East Java offshore has a history of whole mud losses ranging from seepage to total losses. Even though total losses while drilling carbonate zones are well known and documented, it has continued to plague drilling operation and resulted in non-productive time (NPT). Standard Lost Circulation Materials have been previously prepared and pumped when encountering total losses zones with unpredictable and less than desirable results. Therefore, a patented organic cellulose fiber blend was introduced to the fluids system to encounter the total losses zone. This specially engineered blend LCM is highly effective for sealing large fractures or highly permeable fractures without invasion causing damage to pay-zone formations. These particles creates an impermeable filter cake thus minimizing solids invasion into the formation.
Invasion tests were conducted using large pieces of crushed rock as well as 20/40 frac sand as filtration media in order to establish minimum fluid invasion into the formation. The test results were reviewed and comparison confirmed that they illustrated the field experiences exceptionally well. A significant improvement in handling total losses was shown in this East Java development well. This special LCM proved to seal the total losses zone and enabled continued drilling to section TD, casing running and cementing without problems.