Research and Application of Fracturing Huff and Puff Technology in Low Permeability Reservoirs

Abstract

Abstract As low-permeability reservoirs are being developed, the formation pressure and production gradually decrease, and the effectiveness of using conventional huff and puff techniques to improve single well production is deteriorating year by year. To address this issue, this article proposes a fracturing based huff and puff technology. Fracturing huff and puff technology is mainly divided into three stages. The first stage is energy storage, in which low displacement water is injected to supplement formation energy, the second stage is oil washing, in which high displacement water is injected into nano micro lotion to improve formation oil washing efficiency, and the third stage is capacity expansion, in which high displacement water is injected to replace nano micro lotion to expand oil washing coverage. Fracturing huff and puff technology was implemented in 10 wells in the low-permeability reservoir, resulting in an average cumulative increase of 203.65 tons of oil. Taking the typical well M130-4-8 as an example, firstly, during the energy storage stage, the injection rate is optimized to 2m3/min and the liquid volume is 1000m3 through reservoir conditions and numerical simulation. Secondly, in the oil washing stage, through indoor performance evaluation and numerical simulation optimization, 1700m3 nano-microemulsion with oil washing efficiency > 40% and solution particle size <15 nm was injected with a displacement of 3 m3/min. Finally, during the capacity expansion stage, numerical simulation was used to optimize the injection rate of 3m3/min and liquid volume of 600m3. The use of fracturing huff and puff technology for energy storage, oil washing and capacity expansion has significantly increased the production capacity of a single well, effectively supporting the development practice of fracturing huff and puff technology in low-permeability old area reservoirs. The next step is to expand its application in low-permeability old area reservoirs.