Wireless installation delivers efficiencies

The San Joaquin Valley in the heart of central California is known primarily for agriculture, with an estimated 12% of the agricultural products in the US coming from this area. The valley also is the largest petroleum-producing region in the state.

Just outside Bakersfield, Plains Exploration & Production Co. (PXP) transformed its steam injection metering and data acquisition systems into a sophisticated, automated process comprising a large network of WirelessHART transmitters and industrial broadband radios.

The application
PXP’s Hopkins lease in the South Belridge field consists of more than 200 wells distributed over approximately 1 sq mile (2.6 sq km). Continuous steam injectors play a critical role in the amount of oil produced.

Originally, each injector was fitted with a chart recorder that metered and recorded steam. To track these readings, operators were required to visit each of the approximately 120 injection wells every day to visually interpret the chart recorders’ graphical readings, log them on a clipboard, manually convert this measure to a flow rate, key it into a spreadsheet, and send the final numbers to the Bakersfield office, where a clerk entered the figures into a database.

This approach was very manpower intensive. The chart recorders themselves required recalibration every three months, and it was difficult to accurately interpret their readings. Secondly, concerns existed about data integrity from potential recording errors during the several handoffs and manual entry steps required. Lastly, the process consumed much of the operators’ time and provided only one data point per day, so should a problem arise at a well, PXP suffered response lag times in dealing with the issues.

The project facilities engineer at PXP saw these inefficiencies as an opportunity to improve processes. After equipment investigation, analysis, and discussion with operations personnel, he was able to implement a new wireless metering and monitoring system. The opportunity to implement a wireless solution made deployment quick and economical.

Technology at work
The new automation system began as a pilot project during which 10 Rosemount 3051S WirelessHART pressure transmitters were installed at four wells.

Two transmitters were placed on each well to measure the downstream pressure at the wellhead and the upstream pressure before the steam passed through a choke. On dual stream wells, a third transmitter was installed, so each stream had its own downstream transmitter and a shared upstream transmitter. Pressure transmitters communicated through the self-organizing mesh network to the Emerson WirelessHART gateway, where the process variables, process diagnostics, and instrument diagnostics were converted to Modbus TCP/IP data. ProSoft Technology 802.11 industrial broadband radios connected gateways in the field to an industrial PC in the office a mile away, forming the backhaul network - an alternate wireless communication system that moves data from points in the field to the business system.

During the pilot project, PXP brought in a company to test steam levels and report a true number for the amount of

steam being injected in a well. PXP compared the steam test results from the wireless transmitters and chart recorders and found the transmitters readings were about 10 times more accurate, on average.

“We were surprised by how much more accurate of a reading this new technology was able to deliver,” Michael Fischback, PXP project facilities engineer, said.

Accuracy is money. Inaccurate steam metering translates into expensive repairs. Over-injecting steam leads to higher than necessary operating costs, and under-injection results in missed production opportunities.

Once the project was validated, the plan was rolled out across approximately 120 wells. In total, 249 Rosemount WirelessHART transmitters were installed, with four gateways aggregating data and three ProSoft Technology industrial radios communicating the data to an industrial PC in the field office.

Wireless system delivers benefits Reduced maintenance – Emerson recommends calibration for the Rosemount WirelessHART transmitters (delivered pre-calibrated) once every five years as opposed to the three-month calibration cycle suggested for chart recorders. Real-time data – Wireless connectivity allows for live data feeds, which delivers improved response times and smarter decision making. Predetermined set points trigger notifications for operators to see instantly if a well deviates from predetermined goals. Data are archived permanently and can be trended for better analysis and decision making down the road. Increased efficiencies – The new system gives operators the data they need to better prioritize their day as soon as they arrive on site, freeing them to focus on more productive activities. Profitability – In enhanced oil recovery (EOR) projects, steam can account for 40% to 65% of a producer’s costs and is responsible for much of the revenue derived from a well. At today’s prices, the cost of steam at Hopkins exceeds US $10 million, annually. With the new system in place, PXP can distribute steam with improved accuracy.

From the office, data is sent to PXP’s intranet, where it is tied into two ProGauge Technologies custom designed web-based software packages. One enables operators to log in and view well data, print reports, and view alarms. The other is a statistical analysis tool with historical data, designed to provide a higher level look at the field for trending. It provides a visual overlay of the well sites, enabling reservoir and production engineers to view data by clicking on a well, or to trend data, calculate steam to oil ratios, and more.

A .csv file is generated daily and imported into PXP’s reporting database from which allocations are determined and distributed to various internal and external entities.

Implementation
According to Fischback, “Installation of the Emerson pressure transmitters was merely a matter of removing a mechanical pressure gauge and screwing on the new instrumentation. Installation of the ProSoft radio was as simple as mounting the radios onto a backboard. The installation of the ProSoft radios took no more than a day.”

Bob Karschnia, vice president of wireless solutions at Emerson, explained the advantages: “Upstream oil companies have a limited amount of time to deploy any kind of solution to help them solve their problem, so the faster they can get that solution deployed, the better. The advantages of using both the ProSoft Technology solution and the Emerson Smart Wireless solution are the ease of deployment. Both solutions have a straightforward user interface that allows you to configure and set up the networks almost instantaneously. They are very highly engineered solutions that take the complexity out of the user’s hands and build them into the products.”

The biggest attribute of this system is that it allows operators to see performance problems more quickly and react with better priority and increased time efficiency.

Results
After a successful pilot, PXP will automate 25 new wells on the Hopkins lease with wireless vortex meters, with the long-term goal of continually improving operations. The company expects to see oil production increase as a result of the implementation of this system and anticipates greater efficiencies and reduced costs. PXP will review the results of this installation and use that information to determine where deployment of this technology can further benefit operations.

“We’re pleased to see the results of this,” Fischback said. “It’s got our operations team excited. Deploying technology to help continuously improve our operations is a step in the right direction.”