US2638917A - Reduction choke for oil and gas well systems - Google Patents

Description

May 19, 1953 L. c. CLAIR REDUCTION CHOKE FOR OIL AND GAS WELL SYSTEMS Filed Sept. 6, 1950 3 Sheets-Sheet 1 INVENTOR. (9 ovi z/ A TIORIVE Y L. C. CLAIR REDUCTION CHOKE FOR OIL AND GAS WELL SYSTEMS Filed Sept. 6, 1950 May 19, 1953 3 Sheets-Sheet 2 JNVENTOR.

$30M BY m ul 52 Wl A m 1 U H H IN V EN TOR.

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I I I 0 u May 19, 1953 REDUCTION CHOKE FOR OIL AND GAS WELL SYSTEMS Flled Sept 6 1950 Patented May 19,1953

UNITED STATES PATENT OFFICE REDUCTION CHOKE FOR OIL ANn GAS WELL SYSTEMS Louis C. Clair, Bernice, La. i 7 Application September 6, 1950, Serial No. 183,313.

7 Claims. (01. 137-340) My invention relates broadly to oil and gas well systems and -more particularly to an improved method of operation and construction of non-freezing reduction choke for use in such systems.

One of the objects of my invention is to provide an improved construction of reduction choke for oil and gas well systems in which the thermodynamic characteristics of the oil and/or gas flow are employed to provide a temperature gradient in a reduction valve system insuring continuous flow of oil and/or gas without channeling and without freezing. I g

Another object of my invention -is to provide a construction of reduction choke for oil and gas well systems in which a continuous flow of oil and/or gas may be maintained and the thermodynamic properties thereof utilized for maintaining flow, while prohibiting channeling and avoiding freezing in the flow path through the choke.

Still another object of my invention is to prooil and gas well systems in which a spirally arrangedbaflle surrounds an'expansion chamber in which I provide a regulatable reduction valve associated with the spirally arranged baffle within compact dimensions rendering the installation practicable in oil and gas well systems Where pressures of theorder of 2000 lbs. per square inch, or more, and temperatures of the order of 120 F. to 145 F. may be effectively controlled to develop temperatures of the order of 35 F.-40 F. at separator pressures of the order of 500-800 lbs. per square inch, the entire process being accomplished Without freezing.

A further object of my invention is to provide a method of operation of oil and gas well systems whereby a spiralling movement of oil and/or gas is employed for controlling temperatures within an expansion chamber and pressure and temvide an improved construction of expansion chamber for oil and gas reduction chokes which is disposed axially within a cylindrical warming chamber which is elevated in temperature by the nascent temperature of the incoming oil'and/or gas and the temperature cycle through the assembly balanced to insure against freezing while effecting the required reduction in pressure from 2000lbs. or more to separation pressure. 7

Still another object of my invention is to provide a combined temperature controlled valve chamber and expansion valve by which the nascent oil and/or gas well pressure andtem'perature may be applied to the temperature con trolled valve chamber and reduction in pressure effected through the expansion valve, while avoiding freezing during the drop from nascent -oil and/or gas pressures to separation pressures.

' 7 Still another object of my invention is to provide a construction of reduction choke for oil and gas well systems in which an expansion chamber is concentrically disposed withina warming chamber and a reduction valve arranged within the expansion chamber andthe said expansion chamber secured to a temperaturegradient extending longitudinally thereof and a pressure flow in .a controlled spiral direction from nascent gas and/or oil welltemperature to a separation temperature and pressure whil maintaining the system free of freezing.

Another object of my invention is to provide an improved construction of'composition temperature control system and reduction choke for perature reductions efiected without freezing.

