US2787125A

US2787125A - Underground storage system

Info

Publication number: US2787125A
Application number: US320297A
Authority: US
Inventors: George R Benz
Original assignee: Phillips Petroleum Co
Current assignee: Phillips Petroleum Co
Priority date: 1952-11-13
Filing date: 1952-11-13
Publication date: 1957-04-02
Anticipated expiration: 1974-04-02

Description

April 2, 1957 G. R. BENZ 2,787,125

UNDERGROUND STORAGE SYSTEM Filed Nov. 15, 1952 3 Sheets-Sheet l INVENTOR.

April 2, 1957 G. R. BENZ 2,787,125

UNDERGROUND STORAGE SYSTEM Filed -Nov. 13, 1952 3 Sheets-Sheet 2 IN V EN TOR.

(iJHBmz A ril 2, 1957 G. R. BENZ 2,787,125

UNDERGROUND STORAGE SYSTEM Filed Nov. 13, 1952 3 Sheeds-Sheet 3 PROPANE DETECTOR I JINVENTOR.

611?. Benz -D- 4 MM 3" M AT ORNEY pressure of the stored material in a safe manner.

:problem becomes extremely acute where it isnecessary oil-season.

limestone formations.

z,7s7,1 2s x UNDERGROUND STORAGE SYSTEM George R. Benz, Bartlesville,kla., assignor to Phillips Petroleum Company, a corporation of Delaware Application November 13, 1952, Serial No. 320,297 Claims. (CI. 61- 5 This invention relates to underground storage systems.

The constantly. expanding production of liquefied petroleum gas hascreated a definite problem in providing suitable storage facilities for this material. Due to the high vapor pressure of. liquefiedpetroleum gas, particularly 0 one, the cost of storage in surface equipment, such as steel tanlas, becomes excessive due to the massive construction required to withstandthe vapor This to store large quantities of such materials during the in addition to the expense involved, the use of steel tanks is limited by shortages in production.

In order .toovercome these difficulties, it has been proposed to store liquefied petroleum gas in porous water bearing formations, inwater leached caverns in salt formations, or in abandoned mines in impermeable shale or Further, underground concrete storage tanks and buried sections of pipe have been used to a limited extent in the storage of liquefied petroleum 'In accordance with this invention, an underground storage system for liquefiedpetroleum gas is provided which is capable of storing'extremely large quantities of this material at a very small unit cost. Further, a number of operatin and safety features are provided toinsure a long period of trouble-free operation of the storage system, easy and reliable introduction of the material storage facilities of novel construction and arrangement,

said facilities providing storage at a'minimum unit cost.

It is a further object toprovide a system in which the material can be easily introduced into the storage system and removed therefrom.

It is a further object to provide a system in which the pumping equipment, together withthe filling and dispensing lines, are readily accessible to workmen.

It is a still further object to provide an underground storage system capable of storing materials, such as propane, having a high vapor pressure for an'extended period with a minimum of operating ditficulties;

Various other objects, advantages and featuresof the invention will become apparent from the following detailed description taken in conjunction with theaccompanying drawings, in which:

Figure 1 is avertical sectional view,partially in elevation, of the underground storage system of this invention;

Figure 2 is an enlarged horizontal sectional view of the tunnel system, looking downwardj Figure 3 is an enlarged vertical sectional view of the lower portion of the shaft showingthe equipment positioned therein; I

Figure 4 is a sectional view takenalong the, line 4 4 of Figure 3, looking in the direction of the f'arifows; and

barrier l4 resultsin an escape ofpropane vapors from .19. of a large excavated region, as illustrated in Figure 1,

170, Figure .2,

2,787,125 Pfatented J Apr. 2, 1 957 Figure 5 is a perspective view of the end of the filling and dispensing conduit.

Referring now to the drawings in detail, and particularly to Figure l, the underground storage system of this invention includes one or more underground storage caverns, one of which is indicated by reference numeral it will be understood that each cavern can consist or, alternatively, the cavern can comprise a series of elongated individual storage chambers of cylindrical or rectangular cross section with the axis in a horizontal or vertical direction, as desired, all of the chambers defining the cavern communicating with a common, tunnel leading to a central shaft in the manner'hereinafter explained.

