Abstract: Arrangement of well pattern in a extra-low permeability fault-block reservoir is affected by its geometry and nonlinear flow features. Taking Hua-17 block in Jiangsu oilfield as an example, different well patterns are designed in view of its different geometries, and the nonlinear flow features are considered. Then the development effect of each well pattern is evaluated using the nonlinear flow numerical simulation software. The results show that for the banding-like fault block reservoirs that two rows of vertical wells can be arranged, the optimal pattern is the one with the injection wells arranged opposite every second production well; for the small-size banding reservoirs, a horizontal production well and a vertical injection well can be arranged, and the optimal location of the vertical well is the periphery of the horizontal well's hoe; for the triangular reservoirs which can arrange a few vertical wells, the injection well should be arranged outside the production well line to achieve the optimal development effect. This research provides a new method for well pattern optimization of extra-low permeability fault block reservoirs.

Key words: extra-low permeability, fault block reservoir, well pattern optimization, nonlinear flow numerical simulation