Upstream oil & gas sector commonly generate oily sludge wastes. This waste can be treated with many methods according to the technical-economic assessment. Recently, co-processing technology usually being chooses in Indonesia. Therefore we need to evaluate co-processing in the legality, technique and economic aspects as the treatment option in Indonesia. The use of co-processing technology as Alternative Fuel and Raw Materials AFR) in cement industry can be implemented into 3 categories, i.e. co-processing of waste, alternative raw materials and mineral components. According to the legality assessment, co-processing comply with Ministry of Environment (MOE) requirements in utilization license because there are three cement industry licensed by MOE, minimal waste heating value 3,000-7,000 kKal/kg (above 2,500 kKal/kg or 4,500 BTU per lb) and controllable emission quality. At the technical aspect, co-processing can be execute easily, fast, practically and total solution (no slag and bottom ash) with no long term liability for the generator. Oily sludge wastes only need to be handling/packing and then transport to the Collector/Profiteer, treatment less than one month for a thousand ton of wastes and wastes actually destroyed without any residue. At the economic aspect, co-processing approximately costs about U$ 80-170 per ton. This cost is more competitive than other methods. Beside that aspects, co-processing give ecological benefits as a waste recovery and decrease the cement industry emission rate. Finally, co-processing is decent to be considered as the main option for oily sludge treatment according this study.

Introduction Oil and gas exploration and production activities are faced with major challenge these days, when they deal with HSE issues especially for environmental issues. This paper describe environmental management performance at Subang Field, PT. Pertamina EP, Indonesia based on PROPER indicators as parameters to comply government regulation Existing Condition PT Pertamina EP is a state-owned oil and gas company, engaged in managing the upstream oil and gas production through a more manageable exploration and exploitation activities, consists of 18 field that operated all over Indonesia. Based on Government's Law of Environmental Management, PT Pertamina EP has to manage all of upstream activities, including environmental aspects, especially environmental impact caused by upstream activities. Government already set up parameters to evaluate company performance of environmental management. The instrument for that purpose is PROPER. PROPER is an integrated strategy of Ministry of Environment to implement Law number 23 Year 1997 regarding Environmental Management. There are four main activities in its implementation include monitoring of company's compliance, applying transparency in environmental management or public right to know, involving public participation in environmental management and obligation of company in submitting environmental management information. PROPER consists of 5 (five) categories: Gold, Green, Blue, Red and Black. Subang Field, is one of field that operated by PT Pertamina EP, located at West Java. The average of oil production from this field is 15.000 bopd. At 2009 Subang Field achievement for PROPER is Green. It has applied successfully not only government's environment regulation but also good relationship to community around Subang Field. To achieve PROPER Green category, Field Subang has utilized and managed environmental parameters such as: Waste managemet system (water, emission, and hazardous and toxic material)Implement ISO 14001Energy conservationCommunity development. The result shows that Subang Field had committed to implement environmentally friendly for all of activities which green process give some advantages for nature resources and community.