Unit developed a unique fleet of AC-powered 1,500-hp land drilling rigs. Unlike some land rigs that require four diesel gensets to power the rig loads, these rigs are outfitted with a unique equipment package that enables competitive drilling campaigns using only three gensets. Unit engages the gensets in a continuous running mode to maintain power for critical operations, only stopping a genset when there is a prolonged period of low power demand. This ensures high availability of the rig’s power supply but requires a longer genset run time.
The challenge is that the internal fuel combustion process of a genset is the dominant contributor to drilling rig emissions. Running gensets longer also increases the fuel spend of the drilling authorization for expenditures (AFE) and accelerates the genset’s hours-based maintenance burden. The conventional method to address these side effects is for the rig crew to manually perform power management. However, manually stopping and starting the power generation can become inconsistent, delayed, or neglected.
The objective of this operation was to automate the power management of the gensets on Unit’s rig. The two main goals were to maintain a high availability of rig power for reliable well construction and to increase the efficiency of the electrical energy delivered.
For this application, SLB recommended Intelligent Power Management that pairs a proprietary controller with a rapid-response battery energy storage system (BESS) to automate power management more safely and efficiently.
Installation of Intelligent Power Management did not require unplanned downtime. The BESS was conveniently connected into the rig power grid, and the rig’s generator controls were swiftly configured to receive the intelligent software commands. All rig power data was streamed into the IPM controller where it could be monitored locally and via remote connectivity. An intuitive user interface screen provided the rig crew with an easy-to-follow visual display of power flow between the gensets, BESS, and rig load demand as well as critical system information.
SLB teamed with Unit to introduce this new technology into the rig operations: demonstrating how the IPM controller directs all power sources to proactively meet demand, harnessing the BESS to discharge stored energy during transient states, and facilitating the minimum quantity of gensets to run at their optimal load without requiring them to quickly ramp up and down. Once the rig crew was familiar with the technology and safety protocol, they welcomed SLB to activate the automated functionality. Intelligent Power Management was given autonomy to orchestrate power delivery 24/7, freeing the rig crew to focus on well construction activities.
Intelligent Power Management was immediately effective when switched to automatic control on the 40-day drilling pad operation, only requiring one genset for flat time operations and using just two gensets to drill ahead. The remaining third genset was finally started when drilling deep in the production hole at the highest pumping pressures. During all conditions, the IPM controller used the BESS to extend the time before activating another genset as well as instantaneously absorb power spikes any time the drawworks lifted off-bottom.
The significant rightsizing of energy delivery via automation is illustrated in the genset utilization comparison with the rig’s conventional method of manual power management. The software expertly managed the genset usage and delivered high availability of rig power while the BESS kept the rig from reaching power-limiting conditions.
Additionally, the IPM controller evenly spread the run time across the gensets to match the rig maintenance plan, and the continued use of this technology on this rig could be equivalent to delaying the genset hours-based maintenance by a year. Simultaneously, Intelligent Power Management improves the reliability with BESS assistance by mitigating genset overuse and providing resilient power.
Well construction demands a large amount of electricity. Yet, inefficient genset utilization has the negative consequence of massive fuel waste. By managing the power demand with fewer gensets, the rig saves tremendously in fuel consumption and to hedge against uncertain fuel price futures.
To gauge the Intelligent Power Management performance, SLB calculated Unit's rig baseline by feeding a year of historical power data into a machine learning tool that was refined with field test measurements to derive an accurate fuel model. Similar to an automobile, gensets are most economical with reduced idling and less acceleration. With the IPM technologies installed, the unnecessary gensets are shut down—not idled—and the essential genset(s) are able to run with greater fuel economy, like an automobile’s cruise control with the BESS handling the power fluctuation for the gensets.
A key metric for measuring the effectiveness of energy delivery is to examine the conversion of genset fuel consumption to the electrical power produced. To visualize this, the IPM controller monitored the genset efficiency in kW.h/galUS. Graphing the efficiency across the daily average of total energy delivered reveals improvement from the rig’s base efficiency.
With Intelligent Power Management, Unit increased genset efficiency by 28% and saved 17,836 galUS of fuel—an average of 446 galUS/d. This improvement eliminated 216 metric tons of the associated CO2e emissions while supplying balanced power and working toward a more balanced planet.
