New Technology: Enhanced Casing Installation field trial

At the end of 2015 and the beginning of 2016, Huisman Well Technology (HWT) deployed for the first time the Enhanced Casing Installation (ECI) system in a deep and deviated well. ECI is designed to reduce well construction costs and related risks by installing the casing while drilling. The downhole drilling equipment can be retrieved extremely fast with a heavy duty winch what results in a significant time reduction. The minimum of open hole time reduces casing and drilling running problems. Thanks to a well-positioned see-through casing joint is the drilling efficiency maintain while vibrations are reduced to ensure an optimum drilling performance. The downhole BHA contains standard components as a steerable mud and MWD equipment which are located inside the casing with a minimum of getting stuck or damaged. Therefore, the BHA can be kept very compact and light what enables it to become retrievable by cable.

The system was demonstrated in the CAL-GT-05 well in Grubbenvorst (NL) of the geothermal operator CLG B.V. The subject well targeted the hard and severely karstified ‘Kolenkalk’ formation which is known of its caverns which may prevent casing to be installed in a conventional way in directional wells. The operation consisted of reaming and drilling from 1740m MD to 1855m MD at an inclination of 42 degrees with 7” casing. The BHA was retrieved using a heavy duty slick line unit with speeds of around 1800 m/s.

The trial, made possible thanks to RVO and CLG, showed the potential of the ECI technology and allowed HWT to finalise the equipment developments and the various running procedures in a real and demanding drilling environment.

Huisman LOC-400 “Heracles” rig was rigged up over LSL-GT-01 in August and this production well was completed in October. Well was successfully drilled and completed; In particular the intermediate section was challenging, high inclination (>50 degrees) drilled with WBM and PDM BHA. The client was satisfied with the flowrates and temperatures experienced during the production test (360 m3/hr / 60 degrees Celsius). The second well LSL-GT-02 was successfully drilled and completed with even a higher well inclination (>60 degrees). Well testing results were also satisfying the client.
For this project, Well Engineering Partners was responsible for the well design and supervision during the execution of the project. The “Huisman-Züblin” joint venture was responsible for the tendering, logistics, provision and coordination of materials & services (contractors) and the execution of the project.