Another and further object of my invention is to provide an improved method of operation of oil and gas well systems and an improved construction thereof as set forth more fully in the specification hereinafter following by reference to the accompanying drawings, in which:

Figure 1 illustrates the application of my improved method and apparatus to oil and gas well systems in connection with the separator system; Fig. 2 showsthe application of my invention to the well head or Christmas tree of an oil or gas well; Fig. 3 is a theoretical diagram explaining the theory of operation of the improved method and apparatus of my invention; Fig. 4 is a transverse sectional diagram taken on line l4 of Fig. 1; Fig. 5 is'a transversesectional diagram on line 5-5 of Fig. 1; Fig. 6 is a side elevational View of the apparatus of my invention; Fig. '2 is a longitudinal sectional View on an enlarged scale through the apparatus of my invention;

Fig. 8 is a view on an enlarged scale of the housing structure for the reduction valve and the reduction valve juxtaposed thereto as provided in the apparatus of my invention; and Fig. 9 shows the manner of assemblin the parts of the apparatus of'my invention.

My invention is directed to an improved method and apparatus for use in oil and gas well systems by which reductions in temperature encountered in oil 'and/ or gas wells may be reduced and controlled without channeling and without freezing. I have determined after considerable research and development that the nascent temperatures and pressures of oil and/ or gas may be employed in the production of forces around an expansion chamber for reducing a thermo-dynamic change concentrically regulated to an expansion chamber and a reduction in temperature and/or pressure efiected along a gradient which at the-outletfoff the expansion chamber may reach a pressure of 500-800 lbs. over a temperature range of from 35 l t-40 F., this control being accomplished without channeling and witliout' 'fr eezing. Here-" tofore in the art reduction of pressure and temperature in oil and gasvvell systems has been accomplished by an accumulation of frost and ice which eventually automatically shuts dow'iithe oil and/ or gas well. Heretofore'it has been-neces' sary to thaw out such frozen new lines by specially constructed line heaters with a'lo'ss b'y' evaporation of the lighter end products} The value (if butane, m thane, propane and ethane, andother end products; has considerably increased with in'-' dustrial developments and it'is important that these products be preserved which is accordplis hed' by niy method and-system. The preserva= tion of 'these' end products is one of the major accomplishments of the method and equipment of my invention. Municipal and government regulations which make mandatory the prevention of waste in the recovery and preservation of all oil and gas well products are complied with by use of the improved method and system of my invention.

Referring to the'drawi'ngs' in more detail, reference character l schematically represents aseparator connected through fluid discharge line 2 and control valve 3 to the inlet 4 of'the cylindrical warming chamber 5 of the equipment of my in vention. The cylindrical- Warming. chamber 5 is connected with a coupling at one end and with a header l at the other end. Because of the'pr'essures involved these connections are made with strong welds. The material of the cylindrical warming chamber is seamless steel pipe of very substantial strength. The coupling 6 projects beyond the end of a cylindrical warming chamber and there is attached thereto by a'wel-cl connection the choke cylinder 8. The choke cylinder 3 is also formed from Schedule 80, seamlesssteel pipe having a header 9 adjustably screw thr'eade'd into the interior of the choke cylinder 8.

A 180 tube turn I9 formedof Schedule 80, seamless steel pipe connects between the side of the warming cylinder '5 adjacent the coupling 6 to a position at one side of the choke cylinder 8 and immediately adjacent the coupling 6. The tube turn forms a path for the oil and/or gas which is moved at high velocity in a spiral path through the interior of cylindrical-warming chamher 5 by reason of the construction of spiral bafiie H which I provide therein. The spiral b'aliie H is formed on the exterior of the tubular expansion chamber 52 which extends axially through the cylindrical warming chamber 5 and is screwthreaded into header at one endand welded thereto at la and is screw-threaded into coupling 5 at (it at the opposite end and welded thereto.

These welds are accomplished during fabrication and before the application pf cylindrical warming 5. The assembly is accomplished by linearly slidchamber 5 over the coupling 0 and to the header ing warming chamber 5 over header 1 and coupling 5 with choke cylinder connected with Warming chamber 5 through turn pipe l0 as shown in Fig. 9.

