Seismic monitoring of disposal wells

A fluid disposal method, said method comprising the following steps:

• a) monitoring seismic activity in a reservoir throughout said method;
• b) injecting a fluid to be disposed of into a first controllable injection point in a first disposal well in said reservoir;
• c) continuing said injecting step until a seismic event of a predetermined value is detected;
• d) closing said first injection point;
• e) switching to injecting said fluid into a second controllable injection point at least 100 meters from said first injection point, said second controllable injection point in said first disposal well or in a second disposal well;
• and
• f) wherein said method has less seismic risk than a disposal method performed without said seismic monitoring, closing and switching steps.

A fluid disposal method, said method comprising the following steps in order:

• a) monitoring seismic activity in a reservoir throughout said method;
• b) injecting a fluid to be disposed of into a first controllable injection point in a first disposal well in said reservoir;
• c) continuing said injecting step until a seismic event of a predetermined value is detected;
• d) closing said first injection point and switching to injecting said fluid into a second controllable injection point at least 100 meters from said first injection point, said second controllable injection point in said first disposal well or in a second disposal well;
• e) repeating steps c-d) with one or more additional controllable injection point(s);
• f) wherein any closed controllable injection point may be reopened for injection after said seismic event at said closed controllable injection point has dissipated;
• g) wherein said first controllable injection point and said second controllable injection point are in a horizontal disposal well and each controllable injection point is fitted with a multi-open-and-close hydraulic fracturing sleeve (MOC frac sleeve) and wherein a seismic detector is positioned over each MOC frac sleeve;
• and
• h) wherein said method has less seismic risk than a disposal method performed without said seismic monitoring, closing and switching steps.