A single-trip multilateral system, Weatherford’s OneTrip StarBurst technology creates a Technology Advancement for Multilaterals Level 4 cemented junction with fullbore liner access to the lateral bore. This represents an advancement to the conventional StarBurst system that required three trips for installation. StarBurst systems, which can be used for new development drilling and reentries, provide access to additional reserves while maintaining original wellbore production. The technology won the drilling tools category of Hart Energy’s 2009 Meritorious Awards for Engineering Innovation.

Since its introduction, the system has brought simplicity to multilateral solutions. “Since the mid-1990s, attempts have been made to create multilateral systems that provide a maximum number of combined features and options,” said Cliff Hogg, Weatherford’s global product line manager for reentry systems. However, in an attempt to create these maximum-flexibility multilateral systems, the industry ended up with solutions that were impractical for a variety of reasons.

Prior to the StarBurst system, many multilateral solutions involved excessive trip requirements. “In many high-dollar offshore environments and deep-well systems, where potential cost benefits of the multilateral should be the greatest, these increased trip requirements can severely impact the economic justification with previous trip-intensive multilateral systems,” Hogg explained.

Also, with many of the previous multilateral systems, a wide range of unique tools were required as part of the downhole junction creation process. “Special casing joints, special material compositions, etc., all led to an increase in system cost and also resulted in longer and more complicated manufacturing, shipping, and mobilization requirements,” Hogg said.

Quantitative risk assessment also came into play prior to the StarBurst system. “As additional trips and operations were being conducted, as new and unique installation processes were being required, and as more requirements were being made with regards to liner orientation and landing depths, the resulting overall risk of the multilateral installation process was increasing,” Hogg said. “This often led to a decision to proceed with a nonmultilateral solution.”

During the last decade, Weatherford has run more than 50 StarBurst systems in 7-in. and 9?-in. wellbores. According to the company, a majority of installations in 9?-in. casing are now using the OneTrip Starburst systems, which have been run in both the North Sea and China.

Since the system’s introduction, focus has been placed on ensuring its compatibility with rotary steerable systems as well as the continual rotation across the window junction resulting from these drilling systems. The perforating process also continues to be improved upon, with refinements in perforating guns and charges resulting in improved penetration capabilities. Finally, the ability to orient and point the perforating gun at the concave face while running on wireline or tubing continues to evolve and improve, making it even more practical to perforate the StarBurst concave in high-depth, high-inclination wellbore systems that might have proved problematic in the past.