The tubular expansion chamber i2 is axially aligned with the discharge pipe M- screw-threaded into the end of header '1 and which may lead to the separator or the storage tanks. The tubular er'zpansion chamber l2 receives at its opposite end the longitudinally extending choke seat 15', formed as illustrated more particularly in Fig. 8. The choke seat 55 the end thereof screw-threaded m coup-ling" 6' by nieans of screw-threads 15a on the' exterior thereof, engaging the screw-threads 6a interiorly of coupling 6. The choke seat [5 is cylindrical in contour and extends from the screw threaded-recess ta. in coupling 6 into the interior of tubular expansion chamber 12. The cholie's'e'at IE5 is provided at its inlet with a 12 frusto-conical valve seat or taper represented at 571", Theoutlet for the choke seat l5 is provided with an expanding or outwardly flared nozzle 5'50 discharged into tubular expansion chamberl2.

A conically shaped-valve I6 is aligned with the seat 15b and is variably controlled by means of rod l'!' which extends through header 9-.

In the form of my invention shown in'Fig'. 1 rod IT is automatically operated by adiaphragm m'o'to'r' valve shown generally at Hi. The diaphragmmotor valve'comprises-a casing i=9 which is suitably supported with respect to the'header 9 for aligning the diaphragm motcrvalve' i8 with the longitudinal axis of the warming cylinder 5 and the choke cylinder 8. The rod l'l, carrying valve ['6 thereon connects with an actuating'rod 20; the axial position of which is controlled by the diaphragm 2|. The diaphragm 21' is contained within a housing 22, one side of which is shown at 23 containing a gas inlet connection 24 and a gas discharge" connection 25. The supply of gas through inlet connection 24 is controlled by the fluid level in theseparator. As the fluid level in the separator rises to a given point a valve (not shown) is automatically opened-admitting gas to inlet connection 24 thus raising the diaphragm 2| and moving rod 20 and connecting rod I! to move valve l6 away from'seat [51), allowing fluid to discharge from the separator. After the fluid level is lowered in the separator the gas,- that increased the pressure against diaphragm ZLi-s discharged automatical ly through discharge connection 2-5 closing the valve Hi against seat I51) and stopping the flow of gas and/or oil in choke cylinder 4 to tubular expansion chamber 42. Diaphragm 24- is biased to a position in which valve I6 is normally seated against valve seat l5?) by means of coil spring 26 located within housing 22 and adj-usted frcm the exterior thereof by a screw device 21. Thus, an automatic control of valve I6 may be effected.

However, there are numerous instances in which the con-trolof valve i6 is required to be manually adjustable, as I have represented in Figs. 2 and- 7. In this arrangement, valve rod ll is externally screw-threaded as represented at llaand is engaged in internal screw-threads 9c in header 9. The screwthreaded rod H extends exteriorly of the choke cylinder 8 and is provided with a manually engageable handle 2 8 thereon whichmay be tripped manually for moving valve .16 to any desired position, with respect to seat l5o. A stufiiing box 29 is provided around rodl'l for controlling the gasket seal 30 and preventing leakage from choke cylinder 8.-

1 Thegas and/or oil at 2000 lbs, or more, bottom hole pressure, enters inlet connection 4 at one side of the end of cylindrical warming chamber 5 and is directed in a spiral path around tubular expansion chamber 12 by the spiral bafile H. The mass of spirally moving gas and/or oil traveling at high velocity is released at the opposite side of cylindrical warming chamber 5, at the opposite end thereof, into turn tube and directed into one side of the end of choke cylinder 8. From choke cylinder 8 the high velocity high pressure flowing gas and/or oil is admitted in a selected quantity by choke valve [6 through valve seat Ib and through a choke seat I5 for release through expanding nozzle l5c into tubular expansion chamber I2 from which the flow is directed into discharge pipe I4.

