Study on the flow characteristics of tight oil reservoirs with linear injection and production for volume-fractured horizontal wells

New technology for developing horizontal well linear injection and production can reduce the spacing and establish an effective replacement system. However, the seepage mechanism needs to be studied systematically. This study considers the outcrop cores in the Ordos Basin using a high-temperature, high-pressure large-scale physical simulation system. A corresponding plate model is used to research the development of volume-fractured horizontal wells with linear injection and production in tight oil reservoirs. The effects of different injection and production spacings and fracture lengths are analyzed and discussed. The results show that the water flooding oil displacement efficiencies of 50 x 50 x 3 and 50 x 40 x 3 cm(3) models are different for the same 0.11 MPa/m injection pressure gradient. The latter model has the highest oil displacement efficiency of 32.91%, and its injection spacing is 18 cm. The injection water is first conducted symmetrically and uniformly along the two injection fractures to the single production fracture direction and advanced uniformly. The pressures at the two ends of the injection fracture are V-shaped and symmetrically distributed relative to the production fracture location. A longer fracture length corresponds to a higher oil displacement efficiency in the models with 36, 41, and 46 cm fracture lengths and the oil and water flow linearly. The seepage distance is smaller than the row distance of conventional well network injection and production wells, so the seepage resistance is significantly reduced, effectively increasing the oil-repelling range. The oil-repelling efficiency is at least 8% higher than the depletion development, demonstrating considerable application potential.