US267796A - Process of preventing the escape of gas from oil-wells between the flows of oil - Google Patents

Description

(No Model.)

C. H. McKEE. PROCESS OF PREVENTING THE ESCAPE 01? GAS PROM OIL WELLS BETWEEN THE FLOWS OF OIL. No. 267,796.

I29, Patented Nov. 2 1, 188Z WITNESSES 14v VIM/T01;

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NITED y STATES PATENT]. OFFICE.

CHARLES H. MGKEE, OF LOOK HAVEN, PENNSYLVANIA.

PROCESS OF PREVENTING THE ESCAPE 0F GAS FROM OIL-WELLS BETWEEN THE FLOWS OF OIL.

SPECIFICATION forming part of Letters Patent No. 267,796, dated November 21, 1882. Application filed September 15, 1881. (No model.) i i To all whom it may concern:

Be it known that LOHARLES H. MOKEE, a citizen of the United States, residing at Lock Haven,in the county of Olinton, and State of Pennsylvania, have invented a certain new and useful art or process of controlling and regu lating the flow of oil from oil-wells by preventing the escape of gas from the wells between the flows of oil, and means for carryingitinto effect; and I do hereby declare-that the following is a full, clear, and exact description of the invention, which will enable others skilled in said art to practice the same.

Oil-wells which flow are constructed and arranged as follows: 'A hole about six inches in diameter is drilled down into the oil-bearing rock, after which a torpedois lowered and exploded and the oil-bearing rock shattered and broken for many feet in each direction. The shattered sand-rock is then removed from the well, which leaves the Well widened for many feet on each side of where the torpedo was exploded. Tubing, usually two inches in diameter, is then inserted into the well. The lower end of the line of tubing is perforated fdr a distance of about forty feet from the bottom of the well. In the tubing, above the cavity caused by the explosion of the torpedo, and at a distanceof about eightyfeetfrom the bottom of the well, is placed a packer, usually made ofrubber, which is made to fit perfectly tight be tween the tubing and the sides or walls of the well. When the tubing is thus fixed in place neither liquid nor gas can escape from the well otherwise than through the perforations into the tubing, and thence up and out through the tubing. With the well thus arranged the oil and gas, which prior to the drilling of the rock were confined in the oil-bearing rock under great pressure, accumulate in the cavity at the bottom of the well. The gas escapes freely until the oil accumulates and rises in the well above the uppermost perforation in the tubing and shuts off the escape of gas, after which the gas occupies the space around the tubing below the packer and above the level of the oil. A great pressure is acquired by the gas as it continues to accumulate in this confined space. As a result, to make room for the gas as its quantity continues to increase, the oil is forced to recedeb In a short time a column of the oil rises in the tubing, and its level in the cavity around the tubing is forced below the uppermost perforation. At this instant the gas commences to rush out through the perforationsinto the tubingand up and outthrough the column of oil. Escaping with great velocity, it carries out with its current the oil which before stood as a column in the tubing, and also much of the oil collected in the bottom of the well. The same process of accumulation of oil and gas is repeated'again and again, and thus the well continues to fiOWr Many wells thus arranged flow at intervals of about one hour; some flow at much less intervals,

while others at greater, dependent upon the.

proportion of oil and gas and the rapidity with which they gather at the bottom of the well. If the packer is placed high in the well and the uppermost perforation in the tubing is placed low, many hours may elapse between flows.

Heretofore during the intervals after the fiowsof oil, and until its level again rose above the uppermost perforation in the tubing, the gas has escaped freely from the oil-wells. At many wells the gas pours out in a constant current fully nine-tenths of the time, and at some wells 2. much greater proportion of the time. The origin of this gas, which abounds and escapes ingreat quantities in some oilproducing districts, is, like that of petroleum, involved in mystery. however, but that a great proportion, if not all, of it is generated by the evaporation of some of the lighter hydrocarbons of the petroleum which takes place upon the oil-bearing rock, in which the oil is confined and held under pressure, being perforated by the drill and the great pressure relieved.

The gas is called the life of the territory, because without it a Well will not flow, and when the gasis exhausted it cannot be pumped. If there is not gas to follow the sucker of the pump in its upstroke a vacuum is produced, and the long line of sucker-rods necessary to be used are almost sure to part or break; and when the lighter and thinner portions of the oil have evaporated and passed off as gas, only the heavy and gummy portionssuch as paraffineremain. These and the oil are retained in the rock as water is held by a sponge.

There is little doubt,

2 acnvoe When formed in the bottom of the well they, and whatever oil of good quality remains behind them, are so difficult to remove that an abandonment of the well soon occurs.

The object of my invention is to preventthe escape of gas from oil-wells between the flows of oil.

To carry my invention into effect I use and insert in the tubing of the well an automatic valve so constructed that it opens only when a high pressure is exerted upon it, and closes only when the pressure is relieved and reduced very low. Any valve that will act in this manner can be used. The one I have invented and prefer is illustrated in the accompanying drawings, in which Figure 1 represents a vertical section, and shows the connections of the valve with the tubing of the well, and Fig. 2 is a sectional top'view of a piston-rod, nut, and groove, which parts are hereinafter described.

