US2943640A - Manifold for dual zone well - Google Patents

Description

July 5, 1960 JAMES MANIFOLD FOR DUAL ZONE WELL 3 Sheets-Sheet 1 .Filed Sept. 11, 1956 .Hlli'i ma k M M w July 5, 1960 G. JAMES MANIFOLD FOR DUAL ZONE WELL 3 Sheets-Sheet. 2

Filed Sept. 11, 1956 IN V EN TOR. far/0r: jar/7a.:

y 1960 G. JAMES 2,943,640

MANIFOLD FOR DUAL ZONE WELL Filed Sept. 11, 1956 3 Sheets-Sheet 3 United States Patent 7 2,943,540 V MANIFOLD FOR DUAL ZONE WELL Gordon 'James, Houston, Tex., assignor to Gulf Oil Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Sept. 11, 1956, Ser. No. 609,320 2 Claims. (Cl. 137-594 This invention relates to apparatusfor the control of flow from oil and gas wells and more particularly to apparatus for installation at the well head of a dual zone well to control the rate of flow from each zone.

Usually it is necessary to control the rate at which oil is produced from wells at a rate somewhat lower than would flow through wide open tubing and lines at the well head either because of laws setting maximum allowable production or in order to maintain pressure on. the reservoir. The usual method of control of the produc-I tion from the well is by installation of an orifice or section of pipe of restricted diameter co'mmonly referred to as a choke, in the lines delivering the oil from the well. Changesinthe rate of flow can be obtained'by replacing the choke with one of a different size. The chokes are subject to severe wear and corrosion because of the entrainment of sand' by the oil produced or the presence'of corrosive substances, principally sulfur compounds, in the oil, which alsomakes replacement .of the chokes necessary. Apparatus is required at the well head to isolate the choke from the pressureof the well and from any pressure that may exist in the delivery line from the well to storage apparatus to allow replacement of the choke. This apparatus, along with the necessary mixture valves andother'equipment required for safe operation of a well often results in bulky structures, vulnerable to damage, at the well head. i

Many wells are dually completed to permit production from more than oneoil producing horizon, thereby allowing "a saving in drilling and easing costs. In some instances "maximum allowable rates of production are set for each horizon. By producing simultaneously from two or more horizons, the rate of recovery of oil from a single well can be increased. Because of dilferent pressures on the different zones it is essential to keep the production from thekdifierent pay zones separated. This requiresseparate tubing strings and othercontrol equipment at the Well head, thereby tending to make the equipment even more bulky and more likely to be damaged,

for example,by rigs during reworking of a 'well.

This invention resides in a compact manifold for con 'trol of production from dual zone wells having separate passages for connection'through valves to the separate tubing strings from each of the different production zones in the w'ell,: and separate outletsfor the production from each'of the zones. Ducts from the passages to the outlets contain chokes limiting the rate of flo'w and valves arranged to permit-isolation of the chokes. Figure 1 is an elevation view of flow control apparatus for a dually completed well showing the' manifold connected with other well head equipment. c 5 Figure 2 is ahorizontal sectional view along section line II-11 in'Figure '1 with the valves Within themanifold in a closed position. 7 2 T Figure 3 is a horizontal sectionalview along the see-- .the manifold in theiclosed position.

Figure 4 is a vertical sectional view of the manifold t .9 3., i Patented July 5 1960 a bull plug 26 tapped to receive a test cock 28. Line tionline ILL-III in Figure 1', also showing the valves in l pipe 24 is connected to a plug valve 30 to which another section 32 of line pipe closed with a bull plug 34 and test cock 36 is co'nnected. The tubing strings 10 and 12 are supported within the tubing head 16 by conventional dual completion tubing hangers such as double tapered hangers, not shown in the drawings.

A tubing head top 38 is secured to the flanged upper end of the tubing head 16 by means of a hold down ring 40. Mounted on the upper end of the tubing head top 38'is a dual completion gate valve 42. Gate valve 42 is of Well-known construction having a pair-of separate passages extending therethrough communicating with the tubing strings 10 and 12 for separate delivery of the oil produced from each zone. A second dual completion gate valve 44 is mounted on the upper end of the gate valve 42. It is a common practice'to complete-a well with two master gate valves in series, leaving one wide openduring operation of the well to'avoid cutting of the gate and thereby insuring its'functioning'in the event of failure of the other gate valve. a

Connected to the upper flange of dual completion valve 44 is a dual completion manifold housing 46. The mani-T fold housing 46 has separate passages; to be more fully? described later, through it for separate delivery of production from tubing string 10 to an outlet pipe 48' and from tubing string 12 to an outlet pipe 50. A dual completion companion flange '52 is' secured to the upperend ofthe manifold 46. Companion flange 52"is drilled and tapped to receive bull plugs 54 and 55 to which gauge cocks 56 and 57 supporting gauges 58 and 59 are con-. nected. c

