Figure 5
The map view (a) and M–t diagram (c) of the surge B seismic events occurring between April 1, 2014 and May 31, 2014. The injection wells operated during the second cycle are marked as red triangles in (a). The blue line L2 in (a) and (b) marks the position of profile shown in Fig. 7b and c. (b) The reservoir gas pressure distribution interpolated from the wellhead pressure increments relative to April 6, 2014. Current and previous earthquakes are marked as red and grey cycles, respectively. Triangles are injection wells in operation during the second injection period. (d) The pressure increments of the four representative wells. The gas injection started from the HUK17, and other wells began gas injection successively in the following 10 days. Three wells (HUK5, HUK3, and HUK14) were closely located in the western part of the reservoir but had prominent different well pressure.
