GB758180A - Improvements in or relating to method of and apparatus for penetrating and fracturing a well formation - Google Patents

Abstract

758,180. Blasting devices such as gun perforators. MOHAUPT, H. H. Dec. 22, 1954 [Jan. 25, 1954], No. 37025/54. Classes 9(1) and 92 A blasting device or gun perforator 10 for opening up strata bearing oil, gas &c., in the neighbourhood of , a well bore comprises a powder chamber 12 and a barrel 14 to which is attached a directing shoe 16. The device is lowered into a well bore by a cable 30, through which extend conductor leads to an electric igniter 40. On initiation, the igniter fires the powder charge 24 in the chamber 12 and the gases from the charge propel a missile 26 along the barrel and through a sealing cap 58 attached to the barrel by an adapter 54. The shoe 16, which is secured to the cap 58 by screws 64, has an arcuate channel 28 which deflects the missile laterally into the part of the rock formation to be fissured. The shoe, which may be of cast iron, is shattered by the missile. Surrounding the hardened steel core 44 of the missile, Fig. 3. is an aluminium jacket 46 having a flange 48 to which is pinned a mild steel base 50. The flange 48 serves to seat the missile in the barrel. In an example the device is 27 ft. long and has a maximum diameter of 4 inches with a bore diameter of 2# a inches. The outer diameter of the missile is 2 # inches and the diameter of tht core 1¢ inches. The total weight of the missile is 2.4 lbs. and of the charge 2.04 lbs.