Case Study of Utilizing Intelligent Coiled Tubing to Address the Extended-Reach Well Challenges
Authors: Arstianti Haleyna , Rahimov Khalid , Cahyono Agus , Wijaya Rio , Jodhitya Mohamad Ressa , Hariara Benny , Hermawan Muhammad Rofiq 
Published: March 2024

As the West Madura Offshore field is getting mature and number of the well drilled from the platform increases the need arises to improve reservoir drainage area with horizontally drilled well trajectories. PHE40-A8ST is one of the wells that was side-tracked with 5,911-ft of horizontal section as to access the Kujung gas formation (see Fig 18 & 19 for wellbore trajectory & completion schematic). As part of the cost optimization to minimize well construction cost, side-tracking activities drilled with offshore drilling rig are perforated and placed on production without the drilling rig. The well intervention operation is conducted after the drilling operation with the objectives to clean up the wellbore, add perforations, to initiate production with nitrogen lifting and, if required, to perform acid stimulation. Due to the horizontal wellbore trajectory, along with the objectives to minimize the number of runs on this relatively complex well intervention operation, Intelligent Coiled Tubing (ICT) technique was proposed. The ICT technology enables the operation to be carried out efficiently without the need to switch between slickline, wireline and CT equipment on the well. This ICT technique allowed the operator, Pertamina Hulu Energi West Madura Offshore (PHE WMO), to access the horizontal well at the target depth, performing the multiple operations and finally put the well on production in a safe, risk managed, and efficient manner.

The Intelligent Coiled Tubing Technology consists of a customized bottom hole assembly which provides real time downhole information from the various sensors. This real-time information is used to provide accurate depth correlation prior to perforation of the well, along with providing data for assisting the acid stimulation and nitrogen lift.

The selection of an ICT system was carefully considered during the planning of the well and considered the other options that were available (ie. Electric Line Tractor run for the perforation on horizontal well). Job timing and operational risks were considered between the two options, and it was decided to perform the operation using ICT system.

The decision to work on PHE40-A8 well using ICT was not made from the beginning and the conventional CT was already at the well site, working on on-going CT work campaign on another well. This change in plan lead to the mobilization of ICT conversion kit to the well site that took several days. While waiting for the conversion kit package to arrive at well-site, a cleanout run, and Memory GR-CCL run were performed using conventional coiled tubing unit. Upon arrival of ICT conversion kit on wellsite, ICT electrical wire was injected into the existing CT pipe at the wellsite and the subsequent operation on the PHE40-A8 well was performed using ICT: perforation run, nitrogen unload run, and perforation acid wash run.

The operations were performed efficiently as per plan, with the well being put on production and delivering to expectations. This paper provides the detail of the operations that were performed within well, PHE40-A8. This paper is also to record the process that can be referenced to for future development of the Kujung field.