The Development of a Coiled-Tubing Deployed Slow-Rotating Jet Cleaning Tool that Enhances Cleaning and Allows Jet Cutting of Tubulars

摘要

Tubular restrictions from scale buildup can significantly reducehydrocarbon production and the overall production capacity ofa well. Before production can be restored, this buildup must beremoved. Although scale buildup is a global problem, thematerial composition and characteristics of scales can varydrastically, even within the same field. Therefore, most toolstraditionally used for scale removal cannot efficiently removescale in all well conditions. This paper discusses a recentlydeveloped, customized jet cleaning tool that resolves some ofthe problems inherent with scale-cleaning operations.Traditional jet cleaning tools have not adequately controlledjet dwell time, which has severely impacted their operationalperformance. Depending on the type and hardness of thescale, many removal methods cannot control the jet dwell timerequired to accomplish scale removal. Because the required jetdwell time increases with the hardness of the buildup material,cleaning efficiency can be measured by the capability of thescale-removal method to control dwell time. A new, slowrotatingjet cleaning tool maximizes jet dwell time withoutintroducing repetitive cyclic effects on a coiled tubing (CT)workstring.The slow-rotating jet cleaning tool can also be used forcutting tubulars. Previously, tubulars could only be cut bymechanical, explosive, or chemical methods. CT was usedeither for deploying positive-displacement motors (PDM’s) forrotating mechanical cutters or to deploy pressure-activatedfiring devices that initiated the firing sequence in explosive orchemical cutters. The slow-rotating jet cleaning tool can be usedto cut tubulars when limitations exist for other cutters.This paper discusses the evolution of CT cleaning procedures,alternatives to cleaning with CT, and the design andapplication of the new slow-rotating jet cleaning tool. Casehistories discuss the use of the jet cleaning tool for removingscale and production buildup on tubing walls. The new tool canbe used for performing through-tubing cuts and can help reduceservice costs for difficult applications, such as those involvinglong bottomhole assemblies (BHA’s). The capacity of the newjet cleaning tool to control jet dwell time and pump abrasivefluids helps reduce the risks, obstacles, and costs associated withtraditional cleaning and cutting methods.