It's easy to turn on the water for drinking, cooking or taking a shower at home. It's more difficult in a desert in the middle of nowhere, especially when vast amounts of water are needed and there's little or no infrastructure.
This is the problem faced by hydraulic fracturing, or fracking, which uses high-pressure water, mud and sand to fracture shale rock to release the oil or natural gas trapped in its underground layers. Ensuring a continuous supply of the water needed for wellsite operations is a logistical challenge that's labor-intensive and sometimes risky, but still crucial for cost control and profitability.
The U.S. Geological Survey estimates fracking at one well can require as much as 16 million gallons of water, depending on the length of the well bore, number of stages involved, and the design of the proppant particles such as sand or ceramic pellets that keep fractures open. Transporting water to the site must be planned and accounted for during a well's initial construction.
Setting up a water supply typically takes two to eight weeks, and involves scouting water sources, negotiating rights-of-way with landowners, installing temporary or permanent piping, pumping water to the wellsite, and storing it in tanks or large, membrane-lined containment ponds (Figure 1). Most large petroleum exploration and production companies have full-time water transition teams to handle these jobs, but small and medium-sized operators more often subcontract to water transfer service providers.
“Having sufficient source water available and delivering it reliably to the well pad location is an essential component of the supply chain in fracking and completing a new well,” says Reed Taylor, founder and CEO of Flowpoint Water Solutions in Midland, Texas, a water transfer & logistics firm serving the Permian Basin. Petroleum producers usually contract with Flowpoint to identify water sources and provide the logistics to get water to the site.
Miles to cross, pumps to organize
Flowpoint reports the distance between water supply storage facilities and wellsites they serve is usually three to 10 miles, which they typically cross with 12-in. diameter lay-flat hose or temporary pipes. Keeping water moving to meet fracture rates on the well pad requires synchronizing multiple pumps along the line, including many deployed in remote and inaccessible places. For most water transfer services, running pumps means sending field operators to manually monitor each pump while in operation, starting or stopping them as needed, spotting and fixing leaks in the line, and recording transfer volumes.
To streamline water transfers and improve efficiency, Taylor researched automation solutions, but found mostly ineffective, off-the-shelf telemetry products—until he met Harry Browne, CEO of Flow-Sync in Dallas-Fort Worth, and immediately invested in the start-up. Flow-Sync estimates wells in the Permian Basin may actually need as much as 42 million gallons of water, and provides automation by supplying integrated, skid-based, water-transfer pump controls, which simplify and optimize complex water transfer logistics for fracking operations (Figure 2).
Figure 2: Flow-Sync pumping skid with solar-powered control combines its Transfer Calc software that calculates flow rates and models flow operations with a cyber-secure automation platform, cloud-based data storage and analytics, and an Internet-based SCADA interface that lets operators interact with the system from anywhere. Source: Bedrock, Flowpoint, Flow-Sync
“Water supply logistics is a corner of the energy industry that doesn’t get much attention. While many oilfield facilities implement automation, PID loops, alarm notifications and other basic control functions, this hadn’t yet transitioned to temporary water transfer operations," explains Browne. “On the surface, water transfer appears to be a relatively simple operation, but it presents many challenges. Getting the water to the well often involves synchronizing two to four large, 600-hp or 375-hp diesel pumps spread out over the length of the transfer line. The pumps must be started and brought up to operating speed in series, and ramped down in series to stop every few hours. The process is repeated around the clock with each stage of the fracking operation, which can run for several weeks.
"Starting up a line may also require multiple boosters that must be manually sequenced in stages. It can be tedious. You may turn on your first pump and experience some lag time, during which the system builds pressure, which brings you the first booster pump. If you run it too fast, you could suck the line down to where it will collapse.” Browne adds that coordinating these processes traditionally requires multiple operators, who may be communicating only via mobile phones from areas with spotty service.
Browne and Flow-Sync have automated these processes by combining software applications that calculate flow rates, a cyber-secure automation platform, cloud-based data storage and analytics, and an Internet-based SCADA interface that lets operators interact with the system from anywhere.
Calculate for flow control
Taylor and Browne report that an efficient water transfer operation begins with analyzing the transfer line hydraulics to determine how many pumps are required to satisfy the design flowrate and route topography. They add that Flow-Sync’s Transfer Calc software provides a simple, intuitive interface to quickly model flow operations. At startup, its results are reconciled with readings from pressure and level sensors and flowmeters to identify equipment problems that could lead to downtime. These readings go to the control system, which uses them to optimize flow to the site.
The complex pump control necessary to implement Flow-Sync's flow models is performed by Bedrock Automation's Open Secure Automation (OSA) Remote control system that combines PLC, RTU and edge control, universal I/O and intrinsic cybersecurity, and enables automation that leverages the economies of open technologies by eliminating vulnerability to cyber-attacks in a rugged all-metal package built for the extreme conditions typical of water-transfer applications.
