Synchronous injection-production energy replenishment for a horizontal well in an ultra-low permeability sandstone reservoir: A case study of Changqing oilfield in Ordos Basin, NW China

WANG Jing,LIU Jungang,LI Zhaoguo,LI Hongchang,ZHANG Jiaosheng,LI Wenqing,ZHANG Yuanli,PING Yi,YANG Huanying,WANG Ping

Table 4 Formation breakdown pressure and inflection point pressure of Well MP93 (well depth 2370 m).

Artificial fracture No. Formation breakdown pressure/MPa Converted formation breakdown pressure range/MPa Converted wellhead water injection pressure/MPa Inflection point pressure on water absorption curve/MPa ① 44.8 33.6-40.3 9.90-16.62 10.5 ② 49.1 36.8-44.2 13.12-20.49 ③ 50.0 37.5-45.0 13.80-21.30 ④ 49.7 37.3-44.7 13.57-21.03 ⑤ 52.9 39.7-47.6 15.97-23.91 ⑥ 45.5 34.1-41.0 10.42-17.25 ⑦ 45.5 34.1-41.0 10.42-17.25 ⑧ 34.9 26.2-31.4 2.47-7.71 ⑨ 51.8 38.9-46.6 15.15-22.92 ⑩ 35.0 26.3-31.5 2.55-7.80 ? 43.9 32.9-39.5 9.22-15.81 ? 52.2 39.2-47.0 15.45-23.28