- As is best illustrated in Figure 4 of the drawings, a pair of passages 60 and 62 extend vertically upward through the manifold housing 46. Leakage at the upper and lower ends of the passages 60 and 62, where'they are connected to companion flange 52 and the upper flange of dual completion gate valve 44, respectively, is prevented by conventional sealing members, not shown, such as double tapered seals. A downwardly and lateraly extendlng port 64 connects the passage 60 with an upper hori' zontal duct 66. Duct 66 communicates through a conduit, not shown in Figure 4, with a bore 68 atthe same elevation as duct 66. An outlet 70 to which outlet pipe 48 is connected opens into bore 68. A port 72, similar to port 64, connects passage 62 with a lower duct 74 which communicates through a: conduit, not shown in Figure 4, with a bore 76. An outlet 78 to which outlet pipe 50 is connected opens into bore 76.

Referring to Figure 2 of the drawings, the' duct 66 extends horizontally from the rear face -80 of manifold housing 46 past the port 64 and intersects a conduit 82 extending horizontally through the. manifold at right angles tothe duct 66. Conduit 82 in turn intersectsibore 68 which extends through the manifold housing parallel to ductv66. A valve seat 84 is heldin duct 66 at a posiQ tion between port 64 and the intersection of the duct with the conduit 82 bya valve cage 86. A valve stem;88 movable longitudinally in duct 66 by means of threads engaging threads in a valve'bonnet 89 secured to the manifold housing 46 isadapted to engage the valve seat 84 and prevent flow from passage 60 through the manifold. Valve stem 88 extends outwardly through the valve cage 86, packing 90 and a packing gland 92 at the inner end of the bonnet 89.

In the embodiment of the apparatus illustrated in the drawings a variable choke is provided for control of the flow from tubing string to outlet 48. The variable choke consists of a choke orifice insert 94 screwed into the conduit 82 and a needle valve plug 96, the position of which can be varied by an adjustable choke assembly 98 to control the effective opening of the orifice insert '94. The end of the conduit 82 opposite the adjustable choke assembly is closed by a target 1G0 held in place by a bonnet 1-02 and studs 104. The target 180 contains a lead insert 106 which resists wear of the high velocity stream discharged from the choke.

A valve seat 108 is held in place in bore 68 by a valve cage 110, packing 112, and packing gland 114 in the manner described for valve seat 84. A valve stem 116 is adapted to engage the valve seat 108 and isolate the conduit 82 from pressure which may exist in the outlet pipe connected with outlet 70 when the orifice insert 94 is to be changed. Valve stem 116 is in threaded engagement with a valve bonnet 117 secured to the manifold housing 46.

Referring to Figure 3, a valve seat 118 is held in duct 74 at a position between the intersection of port 72 and duct 74 and the intersection of duct 74 with a conduit 120 by means of a valve cage 122. A valve stem 121 adapted to engage the valve seat 118 extends out of the manifold housing 46 through duct 74 and the valve cage 122. Leakage out of the housing along the valve stem 121 is prevented by packing 124 and a packing gland 126 at the inner end of a valve bonnet 127 secured to manifold housing 46. A positive choke orifice insert 128 is screwed into conduit 120 between the intersection of the conduit 120 with duct 74 and the intersection of the conduit with bore 76. The discharge end of the conduit 120 is closed by a target 130, similar to target 100. The inlet end of conduit 120 is closed by a bonnet 132 tapped to receive a bleeder valve 134.

Conduit 120 intersects bore 76 which in turn opens into outlet 78 for discharge of fluids from the manifold. A valve seat 136 is held in place in bore 76 between the intersection of the bore 76 with the outlet 78 and the intersection of the bore 76 with the conduit 120 by a valve cage 138. A valve stem 140 adapted to engage the valve seat 136 extends outwardly from the valve seat through the valve cage 138 and a valve bonnet 141 secured to the manifold housing 46. Leakage around the valve stem is prevented by packing 142 and packing gland 144.

The dual completion manifold has been illustrated with a variable choke in the upper conduit 82 and a positive choke in the lower conduit 120. The positions of the positive choke and the variable choke can be reversed or both of the conduits can be provided with the same type of choke which can be either a variable or positive choke. The conduits 82 and 120, and the bores 68 and 76, are, in effect, merely continuations of ducts 66 and 74.