Flow-Sync deploys OSA Remote modules in the wiring cabinet of its patented, self-contained, portable skids (Figure 3). They're easily connected to the pumps, so transfers can be monitored and controlled from anywhere. OSA Remote has universal I/O configured to read and write tags from the skid’s sensors, and its OPC UA communications delivers data to the overall system.
Figure 3: A Bedrock OSA Remote PLC (upper right) in Flow-Sync's control enclosure provides rugged, cyber-secure control for its skids, and coordinates Flowpoint's pumps to ramp up and down safely, improve efficiency, and optimize its water transfers. Source: Bedrock, Flowpoint, Flow-Sync
“I like the simplicity of having as few components as possible and being able to mount them securely,” says Browne. "This simplifies skid assembly, improves reliability for portable equipment, and requires fewer spare parts. Bedrock's system was easy to configure. Its integrated development environment (IDE) software tool is free and easy to use. We couldn't have executed the complicated pump sequencing as easily or economically with any other IDE.
“We especially liked that OSA Remote's cybersecurity is built-in. Any interruptions to the data communications in our automation system could be catastrophic; if hackers gained control of the water flow, they could shut down the transfer or the fracking itself. That’s one reason we chose OSA Remote over other options,” adds Browne. “We're deploying these devices in the desert, so the fact that Bedrock is robust and temperature-rated to 176 °F (80 °C) is also important. Plus, we're transporting controls on a trailer, over pretty rough roads, and they take a beating. The first control platform I used was a custom-designed board with an inexpensive PLC, and we had vibration issues. We haven't seen any of these problems with Bedrock's system.”
Interface for big-picture interactions
To allow Flowpoint and Flow-Sync's equipment and users to interact with their automation system, Taylor and Browne report they use Ignition web-based SCADA software from Inductive Automation. The SCADA system integrates with Bedrock's controls and cloud computing from Amazon Web Services (AWS), where Amazon Elastic Compute Cloud EC2 servers host an SQL database. This Industrial Internet of Things (IIoT) architecture is scalable for processor memory and disk storage, and the OPC UA connection to OSA Remote extends its secure PLC architecture to remote locations via TCP/IP.
Browne adds that combining OSA Remote, Ignition's database and AWS cloud-computing delivers “real-time status,” which improves operator productivity by enabling them to see the entire operation and interact with it from any location. “Operators can see the big picture, which is significant when most of our work is in rural areas," he says. "If you're trying to start up multiple pumps at once, or bring things up or down in series without exceeding pressures or overfilling pit levels, this gives you real-time information to support your decisions. Or, if your tanks are getting low and you need to turn on pumps to boost the supply, you can see exactly what you need to do, and do it. This is IIoT the way it’s meant to be.”
Taylor adds: “Our unique automation platform puts the entire process in the operator’s hands. The Ignition interface is graphical and interacts easily with employees and customers. Users can start or stop pumps, monitor the health of the pump, change flow rates, regulate line pressure, or check level or pump speeds at a glance.”
Fewer leaks + less downtime = more productivity
Because finding and fixing leaks is also crucial for water transfer operations, Flow-Sync's Max software monitors its water lines, and provides continuous leak detection. Once a pump starts, it takes about 10 minutes to achieve steady-state operation, which Max anticipates. If a significant deviation is detected, the software signals OSA Remote, which can provide alarms, stop the process or part of it, or perform other preset mitigations.
“You have trucks and vehicles all over the place, bumping up against your lines as they steer to avoid puddles or other obstacles," explains Taylor. "This makes leaks inevitable, and effective detection, response and management can have a six-figure impact on operating costs. Users risk costs of lost water, downtime and repairs, and because operators often blend brackish waters, clean-up costs can also reach six figures. Plus, if a leak occurs overnight, you could flood out a road or impoundment wall in minutes.”
Once an effective leak program is in place, Browne and Taylor estimate that Flow-Sync's skid-based automation system can increase the productivity of water transfer operators by more than 50%, immediately detect problems, and further reduce downtime. Instead of the usual single operator managing a single pump, the automation system lets one operator reliably control an entire transfer operation, allowing a second operator to stay nearby as a rover.
“We're in the business of finding and selling water, so we must monitor and track inventory and expenses," adds Taylor. "Without Flow-Sync’s patented. automated data management system, if expenses came after you moved on to another project, you'd have to find paperwork, read meters manually with pictures, map it to the appropriate project, etc. “Now we generate reports in real-time every day. We're capturing all metering and flow rates in a database that we can make accessible to our customers and water suppliers. From a single screen, we can control activity on any job site, commit cost and inventory, and manage millions of gallons of water from multiple locations simultaneously.”
