US2031505A - Container for explosives - Google Patents

Description

C. O. RISON Feb. 18, V1936.

CONTAINER FOR EXPLOSIVES Filed NOV r- 15 Patented Feb. 18, 1936 UiuTED STATES PATENT OFFICE of one-half to Indian Territory Illuminating Oil Company, Bartlesville, Okla., a corporation of New Jersey -Application November 15, 1933, Serial No. 698,100

6 Claims. (Cl. 102-4) My invention relates to containers for high ex depth for detonation as when shooting a well,-

or for other purposes incidental to oil i-leld practice. f

Due to the instability of nitro-glycerine used in the oil and gas industry, many premature explosions are directly caused by the nature and character of the container for the reason that containers as heretofore employed do notprotect the explosive from effects causing its premature decomposition and/or explosion. For example, many explosions are caused by transfer of heat through the walls of the container incidental to friction or abrasionthereof with the walls of the Well while the charge is being lowered, resulting in expansion Yof the liquid and inmany instances the expansion occurs to such an extent as to cause overilow of the container.

Other explosions are caused by conduction of earth electricity through the walls of the container, by static electricity generated incidental to the lowering operation, and by leakage of the container through puncture and failure of the joints or seams.

Attempts have been made to overcome some of I the above defects by constructing the container from non-metallic material, such as fibre, impregnated paper, wood pulp, or of plastic substances, such as asphalt, or asphalt-'gilsonite and the like. f

These containers, however, have not' proved satisfactory, owing to the fact that acidity is residually present in their composition, or acidity is later created by chemical reaction in the materials themselves. The presence of acidity is a most likely cause for premature explosion because acidity tends to the instability of the explosive and .in many instances sets up a chemical reaction producing its decomposition. Such containers are also subject to eiects of solubility, heat and frangibility under high hydrostatic pressure, all of' which tend to cause of premature explosions.

In many instances, the containers, even when they are properly placed in a well do not completely shatter under the force of the explosion with the result that large pieces driven from the top of the well are likely to strike sparks that may ignite the vwell flow, or they may cause serious injury to persons in the lvicinity of the well. These large pieces also, in many instances, prg.

duce a bridging eect in the well that requires* considerable expense on the part ofthe producer in drilling out oraround the bridge.

Containers of a plastic nature, such as those constructed of asphalt, or asphalt-gilsonite, often 5 cause irreparable damage to the well for the reason that the heat and force of the explosion drives the softened material deeply into the sand, thereby closing the pores and flow channels through which oil enters the well. v

The principal objectsv of the present invention are, therefore," to provide a container having dielectric properties, capable of resisting static or other electric currents and magnetic conditions in the well, to provide a shell body that is dense and hard so that it will not absorb the explosive or well fluids, to provide a. container that is a relatively poor conductor of heat either through friction or high well temperatures, to provide a container that resists abrasion and punotures, to provide a container construction that readily withstands hydrostatic pressures in the well, but which is of extremely light weight so that it is readily disrupted into very small fragments under force `of the explosion, and to provide a container that is entirely free from acidity or material that Will chemically react with the explosive.

In accomplishing these and other objects of the invention, I have provided improved details of structure, the preferred forms of which are illustrated inthe accompanying drawing, wherein:

Fig. l is a vertical sectional `view through a well hole illustrating a nitro-glycerin containing shell constructed in accordance with my invention and shown as being lowered into position for shooting a well. f

Fig. 2 is a perspective sectional view of the container.

Fig. 3 is a cross sectional view through the container on the line 3 3, Fig. 2. 40

Fig. 4 is a detail sectional view through the funnel member on the line 4 4, Fig. 2, particularly illustrating the vent openings for relieving the container of air as' it is being iilled with nitro-glycerin. 45

Fig..5 is a vertical section through a modiiied form of shell completely closed at both ends and adapted for containing an explosive and'a timed 'or automatic detonating, exploding, or igniting device.

Fig. 6 is a vertical section through a container lequipped with a modified form of funnel member,

and showing the tubular sections secured together by a threaded insert.

Fig. 7 is a similar view through alstill further 55 modiied form, wherein the tubular sections of the container are secured together by a sleeve insert;v

Referring more in detail to the drawing:

I designates a container which includes an elon. gated cylindrical body of suitable diameter to pass through the well casing 2 and of suicient length tocontain the -required amount of explosive de- Y able connection 6.

