After completing the drilling phase of the 8½″ section for a well in a giant mature field offshore Abu Dhabi, due to geomechanical challenges it was not possible to run the 7″ liner in a shale formation which was open for a long period of time due to rig repairs (top drive failure in open hole), exposing all reservoirs and compromising the field development strategy. After several unsuccessful attempts to run the liner and leaving a drilling BHA in the hole during one of the cleanout runs, it was decided to sidetrack around the fish to intersect the original 8½″ open hole section in order to recover the original hole and isolate the reservoir flow units from each other, which was critical for the field development since more than five reservoir layers were opened with water and oil bearings increasing the risk of damaging the reservoir integrity due to potential cross flow. Detailed measurement-while-drilling (MWD) survey analysis was conducted for the original hole in order to enhance surveys accuracy and minimize positional uncertainty. Typical survey management practices were implemented for Sag and Drilling String Interference; other techniques such as Dual Inclination, In-Field Referencing, and Multi Station Analysis were also applied. The implementation of these different survey management practices and their respective results are covered in detailed in the current article. Comprehensive planning was carried out, the sidetrack was accomplished and the original hole was successfully intersected at the first attempt. The advanced applied survey management techniques were crucial, particularly in the absence of magnetic ranging as the interval to intersect was open hole. The outcome of these corrections resulted in a shift of 8ft to the final well position, ensuring the correct direction and position for a successful attempt to intersect the well. This intersection was particularly challenging as the original hole had a 3D profile, thus it was critical to minimize both vertical and azimuthal uncertainties. Intersection was achieved with an RSS BHA, and the success of this intersection without magnetic ranging capability was only based on following a planned well trajectory that intersected the original hole surveys, clear validation of the accuracy of the surveys for both original and sidetrack holes. Achieving this challenging directional drilling goal allowed the completion of the well as per original plan, which was critical for the field development plan of these reservoirs. Based on the fact that there is very limited existing literature covering similar cases to the one presented, this current case represents a solid successful reference to be replicated in similar cases in the future covering these challenging applications of advanced survey management techniques.

Stuck pipe is one of the biggest challenges in the drilling sector and is a multi-billion-dollar issue. Recovering from stuck pipe absorbs significant cost and time. Durations for stuck pipe events and recovery can be mostly variable from a few days to up to over a month to resolve. When attempts to release the stuck pipe by jarring or acid fail, the operating company and drilling contractors are left with little option but to sever the drill string and prepare for side-track operations or even abandon the hole. Traditional pipe severance methods in the event of a stuck pipe situation typically take significant time (often days, and sometimes weeks), require specialist tools, Service Hands, and are usually reliant on wireline services to deliver the severance method. In 2018, a Major Operating Company in UAE faced a challenging high-sticking Formation, which caused massive NPT, stuck of drill strings, and loss of drilled section holes. Brainstorming within the Drilling Engineering team took the campaign to the next level of pre-planning to reach deep access in the hole to be able to achieve zonal isolation by spotting cement plugs through drilling BHA, find a solution to save the hole and recover the pipes in an efficient, cheap and productive manner. An environmentally safe pre-planned solution to severe the drill string was proposed to help save the wells and allow an excellent methodology to save the wells/fields from stuck pipe risks. The engineering solution allows a fast recovery of drill pipes using a downhole tool as a part of drilling BHA, with the option to activate it if required, by dropping a smart dart and circulating with mud for a specific time to apply cut string with two option, either spotting cement with recovered BHA or lift BHA with fish neck to try to fish in the hole.