Abstract
Achieving effective fluid coverage of stimulation operations in deepwater frac-pack completions is often challenging due to a variety of factors, including, but not limited to, the length of screened intervals, the uncertainty of damage mechanisms, and the ability of diversion materials/fluids to divert beyond the screens and into the formation. This case study demonstrates a successful technique used in conditions not previously attempted.
This treatment in a deepwater, frac-packed well with fiber-optic-equipped coiled tubing (CT) and a rotating, hydraulic high-pressure jetting tool achieved the successful stimulation of a 500-ft-long frac-packed zone after several previous failures using different techniques. By using a CT equipped with fiber optics and downhole measurement tools, engineers were able to perform a data-driven operation based on real-time bottomhole measurements and distributed temperature surveys.
This successful treatment improved productivity by 75% compared to the well before treatment. Typically, treatments of this nature are investigated and techniques for a field or region are refined over the course of multiple stimulation operations of large numbers of similar wells in the area. However, in deep water, most fields have only a very small number of wells. The costs associated with gaining wellbore access to conduct an acid treatment and with handling produced stimulation fluids are very large compared with costs in other geographic areas. Each individual well has a high productivity, and improper stimulation is an enormously costly lost opportunity for the operator. This makes it very important to ensure that every job is performed as optimally as possible, without resort to iterative or empirical methods. This method increases the opportunity to produce a successful treatment the first time and expands the technical envelope of application. These enhancements should allow other operations of this type to be conducted that previously would have been too high risk to consider.
This was a high-pressure application compared to previous operations. It was one of the longest fiber optic cables injected into a CT reel. Modifications were made to the CT reel to support the expanded weight. A stronger type of fiber optic carrier had to be utilized. A customized testing and validation procedure had to be used to extend the operating envelope of the fiber-optic-enabled downhole tools to perform reliably.
