Unconventional hydrocarbons have an increasingly important role in meeting the world’s energy needs. Advancements in horizontal drilling and hydraulic fracturing have led to the commercial production of unconventional oil and gas and “the shale revolution” in North America. The industry, however, is under increasing pressure to reduce project costs and the environmental impact. This requires new technical solutions and improved technologies.
The Limitless™ Frac System (Limitless™) is a new, innovative completion system that has been developed by Advanced Upstream Ltd. The system is an alternative to plug-and-perf which is currently the most commonly used frac technique in North America. Compared to plug-and-perf, Limitless™ requires a smaller footprint, utilizes less water and fuel, and requires less field personnel and equipment contributing to a decrease in safety concerns. This allows operators to improve operational efficiency saving time and money and meet their ESG requirements.
Design and Performance
Limitless™ features a compact, intelligent, programmable dart made of magnesium alloy as shown in Figure 1. The dart is programmed and launched at surface to land in a specific sleeve. Reliable, miniature electronic onboard sensors allow the dart to track its location within the wellbore and “activate” the dart before landing on to the target sleeve. After the frac treatment, the dart dissolves leaving behind a large bore for production.
A short video of Limitless™ is provided below.
“We wanted to create a gold standard in completions and we are pleased to see how the system performs in the field,” says Tom Watkins, inventor of Limitless™ and CTO at Advanced Upstream.
Several field trials in North America are ongoing. Up-to-date data shows that the new system helps to reduce complexities, risks, costs and avoid limitations of traditional frac completion techniques. Thus, the new system eliminates the use of wireline, guns/setting tool/plugs, coiled tubing milling, and wellbore cleaning which are required in plug-and-perf operations. Darts pumped downhole to date have functioned as expected and operated target sleeves correctly, with the darts beginning to dissolve shortly after pumping operations have been completed. The system allows constant frac rates and more frac stages in long laterals. The system eliminates the constraints of coiled tubing reach and the concern about not being able to access the farthest stages at the toe of the lateral.
Limitless™ provides a wide range of benefits, in particular for extended reach wells, improves project efficiency and economics while lowering the environmental impact and HSE hazards of frac operations. Benefits of Limitless™ are (but not limited to) as follows:
- The fastest hydraulic fracturing method currently available; the method is intervention-less and leaves behind a full ID after stimulation
- Full ID and designed for cemented and open hole applications with zero limitations or restrictions
- Darts are programmable on the surface, unlimited in stage count, and can be launched to open one or several cluster sleeves
- Each sleeves porting provides single plane, and uniform entry hole diameter for less tortuosity during fracture stimulation, which results in lower frac initiation pressure by up to 25%
- Each sleeves ports are made of hardened material to prevent unwanted diametric growth during stimulation to provide equal and uniform proppant placement across each cluster
- Launch on the fly and deployment under pressure capability eliminates overflush of the formation and reduces time between frac stages to two minutes or less
- Continuous operations allow more lateral feet completed per day for the highest efficiency with greatest fluid savings offered
- Dart is made of dissolvable magnesium alloy, enabling immediate unrestricted flow back after frac
- Zero wireline, coiled tubing, or jointed pipe are required during or after fracture stimulation
- Zero cranes or related personnel are required within the redzone during fracture stimulation
The industry is thriving to be more efficient and meet increasing environmental requirements and regulations. Lower consumption of water and fuel and lower project costs is the new name of the game in hydraulic fracturing. LimitlessTM allows operators to eliminate many of the challenges of hydraulic fracturing while allowing the length of the lateral to be re-invented.