In Fig. 2, the connection is made by providing the upper section 4 with a reduced threaded neck 1 forming an outer annular stop shoulder 8 with the outer face thereof while the lower section 5 is provided withan internal threaded socket portion 9 to engage the threads of the neck I which ter-V minates in an internal shoulder I for'engaging the end face II of the neck when the shoulder engages the upper end I2 of the socket to provide a tight joint and a substantially continuous wall structure.

If desired, the-.joint may be additionally se cured by a cementitious material or gaskets between the shoulders 8- and I0. 'I'he bottom end of the wall section 5 is pro- I vided with a closure member i3 including an externally threaded body portion I4 engaging internal threads I5 formed in the lower end of the section 5 and which is retained against rotation therein by fastening devices such as screws I6 extending through counter sunk openingsl'l in the wall of the section and into threaded openings I8 in the-threaded body portion i4. The lower end of the body portion terminates in a funnel shapedv bottom I9 having a depending lug 20 provided with a, transverse aperture 2l to which may be attached a hollow cylindrical anchor vtubing for the purpose of placing or anchoring the lled container at a predetermined depth above the bottom of the wellor by which a suitable weight may be with the well casing.

The end of `the upper section is internally threaded as at 22l to receive an externally threaded iill or funnel member 23 through which the nitroglycerine-is poured into the container. The ll member include'sia body portion 24 of substantially secured to retain the container in axialalignment the same diametras that of thev container vand is provided with an'externally threaded skirt portion 25 engaging in the threads 22 to secure the iill member Vto the container. The iill member is also locked in position -by screws 26 extending through counter sunk openings 21 in the shell and into threaded sockets 28 formed in the skirt 25.

The upper end oi the funnel member is provided with a conical recess 29 terminating in a channel` 3D that is formed in a boss 3| depending -from the body portion 24. The funnel member 1s provided with one or more air outlet ports 32 ex o tending from the upper portion of the recess 29 through the body portion and communicating with the interior of the shell through the space 33 l between the boss 3l and skirt 25, as clearly shown in Fig. 5.

The funnel member is also provided with a. suitable bail 34 having inwardly directed ends 35 anchored in the body portion 24. A

In carrying out the present invention, the wall sections, as well as the bottom closure and funnel members are formed of AWrapped or molded bakelite, a material composed of specially prepared phenolic resins having extremely high dielectric qualities particularly adapted for nitro-- The material is also relatively light in weight and owing to itsl strength, the containers may be constructed with relatively thin walls, fully capable of withstanding hydrostatic well pressures and weight of the nitro-glycerin contained therein, as well as the weight ,of other filled containers that practice in placing large explosive charges.

may be suspended therefrom, as in customary` 'Ihe material while being extremely tough and resistant to breakage is readily disrupted into very small fragments under the force of an explosion so that the parts vthereof will not in any way damage the well or iiow of the well iiuid through the oil sand.

While as above stated, the cylinder walls may be-formed of molded bakelite, I prefer to construct thev wall sections of a plurality of layers of thin fabric or preferably unsized absorbent onehundred percent cellulose paper capable of absorbing a phenolic binder or varnish and compressed into tubular form. The binder or varnish is a product of chemi al reaction of formaldehyde upon phenol or'cresol and in order to assure neutrality or alkalinity in the iinished product, the chemical reaction is carried on in the presence of an alkaline catalyst, otherwise the product may contain considerable amounts of unreacted phenol or cresol, or intermediate products Aof chemical reaction that might produce acidity.

It is found that a certain percentage of nitrogen may be present depending upon the character of the-paper and the particular refinement of chemical binder or varnish employed. This nitrogen would indicate that nitrogenous materials are present, but by using a particular alkaline catalyst, such as sodium hydroxide, it is possible to provide a binder substantially free of nitrogen.

an acid process, it *is possible to provide a paper substantially free of nitrogen or nitrogenous materials.

In constructing the sections, the absorbent paper or fabric is run through a bath of the prepared binder andthen passed through a drying chamber, after which it is wrapped under tension A upon a heated mandrel, .and/or molded in a l press, under high pressure.

' The funnel and bottom members are preferably molded from bakelite as follows: phenolic resins in powdered or sheet form manufactured by the reaction of formaldehyde upon phenol or cresol in the presence of a particular alkaline catalyst, such as sodium hydroxide, are used in hot hydraulic presses having hardened steel molds shaped to produce the desired contour of the members.

In connection with the molding step, it is found that a considerable quantity of volatiles are produced. They may be eliminated, however, to a comparatively high tensile and compressible When the containers are formed by the wrap process, they are additionally heated after the. mandrel has been .removed so as to assure full cure on the inside as well ason the outside of the container walls.

