Method and apparatus for effecting perforation of a well casing with a casing gun while maintaining pressure in the well bore at a lower level than the pressure in the surrounding reservoir at the point of perforation. Before production tubing is run into the well, the casing gun is deposited in the bore below the desired production level. After the tubing is installed, borehole pressure is reduced to the desired level by swabbing the tubing and an automatic coupling and decoupling pickup tool i...

A perforation hand punch for coding cards has a coding field 31 in its male-female perforation arrangement having four columns and two rows. Accordingly, 4 punch pins may be distributed in a 8 punch pin positions 32, 34, 36, 37, 38, 39, 41 and 42 in a coded manner. Consequently more than 50 different person-related perforation coding can be provided which have 4 holes in each case as standard, so that the risk of forgery as a result of over-punching as in the case of mixed 2- and 4-hole coding i...

A dissolvable repair device, and a method utilizing the same, that is intended to aid in the repair and healing of a perforation in body tissue, such as a nasal septum. The repair device is intended to be placed over the area of the perforation to act as a scaffolding for the regrowth of tissue over the perforation. The repair device is made from a bioerodable material that is dissolvable upon exposure to certain fluids, including body fluids. Over time, the repair device will dissolve, allowing...

A perforation and image exposure system comprises an image exposure apparatus and a punch unit. The image exposure apparatus has a first reference pin for defining a lateral position of a plate through contacting with one side edge of the plate contacting a pair of first positioning pins, and image exposure means for exposing the image into the plate subjected to positioning by the pair of first positioning pins and the first reference pin. The punch unit has a second reference pin for defining ...

A device for the cross perforation of webs, preferably paper webs for producing sacks, comprises a rotatingly driven perforating blade and a grooved roller, both of which are mounted on a machine frame and between them passes the web to be perforated. To adjust the penetration depth of the teeth of the perforating blade into the ring grooves of the grooved roller, there is at least one adjusting device for changing the distance between the axes of rotation of the perforating blade and the groove...

A perforating gun for perforating a section of a well casing in which a plurality of explosive charge units are mounted on an elongated mounting strip in a pattern corresponding to the desired pattern of perforations in the well casing. The areas of the mounting strip that receive the charge units have a greater width than the remaining areas of the strip to provide an increased support surface for the charge units. Each charge unit is formed by a case connected to a cap to provide a housing for...

A perforated separation line forming apparatus which is characterized by: an edged rotary body (2) having a round slitting edge (1); and a receiving rotary body (4) having a receiving circumferential surface (3) that the round slitting edge engages; wherein the edged rotary body (2) and the receiving rotary body (4) are arranged to clamp a perforated line forming position (6) of a continuously fed transfer material (5) therebetween; wherein the receiving circumferential surface (3) of the receiv...

The invention relates to a forge-proof document comprising a security feature in the form of a perforation pattern which displays gray tones when viewed against a bright background, wherein the document is manufactured from a material which transmits light to a limited extent, at least some of the perforations forming part of the perforation pattern extend over only a part of the thickness of the document at the position of the perforation, and the thickness of the remaining part of the document...

Perforations into an earth formation from a wellbore may be analyzed as to location, shape and radial depth by placing an inspection apparatus in the wellbore including an acoustic signal transmitter for transmitting acoustic signals over a broad bandwidth for a limited time, and receiving reflected or resonant acoustic signals excited in nearby perforations. The amplitude of the resonant frequency will reach a maximum when the perforation is at a midpoint between the transmitter and receiver. T...

In accordance with an illustrative embodiment of the present invention, a well perforation cleaning tool includes a fluidic oscillator that creates pressure changes which induce cyclical stresses in the damaged skins of the perforations and causes the skins to disintegrate in order to improve the productivity of the well. Cylindrical filter tubes having a plurality of sets of slots are adjustably mounted at the upper and lower ends of the tool to provide resistances which confine the pressure ch...