USRE5434E - Improvement in methods of and means for increasing the capacity of oil-wells - Google Patents

Description

E. A. L. ROBERTS. I Method of,and Maans-for,lncreasing' the Capacity of Oil-Wells.

Reissued June 3,1873.

lllf/llllll/Il/l/ I S I UNITED STATES PATENT QFFIGE.

EDWARD A. ROBERTS, 0F. TI'IUSVILLE, PENKS'YLVANIA.

I am m' METHODS or AND MEANS ron mcmsma Tm: CAPACITY or OIL-WELLS.

vSpecification forming part of' Letters Patent No. 59,936, dated November 20, 1866; antedated MayQO, 1866 reissue No. 5,484, dated June 3, 1873; application filed May 24, 1873.

To all. whom it may concern:

Be it known that I, Enwmn A. L. Ron- ERTS, formerly of the city, county,'and State of New York, but now of Titusville, in the county of Crawford and State of Pennsylvania, have invented a new and useful Improvement in Process of Increasing the Capacity of Oil-Wells, and also of restoring oil-wells ;to

- productiveness,and of apparatus therefor; and

1 do hereby declarethefbllowing to be a full, clear, and exact description thereof: f

My invention relatesto a new' and useful method or process of restoring oil-wells that have become clogged to productiveness; also, of increasing the capacity of oil-wells; and also, to certain improvements in apparatus for causing explosions in such wells.

Petroleum or oil taken from oil-wells is, before it is removed, contained in the seams- .usually' in the second or third stratum-of sand-stone, or other rock abouuding in the oil region, as represented in Fig. 1 of the accompanying drawings.

Figure 1 represents a sectional view of the different stratums of rock usually fouudin oilproducing regions; and the'seams containiu g the oil are represented by the irregular linestraversingthe second and third stratums ot' sand-stonerock thereon shown. N and N represent'wells sunk-into the rocks. In order to-take the oil from the seams or crevices in the rock, wells must be sunk which shall-tap or intercept the sea-ms, or some of them, containingthe oil. Thewells are frequently sunk to a depth of from eight hundred to nine hundred feet below the surface of the. earth,

- land usually from three to' six inches in diameter; and it frequently happens that a 'w'ell willbe'sunk for a great distance into or throngh the rock containing' the oil without I tapping or passing';throug'h any of the seams in which-itqiscohtained, as shown at N, Fig. 1. ;When this happens to be the case, the wellis sometimescmade available by increasinguitsjdiameten:until-ittaps some of the seams.';' .'l his has,; been done. by boring from thetop, all the way-down into the stratum of rdcktontaining the ,:=,oil, and is attended with i -nearlyshm w1l lab9tand expense asl boring thef-wellf'in the-first instance lt also;

.. aquenfly happens that the intersected by the well isvery small, orthat the aperture into the well from the seam is very small, in

eitlier of which cases it is very liable to be come eloggedor stopped up, during the working of the well, by substances contained therein,

which 1 prevent the oil from flowing' or being sucked into the well. These substances are either foreign matter-such as bits of rope,

sticks, dirt, particles of rock, 8tc.. which have dropped into the wellor are the result of coagulationor accumulation of matter contained in the crude oil itself, and forming what is known as B. 8., and sometimes, probably also, the deposit of waxy matter known as crude parafline,and, occasionally, calcareous or other mineral deposits. Attempts have been made to remove these stoppages-sometimes by enlarging the diameter of the well, as before stated, and at other times, when the obstruction is slight, by forcing air down to, or near the bottom of, the well, and allowing it suddenly to escape. It is desirable, in order. to increase the productiveness of wells, as well as to prevent stoppages from obstructions.

vicinity of the explosion isscoured' and trit-' urated, and insome instances fractured. The

elfect of such explosion'is to soften or melt tlie B.- S. or pnrafflne, and, by the direct or reactivefpressureof gasor air, to cleanse the seams as well as the face of, the rock, thusde t'a'cliingand removing all foreign" substances,

while,whB .-f 1 ture of the rock'takes place, mwsem s r .f q cet i nsda' and o r 7 capacity Qfithe en is increa d andpjin those ztamping, i-n connection with the employment,

and gases are forced into all the fissures and cavities of the rock and soften, melt, or liqnefy the parafiine or B. 8., while, upon contraction or condensation of the gases or vs.

per, a reaction takes place, whereby the obstructions are forced .out of the seams and the passages are thereby reopened. At the same time the effect of the shock is to triturate and scour the well, detaching and removing all calcareous or mineral deposits.