While the apparatus and method of my invention is applicable to a wide variety of conditions existing in the petroleum industry, involving various temperatures and pressures, I have selected for purposes of illustration certain characteristics to which I have found my invention applicable. That is, for bottom hole pressures of 2000 lbs. per square inch, or more, at a temperature range of 120 F.-l45 F. a spiral flow is secured confined by spiral baffle I l within cylindrical warming chamber 5 and directed through the turn tube I0 into choke cylinder 8. The temperature gradient through the cylindrical warming chamber 5 reduces longitudinally of the cylindrical warming chamber 5 because of the cooling effect of the expansion chamber I2, particularly at the nozzle position l5c. In certain installations this temperature gradient has been such that the turn tube ID for the initial temperatures of 120 F.-145 F., and the pressure heretofore noted, has been of the order of 80 F.- 105 F. The gas and/or oil, of the characteristics noted, when passed through the reduction valve I6 and valve seat l5b and through choke seat and expansion nozzle I50 reach a temperature range of the order of F.- F. The oil and/or gas is discharged at discharge pipe I4 at this temperature range and at pressures of the order of- 500-800 lbs. per square inch, and without freezing. The spiral control of the gas and/or oil prevents channeling and the concentric relationship of cylindricalwarming chamber 5 and tubular expansion chamber 12 insures operation of the system above freezing temperature. Thus I am able to obtain within compact dimensions highly efficient operation of the method and system of my invention.

In Figs. 2 and 6, I have shown the application of my invention as herein described to the Christmas tree 3| of an oil or gas Well leading through connection 32 to the valve 3 and inlet connection 4, as heretofore explained.

It will be observed that the piping leading to the cylindrical warming chamber 5 and the turn pipe I0 and the discharge pipe M are all of an interior diameter substantially equivalent to the radial distance between the cylindrical expansion chamber I2 and the inside wall of the warming cylinder 5 to eliminate all constrictions in the flow path except the constriction provided by the expansion valve l6 and coacting with the seat I5b. That is to say the internal diameter of turn pipe 10 is always greater than the radial distance between the outside wall of cylindrical expansion chamber I2 and the inside surface of warming cylinder 5 and also the diameter of the pipe constituting inlet connection 4. The reduction therefore is effected in a zone which is at elevated temperature and freezing during the expansion process is thus prevented.

In Fig. 9 I have shown the manner of assem-' bling the apparatus of my invention in which the unit formedby the coupling 6 and header 1,.

to assembled or disassembled position. The ar-' row indicates the direction of movement of the unit formed by cylindrical warming chamber 5, turn tube 18 and choke cylinder 8 during the disassembling of the apparatus. A reverse translatory movementis employed in assembling the apparatus. Thus the assembly and disassembly of the apparatus is very simple and may be effectedwithout any requirement for any consider-' able degree of skill. That is the assembly merely requires the sliding of the cylindrical warmingchamber 5 and the choke cylinder 8 into position over coupling 6 where the unit may be revolved to connect the end of Warming cylinder 5 with thethreaded header 1.

Sealed relationship is maintained between warming cylinder 5 and header 1 by a very tight screw-threaded connection supplemented by appropriate gaskets. A similar sealing connection is provided between the other end of warming cylinder Band coupling member 6 and between the end of choke cylinder 8 and coupling member 6 through appropriate gaskets. The header 9 connects with choke cylinder 8 through atight screw-threaded connection supplemented by appropriate sealing gaskets.

The temperature of high pressure oil and gas wells with which the equipment of my invention is associated is'related to the rat of production flow taken from the Well. The greater the flow at the high well pressures, the higher will be the.

temperature. The internal freezing temperatures of high pressure oil and gas are much different than the freezing temperatures at atmospheric pressure. These factors have all been taken into account in the development of the equipment of my invention. The performance of the equipment of my invention has been very effective in preventing the freezing of hydrates that form in oil and gas lines at the point of pressure reduction. The fact that the incoming hot oil and gas is forced to flowin a path adjacent the choke cylinder 8 and around the expansion chamber 12 prevents freezing at the pressure reduction position. The gradual cooling of the incoming oil and gas which is caused by passing over the expansion chamber insures a very close temperature range for the expanded oil and gas that has passed through reduction chamber, and without the Wide range temperature drop, therefore allowing hydrates that form in lines at the reduction point to pass without freezing.

