The development of carbonate reservoirs in Shunbei Oilfield is based on acid fracturing. For the characteristics of high temperature and high pressure pure limestone reservoirs in this area, the FCES-100 flow director was used to test the acid-etched conductivity in the laboratory. The rock samples were selected from a group of reservoir limestones in the area. The experiment shows that under the same condition of acid rock contact time, the acid-etched conductivity is greater than that of cross-linked acid; the optimum acid-rock contact time for turning acid is 40 min; the turning pressure of turning acid and cross-linked acid is 40 MPa and 46 MPa, respectively. When the pressure is lower than the turning closure pressure, the conductivity of the acid?-etched fracture is greater than that of the sanding acid-etched fracture. When the pressure is higher than the turning closing pressure, the conductivity of the acid-etched fracture is smaller than that of the sanding acid-etched fracture; the long-term conductivity of acid and cross-linked acid decrease rapidly within 48 h and 72 h, respectively, and become stable after 96 h and 120 h, respectively. Studies show that in the acid pressure design, it is necessary to optimize the injection method and the amount of acid to improve the acid-etched effect.
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