Jun 26, 2012Global oil and gas firm Statoil has begun the deployment of a low-frequency (LF) radio frequency identification solution that will track the use of drill equipment as it is lowered into and removed from offshore drill holes, thereby retaining a record of how much and how frequently the equipment is used, and thus the amount of useful life it retains. That information will allow the company to better manage its inventory, and ensure that equipment is not used longer than it should be, or discarded before reaching the end of its lifespan.
The solution, known as the Drilling Operations Tracking System (DOTS), is provided by Norwegian RFID firm Trac ID Systems, and consists of 125 kHz RFID tags and readers compliant with the ISO 18000-2 standard, as well as software to manage the RFID read data.
Statoil maintains offshore oil-drilling operations worldwide, including in the North Sea and the Gulf of Mexico, as well as off the coast of Africa.
With the RFID system, the company also intends to improve its usage of drill pipes based on better, more accurate data regarding the length of time that each pipe has already been used, says Marianne Høie, Statoil's senior advisor of drilling technology, and to reduce exposure time for the rig crew on the main deck. Currently, data about the pipes and their usage is recorded manually using a Microsoft Excel spreadsheet—a process that is prone to errors. In addition, she says, "the rig crew spends a long time on the main deck taking different measurements of each drill pipe." While carrying out these tasks, workers are exposed to various hazards on the main deck, where heavy equipment is operated near the well opening. "RFID will reduce the amount of time spent on the main deck by the rig crew," Høie states. "They will only need to scan each pipe by the handheld scanners, and they will be able to get all the drill-pipe information they need."
Oil-rig equipment consists of a series of drill-pipe sections joined together in a string and lowered into a drilled well. A pipe's location within the string, along with how long it remains in operation, can dictate its lifespan. Tracking that information by paper, however, is complicated, and can lead to a piece of equipment being retired before it needs to be, or the risk of a weakened drill pipe being used that should have been removed from inventory. For example, in the event that records regarding a particular piece of equipment are incomplete, the owners will discard that item rather than risk using it after it has reached its maximum usage life.
For the deployment, Statoil will screw a Trac ID 125 kHz passive RFID tag into a machined, threaded recess on each pipe, and then apply a specific Loctite glue to further secure it into place.
A TPF-35-EX-45 fixed reader, developed by Tectus Transponder Technology GmbH in cooperation with Trac ID Systems, will be mounted near the well opening, in order to read the tag as it passes down the well hole on a drill pipe. The interrogator has a read range of up to 400 millimeters (16 inches), and its antenna is typically placed around the well's opening, fixed with brackets so that it cannot be displaced. In offshore operations, however, most drill floors are different, and the antenna housing needs to be adjusted for each installation, says Manfred Vonlanthen, Trac ID's director of sales and marketing. The maximum inner diameter of the antenna is 500 millimeters (20 inches); thus, the antenna is designed for fast removal, if necessary, to facilitate any well repair work performed in an area where the equipment used is bigger than the antenna's diameter. The reader itself is typically placed somewhere on the drill deck, or in the "drillers' cabin," located nearby, depending on the rig's size and design.
The reader is connected via cable to the local server on the rig, and all data is processed and stored by DOTS software operating on the server. The local server can also forward that information to Statoil's central back-end system, located on the mainland via the company's internal local area network (LAN) or wide area network (WAN) connection, or to the global asset database (a service provided and hosted by Trac ID Systems) via an Internet connection. Most offshore sites utilize optical fiber connections to their on-shore systems. In a few cases, communication is achieved via satellite.
Each time that a pipe is lowered into and then raised out of the well, its tag ID number, along with the time and a date stamp, are automatically recorded, and the DOTS software determines a total number of hours that the pipe to which the tag was attached remained within the well, and thus its amount of remaining useable life. The system can also track how deep the tagged item drops into the hole, based on the number of additional tags read as the pipe is inserted into the well.
Data about the pipes and their usage is stored in Trac ID's DOTS software suite. DOTS systems are integrated with the global asset database, and data can then be made available for approved third-party companies.
The DOTSAlert module detects problems based on exceptions to a predetermined set of rules (such as a maximum and minimum number of pipes, as well as the identification of any pipes that have exceeded their useful life) configured in the DOTS software.
Notification of all alerts is provided graphically on the DOTS user interface panel, on a computer located within the drillers' cabin. Audio notification in that cabin may also be provided, Vonlanthen says. All alerts are logged in the database, and are accessible for historical data following the event.
The Statoil pilot, completed earlier this year, faced several challenges with regard to the use of RFID technology, Vonlanthen explains. The tags needed to withstand a combination of high temperatures, pressure and vibration within a steel environment that could contain hydrogen sulfide gas and damaging liquids. "The design and mounting methods required special consideration to achieve maximum reading performance, best possible protection from heavy handling tools and, at the same time, maintaining the integrity of the equipment," Vonlanthen states. Once this problem was solved, the reader system needed to guarantee the correct reading of all tags at high speed—up to 2.5 meters (8.2 feet) per second—without interfering with the drilling operations, and while complying with requirements for the use of electronic equipment in environments in which there is a potential for explosion. "At the same time, it was our goal to base the system on open standards as far as possible, to avoid the development of a proprietary solution. The combination of all these factors was a real challenge which pushed the possibilities of available RFID technology to its limits."
Statoil is still in the process of installing the system, one site at a time. "The success of the first installation is very critical," Høie says. "Therefore, we are spending a lot of time and effort to identify the best setup that will enable DOTS to give the best performance. We also must assess all the risks involved with introducing a new system like DOTS offshore." Once the setup for DOTS is finalized and the first installation is successful, she adds, "we will be able to broadly implement RFID on our offshore installations in Norway."
The first deployment is expected to be taken live by the end of this year.
For the past five years, Vonlanthen says, Trac ID has been working with oil and gas companies Statoil, Eni Norge and ConocoPhillips to develop and commercialize a similar system for tracking individual pieces of drill pipe while they are in operation. The resulting solution has been used by energy firm Petrobras (see Petrobras Opts for RFID to Track Drill Pipe), which has been utilizing the tagged pipes in its operations for the past two years, and is still doing so. To date, none of the RFID tags mounted in these pipes has failed to perform, the company reports. Weatherford, which provides its equipment for use by Petrobras, is employing Trac-ID's Asset Tracking system on a daily basis, in order to capture inspection results and track the pipes through the supply chain, thereby providing Petrobras with information regarding each individual piece of pipe.