In the drawings, A represents a chamber about five inches in diameter, with two valveseats, b b and 00.

B is a double-seated valve resting on its two seats, I) b and c c.

T and U represent the tubing leading from the well and to the tank, respectively.

Immediately above the valve-chamber is a piston-chamber, G, with a piston, P, fastened on a shaft or rod, D, by means of two'nuts, e

andf.

Close to the piston-chamber is a flange, h, on the piston-rod D, upon which flange is placed weights V, X, Y, and Z.

I I are posts on which is placed a guide, K, for the piston-rod, the guide being held on the posts by two nuts, Z and l.

Onthe lower end of the piston-rod is a nut, g, and on the side of the lower end of the pistonrod is a groove, 0.

The area of the valve-seat 0 dis 3 inches, the area of the valve-seat b b is 1533 inches, and the area of the piston is 123 inches. The figure shows the valve closed. The pressure of the gas in the well is communicated through the groove 0 into the chamber A. The area chamber is required to lift a weightequal to one pound at V X Y Z.

If the weights V, X, Y, and Z equal ten pounds, as soon as the pressure in the valvechamber exceeds fitty pounds to the square inch, the piston is forced upward and lifts the double-seated valve out of place. The oil and gas from the well are then at liberty to pass from the well out through the tubing T and U. They buoy up the double-seated valve,

which is made in the shape of a cup and very light. It cannot drop into its seat until the piston is lowered, and this cannot take place until the pressure is so diminished in the valvechamber that it is not sufficient, when exerted on the piston-head with an area of 12 square inches, to support the weights V, X, Y, and Z. When the flow of the well is about over, and the pressure has fallen so that the piston is lowered, still the cup-shaped double-seated valve will not settle into its place so long as there is pressure orcurrent enough to prevent its becoming seated.

It will be readily understood thatthe relative areas of the valve-seats, piston, and piston-rod, and the corresponding amountof pressure, size of weights, &c., may be varied from the dimensions and form above described in valves ofdift'erent size or construction without departing materially from the nature ofmy invention, either as to the process or the mechanism.

The automatic valve which I have described can be conveniently placed in the derrick at the top of the tubing T, which leads downinto the well, and made to form an elbow with the tubing U, which leads to one side to the tank. The weights V, X, Y, and Z can be varied at pleasure, so that when the valve is placed on a well which flows best with a strong head of gas the valve, by being heavily weighted, can be made to open only at a high pressure. The reverse can be practiced with a well which flows best with a small pressure of gas. A spring and screw may be employed in place of the weights to regulate the degree of pressure.

By using such a valve as described I prevent the escape of gas between the time at which the well has emptied itself and until a head of gas and oil has collected and acquired sufficient pressure to throw the valve open. In so doing I not, only prevent the free escape of gas and save it to the territory, but I have the advantage of a great quantity of confined gas on hand each time the valve opens. This rushing out with great velocity carries outwith it more of the oil accumulated in the bottom of the well than will a less quantity of gas with a less pressure. It is also more likely to blow out any paraffine which may have gathered at the bottom of the well or in the tubing.

I also claim an advantage in the use of the process described in this, that at the instant the valve opens not only is the oil and gas in the cavity at the bottom of the well and in the tubing under great pressure, but this same pressure is exerted on the honey-combed porous rock in which the oil and gas exist for many rods in each direction from the well.

When the valve opens, instantly the pressure' is relieved at the bottom of the well. As the oil and gas rush out of the well the liquid and gas about the bottom of the well are induced to flow toward it and take the place of that which is thrown out by the flow. Thus as each flow takes place currents of oil and gas from ICC IIO

, flow longer than it otherwise would, and that the rock surrounding the well are induced toward it more effectually than can be done by any pump now in use, and as a consequence, by the use of this process, a well-is made to drain a larger territory and produce more oil than an adjoining well without the use of it.

Besides blowing out the par-affine and maklng a well drain alarger territory and produce more oil than it would without the use of the process, I further claim that by this process I save oil in preventingits evaporation and passing 06' as gas; that I prevent the accumula tion of paraffine and the heavy hydrocarbon substances from forming by hindering the escape of the lighter ones; that Iincrease the life of the territory by saving it in condition to I preserve it in condition so that when it quits flowing it is in condition to stand pumping better and longer than it otherwise would.

Having described my invention and the advantages gained by the use of it, what I desire to claim and secure by Letters Patent is- 1. The combination, with an oil-well tubing, of an automatic check-valve, substantially as and for the purpose described.

2. An oil-well tubing having a valve attached thereto, and in combination therewith,

4. The double-seated relief-valve B, in com-- bin ation with the piston, piston-rod, weightssuch as V, X, Y, and Z-guide K and its supports, nut g, and groove 0, substantially as described.

GHARLES H. MOKEE.

Witnesses:

E. P. GEARY, I TATLOW JACKSON.

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