Publications

Total loss circulation at XX field has been a major issue in North West Java mature area. The section where it occurred is rather unique and complicated. heterogeneity of reactive clay formation at the top, which is very sensitive to water and limestone at bottom which total loss happened make this well really hard to handle. For the reactive clay formation, KCL Polymer Mud should be used to decrease the swelling process. Another problem is lost circulation at limestone formation which is caused by high-permeability of the fracture, while higher Equivalent Circulating Density (ECD) may worsen it. Mud Cap Drilling (MCD) system is implemented to maintain stable hydrostatic pressure in the bottom hole and prevent wellbore instability. In this MCD process, mud is pumped concurrently from the drill string and the annulus with sufficient pumping rate. The other effect of pumping mud through the annulus is to prevent swelling of the clay above the lost circulation zone. In practice, XX well can be safely drilled through the Clay Formation and Limestone Formation to the designated target depth using a mud cap drilling system. By deploying this system,we are able to keep the well under control when passing both the reactive Clay Formation and the thief zone at Limestone Formation effectively, which, in turn reduced non-productive time and costs.