RIASSUNTO
Abstract
PT Pertamina EP operates a large number of mature oil and gas fields across Indonesia, some of which have been producing for over 70 years. These fields are typically characterized by aging facilities, depleted reservoir pressures, extensive artificial lift, very high water cut, produced water management issues and sometimes a shortage of fuel gas supply, which creates enormous challenges for operators. In 2007 Pertamina embarked on a campaign of field reviews to try to identify to the true potential of the fields and reverse the production decline. The reviews followed Shell's ‘Producing the Limit' business process and made use of technical expertise from both Pertamina and Shell.
Each review covered the complete field or structure from reservoir to export and used a multi-discipline team of staff with an intimate knowledge of the field, paired up with external ‘Technical Challengers'. The process provided a structured and systematic approach for mapping out and analyzing a field and helped to identify the maximum production that could be achieved under ideal conditions. A portfolio of opportunities (or projects) were then developed which would allow the current production to be increased towards that limit. Every review included a field visit to validate opportunities and to gather ideas from operations staff. Asset integrity and HSE issues were also addressed, since these would ultimately impact on field performance.
By end 2009 a total of thirteen reviews had been completed, which evaluated opportunities to more than double the production from the fields and identified new exploration and appraisal prospects which could extend the field life. The implementation programme has already generated a 37% increase in production potential. In addition, 30 best practices have been shared amongst the teams, several high risk asset integrity issues have been addressed and the multi-discipline teamwork has continued as a standard way of working.
Introduction
PT Pertamina EP (PEP) was established in 2005 as the operating subsidiary of Indonesia's national oil and gas company, PT Pertamina (Persero). It explores, develops and operates primarily in land-based working areas across Indonesia. The portfolio of producing fields includes a large number of mature developments that have been passed between operators over the many years of production history. A key challenge has been to piece together a field development and production history from the many data sources that have been created over the field life. The portfolio of mature fields is gradually being replenished with newer developments emerging from the exploration programme and a campaign of acquisitions.
In 2006 PEP embarked on a Transformation Journey to become the ""Number 1 Oil and Gas Producer in Indonesia?? by 2011 and to be recognized as ""World Class?? by 2014. An integral part of this journey has been a rigourous review of the producing fields to identify and implement opportunities to reverse the production decline. In March 2007 PEP and Shell formed a joint team to conduct the reviews using Shell's ‘Producing the Limit' business process.
The Opportunity
The maturity of the fields and a shortage of historical information provides many challenges for reservoir management teams and operators. Over the field life there has been a tendancy to commingle more and more intervals in each well to maximize the production, but this has created uncertainties about the contribution and recovery from each reservoir. Most wells are now pumped, which makes access for production logging tools difficult. Locating and quantifying the remaining reserves is a key to making a step change in production performance.