RIASSUNTO
Abstract
One of the most frustrating and costly aspects of any wellbore intervention operation is when little or no progress is made during a trip in the well and tools are returned to surface showing no visible signs of performing work. Conversely but equally frustrating is when a downhole tool becomes worn or damaged beyond its useable life and the operator continues to try to make progress based on readings from traditional surface-based indicators and gauges. These situations are becoming more common as wells become deeper, more complex and technically challenging to intervene.
To address these problems, a ""smart intervention?? system has been developed that provides a new level of process control to the operator while intervention work is being carried out. The system incorporates a short, modular MWD-style sensor sub that is integrated into the bottom hole assembly (BHA). Measurements such as weight on bit, torque, RPM, bending moment, vibration, annular and bore pressures are gathered downhole to provide a clearer picture of what is occurring at and around the downhole tools. Information is then transmitted to surface using mud pulse telemetry and viewed on a rig floor monitor. The system allows the operator to make informed decisions and take immediate action to optimize the intervention being performed.
This paper discusses initial system integration and field testing, benchmarking and analysis, as well as results of, and lessons learned from, early field case histories. The tests and field runs demonstrate the potential of this systems approach to provide economic benefits through significantly improved efficiency, reduced uncertainty, better reliability and less wear and damage to downhole tools and equipment.
Introduction
In today's times of record rig rates and associated operating costs, stakeholders are placing paramount importance on the avoidance of unnecessary, unproductive trips in the well. The same applies to the broader scope of well intervention applications such as milling, cutting, washing over, and casing exit work.
As wells become deeper, more tortuous and technically challenging to intervene, the need to know more about what is actually occurring at the downhole tools becomes increasingly critical. Traditional surface-based indicators and gauges often do not reflect what forces are actually being exerted at and around the downhole tools. Integrating real-time MWD data into well interventions will lead to a step change in the industry. A new smart well intervention system has been developed around an MWD-style intervention performance sub that contains a variety of sensors, gauges, and electronics and is integrated into several well intervention bottomhole assemblies. The ability of this system to gather critical downhole measurements and transmit them to surface for viewing, both at the rig and from a remote real-time operating center, affords the operator a completely new level of control with real-time decision-making capabilities. This, in turn, can lead to more efficient and reliable well intervention and significantly reduce the customer's risk exposure.