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 4.75in., the 2.375 in & 3 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.


Advantages of Coiled Tubing Drilling (CTD):



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: 2.5 in. - 3.125 in.

Hole sizes: 2.75 in. - 4.75 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:


Add drain sections to existing (mature) wells

Typically via Thru-tubing re-entry


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