About Coiled Tubing Drilling (CTD)

The Coiled Tubing Drilling (CTD) is a technology to improve efficiency and increase the production of old oil wells with low equipment and drilling cost. To cover hole sizes from 2.75 in. up to 5.5 in., the 2.25 in. & 3.125 in. tool has been developed. The modular nature of the system provides flexibility in configuration, allowing the level of service to be tailored at the rigsite for CTD operations in standard and thru-tubing re-entry slim hole applications to meet customer service needs. This also includes casing exit operations like whipstock setting or window milling.
Utilizing wireline real-time system control and e-line high speed data transmission, or mud pulse data transmission, operations can be performed efficiently in under-balanced and over-balanced applications using any type of drilling fluid including aerated drilling fluid, foam or gas.
The system’s set-up options consider issues of pass-thru restrictions in thru-tubing re-entry operations and are able to cover high build up rate needs as well as extended reach applications and geo-steering requirements.
CTD BHA:

Advantages of Coiled Tubing Drilling (CTD):
Tripping:
Fast
Less connections
Real-time Communication uphole & downhole (Wireline Type):
Via e-line updates fast
Full real-time control
Constant Circulation:
Stable down hole pressure
Reduced swab and surge effects
Reduced potential of getting stuck
Easier Underbalanced & MPD operation:
Simplified use of multiphase/ compressible fluid
Limited formation damage
Safer pressure deployment into live wells:
Proven equipment & procedures
Snubbing capability of CT
Limitations of Coiled Tubing Drilling:
Coil diameter & length:
Limited pull & push force, cycle times,
Length of lateral section
Limited mud hydraulics
Less reliable standard depth measurement
System / Hole size:
Tool sizes: 2.25 in. - 3.125 in.
Hole sizes: 2.75 in. - 5.5 in.
Operating/ Drilling Mode:
Sliding mode only
Special training requirements for personnel
Offshore operations:
Equipment can exceed lifting capacity
Rig modifications may be required
Coiled Tubing Limitation Improvements:
Latest high-end CT Technology allows:
Depth Correlation
Real-time drilling dynamics control
Real-time ECD management
Extended Lateral Reach
Main CTD Applications:
Objective:
Add drain sections to existing (mature) wells
Typically via Thru-tubing re-entry
Challenges:
Depleted Reservoirs & Low ECD But Stable Formations
Small Hole Sizes
Main Activities:
Casing Exit
High Build Rate landing section
Horizontal Reservoir section-Geo steered
Slotted liner or barefoot completions
Base Functions:
Modular BHA setup
Selectable steering control
Aligned down hole sensors and geo-steering capability
LWD Service:
Geo-Steering Service
Electronic magnetic Resistivity Service
Gamma Ray Service