Publications

Implementation of Underbalanced Drilling (UBD) technique to address drilling challenges has been proven to minimize reservoir damage issue, assists reservoir characterization and identify productive zone of hydrocarbon. However, there’s always concern on how to maintain the underbalanced condition whenever tripping operation is being performed while drilling and completion. Several options such as tripping in live well, killing the well using kill mud, overcome the formation pressure using snubbing unit, or isolate the well using a tool designed specifically for this purpose. All these options have direct implications to the operational safety, drilling objective and overall project costs. The Downhole Isolation Valve (DIV) has been installed in many underbalanced drilling operations and proved assisting drilling operation to isolate the well, eliminating the requirement of snubbing unit which may have safety implication and avoids pumping kill mud which may induce reservoir damage issue, the contrary of UBD application. The DIV provides capabilities to isolate the well at certain pre-calculated depth to overcome pipe light situation. Tripping operation was improved significantly in terms of time and cost efficiency without compromising safety in live well of UBD operation. Onshore field on the border line of West Java Indonesia was drilled using underbalanced drilling technique in a low formation pressure environment. The drilling objective was to verify the estimated remaining reserve from deeper layer volcanic formation as the benchmark for decision making for further field development stage. This paper will elaborate the successful of DIV utilization in UBD operation during installation and tripping, procedures, and overall drilling performance.