Earth fracturing apparatus
AssigneesThomas A. Edgell, Roberta K. Tillinghast
InventorsWilliam H. Snyer, Ralph E. Williams, John Wisotski
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Abstract
An earth fracturing apparatus has a casing of reactive metal containing a central, double ended charge load that is simultaneously detonated from both ends; and a pair of opposed end charges at opposite sides of the central charge load, the end charges being concavely dished toward the central charge load and having a liner of reactive metal on the dished face. The end charges are simultaneously peripherally initiated to explode with a collapsing detonation wave toward the central charge load. Void spaces between each end charge and the central charge load contain an oxidizer that may be under pressure. In a modified form of the apparatus, the end charges are omitted and the central charge load alone acts as a perforator for well pipe.
Claims22
An improved earth fracturing apparatus of the kind having an elongated casing containing a pair of opposed end charges and a laterally directed intermediate charge, wherein the improvement comprises:
- (a) said laterally directed charge being substantially centrally located along the axial length between the oppositely directed end charges for creating a central area of high pressure upon detonation;
- (b) each of the end charges having a liner of reactive metal on its respective inwardly directed face for forming a metallic vapor upon detonation of the end charge;
- (c) the end charges and the centrally located laterally directed charge being substantially spaced along the axis of the casing to form a void area between the central charge and each end charge, the void containing an oxidizer that reacts with the metallic vapor upon detonation of the end charges to enhance the period of high pressure resulting from detonation of the end charges;
- and
- (d) detonating means for exploding the centrally located charge and the end charges, the end charges being detonated substantially simultaneously at a time no sooner than the detonation of the centrally located charge, the shock waves of the end charge detonations meeting near the position of the centrally located charge to reinforce the pressures generated by explosion of the centrally located charge.
An improved earth fracturing apparatus of the kind having an elongated casing containing a pair of opposed end charges and a laterally directed intermediate charge, wherein the improvement comprises:
- (a) said laterally directed charge being substantially centrally located along the axial length between the oppositely directed end charges for creating a central area of high pressure upon detonation;
- (b) each of said end charges having a main body of high explosive with an inward side facing toward said laterally directed charge;
- (c) means for peripherally initiating the explosion of said main body to form a high pressure detonation wave collapsing over said inward side;
- (d) said end charges being axially spaced from the laterally directed charge in the casing to form a void area therebetween, the void providing space for the high pressure detonation wave to form;
- and
- (e) detonating means for exploding the centrally located charge and the end charges, the end charges being detonated substantially simultaneously and at a time no sooner than the detonation of the centrally located charge, the shock waves of the end charge detonations meeting near the position of the centrally located charge to reinforce the pressures generated by explosion of the centrally located charge.
An improved earth fracturing apparatus of the kind having an elongated casing containing a pair of opposed end charges and a laterally directed intermediate charge, wherein the improvement comprises:
- (a) said laterally directed charge being located near the center of the axial length between the oppositely directed end charges for creating a central area of high pressure upon detonation;
- (b) each of said end charges having a main body of high explosive with an inward side facing toward said laterally directed charge;
- (c) means for peripherally initiating the explosion of said main body to form a high pressue detonation wave collapsing over said inward side;
- (d) said end charges being axially spaced from the laterally directed charge in the casing for a sufficient distance to permit formation of a high pressure detonation wave therebetween;
- and
- (e) detonating means for exploding the centrally located charge and the end charges in predetermined sequence.
Dependencies are inferred from the claim text.