Oil and gas wells can last 100 years, but they do not last forever. And when a well reaches the end of its life, it needs to go through a decommissioning process to preserve the surrounding area and make sure there is no environmental contamination in the future.
The decommissioning process begins with a one or two year diagnostics period before the actual decommission. During this period, engineers gather data about the condition of the well so they can make a plan that eliminates risk after the decommission.
Engineers need a lot of data during the diagnostics period, but not all the data can be gathered automatically. To get the information they need, oil and gas companies send teams of engineers out into the field to gather the data.
Shell understood the hassles of decommissioning, and knew there had to be a better, safer way. And when the company’s engineers heard about a simple solution for remote pressure and temperature monitoring called HiberHilo, they figured it was worth testing.
Cost and safety are major considerations
Crew trips are expensive: they can cost anywhere more than US$10 000 per trip, depending on the location and the size of the crew. The trips also present a safety risk, which is especially sensitive in an industry committed to a zero-accident rate. And, because the measurements are done by humans on an infrequent basis, there is more room for error and a longer response time to any well integrity issues.
The Nederlandse Aardolie Maatschappij (NAM) and Royal Dutch Shell wanted a better way to monitor well integrity. In a joint project, the companies tested a measurement system that leverages wireless IoT on a well awaiting abandonment that was still connected to a pressure monitoring system.
The purpose of the test was to evaluate the speed and ease of installation, compare the output of the sensor to an existing wired measurement system, and evaluate the future possibilities of this unwired approach. Both companies wanted a system that was easy to install, easy to use, and easy to trust. HiberHilo met all three of these criteria.
Installation of HiberHilo was lightning fast. The entire installation took less than three hours, with the sensors obtaining a satellite connection within 15 minutes. In fact, the installation was so fast, the engineers estimated they could have done another 15 installations that same day, which makes the application of HiberHilo in remote areas even more interesting.
Wireless versus wired
Right out of the box, the HiberHilo system reliably sent data to Hiber’s cloud. After some optimisation, 99.8% of the data collected at the wellhead was successfully pushed to the central server. Reliability is important, but so is accuracy. NAM and Shell specified that accuracy levels should be within a 10% range of control data provided by the wired system that was installed alongside.
In fact, the accuracy was astonishingly close, with the satellite sensor’s data deviating just 1.87% away from the control data, when compared on a 0 - 40 bar range. On average, the satellite data was 99.75% as accurate as that of the wired system, according to Shell and NAM.
Shell was so impressed with the satellite-based approach that the company decided to move forward with a global framework agreement that lets subsidiary companies and entities transition to satellite IoT as fast as possible.
Read the article online at: https://www.oilfieldtechnology.com/special-reports/01112021/shell-looks-to-wireless-for-well-monitoring/