Managing Downhole Parameters During Re-entry and Intervention to Improve Operational Efficiency

Abstract

As well complexity increases, re-entry and intervention operations are becoming increasingly ambitious in both their objectives and their risk profile. At the same time, intervention and service tool operating parameters downhole are traditionally controlled by making surface adjustments based on surface readings of hook load, rpm, torque, etc. A system has been developed that measures all the physical parameters downhole at the intervention tool itself, and transmits them to surface for rig site and remote viewing, enabling real time control of intervention operations. The new system has been used with fishing tools, sidetracking systems, and a variety of different service tools. The system captures and computes all the service tool operating parameters downhole, then uses a measurement-while-drilling (MWD) tool to send selected and critical parametric information to surface. Furthermore, bi-directional capability allows parameter formats to be updated throughout the job. A great deal of learning has been acquired from operating the new system, mostly in the form of parameter detection, quantification, and job management; such as: detecting delicate and ultra-light events; quantifying actual torque and drag; managing helical lock-up, untoward vibration events, and exit window trajectory and quality. In conclusion, a significant number of runs have shown that surface and remote viewing of actual operating parameters in real time has enabled improvements in operational efficiency by improved decision-making that led to reduced job times. The purpose of this paper is to demonstrate this learning through multiple case histories. A new system provides the ability to view actual downhole parameters of fishing tools, service tools, exit tools, etc. in real time, and remotely, during re-entry and intervention operations. The system is shown to have a significant impact in removing uncertainty and driving improvements in operational efficiency. Introduction A significant portion of unplanned nonproductive time (NPT) costs are incurred during wellbore intervention operations, casing exits, fishing, milling and de-completions operations. Improving operational efficiency by avoidance of unnecessary, unproductive trips in the well during wellbore interventions leads to immediate cost savings. Reserves are often stranded in deep, complex reservoirs and due to economic or environmental constraints sometimes have to be connected from a single drill site, resulting in wellbore construction methods such as extended reach drilling (ERD) and multi laterals. The drilling industry has developed sophisticated and reliable downhole technologies to operate in extremely hostile physical environments and drill these complex three-dimensional well profiles. Wellbore intervention operations in these same complex well profiles present significant challenges as well, including manipulating mechanical service tools, often at great depth. During interventions, however, sophisticated drilling systems are missing and the tool operator is solely relying on surface measurements such as RPM, hook weight and rotary torque. Traditional surface based indicators and gauges often do not reflect what forces are actually being exerted at and around the downhole tools.