Breaking Low Permeability Fracturing Myth – VICO Indonesia

VICO Indonesia is the operator of the Sanga-Sanga Production Sharing Contract; located onshore of the Mahakam delta, in East Kalimantan, Indonesia. Since inception the PSC has produced over 70% of the estimated original gas in place. The fields are relatively mature with most of the remaining gas resources locked up within the lower permeability reservoirs, where conventional tight-gas completion approaches have not been very effective in ensuring depletion of the resource. A valuable prize of at least 0.5 TCF would be readily achievable, if these lower permeability resources could successfully be developed and recovered.

The lower permeability formations being referred to; are typically sub milli-darcy, and the ability to achieve any kind of sustainable economic production rate has been extremely problematic. Previous attempts at hydraulic fracturing within VICO, over nearly three decades, have been dramatically ineffective and have rarely enjoyed any sustained production improvement at all. Geologically the reservoirs are best described as distributary river channels, in a lower deltaic plain environment and therefore these individual sands can vary in size and connectivity quite substantially. Alternative technologies, such as horizontal drilling are being applied, but only within those sand bodies which are larger and which can therefore readily support the economics associated with horizontal well drilling.

In 2006 a detailed technical review of the previous 30 Years of hydraulic fracturing operations was commissioned, this review noted that there were five basic ‘skins’, which were causing problems for hydraulic fracturing. These ‘skins’ were: wellbore integrity, execution QA/QC, relative-permeability, regional tectonics and poro-elasticity. The data was extremely convincing and based upon the review a decision was made to implement a five well pilot in order to confirm the findings and present solutions.

This paper will describe the long and difficult journey of VICO hydraulic fracturing, from the original treatments through the recent review, the fracturing pilot from 2007 - 2009 and into the early stages of the new fracturing campaign planned for 2010 - 2012, The paper will present the results of the detailed study, the implementation phase of the pilot and the forward plan for the VICO low permeability zone(s) based upon the significant progress, successes and deliverables of the fracturing pilot in the Nilam G-Sands.