The finished product when completed is an' in'- soluble and infusible body which presents a neutral or alkaline surface to the explosive and has strength as Well -as extremely high cli-electric properties. Itis impervious to heat, water, oil

and most chemicals. It is `of uncommon strength and toughness and will not warp or deteriorate with age. t

The tube as well as the funnel and bottom members are readily machined to form the threaded joints whichsecure the parts together.

' In Fig. 5 is shown a modied form of container wherein both ends are closed py solid molded bakelite plugs 35 and 36 h'aving threaded portions 31 to be received in the threaded ends`33 :of the tubing and Vhaving apertured lugs 39 through which a bail is installed for securing the lowering cable as well as the weight as in the ordinary container illustrated in Figs. 1 and 2.

This type of container is known as a bomb and lis particularly constructed tol resist the hydrostatic pressure of the uid column in the well andA for containing explosive and a timed or automatic detbnating, exploding or device for V setting off the bomb.

In Fig. 6 is shown a modified method of securing the bail wherein twisted wires 4|! are imbedded into the molded material and have projecting eyes -4l by which a bail is installed for securing the lowering cable. In this form of the invention, the

upper and lower sections are secured together by' a threaded insert 42 formed of the same material as that of the sections. A.

In Fig. 7 the head Aof the funnel member is provided with horizontal openings 43 through whichthe ends 44 of a wire bail 45 are threaded to be Y Y attached to the body of the bail portion, as shown at 46. In this form of the invention, the insert *41 is simply a sleeve vcemented to the inner face of the abutting sections;

In using/a container constructed and assembled as described, the nitro-glycerin is poured into the funnel member so that it flows through the channel 30 to fill the container.

As`the liquid .nitro-glycerin enters the con? c tainer air is 'expelled throughthe openings 32.-

Therequired length of hollow cylindrical anchor tubing 48 is secured to the lug 20 by a nail or rivet 49 extendingthroughrthe transverse rivet therein or a suitable weight, not shown, maybe secured to the lug ZAL-as the case may require and the loaded shell is lowered into the well by a cable 50 and a detachable torpedo hook 5| /attgched to the lhan e4.

c 'Ihe container'is thenvrapidly loweredinto the well, but friction thereof with the walls of the I well will not generate st atic electricity, nor-will friction cause heating of the nitroglycerin even though the weltbeextremely An'ooked andthev the major portion of its descent.

If'a large explosive charge is required, additional iilled shells maybe Ainserted between the rst shell and the anchor tubing 48. A bomb such'as shown in Fig. 5 may be connected beshown in Fig. 1.

When the' shell or shells is or are in position, the nitro-glycerin may be detonated', exploded,

or ignited in the customary manner. .The explosion occurringwill completely shatter the yentamer contacts-with the wen casing duringtweenthe hook .and the upper container, as

container into smalll fragments which may be readily ejected or flowed out without causing damage to the vwell or-injury to persons in the vicinity thereof.

' A container constructed as described is entirely free of acidity and does not subject the nitro-g glycerin to decomposing effects that might produce premature explosions.

It 1s thus apparent that the Shen may be safely set at any predetermined depth in deep or crooked Wells without danger of premature explosions that might seriously damage or causeloss of the Well. Y

It is mso apparent that due td the solidity of the shattered shell fragments, they cannot cause to. the sand or otherwise obstruct the iiow capacity of the well.

What I claim and des"V 'to secure by Letters l Patent is:

1. A .nitroglycerin container formed of dielectric material treated to eliminate acidity normally present in theAnaterial.

2. A nitroglycerin container including a shell formed of fibrous material, 'anda binder pro-'- duced by reaction of formaldehyde upon phenol in the. presence` oft a suicient amount of an,

alkali to insure against presence of acid in the shell at` any time during eilective life o f the Shell. v

3. A nitroglycerin container includingV a shell formed of a carrier, vand a binder produced by reaction of formaldehyde upon phenol in the *presence of a suflicient amount of an alkali to insure against Asubsequent reaction Yof residual acidity in the ffinished shelll with nitroglycerin contained within the shell.-

-4. A nitroglycerin container including a shell formed of iibrous material, and a phenolic binder containing a suilicient amount of' an alkali to 'neutralize any acidity set up in the shell Vby reacteristics set o'ut in claim 2, but in which' form? aldehyde is reacted with cresol in manufacture ofthe binder element.

' AfcAnEvfo, Bison.

alkali to insure against)` subsequent reaction of acid' occurring in the ma-

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