In October 2008, automation vendor Emerson Process Management received orders from PDVSA, the Venezuelan state-owned oil company, for the first two phases of a program to install Emerson Smart Wireless technology in the Morichal District oil fields. The reported multimillion-dollar orders include monitoring of more than 180 wells by nearly 700 Emerson devices arranged in a self-organizing wireless “mesh” network.

These type networks route data via radio-signal pathways that are able to overcome obstructions or interference because each wireless device can act as a router for other nearby devices, thereby passing the messages along until they reach their destination, meaning the signal can “go around” an obstruction.

Major automation vendors besides Emerson, including Invensys Process Systems and Honeywell Process Solutions, also have wireless solutions for industrial applications that are being applied in the petroleum industry. Another vendor is Apprion, which specializes in managing industrial wireless networks.

For most industrial applications, elimination of wiring costs is the major benefit of wireless. In a number of cases, vendors and users report, production and equipment monitoring applications that in the past couldn’t be cost-justified are with the availability of wireless now viable, with the range of savings estimated at anywhere from 25% to 90% of the cost for comparable wired applications.

For the upstream oil and gas industry, this benefit is especially enticing, as communication of wellhead data from wired instruments often proves unreliable due to grounding problems and harmonics generated by electronic-drive equipment at the well pads. In many cases, the problem of false readings can be solved only by burying heavily armored cables in trenches, which is both time-consuming and expensive.

Wireless instrumentation at the wellhead can be a real-time indicator that gross oil flow — dependent upon the ratio amongst oil, gas, and water produced — has changed. For example, at BP’s Wytch Farm oil field, Western Europe’s largest onshore oil field, Emerson Smart Wireless Transmitters are used to continuously monitor annular and tubing wellhead pressure. Pressures previously were measured by gauges that were manually read once or twice a day.

Chris Green, BP manager, said, “Wired transmitters were simply too expensive due to the wiring infrastructure needed.”

In the first two phases of the Morichal project, more than 40 well pads will be equipped with Smart Wireless Gateways serving as network hubs for the field instruments. A total of 450 Rosemount wireless pressure transmitters and 235 wireless temperature transmitters will provide data from 180 individual wells, which are generally about 200 to 260 ft (60 to 80 m) from the well pads.

Philip Schwarz, oil and gas industry marketing manager, Emerson, said, “Most onshore oil and gas wells lag in terms of instrumentation and automation sophistication, primarily because of their remote location, which introduces challenges related to power and other type resources. But with wireless transmitters you’re looking at self-contained units with enough power to last 10 years. In addition, the knowledge and expertise needed to more closely monitor those wells can be brought to bear from a central location rather than having to be brought to the well.”

Having sophisticated instrumentation at the surface of the wellhead still only automates about one-half of what is needed, said Schwarz. The next milestone will be achieving below-surface measurements at a cost-effective price. Real-time downhole electronic measurement to date is wired and costs hundreds of thousands of dollars to purchase and install.

“This technology is mostly applicable at present to wells with very high production rates,” said Schwarz, “which represent less than 20% of all wells producing around the world. With time, technology adoption, and future innovation, we’ll see more producers adopt sophisticated automation practices on the surface. Downhole technology also will become cheaper and more reliable.”

The potential, said Schwarz, “is for wireless to make oilfield operations more like that of a factory or processing facility, but here the ‘factory’ may encompass a very considerable amount of acreage.”

Applications and innovations

Besides production and equipment condition monitoring, wireless network applications include security-related uses, i.e., video surveillance, access control, and intrusion detection; mobile asset and material tracking; and monitoring of hazardous environments.

Challenges remain to be overcome, however, if wireless is to realize the widespread use some foresee.

Performance issues related to wireless applications might include coverage, latency, and throughput. This overall challenge is heightened by the differing approaches of major industrial vendors for products that most often operate in the 868/915 MHz and 2.4 GHz unlicensed bands of the radio spectrum, including ZigBee, Wi-Fi, WiMAX, and RFID.

To limit the technical disparity of emerging proprietary solutions, a new standard — ISA SP100 — has been promulgated, with compliant commercial products expected on the market this year. Best practices are being disseminated through the Wireless Industrial Networking Alliance (WINA).

“There’s never one size that fits all, and there’s no place that’s truer than in petroleum exploration and production,” said Steve Lambright, a company vice president with Apprion. “An offshore platform, made of metal and surrounded by water, is a challenging environment. Diversity in terms of using multiple frequencies, multiple technologies is the key. You might choose 900 MHz wireless Hart for production and condition monitoring, employee WiFi at 2.4 MHz, and asset tracking at 5.8 MHz. If you try to force one portion of the spectrum, it leads to problems.”

This being the case, one question that has arisen is, shouldn’t all forms of wireless — e.g., asset tracking by means of RFID tags or wireless mobile communications — also be managed by the same network management tools as for production monitoring? And as wireless proliferates, shouldn’t wireless and wired networks be part of one single plant network?

“Applications have to coexist and interoperate, requiring common systems management to address performance, security, and management concerns as they scale,” Lambright said.

This was the origin of Apprion’s Intelligent Operations network (ION) System for administrating all types of wireless — providing centralized configuration and a single interface to integrate and manage devices, networks, and applications. The ION System can also “plug into” a systems management solution already in place to establish a single system for wireless and wired networks.

Kindred applications

“The killer application isn’t field instruments,” said Hesh Kagan, Invensys Process Systems, “it’s solutions for worker mobility. There’s so much to be gained by allowing engineers to get information no matter where they are, even remote from the facility. Those enterprise applications don’t tread on the control systems network but have a real return on investment.”

To bolster its offerings in this area, in August 2008 Wonderware, an Invensys business unit, acquired SAT Corp., a Houston-based mobile solutions company. Its solutions enable remote workflow, procedural, and general task management, typically focused around asset maintenance and compliance.

For example, Kagan said, “RF tags can be used to download the proper procedures relevant to a particular piece of equipment.”

In addition, Invensys partners with Motorola — an Apprion investor — for wireless network infrastructure hardware and software. Motorola, through its enterprise mobility division, also can provide the actual handheld devices used to access the network.

“For upstream oil and gas,” Kagan said, “we’re working with some of our larger customers to design networks for offshore oil rigs that combine wireless video, operator mobility for maintenance management, and real-time location services for both equipment and personnel. Packages exist today that allow rule configuration of alerts based on equipment and personnel locations and even where they are in relation to each other.”

Wireless networks tend to be hierarchical, Lambright said, with the lowest level using wireless HART, ISA 100, or other technologies for aggregation at the device level.

One level up, the 802.11 brand of WiFi or 802.16 WiMax can be used for aggregation across a defined area. Finally, across wider areas, perhaps encompassing several offshore platforms, WiMax or other technologies can be used.

One development on the horizon that may prove significant will be the release in the near future of chip sets that allow battery-powered sensors to “speak” 802.11 WiFi, perhaps leading to even greater proliferation of industrial sensors.

There’s significant flexibility in how wireless networks can be configured, Kagan said, but for that very reason it takes due deliberation to choose an approach that matches intent. “People come to us with a particular problem,” he said, “without thought as to the underlying structure needed to support the end devices.”