Automation in Drilling
|FIG 1: Typical remote communications network and components.|
Most of the general public is unaware that there is an automation revolution happening in the exploration and drilling segment of the Oil & Gas Industry. Like most automation endeavors, this revolution is being driven by the demand for improved efficiency, accurate reporting, and escalated safety requirements.
The fast-paced drilling taking place in current shale gas exploration and production sites requires improved process efficiency. Shale gas is a revolution in and of itself, with promises of lower energy costs and less carbon dioxide emissions than traditional hydrocarbon energy sources. Improved efficiency demands are a result of the wide geographic spread of shale plays and the need for multiple wells to drill and frack in order to tap into the gas that is trapped in the shale rock. Companies are also performing advanced analytics on their drilling operations, which allows them to predict conditions and events before they happen based on the outcomes of previous operations. Improvements in efficiencies have allowed companies to reduce drill time to two weeks for some wells, and to set drill time goals closer to 7 to 10 days for others.
The need for accurate reporting ranges from demands for corporate and industry analysis to the requirements established by government regulations. For example, the Environmental Protection Agency (EPA) is driving companies to provide accurate reporting. Missing data in these reports can result in hefty fines.
|FIG 2: Device communications with an OPC server and client.|
And finally, the Deepwater Horizon incident of 2010 has escalated safety concerns in both offshore and onshore drilling operations in which several different drilling contractors and service companies are operating simultaneously on a rig. Automation can provide the means to improve safety in these situations. According to the 2013 ARC Insights report “Wireless Strategies for Unconventional Reservoirs,” transportation to rigs is a major safety concern. In fact, the leading cause of death among rig workers happens while en route to a rig. While loss of life is obviously unfortunate, these types of incidents are very expensive as well. Companies are turning to automation as a way to reduce the amount of required traveling.
To satisfy these efficiency, reporting, and safety requirements, companies are now remotely collecting data and monitoring drilling operations 24/7. Corporate drilling centers are emerging that enable seasoned staff to keep a careful eye on each of the many concurrent operations that are going on at different sites in the field. This allows experts to ensure proper operations from a safety standpoint and to provide instant expert input when needed. These drilling centers allow them to remain “on the beach” and not have to travel to remote sites every time their experience is needed or an issue arises. Data is also continually being collected and stored to empirically develop analytical models that can be compared to the real-time scenarios of a current drilling operation.
|FIG 3: Redundant communications directly between enterprise applications and devices can overburden the devices and network.|
The importance of data collection
Communication outages can result from weather conditions or physical obstructions, like a crane swinging in the way of a transmitter. The result of an outage is less data than what is desired, often containing pockets of missing data. For industry safety and efficiency initiatives, this is unacceptable.
How OPC can help
Open Connectivity via Open Standards (OPC) is a set of communication standards for industrial automation devices, applications, and systems. The OPC Foundation (http://www.opcfoundation. org/) owns the standards and works with the Automation Industry to keep them up to date by revising existing standards and creating new standards when required. The value of OPC lies in its interoperability. OPC enables industrial control devices to communicate with applications that need to send and receive data to and from devices. An OPC server with a robust platform of device drivers and client connectivity can communicate directly with a wide variety of PLCs and other data sources in a facility, and then serve up that data via OPC. In the general automation industry, this is especially helpful because applications that need data from various sources only have to support the OPC standard as opposed to supporting all of the different native device protocols associated with the wide range of vendors. These applications are referred to as “OPC clients.”
|FIG 4: AN OPC server on each rig (acting as a data aggregator) improves data collection across the enterprise.|
Remote communications through a Wide Area Network (WAN) from the enterprise directly to an assortment of devices and data sources on a rig can be troublesome. Serial communications and retries caused by unresponsive devices can tie up the network and slow down communications.
