Large-Scale Energy Storage Volumetric Fracturing Technology for Horizontal Wells in the An 83 Shale Oil Reservoir

Early single-well stimulation attempts in the An83 shale oil reservoir failed to achieve the desired results due to its tight formation and poor energy replenishing effect. According to the previous attempts at energy storage by water injection and refracturing experiments, formation energy was replenished through water injection and the fracturing tools were upgraded. On this basis, extreme clustered perforation, differential reservoir stimulation and multistage dynamic temporary plugging were studied to improve the complexity of fractures, and the well shut-in time was optimized. Finally, the large-scale energy storage volumetric fracturing technology was formed. Field testing results showed that the production of horizontal wells was significantly increased by using the new technology, and the daily oil production of a single test well achieved up to 7 times that of adjacent wells. After 10 months of production, the cumulative oil increment of a single well reached 2 010 tons, with good economic benefits. The technology can replenish the energy of reservoir and effectively stimulate the reservoir, providing a reference for the development of other similar reservoirs.