Objectives
Microflux control system delivers a system that eliminates the narrow-margin drilling problems such as lost circulation, pressure ramps, and a narrow drilling window of 0.2 lb/gal with variable mud weights and formation pressure uncertainty. It also provides a more precise method to predict and control the annular pressure profile while detecting and controlling loss and gain influxes. Last but not least, it enhances overall operational safety by gaining control of downhole events.
Secure DrillingSM MPD services and the Microflux system improved operational performance during drilling operations.
Results
Using the Microflux system at the surface, the operator achieved equivalent circulating density (ECD) management by using variable mud weights, controlling the surface backpressure (SBP), and monitoring the annular flow. The system has proven the capability to accurately determine the precise drilling pressure profiles such as pore pressure and fracture gradients by recording the bottomhole pressure where an influx from the formation and fluid losses occurred and performing formation integrity and inflow tests.
In addition, the Coriolis mass flow-meter supplies valuable information and helpes distinguish between different types of well events. Using the Microflux system, the operator achieves a high- pressure/high-temperature fingerprinting, ballooning identification and quantification, and management of the mud-weight program. These portions provided confirmation of a statically underbalanced condition during connections and verified the need to increase mud weight.
Value to Client
In a well identified to be unsafe and inefficient using conventional drilling technology, the managed pressure drilling (MPD) using the MicrofluxTM system eliminated numerous drilling-related problems during operations. It also enabled the operator to acquire well information that would have been challenging to obtain using conventional technology by performing formation integrity and inflow tests.
Using the SBP, the Microflux system promoted lowering mud weights and controlling the bottomhole ECD. The lighter mud weight balanced the hydraulic condition between the pore pressures and fracture gradients, enabling the operator to drill farther. Despite the high-formation temperatures, the Microflux system performed periodic dynamic inflow testing, dynamic formation integrity testing, and dynamic leakoff testing. This testing helped determine the pore pressures and fracture gradients more accurately.
The Coriolis mass flowmeter was effective in monitoring well behavior and providing information about detecting and managing well-control situations. The flowmeter also helped with inflow testing, formation integrity testing, and leakoff testing. The resulting information helped to gain the accurate loss and gain rates, which provided the operator with the actual annular pressure profile; the cumulative effect of MPD using the Microflux system enabled the operator to enhance overall safety, making it possible to drill this well.
The operator drilled approximately 10,826 ft (3,300 m) using the Microflux system. The formation pressure across the wellbore ranged from -16.1 to -17.8lb/gal equivalent mud weight using a drilling window as narrow as 0.2 lb/gal across the -2/1 8in. section.
Location
Egypt
Formation
Not specified
Well Type
Offshore, vertical with side tracks
Rig Type
Jackup
Hole Size
• 4/1-12 × 4/3-14 in.
• 8/5-10 × 4/1-12 in.
• 2/1-8 in.
• 6 in.
Measured Depth
• 12,073 to 18,897 ft (3,680 to 5,760 m)
• 14,379 to 17,345 ft (4,383 to 5,287 m) side tracks
Products/Services
• Secure DrillingSM services
• Microflux control system
• Model 7875 rotating control device
• Coriolis mass flowmeter
By Weatherford