A tunnel 11 connects the cavern 1 0 with an enlarged shaft 12 extendingto the surface, and thebottom' region of the shaft preferably extends a short distance below the floor of the tunnel, thereby defining a recess or well 13. It will be understood that, where a plurality of caverns are utilized, each cavern can be connected to the central shaft by a separate, preferably horizontal,

tunnel. One such additionaltunnel is indicated byreierence numeral liar and it .connected to a cavern llla in accordance with the invention, each tunnel incorporates a sealing structure, preferably disposed at the end of the tunnel remote from the shaft, to the end that liquid or vapor cannot leak from the caverns into the tunnels or shafts, even where the stored material is quite volatile and, therefore, develops a highvapor pressure. A suitable sealing structure is shown in connection with tunnel 11, this structure including asmassive elongated barrier or plug. 14, preferably formedfrom poured concreteand disposedin the tunnel adjacent its opening into thecavern. Spaced toward. the shaft from the barrier. 14 is a second plug or barrier 15,.preferabiy formed from poured concrete and substantially shorter than the barrier 14. In this manner, a'chamber 16 isdefined intermediate the barriers 14, 15 which can be filled with water or other suitable liquid. Such liquid is introduced into or removed from the chamber 16. by a pipe 17 or one endltl of which eigtendsthrough thebarrier l5 and communi-cateswith the chamber 16, the other end of the pipe extending upwardly through the shaft, as indicated in Figure 3, to the. surface. p

, Preferably and advantageously, the liquid chamber to is water, and itis maintained under a pressure greater than that existing within the cavernitl to the end that any leakage which occurs through barrier 14 :will. be leakage of water from the chamber 16 into the cavern rather than lealQa g-e ot propane or other stored material from the cavern into chamber, 16. IIlSGlllt. cases, the water or other liquid in chamberlo is not pressurized and. the pipe 17 serves as a ventconnecting chamber lti with the surface. .Under such conditions, lealragemof propane through the barrier 14. will firstdisplace water and later propane from chamber 16 and resultin an overflow of Water from the pipe 17 at the surface, which ser as as anindica-tion of such leakage. it will be understood that the chamber can either be filled with water or merely be filled with air. .Where. air is present in the chambenjthe described leakage bf propane through the enemas pipe 17 at the surface which, when detected, indicates such leakage. The surface equipment associated with pipe 17 can, therefore, include a water storage tank 55,

a pump 56, a control valve 57, and/ or a propane analyzer tor detector s.

A large tubular conduit 20 extends through the barriers 14 and 15, one end 21 of the conduit extending into and communicating with the cavern and the other end 22 of the conduit extending into the tunnel 11. The end 22 of the conduit is closed and sealed by a flanged metal cap 23 bolted thereto. The portion of the conduit 29 extending through barrier 14 and, if desired through barrier is provided with a number of spaced fins or plates 24 which are embedded in the concrete or other material making up the barriers. it will be evident that the conduit '20 permits access to the cavern by a workman, and th fins embedded in the concrete are a material factor in preventing leakage of propane or other stored material through the concrete barriers. The barrier 15 afiords an additional sealing action, prevents water in chamber 16 from leaking into the tunnel, and serves as a sealing barrier in the event of the failure of barrier 14.

In further accordance with the invention, a filling and dispensing line 25 extends through the barriers i4, 15 and has one end 26 thereof disposed within the cavern 10. Preferably, the end part of the line is elevated, as by providing supports 27 beneath the line, and a slot 23 is provided at the under side of the line. In this manner, fluids are easily introduced into the line from the caverns or pass into the cavern through the line, and there is no tendency for the end of the pipe to become clogged by rocks or other debris accumulating at the bottom of the cavern. If desired, perforations can be provided in the end of the line, either to replace the slot 23 or in conjunction therewith, and additional perforations can be provided as at 29 in a portion of the line which rests upon the floor of the cavern to allow removal of residual portions of stored material.