During the normal operation of the dually completed well, production from tubing string 10 is carried upwardly through the tubing head 16 and dual completion gate valves 42 and 44 to the vertical passage 60 in the manifold housing 46. The flow continues through port 64 to duct 66. During operation of the well both of valve stems 88 and 116 are withdrawn from engagement with valve seats 84 and 108, respectively, to permit flow from duct 66 to conduit 82 and from conduit 82 through bore 68 to the outlet 70. Similarly valve stems 121 and 140 are in the open position and flow from tubing string 12 enters passage 62 and then proceeds via port 72, duct 74, conduit 120, positive choke 128, and bore 76 to outlet 78;

If it should become necessary to change one of the chokes, for example choke 128, valve stems 140 and 118 are screwed into engagement with valve seats 136 and 118, respectively, to isolate the choke from the pressure in passage 62 and the pressure in the outlet pipe 50 connected at outlet 78. Pressure in the conduit is relieved by means of test cock 134 after which bonnet 132 is removed from the housing and the choke 128 is replaced. Replacement of the orifice insei-s 94 of the variable choke assembly is accomplished in a like manner.

This invention provides a compact structure of high rigidity for well head connections of dually completed wells. The arrangement in the manifold of the ducts for one of the production zones above the ducts for production from the other zone reduces the lateral dimensions of the manifold and greatly increases the rigidity of the structure at the well head. Reduction of the lateral dimensions is important in reducing the leverage of any blow to the well head connections, which, combined with the added rigidity of the structure, reduces the damage which is likely to be incurred if the well head connections should be struck by a rig used in reworking or other servicing of the well.

I claim:

1. A dual zone manifold for separate control of fluid streams from a dual zone well comprising unitary manifold housing having a first end, a second end opposite the first end, a first side, and a second side opposite the first side; a first passage extending upwardly through the manifold housing near the center thereof; a second passage extending upwardly through the manifold housing adjacent the first passage; the first passage being positioned nearer than the second passage to the first end of the manifold housing; a first port extending from the first passage toward the first end of the manifold housing; a first duct extending into the manifold housing from the first side of the manifold housing between the first passage and the first end; said first duct intersecting the first port and continuing past the first port to a position closer than the first passage to the second side of the manifold housing; a first bore extending from the first side of the manifold housing into the manifold housing between the second passage and the second end of the manifold housing to a position closer than the second passage to the second side of the manifold housing; a first conduit extending through the manifold housing from the first end to the second end between the passages and the second side of the housing; said first conduit intersecting the inner end of the first duct and the inner end of the first bore; means for closing the ends of the first conduit; 2. first outlet extending inwardly from the second end of the manifold housing and intersecting the first bore; valve means in the first duct between the intersection with the first port and the intersection with the first conduit; valve means in the first bore between the intersection with the first outlet and the intersection with the first conduit; a choke in the first conduit between the intersection of the first conduit with the first duct and the intersection of the first conduit with the first bore; a second port extending from the second passage toward the second end of the manifold housing at a lower elevation in the manifold housing than the first port, a second duct between the second passage and the second end of the manifold housing extending inwardly from the second side of the manifold housing below the first bore; said second duct intersecting the second port and continuing past the second port to a position closer than the second passage to the first side of the manifold housing; a second bore below the first duct extending from the second side of the manifold housing into the manifold housing between the first passage and the first end of the manifold housing; a second conduit extending through the manifold housing from the first end to the second end between the passages and the first side of the housing; said second conduit intersecting the inner end of the second duct and the inner end of the second bore; means for closing the ends of the second conduit; a second outlet extending inwardly from the first end of the manifold housing and intersecting the second bore; valve means in the second duct between the intersection with the second port and the intersection with the second conduit; valve means in the second bore between V the intersection with the second outlet and the intersection with the second conduit; a'choke in the second conduit between-the intersection of the second conduit with the second duct and the intersection of the second conduit with the second bore; means closing the ends of the first and second ducts and the first and second bores to prevent flow through them out of the housing; and means for closing the upper ends of the first and second passages.

2. Apparatusas set forth in claim 1 in which the valve means in each of the ducts comprise a valve seat positioned in the ducts between the intersections of the ducts with the ports and the intersections of the ducts with the conduits; a valve cage in each of the ducts engaging the end of the valve seat nearest the intersection of the duct with the port; a valve stem in each of the ducts extending from outside of the manifold housing through the duct to engage the end of the valve seat nearest the port intersecting the duct; packing means surrounding each of the valve stems and engaging the outer ends of the valve cages to prevent leakage from the housing; and valve bonnets secured to the manifold housing adapted to compress each of the packing means against the valve cage to hold the valve cage against the valve seat.

References Cited in the file of this patent UNITED STATES PATENTS Waite Apr. 14, 1953

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