Treatment well tiltmeter system

An apparatus, comprising:

• an active treatment well comprising a bore hole extending from a surface into a strata;
• a casing located within the bore hole, the casing having an exterior surface and an interior surface, which interior surface is defined by a hollow bore;
• a movable fluid located within the bore hole;
• and
• a tiltmeter array located within the bore hole, the tiltmeter array comprising at least one tiltmeter assembly, each of the at least one tiltmeter assembly comprising at least one tiltmeter sensor for measuring the effect of the movable fluid on the strata.

A process, comprising:

• providing an active treatment well comprising a bore hole extending from a surface into subsurface strata;
• installing a tiltmeter array within the bore hole, the tiltmeter array comprising at least one tiltmeter assembly, each of the at least one tiltmeter assembly comprising at least one tiltmeter sensor;
• flowing a fluid through the bore hole;
• and
• using the tiltmeter array to measure the effect on the subsurface strata caused by the flow of the fluid.