Abstract
Field BM is an oilfield in off the coast of Sarawak, offshore Malaysia that has been producing for more than 50 years with much infill opportunities lying around. The recent drilling campaign in July until September 2023 has unlocked new potential breakthrough in the area. With more than 200 strings in place, drilling and completing a new well in the area is a great challenge. Navigating through the complex well design, team has taken the challenge to complete the well with cheapest cost, in short, execution optimization is required while not compromising the well productivity.
Due to the nature of targeted reservoirs having weakly consolidated sand, downhole sand control is a must and the most proven method for Field BM is the internal gravel pack. Well 42 was designed with five (5) zones High-Rate Water Pack (HRWP) in 7″ casing. Utilizing the available conductor slot/surface location, it was completed as a high angle well at maximum of 85 degrees deviation to reach all the targeted reservoirs. Having to perform 5 zones HRWP treatment, team was looking for optimization to expediate the execution in effort to reduce the well cost. Hence from the original plan of conventional stack pack technique, team selected 7″ Enhanced Single-Trip Multizone system for Well 42 with estimated reduced execution timing by 50%. The multi-zone single trip system enables single trip multi-zone perforation, single trip of workstring gravel pack operation of all five (5) zones and selectively flow each zone with the screen assembly.
Post drilling reservoir section of Well 42, some changes on the reservoir targets are required where the total reservoir section has increased, and the pumping technique also change from HRWP to Fracpack. The flexibility of the multi-zone single trip system where longer intervals with various zone lengths and higher pressure rating up to 10,000 psi provides the team with alternative option to accommodate the drilling surprises. Within the short time gap between drilling and completion, team managed to deliver the well incorporating all the changes and successfully delivered the well with the production as per target.
Fracpack method is applied in some of the zones as optimization in effort to prolong the effectiveness of the sand control post drilling as no oil-water contact observed from the open hole log. Well 42 is the first in the world 7″ multi-zone single trip system with the highest number of zones in high angle well (5 zones, well maximum inclination of 85 degrees).