While I have described my invention in certain of its preferred embodiments I realize that modifications may be made, and I desire that it be understood that no limitations upon my invention are intended other than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is as follows:

1. A reduction choke for oil and gas well systems comprising a tubular expansion chamber, a cylindrical screw-threaded header on one end thereof, a coupling member on the other end thereof and extending radially therefrom, a spiral bailie formed on the exterior of said chamber between said header and said coupling member, a cylindrical warming chamber, a choke chamber, a tubular member interconnecting said chambers,

5 connected meager w said "cylindrical' warmin'g chamber being screwthreaded" to engage-said screw th-readed header, both said warming chamber and said choke chamber being interconnected by said coupling member; a cylindricarheader carried by theend of said" chokachaniber and an adjustable valvememb'er' carried"by said last mentioned header and adjiist'abie thereinTOr' controlling said tubular. expansion" chamber.-

2. Ared'uction"choke foroil and gas well systerns comprising a tubularexpansiom chamber, a cylindrical header on" one end thereof; a c0upling member on the other end thereof and projecting radially therefrom; a spiral'baffle formed onsaidch'amber between said" header and said coupling, member and extending radially for 'a distance corresponding to the radii'o-f said cylindricalhea-der and-said coupling member, a. cylindricalwarming chamber, a choke chamber connected with the' end of said cylindrical Warming chamber, the diameters ofsaidchambers being suchtha't they-establi'sha snug fitwhen movedin an axial direction'over said coupling" chamber and said header, andmeans-securing saidrcylindrica'l' warming chamber to saidheader 'andto said coupling member.

S'jA reddc'tion choke for oil'and gas well'syste'nisas' setforth inclaim- 2'inwhich an expansion'valve is carried by'said coupling member'and connectedWith*said*tubu1ar expansion chamber.

42 A- reduc'tionchoke for oil and gas well systems as set forth in claim 2"in which an expansicn valve iscarried-by said coupling'means and projectsthrough said coupling member and concentrically-into=said-tubu1ar expansion chamber and -wherein'an adjustable valve iscarried by said choke'chamberand variably adjustable for ad'- just-ing saidexliansiorr valve.

5; A reduction choke for'oil and gas W611 systems-asset forth in claim 2' in which the discharge-connection is established through said head WiHFS'aidWJUbUMI expansion chamber and in which an intake connection isprovidedinone side of said warmi-ng chamber and in which a discharge connection extends from said warming chamber in a-== position adjacent said coupling m-em-ber and opposite-said intake connection.

65 A-reduction choke foroil and gas well'systerns as set"forth:iin. claim 2. in"; which: the"; disa connection: is. established: through said? head with said tubular expansion chamber'iand iniwhich aniintakeiconnection is provided in: one side. of saicllwarniing chamber, a dischargeccona necticn extending" from saidi 'warming' chamber: in' a position adj acentisaidaconpling member' and. opposite saidtintake connection, an expansion valve carriedby saidrcoupling'member anctad justableto variousx positiens in saidchokechame her, and a connection from. sa-iclilast't mentioned discharge connection to. said choke: chant-heron: the opposite side. of. saidncoupiing chamber: and; in a position immediately. adjacent said. expan'-' sion valve.

7. A" reduction chokeforroil' and: gas W61], SyS- teni'sincluding; a. cylindrical. Warming chamber having an intake inxone side adjacent: 13119-811115 thereof, an: outlet located at the oppositeciside adjacent-the other end thereof; a choketcham ber coariially ali'gnedrwith oneLendof saicl'iwarrrr ingchamber, a coupling member extending be"-. tween said Warmingchamber and saicl'c'nok'ei chamber coincident with the axis of each ofsaid' chambers, a connection between said". choke chamber and the saidoutlet of. said: warming. chamber, an expansion valvehaving a tubular expansion chamber supported by-saidicouplingmember and projecting throughsaid" warming; chamber, an adjustable: valve supportednby saidchoke chamber and adjustable axially of said: tubular expansion chamber-from thezexteriorof said choke and adischarge connection for the tubular expansion chamber-located at the end'or said warming chamber adjacenttheintake end thereof.

LOUIS C. CLAIR:

References Citedin the file of this patent.

UNITED STATES PATENTS Number Name Date 2,011,100 Woods. Aug. 13, 1935 2,181,654. Davenport Nov. 28,1939 2,191,323. Steenstrup Feb 20, 1940 2,463,892 Martin Mar. 8, 1949 2,471,448 Platon MayBl, 1949

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