Where it is desirable to fracture the rock, I make use of a fluid tamping, which is thus applied: When the flask is placed in position,

it the well should not contain a sufficient amount of water to act as tamping, as it usually does, unless it has been pumped out,

a sufficient quantity of water is introduced, into the well before the contents of the flask are ignited, so that the column of fluid above the flask will have the requisite gravity to confine the efl'ect of the explosion to the rock in the immediate vicinity of the flask, and s0 facilitate the fracture.

In .order more fully to explain my method of operation, Iwill. describe the apparatus which I prefer to use.

Fig. 2 represents a sectional view of a hollow flask, made of iron, glass, or other material, and filled with powder or other explosive material or gas, with a cover and means of letting the same down into the well and exploding the contents. a is the body of the flask containing explosive material. b is a cover screwed down on the top of the flask,

water-tight, covering the aperture-through which the explosive is introduced. 1 l are two small lugs placed at or near the top of the flask and on opposite sides of the cover, to which cords are fastened to-assist in low-- ering the flask into the well and in removing it, if. for any reason, the contents should not have exploded. c is a stufling-box or gland, through which the wire d, passes, which connects at one end with .a small quantity of fnlmiuatiug-powder upon the disks c c at the-extremity of the wire in the interior of the flask, and at the other end with a cord extending out of thewp of the well and sufflciently strong to enable the operator to pull the wire d through the stufllng-box c with suflicient force to ignite the fulminating- 'powderon the disks e e onthe end "of 71116 wire 41,- which will readily ignite the "explosive in=-the flasks. Should electricity the dry contents.

be used to, ignite the contents of the flask,-

flask in any convenient manner, and is usedto assist in lowering the flask into or-in raising it out of the well, and also to guide the weight win its descent to the caps on the nipples. This cord also servesto suspend the torpedo in the proper position in or near the oil-bearin g rock. w is an oblong weight of suflicient gravity to fall rapidly through the water and to explode the caps by the momentum obtained by its descent to the nipples, and should be of slightly greater diameter at the bottom than the space between the tops of the two nipples, 'with a hole running longitudinally through its center, of suflicient diameter to permit it to slip easily over the wire when the flask is in position. The charge may be exploded by allowing the weight to slide'down the .wire, when, on striking the caps, theexplosion ensues. Varnish or other similar 'substances should be applied when the caps are put on the nipples, so as to render the connection between the caps and torpedo impervious to water. In Fig. 3the flask has no detachable cover, but the explosive is intro duced through an aperture'in the bottom of the torpedo, which is stopped by a screw-plug, 0, made to flt water-tight. I prefer to have the flask made of cast-iron or tglass, but it should be sufflciently strongwhen it is lowered to therequired depth, and made impervious to moisture so as to protect it should he of slightly less diameter than the diameter of the bore of the well, in order to slide down easily. The length of the flask will depend upon the amount of explosive force required, care be ing taken not to employ so great a force as to shatter or displace the sides of the well above the oil-bearing rock, which it is desired to have opened or ruptured by the explosion, to guard against which the flask should be some; what shorter than the depth of the oil-bearing stratum. 1 P

Instead of the particular means above derestoring the productiveness of oil-wells by causing an explosion therein, oil-bearing point. 7

2. The method or process of increasing or at or near the the pnoductiveness of oil-wells by resist the. pressure of the water which may be above it causing an explosion at or near the oil-bearing point. in connection with superincumbent fluid tamping, substantially-as set forth.

3. In combination with a torpedo adapted I to deep wells, the employment of a weight and guiding-cord for the purpose of exploding point, consisting of a wire or cord, attached to such torpedo and through which, as a:

medium 'of communicating ignition, the torpedo is exploded.

' In witness whereof I, the said EDWARD A.

L. ROBERTS, have hereunto set my hand.

Witnesses: GEO. WESTIN T. B. KERR.

EDWARD A. L. ROBEBTS.

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