Ultra-heavy Oil Steam Stimulation Technique To Dredge Drainage

The getting larger development scale of super heavy oil in Shuguang Oil field will make up for the shortage of resource substitution, but the characteristics of ultra-heavy oil reservoir and its special properties brought many new challenges to oil production, include high pressure steam injection and low oil to gas ratio, which are main contradictions. Therefore, according to the damage causes, types and levels to the reservoirs in the steam injection (steam soak) process, evaluations and screenings of various injection additives using on-site and development of new technology were presented, which can effectively discharge formation damage during steam injection process, dredge the effective formation pore, change the wetting ability of reservoir and improve the flow capacity of formation fluid, and it can also restore production capacity of oil well, improve steam injection quality, and increase the steam utilization rate and recovery effect of steam soak.Based on reservoir characteristics, oil properties, production in Shu 1 ultra-heavy oil block, this paper simulated the steam flooding process and field conditions with laboratory core-experiment, gave the analysis and evaluation of the formation damage degree and influencing factors. Through the experimental comparison of the on-site water block remover and cleanup additive, a new effective compound production increasing additive, which can discharge formation damage during steam injection, improve injection performance and recover reservoir energy, was accomplished. With the combination of reservoir characteristics, core simulation research and ease drainage experiments were investigated, on-site operation technology was established, and finally formed the ultra-heavy oil steam soak drainage technology which fitted Shuguang oil field. The field experiments performed on the selected representative blocks showed a significant effect.