Coiled Tubing Real-Time Downhole Measurements Reduce Total Exposure to HSE Risks

Abstract

Through a series of examples, this study examines how real-time bottomhole data has reduced or mitigated the risks inherent to coiled tubing (CT) applications, leading to safer job execution. A number of tasks such as rigging up, mixing fluids, pumping, and rigging down are part of conventional CT interventions. Each of these tasks has risks associated with it. With the intent of optimizing CT operations, a fiber optic system was developed to enable real-time bottomhole measurements, allowing live monitoring of interventions. By providing real-time downhole intelligence, the technology has provided the means to operate more efficiently and enhanced the service quality and reliability of the CT services. More importantly, it helps optimize or minimize the tasks associated with conventional CT interventions, reducing personnel exposure to many of the risks. By providing a real-time casing collar locator (CCL), performing an extra dummy run is no longer necessary for all depth- critical operations. Reducing the number of runs not only reduces overall operational time, it also reduces personnel exposure to hazards related to these operations. Downhole pressure and temperature sensors have provided positive confirmation of gun detonation on CT perforating applications, reducing the risk of pulling out of hole with live guns. The monitoring of real-time bottomhole pressure provides a safer way to manage pressure by either assessing and obtaining the preferred perforating balance condition or validating the operation of the choke during a cleanout to avoid gas entry and to maintain a better control of the well. In applications such as matrix stimulations, cleanouts, or even nitrogen kickoff, the system has proven beneficial and effective in optimizing treatment volumes, consequently reducing extended cleanouts and associated flow back and flaring. Finally, this study evaluates the process of making informed decisions during execution of a CT job based on real-time downhole critical parameters and their impact on overall HSE performance.