It will be noted that the line 25 is provided with a valve 30 in the tunnel adjacent barrier 15. The line 25 extends through a T connection 31. to a valve 32 which, in turn, communicates with a line 25a incorporating a T connection 31a and a control valve 36a, the line 25a being positioned within the tunnel 114:. It will be understood that the line 25a leads to another cavern lltla of the underground storage system, and that similar lines can be provided leading through suitable tunnels to a third, fourth, or greater number of caverns, as desired. Branching from the T connection 31 is a line 33 incorporating a T connection 34, a check valve 35, a pump 36, a check valve 37, and a dispensing line 38 which extends upwardly through the shaft to the surface where it is provided with a suitable valved connection 33m leading to liquid loading facilities or other outlet to which the stored material is to be transferred. Branching from T connection 34 is a filling line 39 which, likewise, extends upwardly through the shaft 12 to the surface where it is provided with a valved connection 39m to a pump 3911, or other suitable device for introducing the material to be stored into the cavern. Assuming valve 32, Figure 2, to be closed and valve 30 to be open, it Will be evident that material introduced through filling line 39 passes through line 33, Figure 4, T connection 31 and line 25 into the storage cavern, flow of liquid into the pump being prevented by check valve 35. When the filling operation is completed, the up hole valve 39m in line 39 is closed and the material remains in storage. When pump 36 is actuated, material is withdrawn from the cavern through line 25, T connection 31, line 33, and check valve 35, and passed by the pump through check valve 37 and dispensing line 38 to the surface, it being understood that check valve 37 prevents reverse flow of liquid through the pump. Pump 36 can be actuated by an electric motor supplied with power by suitableleads, not shown, extending upwardly through the shaft to the surface. Alternatively, any other suitable prime mover can be provided to operate the pump, such as an internal combustion engine, the fumes being removed from the bottom of the shaft by the ventilating duct to be hereinafter described.

Further in accordance with the invention, a duplicate pumping and filling system is associated with pipe 251:. This system comprises parts corresponding to elements 33 to 38, inclusive, and these parts are indicated by like reference numerals followed by the letter a. At the sur face, lines 3%, 3% are provided with

valves

38p, 39p and. a. pinup 3%: corresponding to

valves

38m, 39m and pumps 3911, respectively. With valve 32 closed and valve 30a open, the filling and dispensing operations are carried out in the manner already described to introduce material to be stored into the cavern associated with tunnel flu or to withdraw material therefrom. It will be evident, however, that by opening valve 32 the filling and dispensing system 33 to 39 or 33a to 3% can be used in connection with both caverns simultaneously. Furthermore, by proper opening or closing of valves 3% and 30a, filling and dispensing system 330 to 39a can be used to introduce material into or withdraw material from cavern .lii and, conversely, filling and dispensing system 33 to 39 can be used to introduce material into or withdraw material from the cavern associated with tunnel 11a. The pumping and dispensing systems are, therefore, completely flexible in that each such system can be selectively used in connection with either cavern or in connection with both caverns simultaneously.

As previously noted, it is an important object of the invention to provide an underground storage system wherein the valves, pumps, and lines for introducing material into storage and Withdrawing material therefrom are readily accessible to workmen. To this end, the underground storage system of this invention incorporates a hoist 45, Figure 1, which is suspended by a cable 46 and which is movable vertically within the shaft by mechanism including a hoisting motor and winch 47, a derrick 48, and a sheave assembly 49. Since the shaft and the lower parts of the tunnels are sealed off by the barriers 14, 15 so as to prevent presence of the stored material or its vapors therein, the hoist can be utilized to transport workmen to the tunnel levels when adjustment of the valves is necessary, or when the pumps and other structure require maintenance work. The hoist mechanism can also be used to raise or lower equipment such as pipe, pumps, and the like in the shaft. Furthermore, when all the stored material is withdrawn from the cavern, the vapors can be removed by the dispensing lines and pumps from the cavern 10, for example, and workmen can enter the cavern through the conduit 20 for purposes of inspection or maintenance.

Preferably and advantageously, I provide a vent duct 50 extending downwardly through the shaft 12 to a position adjacent the level of the tunnels, and air can be forced downwardly through this pipe by a suitable blower 50a at the surface. Alternatively, a pump can be provided in conjunction with the line 50 to remove gases from the lower part of the shaft thereby drawing fresh air downwardly through the main part of the shaft. The latter procedure is particularly advantageous where the

pumps

36, 36a are driven by internal combustion engines for, in this case, the exhaust products are readily removed through the vent pipe and proper ventilation of the lower part of the shaft and tunnels is effected.

