Cyclic Steam Stimulation Enhanced with Nitrogen

Abstract

The main objective of this paper is show the design, implementation and results of a nitrogen + steam pilot implemented in a Colombian heavy oil reservoir. Given that the answer to the cyclic steam injection has declined significantly in some wells of the interest field due to the high number of cycles, a pilot project to assess the feasibility of injecting nitrogen accompanied cyclic steam was raised. The determination of optimum volumes and injection scheme by numerical simulation was performed in a sector model. Eleven schemes of steam plus nitrogen injection were evaluated. In all schemes, it was tested remained constant volume of injected steam, while the volume of nitrogen varied according to the scheme (pre-injection, post-injection, co-injection or a combination of the above). In all cases, it assumed the injection of nitrogen according to real drive capacity 1200 m3/hour (1017072 ft3/day). The best case corresponds to start injecting only one day with nitrogen, followed by five days of co-injection and ending with a single nitrogen day. Under this scheme an incremental production of 5642 barrels of oil a trial period of six months, with average oil production of 53 BOPD in the same period and maximum rate of 142 BOPD. According to the simulation results, it was decided to implement the pilot steam + nitrogen injection, following the best injection scheme given above; that is, a day of pre-injection (nitrogen only), five days of co-injection (steam + nitrogen) and one day post-injection (nitrogen only). The results of the pilot show that oil production has increased compared to previous cycles, reaching similar results to the numerical simulation forecast. A methodology to implement steam injection enhanced with nitrogen is proposal in this paper, which can be applied in any field of heavy crude scheme developed under cyclic steam stimulation.

Downhole heating and hybrid cyclic steam methods: evaluating technologies from the laboratory to the field

“…Cyclic Steam Stimulation (CSS) still represents the most important tEOR method implemented in the country. However, for fields with multiple wells in advanced stages of CSS, there are significant efforts to study hybrid steam methods as an optimization strategy to extend the productivity of mature wells [5], [25], [26].…”

Combining Steam and Flue Gas as a Strategy to Support Energy Efficiency: A Comprehensive Review of the Associated Mechanisms

“…Under this scenario, the conventional use of steam for heavy crude oil recovery requires alternatives to overcome production, energy, and environmental challenges. In this sense, steam-based hybrid methods, involve the inclusion of some additive to the thermal process, such as solvents, 8,9 chemical compounds 10,11 or gases, 12 representing viable options for increasing the recovery factor, 13 optimizing energy efficiency, and mitigating environmental impact. 14 Hybrid injection of steam and gases (e.g., N 2 , CO 2 , natural gas, flue gas) as a thermal recovery process has been studied since the 1980s.…”

“…Concerning the steam injection scheme with the different gases used as additives (preinjection, co-injection, or postinjection), it varies depending on the geological, petrophysical, and fluid characteristics of each reservoir. 30 For example, for a typical field in the Middle Magdalena Valley in Colombia, the appropriate scheme for cyclic injection of steam and nitrogen was coinjection, preceded and followed by 1 day of N 2 -only injection 12 however, finding an optimal scheme is part of an integrated reservoir engineering evaluation.…”