Lessons Learnt and Evolution of Liner While Drilling Technology from a Pilot Project in India

Abstract Objectives/Scope The Mumbai High field, India, indeed poses significant challenges for drilling and liner running operations due to the problematic heterogenous formation and unstable sub hydrostatic loss prone zones. They can contain cavities, faults, and variable rock properties, making it challenging to predict the formation's behavior accurately. The formation pressure prediction is also tough due to depleted condition. Methods, Procedures, Process Using "Liner While Drilling" technology as a pilot project to drill in troublesome formations was seen as a promising approach to address the unique challenges presented by such formations. Deploying this technology as a pilot project demonstrated the commitment to innovation and a proactive approach to address drilling problems by the operator. It was important to ensure that the technology was well-integrated into the drilling program and that the personnel involved were adequately trained to make the most of the real-time data and capabilities it offers. The success of the pilot project may inform future drilling strategies in the field and potentially lead to more efficient and cost-effective drilling practices. Results, Observations, Conclusions The liner while drilling service is a sustainable technology which combines 4.75in rotary steerable system BHA (Bottom Hole Assembly) with various logging tools, 8.75inhole opener/reamer, a mud motor, and a 7inliner with 8.5in reamer bit to help overcome the challenges while drilling in zones with low formation pressure and unstable formations. Running the liner while drilling helps maintain wellbore stability and reduces open hole exposure. It is also beneficial in reducing the time required by eliminating extra trips as the liner is installed at Target Depth in the first run. Additional runs ensure Cementing the well and then Setting of Hanger along with packer for well completion. Novel/Additive Information A multidisciplinary team used an intense Prejob planning process to examine all potential risks, including liner fatigue, LCM in the drilling mud, BHA Design and Stability, Drilling Dynamics etc. Numerous simulations and analyses of torque and drag, pressure, hydraulics, and maximum bending fatigue were conducted to identify the optimal equipment and Drilling Parameters. The paper discusses details of Liner while Drilling Technology and its evolution in India from Three Trip System to Two Trip System Benefitting the operator for superior and faster well Delivery. The paper also covers lessons learnt from the project and an evaluation of how Liner While Drilling Technology can help operator to deliver the complicated wells.