US2779419A

US2779419A - Reinforced inflatable packer

Info

Publication number: US2779419A
Application number: US417559A
Authority: US
Inventors: Whitman D Mounce
Original assignee: Exxon Research and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 1954-03-22
Filing date: 1954-03-22
Publication date: 1957-01-29
Anticipated expiration: 1974-01-29

Description

FIG. 2.

W. D. MOUNCE REINFORCED INFLATABLE PACKER Filed March 22, 1954 lll/llll/ ll///////////////////////////// Afl/ll////////////////////////l/WI I y INVENTOR.

Wh/fman D. Maurice, By W fi m/Q A T TORA/E).

Jan. 29, 1957 FIG. 'l.

REINFORCED INFLATABLE PACKER Whitman D. Mouuce, Houston, Tex., assignor, by mesne assignments, to Esso Research and Engineering Company, Elizabeth, N. J., a corporation of Delaware Application March 22, 1954, Serial No. 417,559

4 Claims. (Cl. 166-187) This invention relates to well packers. More particularly, this invention relates to an improved well packer of sturdy construction which will not leak or break under the high pressures often found in well operations.

In well operations, a packer is often used to seal off a portion of the well in order to carry out certain opera tions above the location of the packer. In some instances, two packers are used vertically spaced from each other in order to seal off specific formations for the purpose of taking drill stem tests. It is essential while carrying out the aforementioned operations that one have a packer which can be depended on under very high pressures. A great many packers have been devised which usually include a rubber resilient member which is inflated in order to seal off the area to be investigated. These rubber packers have often been not sturdy enough to withstand the high pressures which reach as much as 5000 pounds per square inch or more, and have tended to leak or break. In attempts to provide a packer which can withstand the high pressures often found within a well, packers have been constructed which include a resilient expansible tubular member mounted about a shaft or tubing. The resilient expansible tubular member is connected, as its extremities, to an upper plate and a lower plate, at least one of said plates being slidable. Reinforcement cables, such as steel cables, may be included in the resilient expansible tubular member. However, if the plate at the high pressure end isfree to move on the shaft and the load of the hydrostatic head is carried by the plate at the low pressure end, there is a tendency for the reinforced rubber packer to be forced into the annular space be-- tween the low pressure end' plate and the hole wall. This produces sharp kinks in the reinforcing cables which prevent the packer from returning to its'original diameter when deflated. On the other hand, if the end plate at the high pressure end of the packer is fixed and the low pressure end is free to slide, no cable kinking occurs, but the full load of the fluid column is carried by the reinforcing cables, which limits the load which can be carried to the tensile strength of these cables. The reason the full load is carried by the cables is that if the plate on the low pressure end is free to 'slidewithout restraint, it offers no support to the load and the entire load is carried by the cables.

It is an object of this invention to divide the load between the two end plates in order that a greater load may be carried than would be possible otherwise.

Briefly described, my new inflatable well packer has a means for maintaining tension on reinforcement cables which are imbedded in the resilient inflatable packer thereby preventing the formation of kinks in the reinforcement cables. The tensioning means may, for example, consist of a hollow cylindrical top support, which is filled with liquid before the packer is inflated, and slidably mounted about a shaft. The cylindrical top support has disposed therein a cylindrical member which is rela tively stationary and rests on the bottom of the cylinder when the packet is not inflated. The cylindrical member 2,779,419 Patented Jan. 29, 195

extends laterally from said shaft. A liquid passageway is provided within the shaft and leads from the hollow cylinder so as to permit the flow of liquid from the cylinder upon any downward movement of said hollow cylinder, the downward movement causing the cylindrical member to force the liquid through the liquid passageway.

The liquid passageway leads to a space defined by a second cylindrical member also mounted upon the shaft and having an upturned. flanged portion and a lower packer plate. The second cylindrical member serves to confine the liquid flowing into it and also serves to guide said lower packer plate. By this means, after the well packer has been inflated, any pressure exerted-against the packer, such as the pressure of a fluid column, is transmitted through the liquid passageway to the upper cylindrical support thereby tensioning the reinforcement cables imbedded in the inflatable resilient packer and dividing the load of the fluid column between the top support member and bottom support member.

