine. This approach ignores the importance of the control logic and the sensor and actuator arrays with respect to the safe and effective operation of the rig.
The typical rig control system capability significantly exceeds the subset of controls capability used for any given operational procedure. Therefore, a proven-in-use decision based on how the system was used last time does not provide any information about the the control logic, sensors and actuators that were not used during a prior operation. This leaves a high-risk gap between what has been proven in prior use and what needs to be proven for next use.
There is a real safety-based need for an inspection that encompasses the control logic and sensor/actuator array as they will be used for your specific project. In order to ensure this, you need to go beyond a proven-in-use decision and beyond a typical electro-mechanical inspection protocol. A sensor-based inspection protocol is well suited to address this gap. With a sensor-based inspection, the ability of the system to actually perform the operational and safety functions of your specific campaign can be ensured.
For example, a recent electro-mechanical inspection protocol for a fire and gas system found the system to be in compliance with all electro-mechanical requirements on the rig. But an additional sensor-based inspection protocol discovered that one of the critical thermal sensors was covered in a thin film of oil, and thus would not have been able to detect the heat signature required to trigger the fire suppression function. While the F&G system was electro-mechanically sound and capable of working, the sensor that was supposed to trigger it would have prevented it from doing so.
In another example, following a proven-in-use decision to accept a dynamic positioning system, it was discovered that multiple wind sensors used by the DP system were not using a voting algorithm to resolve differences in readings. The DP operator was expected to notice and resolve differences at the control panel and then act accordingly. This presents a significantly higher risk of a drift-off situation if a faulty sensor was misinterpreted by an inexperienced DP operator.
To summarize, in both cases above, the overall condition of the system was judged to be acceptable by either a traditional electro-mechanical inspection, or a proven-in-use decision. In both cases however, a sensor-based, application-specific inspection uncovered significant safety issues that needed to be addressed by the new operator.
Athens Group Services has implemented sensor-based inspections across our Proven Practices SM methodologies for HIL, acceptance testing, commissioning, inspections and surveys. Contact us to explore this proven inspection methodology to help ensure safe operations on your next asset.