US 3100023 A
Description (OCR text may contain errors)
All@ 6, 1963 R. J. cLEMENTs 3,100,023
MEANS FOR DETERMINING THE FLUID LEVEL IN A WELL Aug- 6 1963 R. J. cLEMENTs 3,100,023
MEANS EoR DETERMINING THE FLUID LEVEL 1N A WELL Filed Dec. 21, 1959 2 Sheets-Sheet 2 United States Patent Otiice 3,100,023 Patented Aug. 6, 1963 3,100,023 MEANS FOR DETERMINING THE FLUID LEVEL IN A WELL Roy J. Clements, Houston, Tex., assigner to Texaco Inc., New York, NX., a corporation of Delaware Filed Dec. 21, 1959, Ser. No. 860,870 Claims. (Cl. 181-5) This invention relates ygenerally to well sounding and in one specilic [aspect to apparatus for use in the acoustic determination of the `depth from the surface to the fluid level in a well.
Mechanical means `for determining the fluid level in a pumping well :are both time consuming `and expensive, inasmuch as the strings of sucker rods and tubing must be removed along with the pump, causing considerable delay in operations and increased expenses. Acoustic well sounding means use sound generated lat the top of a Well, which is reflected from the well fluid surface, the `time of such reflection being observed by the echo of the sound to determine the fluid level. In addition to the sound reflected by the fluid level, there are `also weaker reflections rfrom the succession of tubing collars, tubing catchers and other constrictions or enlargements of the gas column above the fluid level. From the known spacing of the collars on the well tubing, the sound velocity at various levels `and through various `gases can lbe readily calculated, land the distance to the depth of the Huid level in the well readily determined. Since the distance to the fluid level may be many thousands of feet, the sound pulses used in acoustic well sounding must be sufficiently strong t-o travel the distance to the luid and back to .a recording microphone without nullifying attenuation. j
Acoustic well sounding devices generally comprise .an assembly which includes pressure-proof pipes, fittings and instruments which `are mechanically connected to the well undergoing test. The latter instruments, known collectively as :a well -sounder assembly, include essentially a sound generator such as a blank cartridge tiring device, a microphone, Ia recorder, a wadd-ing catcher land bleed-olf control valve. Such a well sounder records directly on chart paper the sound pulses produced by the sound generator, e.g. -by the tiring of la blank cartridge, and directed into the 'annular space between the tubin-g and the casing of -a well, and the various reflections from the well.
It is known that in acoustic well sounding an apparatus may use compressed gas which is suddenly released as a source of sound, while other apparatus may employ blasting caps io-r the generation of sound. Still other devices utilize blank cartridges for the generation of sound but the sound `gener-ating and sound receiving means fare complicated `and have :a serious disadvantage in that disassembly and clean out of black powder `deposits from ythe tiring of blank cartridges is frequent.
Accordingly, it is an object of this invention to provide an improved sound gener-ating device for use in well sounding.
Another object of this invention is to provide an improved tiring device having :a greater efficiency for utilizing the energy from the tiring of a blank cartridge.
Still -another object of this invention is to provide lan improved well sounding gun which is simpler and easier to manufacture, and more econom-ical to use.
These and other objects, advantages and features `of the invention will be apparent from the following description when taken in conjunction with the accompanying drawings wherein:
FIG. 1 is `a schematic diagram of a well head installation showing the attachment of a well sounder assembly thereto;
FIG. 2 is a longitudinal cross-section on .an enlarged scale of the improved well sounding gun; and
FIG. 3 isa graphical representation of the dilierences in sound pulses obtained with my improved well sounding gun, as compared with the prior Iart practice.
The objects of the pnesent invention are achieved by providing a tiring device by which low frequency vibrations are sustained `for a greater period of time in order that the attenuation of the ygenerated sound be lessened.
Referring to FIG. 1 of the drawings, there is disclosed the Well sounder assembly, indicated generally at A, joined at the valve B tothe casing C, which houses the tubing D to deline the annular space C therebetween, a plurality of tubing collars, as indicated at D', and a series of sucker rods at E, the valve at B being used as a shut-olf between the w-ell, and the well sounder assembly at A.
'Ilhe Well sounder assembly includes the Well sounding gun, indicated generally at F, FIG. 1, rand in detail in FIG. 2, a transducer, viz. a microphone, at G, which converts sound pulses to electrical impulses and transmits them t-o the recorder, indicated at H, and a bleed-oft' control valve at I, provided -to permit the release of pressure in the well sounder assembly after the valve B is closed, so that the assembly can be removed. To prevent wadding from the cartridge lired by a well lsounding -gun from entering the well, a wadding catcher is interposed at J at the downstream end of the Well sounder assembly adjacent the joint with t-he valve B at the well head structure.
Referring to FIG. 2, there is disclosed in detail the well sounding gun F comprising means (12) for :supporting a blank cartridge (20) in -ring position, means for tiring the blank cartridge, and means (16) for connecting the firing means to the well sounder assembly and into position for tiring. The means `for firing the blank cartridge include the breech block, with the firing pin and hammer housed therein. The details of this means for tiring including the cocking and safety catches and sear pin are the subject of the copending and coassigned application =for patent for a Well Sounding Gun, Serial No. 588,533, iled May 31, 1956, now U.S. Patent No. 2,993,554, of which this application is a continuation-impart.