-Various other objects, advantages and features of my invention will become more apparent from the following description taken in conjunction with drawing, in which Fig. 1 is a sectional. elevational view of my improved packer shown in the deflated position.

Fig. 2 is a sectional elevational view of my new improved well packer shown in an inflated position.

Referring to the drawing, and specifically to Fig. l, numeral 3 indicates a well into which my new pack-er has beeninserted. Though one packer is shown in the draw ing, it is to be understood that if it is desired to carry on operations which necessitate the use of twoor more packers, my invention can be equally effective by utilizing any number of packers each of which is of a similar construction to that shown in Fig. l. The packer is supported by a cylindrical shaft 4 about which are disposed an upper cylindrical plate member 5 and. a lower cylindrical member 6.

Plate members

5 and 6 are coaxial with the shaft 4 and are vertically spaced from each other. Connected to said

plate members

5 and 6 by vulcanization the accompanying 1 and bonding is a resilient and eX-pansible tubular member 7. These plates are movable longitudinally along shaft 4 and hence move toward one another when the resilient member 7 is inflated. In order to provide a sturdier resilient member 7, a plurality of reinforcement cables 8 may be imbedded longitudinally in said resilient and expansible member 7. Cables 8 may desirably be made of steel although it will be understood that other suitable material may be employed.

In order. to inflate the packer 7, a tubular passageway 10 is provided. This passageway is connected to a pump (not shown) or any other suitable means for inflating and deflating the packer member 7 and opens into the annular space between resilient member 7 and shaft 4. A lower.

end plate cylindrical receiving member 11 having an annular flanged portion 12 is integrally connected to the cylindrical shaft 4, the cylindrical receiving member 11 serving to slidably receive the lower end plate member 6. The lower end plate member 6 has a reduced diameter portion 13. The reduced diameter portion 13 fits snugly into the annular flanged portion 12 of the receiving member 11.

A cylindrical cap 14 is integrally connected to the top. support plate 5 therebyformiu'g with said top support shaft 4 and into a chamber 18 (Fig. 2} defined by plate 6 and receiving member 11.

If the packer is utilized for taking drill stem tests, an additional passageway 9 (shown in dotted lines) must be put into shaft 4, passageway 9 serving to conduct to the surface the formation fluid to be tested.

In Fig. 2 there is shown my new improved packer in an inflated position. As is shown in Fig. '2, the upper plate and the lower plate 6 have moved toward each other thereby forcing the liquid contained within the hollow cylindrical member 16 through the passageway 17 into the space 18 which is formed between the lower plate member 6 and the receiving member 11 due to the upward movement of the lower plate member 6. The liquid contained in space 19, the liquid passageway 17 and the space 13, remains the same in volume because any decrease in volume in space, 19 results in an equal increase in vol ume in space 18 since the cross sectional areas of the spaces 19 and 13' are the same; Hencethere is no longitudinal movement of the resilient tubular member 7 during its lateral expansion.

To prevent the escape of liquid through the small spaces between the sliding surfaces of my new packer, it is advisable to include rubber o-ring 20 in a groove formed in cap 14, rubber O-ring 21, placed in a groove formed in the cylindrical member 15, rubber O-ring 22, in a-groove formed in plate member 5 and rubber O-

rings

23 and 24 in grooves formed in plate member 6.

