Laboratory Tests with CO2, N2 and Lean Natural Gas in a Naturally Fractured Gas-Condesate Reservoir under HP/HT Conditions

Abstract

The study of gas-condensate reservoirs has been a fruitful field of research in the last years because of their peculiar behaviour. Gas cycling is the recovery process of choice for gas-condensate reservoirs but this process can often not be implemented because of economic reasons. Nitrogen is a potential alternative injection gas. Nevertheless, this has also disadvantages. The application of these processes is more complex in the offshore sites. This paper describes laboratory studies performed to evaluate the effectiveness of some gases (CO2, N2, lean natural gas) in displacing condensate from naturally fractured gas-condensate reservoirs (offshore field). Numerous hurdles had to be overcome. The experiments represented the behavior of a reservoir under HP/HT conditions, 334 °F and 8455 psia. The results of CO2 and natural depletion showed little difference in their ability to recover condensate. The natural gas raised the recovery of the light fraction, but, by contrary, the addition of N2 made evident to be less effective than the rest. The residual saturations and condensate recovery were measured and the results are presented. The detailed analyses revealed that natural gas seems to have been more effective in recovering condensate. Under these conditions, condensate recovery will significantly increase if the lean natural gas is injected. The answers are in agreement with the simulation model. The conclusions are relevant to the overall management of gas-condensate reservoir. These experiments will serve as a guideline to develop the long term corporate strategy to improve additional recoveries in Mexico.

Enhanced Gas and Condensate Recovery: Review of Published Pilot and Commercial Projects

“…The requirements towards the reduction of CO 2 emissions and general environmental impact enforced by the Kyoto Protocol (UNFCCC, 1998) and the Paris Agreement (UNFCCC, 2015) made carbon dioxide a favourable agent for pressure maintenance and geological storage. In the USA, CO 2 is widely used for EOR, but its application for enhanced condensate recovery is still a subject of scientific research (Al-Hashami et al, 2005;Shtepani et al, 2006;Gachuz-Muro et al, 2011;Soroush et al, 2012;Narinesingh and Alexander, 2016). Gachuz-Muro et al (2011) performed high-pressure/hightemperature condensate displacement laboratory experiments in naturally fractured reservoirs.…”

“…In the USA, CO 2 is widely used for EOR, but its application for enhanced condensate recovery is still a subject of scientific research (Al-Hashami et al, 2005;Shtepani et al, 2006;Gachuz-Muro et al, 2011;Soroush et al, 2012;Narinesingh and Alexander, 2016). Gachuz-Muro et al (2011) performed high-pressure/hightemperature condensate displacement laboratory experiments in naturally fractured reservoirs. CO 2 injection made minimum difference to depletion, while natural gas injection showed the highest condensate recovery.…”

Potential Application of CO2 for Enhanced Condensate Recovery Combined with Geological Storage in the Depleted Gas-Condensate Reservoirs

“…Use of the CO2 to increase condensate production was studied before. Gachuz-Muro et al [6] performed laboratory experiments for condensate displacement in naturally fractured reservoirs at high pressures and high temperatures. According to their results, injection of CO2 showed little difference to natural depletion and natural gas injection is a preferred agent resulting in maximum condensate recovery.…”

Mitigation of the Effects of Condensate Banking: A Critical Review

“…The main source of CO 2 is the different manufacturing processes that result in the emission of CO 2 as a byproduct (Gale et al 2005). The majority of CO 2 is produced mainly from the industries that involve the use of different fossil fuels (Lucci et al 2011).…”