Abstract
Tangguh Integrated Drilling Project (TIDP) is being rolled out by BP Indonesia as part of long term development plan for Tangguh project in Bintuni Bay, Papua Barat Province. The offshore drilling campaign consists of several development, exploration, and appraisal wells throughout the bay. The complex scope of work for TIDP and regulatory requirement require a systematic holistic approach to come up with appropriate drilling fluids and cuttings waste management strategy.
A multidisciplinary team consists of: Wells Engineering, Operations, Health Safety and Environment, New Wells Delivery, Regulatory Compliance & Environment, Communications & External Affair, Permits, and Central fluids were established to discuss the strategy. Best Practicable Environmental Option (BPEO) tool was decided to be used. The assessment model incorporates weightings for criteria which enables more important criteria to be emphasized and also enables sensitivity checking. BPEO process flow are as follows: define objectives, decision criteria and scoring matrices, weight the decision criteria, identify all possible options, pre-screening, full assessment, review and rank options, and finally identify the BPEO.
The study concludes that for cost effectiveness, practical application, efficiency, HS&E risk mitigation, and reduced (if not elimination of) long term liability, the waste processing and disposal should take place at the rig site. The study further concludes that there is no single best option for all drilling locations due to different constraints. Therefore, the recommendation is to have the combined option of Drilling Cuttings Re-Injection (DCRI) and overboard discharge that can be utilized across all locations in Tangguh. With this study, the team is not only eliminating the environmental and safety risk inherent in offshore drilling, handling and transportation of large amount of drilling cuttings and fluids waste, but it also save costs on constructing several dedicated DCRI wells and reduced 200 drilling days from the jack up rig scope. Another impact is that it reduces the carbon footprint and greenhouse gases coming from the drilling and its supporting activities such as vessel utilization.
The result from this BPEO can support management, engineers, and operations team in the decision-making process to determine the most suitable option among several scenarios or any other complex project. It could also provide a sound justification to the regulators to expedite the permitting process.