In operation, therefore, the packer is first lowered into the well to the location where it isdesired to either seal off the well or, in the case where two packers are utilized, to take tests of specific formations within the Well. The

packer is then inflated by means of passageway until it fits firmly against the side of the well. After the packer has been inflated, any pressure such as that due to the hydrostatic mud column exerted on the packer tends to push plate member 6 downwardly. This pressure is transmitted through the liquid in space 18, tube 17 and space 19 to the upper portion of the hollow cylindrical member 16. The upper portion of member 16 is integrally connected to the upper plate 5 so that the force exerted against the upper portion of the cylindrical member exerts an equal force on the upper plate 5. Hence the steel cables 8 and the resilient member 7 are maintained under tension and no kinks will form within the steel cables. Also, the hydrostatic load is divided between

end plates

5 and 6 in order that a greater load may be carried than would be possible otherwise.

The above described packer apparatus is given only for illustrative purposes and should not be regarded as limiting the invention the scope of which is set forth in the following claims.

I claim:

1. In a well packer, the combination of: a shaft, a coaxial plate; a coaxial hollow cylinder vertically spaced from said plate; a resilient and expansible tubular member connected to said plate and to said hollow cylinder, said plate and said cylinder being movable toward one another in response to the expansion of said resilient and expansible tubular member; a plurality of reinforcing cables imbedded longitudinally in said resilient and expansible tubular member substantially along the entire length thereof; a passageway extending longitudinally within said shaft for inflating said resilent and expansible tubular member; a plate receiving'member integral with said shaft and adapted totslidably receive said plate, said plate and said plate receivingrnember defining a chamber; a solid cylindrical member coaxial with said shaft, said solid cylindrical member being disposed within said hol- 10w cylinder; at second passageway within said shaftcommunicating with said chamber at one end and with said hollow cylinder above said solid cylindrical member, said second named passageway being filled with a liquid providing pressure communication between said chamber and said hollow cylinder and serving, after said resilient and expansible tubular member has been inflated, to transmit any well pressure exerted against said plate tending to decrease the volume of said chamber to said hollow cylinder thereby tensio'ning said plurality of reinforcing cables.

2. In a well packer the combination of. a shaft, a coaxial plate, a coaxial hollow cylinder vertically spaced from said plate, a resilient and expansible tubular membcr connected to said plate and to said hollow cylinder, said plate and said cylinder being movable toward one I another in response to the expansion of said resilient and expansible tubular member, reinforcing means in said re- 7 silient and expansible tubular member extending substantially along the entire length thereof, a passageway extending longitudinally within said shaft for inflating said resilient and expansible tubular member, a plate receiving member integral with said shaft and adapted to slidably receive said plate,said plate and said plate receiving member defining a chamber, a solid cylindrical member coaxial with said shaft, said solid cylindrical member being disposed within said hollow cylinder, a second passageway within said shaft communicating with said chamber at one end and with said hollow cylinder above said solid cylindrical member, said second-named passageway being filled with a fluid providing pressure communication be tween said chamber and said hollow cylinder and serving after said resilient and expansible tubular member has been inflated to transmit any well pressure exerted against said plate tending to decrease the volume of said chamber to said hollow cylinder.

3. A well packer comprising a shaft, fluid-movable spaced apart first and second packer supporting means slidably and sealingly arranged on'said shaft, a tubular inflatable packer member surrounding said shaft and secured at its ends to said first and second supporting means, rcinforcing means in said packer member extending substantially the entire length thereof, a first passageway in said shaft communicating with the interior of said packer member adapted to supply fluid for inflating said packer, first stationary means on said shaft cooperating with said first supporting means toprovide a first fluid-tight chamber above said first stationary means, a second stationary means on said shaft cooperating with Said second supporting means to provide a second fluid-tight chamber below said second supporting means, and a second passageway in said shaft fluidly intercommunicating said first and second chambers, whereby after said packer member has been inflated a load on said inflated packer member resulting from external well pressures will be divided between said supporting means.

4. A device as recited in claim 3 wherein said reinforcing means comprises longitudinally extending cables and said shaft is provided with a third passageway extending References Cited in-the file of this patent UNITED STATES PATENTS 1,801,353 Lancet al. Apr. 21, 1931 Brundred'et al Nov. 9 ,1937