The Hydro-Impact In-Situ Seismic Stimulation Tool

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An operator can install theimpact tool inside the casing of an injection, production, or abandoned well. ASR has two tools, the slimhole design for  5 1/2" casing and the standard design for wellbore casing of 7" diameter or greater.

In an injections well, injected water travels down the tubing and exits a perforated sub installed below a packer. The water then goes around the impact tool before entering the perforation, thus allowing the tool to operate while injection is ongoing. Sucker rods or corods connect the top plunger to the pumping unit. The installation has a standard stuffing box on the tubing to prevent leaks of wellbore fluids and it has a downhole amplifier for enhancing the discharged shock wave. To prevent a pumping unit from encountering or even approaching a zero load, ASR developed a dampening system and incorporated it as part of the tool. Figure 2 shows that the pumping unit bears a baseline load averaging 6,000 lb on the downstroke and the load gradually rises to 16,000 lb on top of the upstroke. Microseconds after the "firing" occurs, the unit experiences momentary drop of 3,000 lb below the baseline load as a result of rod string inertia relaxation. But this is still above the zero load that could sooner or later damage the pumping unit.

The harmonics following release of the shockwave are attributed to rod string compression-relaxation cycles.