Abstract: The pulse-tool is used when injecting liquid into a borehole in the ground. When a pulse-valve of the tool opens, liquid passes through from an accumulator to the ground formation, whereby the accumulator pressure falls and the formation pressure rises. When the pulse-valve closes, the accumulator pressure rises and the formation pressure falls. The pulse-valve is driven to open when the pressure differential (PDAF) reaches a high-threshold, at which the PDAF overcomes a biasing force acting to hold the pulse-valve closed. The biasing force is provided by a pair of magnets, in attraction mode. When the PDAF reaches its high-threshold, and the magnets separate, the magnetic attraction force decreases rapidly. This characteristic helps the pulse-valve to open very rapidly, e.g explosively, creating an energetic penetrative shock-wave out into the formation.

Abstract: For pulsed injection of liquids into the ground, the tool has a rotating cylinder, having through-slots. The tool has an insert, which is pressed against the rotating cylinder. As the cylinder rotates, the slots in the rotor cover/uncover the slots in the insert, creating the required pulses. By suitably shaping the slots, the pulses can have a fast rise-time from closed to open. The insert is shaped to minimize flow interference.

Abstract: When injecting liquids into the ground, imposing pulses on the injected liquid is effective to increase penetration and saturation of the ground. Imposing suckback onto the pulses is effective to make the liquid in the ground behave as a coherent unitary body, surging out and back each pulse, and to super-saturate the ground. The tool includes a suckback-chamber, which is timed to open to the ground formation just as the pulse-valve closes. A biasser (e.g a spring) drives the chamber open and sucks in some of the liquid from the ground. The chamber is then emptied, back to the ground, by the rising pressure as the pulsing tool is recharged. The suckback-chamber can be added to any type of pulsing tool.

Abstract: For injecting e.g. water into ground formation around a borehole, and for superimposing pulses onto the outflow of the injected water, it is important that the pulses have a rapid rise-time. A piston is connected to a pulse-valve of the tool. A bias spring urges the piston towards its closed position. The piston is urged towards the open position by a differential PDAF between the supplied accumulator-pressure and the in-ground formation-pressure. When the pulse-valve is open, the PDAF is falling, until the force of the spring closes the pulse-valve. Then the PDAF rises, but now the PDAF acts over only a small area of the piston. When the PDAF is high enough to ease the pulse-valve open, suddenly the whole area of the piston is exposed to the PDAF, whereby the pulse-valve opens violently.

Abstract: Applying pulses to liquid being injected into wells makes the ground/liquid formation more homogenous, and more penetrative. A system for automatically creating the pulses is described, in which a piston is acted upon by the pressure differential (PDAF) between the supplied accumulator pressure and the formation pressure. The changing levels of the PDAF as the pulse-valve opens (and the PDAF falls) and as the pulse-valve closes (and the PDAF rises) are harnessed to actuate an inhibitor that restrain movement of the valve-piston, and delays opening and/or closing of the pulse-valve. The pulse-valve is engineered to open explosively, and thus create penetrative porosity-waves in the formation. The system includes a pressurized-gas accumulator, and injection-check-valve which can maintain pulsing even when the ground is not saturated, and the static injector, which allows non-pulsed injection only when the ground is non-saturated.

Abstract: For use when injecting remediation liquid via an injection-well into contaminated groundwater, in the ground. The injection equipment includes a pulse-generator, which has an upstream chamber and a downstream chamber, linked by a pulse-conduit and a bypass conduit. The pulse-conduit includes a pulse-port, which opens and closes cyclically. The pulse-port is formed by the interaction of two apertures, one in the motorised rotor, the other in the stator. The rotor and stator may be formed as two facing plates held slightly apart, or as two cylinders one inside the other. The pulse-generator is located at the ground surface and can be adjusted as to pulse frequency, pulse amplitude, pulse rise-time, and as the the differential pressure between the upstream-chamber and the downstream chamber.

Abstract: Applying pulses to liquid being injected into wells makes the ground/liquid formation more homogenous, and more penetrative. A system for automatically creating the pulses is described, in which a piston is acted upon by the pressure differential (PDAF) between the supplied accumulator pressure and the formation pressure. The changing levels of the PDAF as the pulse-valve opens (and the PDAF falls) and as the pulse-valve closes (and the PDAF rises) are harnessed to actuate an inhibitor that restrain movement of the valve-piston, and delays opening and/or closing of the pulse-valve. The pulse-valve is engineered to open explosively, and thus create penetrative porosity-waves in the formation. The system includes a pressurized-gas accumulator, and injection-check-valve which can maintain pulsing even when the ground is not saturated, and the static injector, which allows non-pulsed injection only when the ground is non-saturated.

Abstract: For injecting e.g. water into ground formation around a borehole, and for superimposing pulses onto the outflow of the injected water, it is important that the pulses have a rapid rise-time. A piston is connected to a pulse-valve of the tool. A bias spring urges the piston towards its closed position. The piston is urged towards the open position by a differential PDAF between the supplied accumulator-pressure and the in-ground formation-pressure. When the pulse-valve is open, the PDAF is falling, until the force of the spring closes the pulse-valve. Then the PDAF rises, but now the PDAF acts over only a small area of the piston. When the PDAF is high enough to ease the pulse-valve open, suddenly the whole area of the piston is exposed to the PDAF, whereby the pulse-valve opens violently.

Abstract: For pulsed injection of liquids into the ground, the tool has a rotating cylinder, having through-slots. The tool has an insert, which is pressed against the rotating cylinder. As the cylinder rotates, the slots in the rotor cover/uncover the slots in the insert, creating the required pulses. By suitably shaping the slots, the pulses can have a fast rise-time from closed to open. The insert is shaped to minimize flow interference.