US2465344A - Gas lifting device for flowing multiple zone wells - Google Patents

Description

March 29, 1949. E. o. BENNETT 2,465,344

GAS LIFTING DEVICE FOR FLOWING MULTIPLE ZONE WELLS Filed July 4, 1945 v` A i; 4 JNVENTOR.

' eowm @BENNETT BY v A ATTRNEYS 'generally indicated at 2 and-3.

Patented Mar. 29, 1949 GAS LIFTING DEVICE FOR FLOWING MULTIPLE ZONE WELLS Edwin 0. Bennett, Houston, Tex., `assignor to Continental Oil Company, Ponca City, Okla., a corporation of Delaware vApplication July 4, 1945, Serial No. 603,140

1 Claim. (Cl. 10S-1) This invention relates as indicated to an improved method for producing multiple zone wells, i. e., wells which intercept a plurality of superposed vertically spaced producing zones at least one of which is not under sufficient pressure to raise the oil therefrom to the ground surface.

Whenthe pressure in a producing zone is such v that it is insufficient to raise the column of oil in the well to the surface of the ground, such 'a well can be caused to continue production without pumpingif air or some other gas is introduced into the oil column in the well suciently below the surface of the ground so as to decrease the weight of this oil column sufficiently so that it will be forced upwardly by the pressure available in the producing zone. While this expedient has been utilized in wells producing from a single zone, it has never been accomplished successfully in wells intercepting a plurality of zones and especially where it is necessary to maintain. separate the oil produced from each zone.

It is, accordingly, a principal object of my invention to provide a method capable of achieving the foregoing desirable result.

Other objects of my invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention. may be employed.

In said annexed drawing: I

Fig. l is a diagrammatic, broken, vertical section through a portion of a well intercepting two producing zones and illustrating one embodiment of the method comprising my invention;

Fig. 2 is a view similar to Fig. 41 but showing an alternative mode of operation of my improved process; and

Figs. 3 and 4 are, respectively, views similar to Figs. 1 and 2 but showing alternatively still another modification of my invention.

Referring now-more specifically to the drawing and more especially to Fig. 1, there is here illustrated a single well provided with a casing generally indicated at I, which vintercepts two vertically spaced super-posed producing zones The casing I has arranged preferablyV coaxially therein two strings of tubing generally indicated at 4 and 5, whereby there are provided within the case 2 portion of the well three substantially independent columns.

Positioned in the4 outer column, i. e., in the space between the tubing 4 andthe casing l, is

' an annular packer 6 of conventional design, and

similarly, in the intermediate column' between the tubing 4 and 5 is another packer 1, likewise of conventional design. Since packers of this character are available and well known to those familiar with the art, they have been illustrated diagrammatically.

In the embodiment of my invention illustrated in Fig. 1, the casing and each of the tubings is perforated in each of the producing zones, al-

' though it should be noted that the perforations in the tubing 6 may be at any point within or above the producing zone 2 and the perforations in the tubing 5 may be at any point within or above the producing zone 3.

A suitable gas, such as air, carbon dioxide,

natural gas, and the like, may be introduced uny der pressure by conventional means not shown into the intermediate column between the tubings d and 5. Such gas under pressure will be bled through the perforations in tubings t and 5 into the producing columns as illustrated, and such gas reducing the Weight of the rising column of oil in the producing zone will make possible the flowing ofthe column under the pressure available in the producing zone with which it is in communication.'

When a situation is encountered in the field where only one of the producing zones, as for example the lowermost, lacks suiicient pressurey to raise` the oil to the surface of the ground, then an expedient such as is illustrated in Fig. 2 may be employed in which only the tubing 5 is perforated and accordingly gas is admitted to only that column which is supplied by the producing zone in question. Here again, the perforations in the tubing 5 may be at any point within or above the producing zone 3, the location of such perforations being determined largely by the amount of pressure available in the producing zone and the depthof such zone.

The expedient illustrated in Figs. 3 andh Lemploying the same concentric arrangement of casing and tubing is adapted particularly for alternativeloperation of the two producing zones; the expedient illustrated in Fig. 3 operating the upper zone 2 while the lower zone 3 is broken and the expedient illustrated in Fig. 4 producing the lower zone 3 where the upper zone 2 is broken.

In carrying out the modification of my invention as illustrated in Figs. 3 and 4, valved packers generally indicatedat 8.- 9, Il and Il are provided as well as a conventional packer I2. Valve packers 8, 9, III andlL are oi conventional design 'and adapted to be actuated by wires which extend upwardly in the column in which such valve packers are situated. For example, wire I3 is arranged to and connected with valve packer I for operation of the latter; wire I4 is connected with both valve packers 9 and Il! for simultaneous operation thereof; and wire I5 is connected with packer II for operation thereof.

When it is desired to produce only the upper zone, as illustrated in Fig. 3, valve packer 8 will be opened and the remaining valve packers will be closed. Air or other gas under pressure is introduced to the center column, i. e.; into the tubing 5 from which it is bled through the perl forations in such tubing and the perforations in closed and the remaining valve packers will be opened whereupon the air or other gas from the tubing 5 will be admitted to the column between the tubings 4 and 5 thereby raising the oil column in such space as produced from the lower zone 3. Generally an arrangement such as illustrated in Fig. 4 will be operative without the provision of any additional valving means; however, should the pressure in the upper zone 2 be suillcient to drive the oil from such zone into the intermediate column, this can be prevented by suitable available valving means effective to shut oiI the perforations in the tubing l in the area oi the upper zone 2.4

From the foregoing description, it will be observedthat I have provided a method whereby a single well intercepting a plurality of producing zones may be operated so as to provide a gas lift for the stream produced from each zone while maintaining separate production from each zone. Detailed illustration or description of the apparatus necessary has not been given since all of the described apparatus required for the perl upper zone 2, then the valve packer 8 will be l formance of the several steps is old and well known in the art and familiar to those skilled in the art.

Other modes of applying the principle oi the invention may be employed, change being made as regards the details described, provided the teatures stated in the following claim or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

Means for owing oil from two vertically spaced, superposed producing zones in a bore hole comprising a casing arranged within said bore hole provided with means of communication with each of said producing zones,y a nrst string of tubing arranged inside the casing. packer means arranged for sealing the annular space between said casing and said tubing at a point between said two producing zones, valved packer means arranged in the annular space between said casing and said tubing at a point above the upper producing zone, means communicating said i'lrst string of tubing with said casing at each of said producing zones, a second string of tubing arranged inside of said iirst l string of tubing, valved packer means arranged in the annular space between said ilrst and secl 1u:1n1tF.Nc:l-:s CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,242,166 Bennett May 13, 1941 Moore Oct. 13, 1942

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