This paper presents the prejob engineering process and executional summary of the first North Sea application of a novel tubing-conveyed fracturing technique. The logistical challenges that were overcome during the completion of the project will also be discussed. This fracturing technique was implemented successfully to perform a large multistage acid treatment from a semisubmersible rig. Historically, wells in this field have been treated using dedicated stimulation vessels. Acid-fracture treatments have typically been pumped at high rates (50+ bbl/min), treating multiple intervals simultaneously using various methods for fluid diversion, including ball-sealer technology and limited-entry perforating, to ensure every target zone is contacted and adequately stimulated (Alastair et al. 1999). At present, the demand for stimulation vessels is extremely high because of the level of new well-development and general stimulation activity in the North Sea sector. This demand, coupled with a reduction in the number of available stimulation vessels operating in the area, led to the requirement for an alternative method of completing this well.
The overall success of this project demonstrates that there is a viable commercial and technical alternative to the traditional stimulation methodology associated with wells of this type. With further development to improve efficiency, these methods could become competitive with conventional vessel-based techniques.