It will be apparent that I have obtained the objects of my invention in providing an underground storage region or regions of very high capacity for the storage of materials such as propane, the storage caverns being sealed off so that access can be had to the pumping and dispensing system by workmen, the hoist and ventilating pipes cooperating to effect this purpose. Furthermore, the dispensing and filling system is quite adaptable in that either of the pumps can be utilized to pump liquid from either or both caverns during servicing or repair of the other pump. It will be evident that the filling and dissary or desirable, and the pipe 26 is so supported that there is no danger of its becoming clogged by debris accumulating at the floor of the cavern.

While the invention has been described in connection with a present, preferred embodiment thereof, it is to be understood that this description is illustrative only and is not intended to limit the invention.

This case is related to Serial No. 330,856, filed January 12, 1953, now Patent No. 2,749,714 issued June 12, 1956.

I claim: 1. In an underground storage system, in combination,

an underground storage cavern, a shaft extending from the surface of the earth to a region adjacent said cavern,

a tunnel connecting said shaft with the bottom region of said cavern, a barrier "in said tunnel constructed and arranged to seal same against the flow of stored material frornjthe cavern to the shaft, a fluid Withdrawal and introduction pipeline extending from the shaft through said tunnel and said barrier into said cavern, a T connection in said pipeline adjacent the shaft, a control valve in said pipeline between theT connectionand said barrier, a filling conduit extending from said T connection upwardly through the shaft to the surface, and a dispensing system communicating with said T connection, said dispensing system including a check valve preventing flow of fluid from said filling line into the dispensing system, a pump having its suction connected to said check valve, and a dispensing conduit connected to the discharge of said pump and extending upwardly through said shaft to the surface.

2. In an underground storage system, in combination, a pair of underground storage caverns, a shaft extending from the surface of the earth to a region adjacent said caverns, tunnels connecting said shaft with the respec tive bottom regions of said caverns, a barrier disposed in each tunnel and constructed and arranged to prevent flow of stored material from the cavern into the shaft, individual pipelines extending from the shaft through the tunnels and barriers to the respective storage caverns, a common valve communicating with said pipelines, a control valve in each pipeline disposed between said common valve and the associated barrier, and filling and dispensing systems connected to the respective pipelines at a position between the common valve and the control valve, each filling and dispensing system including a filling conduit communicating with the pipeline, a check valve branching from said filling conduit and disposed to prevent fluid flow from the filling conduit therethrough, a pump having its suction connected to said check valve, and a dispensing conduit connected to the discharge of said pump and extending upwardly through said shaft to the surface.

3. In an underground storage system, in combination, an underground storage cavern, a shaft extending from the surface of the earth to a region adjacent said cavern, a tunnel connecting said shaft with the bottom region of said cavern, a pair of spaced barriers in said tunnel extending across the entire cross sectional thereof so as to seal the tunnel against passage of stored material from said cavern, means including a conduit extending from the shaft through both barriers to the cavern for introducing material into the cavern and withdrawing material therefrom, and a pipe extending through the barrier nearest the shaft and having one end thereof communicating with the region between said barriers, said pipe extending upwardly through said shaft to the surface.

4. In an underground storage system, in combination, a plurality of underground storage caverns, a shaft extending from the surface of the earth to a region adjacent all of said caverns, tunnels connecting said shaft with the bottom regions of each of said caverns, a pair of spaced barriers in each tunnel, each extending across the entire cross section thereof so as to seal the tunnel against passage of stored material from said cavern, conduits extending from the shaft through the barriers into the caverns for introducing material into thecaverns and withdrawing material therefrom, and pipes extending through the barriers nearest the shaft, each pipe having one end opening into the region between saidbarriers and the other end extending upwardly through said shaft to the surface. i

5. In an underground storage system, in combination. an underground storage cavern, a shaft extending from the surface of the earth to a region adjacent said cavern, a tunnel connecting said shaft with the bottom region of said cavern, a pair of spaced concrete barriers in said tunnel, each extending across the entire cross sectional area thereof so as to seal the tunnel against passage of stored material from said cavern,means including a con duit extending from the shaft through both concrete barriers to the cavern for introducing material into the cavern and withdrawing material therefrom, a pipe extending through the concrete barrier nearest the shaft and having one end thereof communicating with the region be tween said barriers, said pipe extending upwardly through said shaft to the surface, an enlarged conduit extending through both barriers, one end of said enlarged conduit communicating with said cavern and the other end of said enlarged conduit opening into said tunnel, said other end of the enlarged conduit having a cover plate secured thereto, and fins secured to said enlarged conduit and embedded in said concrete to improve the sealing action of the barrier.

