Figure 3.
Panel a plots elapsed time from about 2980 to 3280 days. The left vertical axis gives S T P flow rate in cubic metres per second and the right vertical axis gives gas pressure in kilopascal. Flow into the system varies through repeated injection periods, while flow into the buffer fluctuates around lower values before increasing sharply near Event 8 and Event 9, then decreases. Gas pressure increases from about 1800 kilopascal to more than 6200 kilopascal by Event 9, then decreases gradually to about 5900 kilopascal. Predicted pressure closely follows the gas pressure trend. Dashed vertical lines mark Events 1 to 13. Panel b plots pore pressure against elapsed time from about 3200 to 3237 days. U R 905 increases from about 42 kilopascal to 60 kilopascal. U R 908 increases from about 35 kilopascal to 45 kilopascal, then decreases to about 40 kilopascal. U R 916 decreases from about 32 kilopascal to 26 kilopascal. U R 919 decreases from about 22 kilopascal to about 3 kilopascal. Dashed vertical lines mark Events 8, 9, 10, and 11. Panel c plots radial stress against elapsed time over the same period. P R 905 increases from about 35 kilopascal to about 49 kilopascal near Event 9, then decreases to about 36 kilopascal. P R 907 increases from about 25 kilopascal to 36 kilopascal, then decreases to about 19 kilopascal. P R 908 increases from about 21 kilopascal to 29 kilopascal, then decreases to about 13 kilopascal. P R 909 decreases from about 18 kilopascal to about 8 kilopascal. Dashed vertical lines mark Events 8, 9, 10, and 11.Gas Test 4. (a) Flow of gas into the system and the buffer; (b) pore pressure response at the deposition wall around the time of peak gas pressure; (c) radial stress on the deposition wall around the time of peak gas pressure. Note: For display purposes in (b) and (c) each sensor has undergone translation along the y-axis