The well sounding gun F is joined to the pipe structure 10 of the well sounder assembly by means of the internally threaded barrel housing 11, which supports the gun barrel 12, the threaded connection being of sufcient strength to withstand the high pressure of the well which may reach 1500 or more pounds per square inch. The breech block 13, supporting the tiring pin assembly, indicated generally at 14, and the reciprocably mounted striking hammer assembly, indicated generally at 15, is located in operative position with respect to the barrel 12 ,by means of the internally threaded union .nut i6, which engages external threads on the barrel housing 11. The nut 16 has an inwardly extending flange portion 17 which fits against the outwardly extending liange portion 18 of the breach block 13 at its coupling end, with gasket sealing means shown at 19.
The barrel 12, of uniform cylindrical cross section, is provided with a choke or restricted portion at 12a, in the form of an inner annulus or rim of uniform dimension thereby to decrease abruptly the cross-sectional area of the barrel 12 at its exit end. It has been found that this combination of barrel and rim choke provides for more eliicient utilization of the enrgy from the tiring of a blank cartridge, thus permitting the use of a smaller cartridge containing less powder and consequently reducing the costs therefor, as well as the replacement expense of parts corroded by excessive gases and deposits from cartridges burning more powder. In a preferred embodiment, the tiring device is designed to accommodate a 410 gauge shotgun shell, filled specially with low velocity, black powder, as compared with the prior use of a 10 gauge shotgun shell, and the barrel length is about 12 inches long. The choke itself is 1&4 of an inch in height and extends as an inner rim over the last 1A inch of the exit end f the barrel.
It is considered thatthe barrel having a rim choke at the exit end as disclosed herein acts as a surge chamber for releasing the energy emanating from the firing of al blank cartridge in a controlled fashion through the 1&4" constriction. This controlled release generates a pulse of lower frequency content than if no constriction had been there. FIG. 3 illustrates the different types of pulses obtained with 4and without the use of a choke. The pulse obtaind through the choke structure disclosed herein has a lower frequency than if the constriction defining the surge chamber were not used. In this manner, the lower frequency vibrations obtained from cartridges -burning black powder are sustained and nulifying attentuation is avoided, while dispensing with the bulky prior art yapparatus and using scaled down equipment and a smaller charge.
Thus there has been shown and described a means by which a sound generated with predominant low frequency vibrations is sustained to more effectively employ acoustic well sounding devices for the determination of the fluid level in a well.
Obviously, many modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and therefor, only such limitations should be imposed as are indicated in the appended claims.
1. In an acoustic apparatus for use in the determination of the depth of the fluid level in a well having tubing and casing therein and so defining an annular space therebetween, the combination of a first means for generating predominantly low frequency sound pulses having communication with said annular space, a second means joined to said first means and receiving reflections from said low frequency sound pulses from said fluid level and converting said refiections into electrical impulses, and having communication with said annular space also, and a third means for recording said electrical impulses joined to said vsecond means and receiving reections whereby the magnitudes thereof are indicated from which the depth of said fluid level is determined, said first means for generating predominantly low frequency sound pulses comprising a barrel having a cylindrical cross section for receiving a blank cartridge at one end thereof and having a choke at the exit end thereof, said choke comprising an internal annular rim for abruptly reducing the cross sectional area of said barrel, and means for firing a cartridge seated in said barrel joined in operative position thereto.
2. In combination with a producing well having casing and tubing therein and so `defining an annular space therebetween, acoustic well sounding equipment comprising a assembly with said well, said assembly comprising sound generating and receiving equipment including a device for producing a predominant low frequency content pule, said device comprising a barrel having an inner annulus to define la rim choke 4at its exit end and adapted to receive a blank cartridge at the other end thereof and means for firing the cartridge seated in said barrel joined thereto, means in communication with said device and receiving sound reections from said `annular space and converting said reflections into electrical impulses, and means for recording said impulses joined to said means receiving sound reflections, said rim choke at the exit end abruptly decreasing the cross sectional area of said barrel.
3. In a well sounder assembly for use with acoustic well sounding equipment including a transducer and electrical recording means interconnected therewith, means for generating a sound of predominantly low frequency vibration content in -communication with said transducer and comprising a cylindrical barrel having an internal annular restriction to define a rim choke `at the exit end thereof and receiving a blank cartridge at the other end, means for firing the cartridge seated in said barrel joined thereto, and means interconnecting the sound generating and firing means with said well sounding equipment, said rim choke at the eXit end aJbru-ptly decreasing the cross sectional area of said barrel.
4. A cartridge firing device in combination with acoustic well sounding equipment including interconnected transducer and electrical recording means comprising a barrel having a choke at the exit end thereof, said choke comprising an internal annular restriction in said barrel for reducing abruptly the barrel cross section, said barrel receiving the cartridge at the other end thereof and being uniform in cross section to provide an unimpeded sound well sounder assembly and means interconnecting said j path in said barrel between the cartridge seated and fired therein and said choke at said exit end, means for firing the cartridge seated in said barrel joined thereto'and positioned axially with respect to said barrel and the cartridge seated therein, and means interconnecting said ydevice in operational relationship with said acoustic well sounding equipment.
5. In the device as defined in claim 4, said barrel having a length of about 12 inches and being adapted to receive a 410 gauge shotgun shell, said choke at the exit end thereof being 1;@4 of an inch in height and extending the last 1A inch of said barrel.
References Cited in the file of this patent UNITED STATES PATENTS 602,422 Batcheller Apr. 19, 1898 1,772,656 Abbott Aug. 12, 1930 y 2,232,476 Ritzmann Feb. 18, 1941 2,560,911 Wolf July 17, 1951 2,900,752 Browning Aug. 25, 1959