6. In an underground storage system, in combination, an underground storage cavern, a tunnel communicating with the bottom region of said cavern, a pair of spaced concrete barriers in said tunnel adjacent said cavern, said barriers being constructed and arranged so as to seal the tunnel and prevent passage of fluid from the cavern into the tunnel, filling and dispensing means for said cavern including a pipeline extending through the tunnel and both of said barriers into the cavern, and means for introducing fluid under pressure into the region of the tunnel bounded by said barriers, and fluid within said region at a pressure greater than the cavern pressure so that any leakage occurring through the barrier adjacent said cavern is from said bounded region into the cavern.

7. In an underground storage system, in combination, an underground storage cavern, a tunnel communicating with the bottom region of said cavern, a pair of spaced concrete barriers in said tunnel adjacent said cavern, said barriers being constructed and arranged so as to seal the tunnel and prevent passage of fluid from the cavern into the tunnel, filling and dispensing means for said cavern including a pipeline extending through the tunnel and both of said barriers into the cavern, means for introducing fluid under pressure into the region of the tunnel bounded by said barriers, and fluid within said region at a pressure greater than the cavern pressure so that any leakage occurring through the barrier adjacent said cavcm is from said bounded region into the cavern, and an enlarged conduit extending from the tunnel through both barriers into the cavern, the end of said conduit within the tunnel being closed by a cover plate, and fins secured to the conduit and embedded in said concrete to improve the sealing action of said barriers.

8. In an underground storage system, in combination, an underground storage cavern, a shaft extending from the surface of the earth to a point adjacent said cavern, a tunnel connecting said shaft with the base of said cavern, a pair of spaced fluid-tight barriers in said tunnel forming a chamber therein, a fluid stored within said cavern under pressure, another fluid occupying the chamber between the two barriers, said latter fluid being under a pressure greater than that of the fluid in the cavern to prevent leak- '3 age of the fluid in the cavern through-the barrier adjacent said cavern, means for admitting fiuids to said chamher and cavern, and means for Withdrawing fluid from said cavernv 9. In an underground storage system in combination, an underground storage cavern, a shaft extending from the surface of the earth to a point adjacent said cavern, a tunnel connecting said shaft with said cavern, a pair of spaced concrete barriers in said tunnel, each sealing the tunnel from fluid flow therethrough, a fluid stored Within said cavern under pressure, a liquid occupying the chantber between the two barriers, said liquid being under a pressure greater than that of the fluid in the cavern to prevent leakage from the latter to the tunnel, and a conduit extending from Within the chamber through the outer concrete barrier, tunnel, and shaft and terminating at a point near the surface of the shaft, said conduit being in open communication with the chamber and containing a column of the same liquid as that in the chamber so that a change in pressure in said chamber is indicated by a change in liquid level in said conduit.

10. In an underground storage system in combination, an underground storage cavern, a shaft extending from the surface of the earth to a point adjacent said cavern, a tunnel connecting said shaft with said cavern, a pair of 3 spaced fluid-tight barriers in said tunnel forming a sealed chamber therein, a fluid stored within said cavern under pressure, a liquid occupying said chamber, a conduit extending from Within the chamber through the outer barrier, tunnel, and shaft and terminating at a point near the surface of the shaft, said conduit being in open communication with the chamber, so that any substantial increase in pressure of the fluid in said cavern in excess of the pressure of the liquid in the chamber may be indicated by the escape of storage fluid from the top of said conduit.

References Cited in the file of this patent UNITED STATES PATENTS 2,114,038 Updegraif Apr. 12, 1938 2,200,665 Bolton May 14, 1940 2,433,896 Gay Jan. 6, 1948 2,459,227 Kerr a- Jan. 18, 1949 2,508,949 Howard May 23, 1950 2,590,066 Pattinson Mar. 18, 1952 2,659,209 Phelps Nov. 17, 1953 2,661,062 Edholm Dec. 1, 1953 FOREIGN PATENTS 104,349 Sweden Apr. 21, 1942