This issue is compounded when different applications across the enterprise ask for the same data from the devices, causing redundant requests over the network. Having an OPC server located on each rig that acts as a data aggregator would help mitigate these challenges and improve data collection by the enterprise. The OPC server can communicate directly and effectively with the devices using their native protocols across the rig’s local network. Once data is collected by the server, it can be served up to all applications in the enterprise that require data in realtime. In this scenario, there are no device retries or redundant requests across the WAN—that alone can improve the data collection capabilities between an enterprise and the equipment and systems on a drilling rig.
The OPC Historical Data Access (OPC HDA) specification can further improve the remote data collection capabilities described in the previous paragraph and illustrated in Figure 4. As discussed, connections back to the enterprise can be dropped for a variety of reasons. Data would be lost during those drops if realtime OPC communications were being used. An OPC server that supports HDA can locally store the real-time data it acquires from the rig devices, and play it back to an OPC client application via OPC HDA when adequate communications are available. When communications are not available, the server will continue to store the real-time data in its datastore and will resume HDA playback where it left off once communications improve.
|FIG 5: An OPC server with a local datastore and OPC HFA support.|
Finally, access to the rich applications of an Enterprise Historian can be challenging and may be too expensive for the task at hand. An additional benefit of having an OPC HDA server located on the rig is that it allows for local operational trending analysis and troubleshooting when coupled with a light-weight OPC HDA application. The relatively low cost and reduced complexity enables engineers closest to the process to leverage historical data. On-site data visibility improves troubleshooting, reduces risk, and improves operational efficiency.
Several companies have working solutions in the field to reliably collect data. One such company is Marathon Oil Corporation, which developed a remote monitoring application called MaraDrill that collects drilling data like Rate of Penetration (ROP), Weight on Bit (WOB), Revolutions per Minute (RPM), mud flow rate, and torque at one second intervals.
This data is known as the Wellsite Information Transfer Specification (WITS) and was specifically developed to support the oil and gas drilling industry. The data is also used for post-well analysis to improve logistics and planning for subsequent wells. For example, by utilizing a local data collector and OPC HDA buffering solution on each rig in the Bakken and Eagle Ford regions where satellite communications are required, MaraDrill and other applications in the corporation can access accurate and complete data in their centralized OSI Soft PI enterprise historian. Seadrill is another example of a company that is remotely achieving reliable data collection. Their complex drill ships and ultra-deep semi-submersible rigs have many different systems and equipment on board, including dynamic positioning, vessel management, power distribution, drilling operations, and subsea systems. Each equipment manufacturer typically provides its own OPC server; however, in order to simplify networking and improve security on the rigs, Seadrill deploys an additional OPC server that acts as an aggregator. It is in constant communication with all of the OPC servers on the rig, but also provides a single connection to shore over the satellite network. This architecture provides the additional safety benefit of completely eliminating the ability to write data directly to the OPC servers on the rig, thus preventing any commands from reaching a piece of equipment that could cause unwanted events or modify reporting records.
|FIG 6: OPC HDA data collection from several rigs across an enterprise|
Increased demands for operational efficiency, reporting, and safety are driving the automation revolution in the exploration and production segment of today’s Oil & Gas Industry. To satisfy these efficiency, reporting, and safety requirements, companies are now remotely collecting data and monitoring drilling operations 24/7. Although remotely collecting this critical data has its challenges, the technology and know-how required to improve communications, prevent data loss, and put critical real-time and historical data in the hands of those who need it most is available today. This technology is based on OPC standards.
An OPC server coupled with a local datastore and OPC HDA support provides real-time data access at the drill site by moving data collection and storage closer to the data source. This gives on-site operations teams access to local data for troubleshooting production issues and optimizing highly-automated but disconnected rig sub-systems.
Incorporating the solutions presented in this whitepaper requires minimal downtime, because configuration can be accomplished without disrupting established communications. Furthermore, these solutions are cost-effective, secure, and field-proven.
Stephen Sponseller is a product manager at Kepware Technologies with a strategic business development focus on the oil and gas market. He has a BS in Mechanical Engineering from the University of Pittsburgh and a MS in Engineering from Norwich University.