Oriented perforating using abrasive fluid through coiled tubing

Designed for multiple completions, abrasive perforating reduces debris obstruction and enhances safety.

Amit D. Nakhwa, Stan W. Loving and Andy Ferguson, Thru Tubing Solutions, Oklahoma City; Subhash N. Shah, University of Oklahoma

Abrasive fluids have been applied in mechanical cutting and perforating systems for years; the result is a precise cut in any size of tubular. In abrasive perforating, the entry hole created reveals no tubular deformation or flow obstructing debris. Consequently, the sand-laden fluid moves past cement, damage zone or filter cake and into virgin formation. Velocity generated through the nozzles propagates abrasive fluid into multiple reservoir layers, creating numerous pathways. Optimizing the perforation directions allows for cost-effective stimulation through conventional fracturing techniques. Therefore, as an alternative to conventional perforating, oriented abrasive perforating is applied to create channels to natural fractures.

This article discusses the development of abrasive perforating coupled with orienting technology for penetrating tubing casing, drill collars and drill pipe, all of which are deployed using coiled tubing or jointed pipe in re-completions. In addition to conventional coiled tubing tools, this system used an engineered weight bar connected to a high-velocity perforating sub.

TECHNOLOGY DEVELOPMENT

Based on operators’ evolving requirements, the need to develop a more economical perforating system arose. As wells with larger horizontal sections are completed, the inability to reach zones of interest further substantiates using coiled tubing and related tools. This technology was developed from using abrasive fluids to cut tubulars with a motor and high-velocity cutting head.¹

Currently, wells are perforated using explosives with Tubing Conveyed Perforating (TCP) and electric line. Although these systems are industry standard, challenges and limitations, such as extensive rig-ups, the presence of debris after firing and restricted ability in extended horizontal sections, do exist. While both systems have been around for years, their inability to completely orientate perforations is inherent.