Decarbonizing Thermal Enhanced Oil Recovery Operations Through Improvements in Saturated Steam Distribution System

Abstract

Petroleum Development Oman LLC (PDO) is Oman's premier oil producer and operates several fields at "A". "A" East and "A" West are located on the eastern flank of the South Oman Salt Basin. As "A" thermal fields contain heavy oil, PDO plans to significantly increase oil recovery by increasing steam injection, which has high energy intensity. The objective of this paper is to demonstrate that the improvement in thermal EOR operation by initiating decarbonization initiatives resulted in a significant reduction in Green House Gases (GHG) emissions. Operational comparison of steam generation unit cost to produce one tonnage of steam for different combinations found that OTSGs is the most expensive combination as it is associated with higher taxation cost (i.e. 90% of total cost is from carbon tax). OT-HRSGs with Miraah Solar combination is found one of the best to reduce the overall unit cost and maximize the production. The Miraah Solar facility was built at "A" to cater for the steam growth requirement. The adaptation of Miraah shall reduce the annual gas usage related to steam production by utilizing the sun's radiation. This facility is one of the largest solar plants of its kind in the world. It has an energy production capacity of 330 MWe of peak thermal energy and daily steam output of 1,980 tons per day. An Energy Assessment (EA) had has been conducted for top energy consumers (e.g. OT-HRSGs, OTSGs, export pumps, etc.) to identify the top high GHG emitters and feature opportunities to reduce their carbon footprint. Miraah Solar enhancement was one of the identified opportunities that will result in GHG saving more than 100,000 TCO2e/yr. In 2021, a 41% improvement is seen in terms of production and GHG reduction. In addition, the Thermal Steam Integration System (SIS) is an integrated and novel system developed to allow all steam generators to be integrated into a system that will smooth the operation and enhance the availability of the steam system/network in both on-plot and off-plot.. This will allow us to reduce GHG emissions from steam systems by 80,000 tons CO2/year by 2030, as well as reduce power consumption by more than 36% from the base case.