US1677349A - Apparatus for lifting oil in oil wells - Google Patents
Apparatus for lifting oil in oil wells Download PDFInfo
- Publication number
- US1677349A US1677349A US716697A US71669724A US1677349A US 1677349 A US1677349 A US 1677349A US 716697 A US716697 A US 716697A US 71669724 A US71669724 A US 71669724A US 1677349 A US1677349 A US 1677349A
- Authority
- US
- United States
- Prior art keywords
- oil
- pipe
- tube
- well
- packer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000003129 oil well Substances 0.000 title description 5
- 239000012530 fluid Substances 0.000 description 21
- 239000007789 gas Substances 0.000 description 13
- 238000004519 manufacturing process Methods 0.000 description 12
- 238000000034 method Methods 0.000 description 8
- 241000191291 Abies alba Species 0.000 description 5
- 230000005484 gravity Effects 0.000 description 4
- 210000002445 nipple Anatomy 0.000 description 3
- 238000010276 construction Methods 0.000 description 2
- 238000005553 drilling Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 1
- 210000004907 gland Anatomy 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 230000000414 obstructive effect Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/12—Methods or apparatus for controlling the flow of the obtained fluid to or in wells
- E21B43/121—Lifting well fluids
Definitions
- This invention relates to an oil production apparatus for practicing the method of raising oil in oil wells.
- An object of this invention is 'the provision of anew apparatus by which 'the natural gas pressure in a well may be i'itilizedl without waste of gas pressure to raise the oil, -my method and apparatusproviding for the utilization of said gas pressure for raising the oil in the well as the level of oil falls in the oil strata.
- Another object of this invention is ⁇ the provision of an apparatusv for cleaning the well of obstructive matter'while at ,the saine time maintaining production and without killing the well.
- a further object of this invention 1s the provision of a pipe adapted to be raised and lowered in a well through regular production apparatus and without shutting off the production of fluid raised from the well.
- Figure 1 is a longitudinal section of a well and apparatus therein, and an elevational view ofapparatus above the well connected with the apparatus within the well.
- Fig. 2 is a .view similar to Fig. l, but illustrating the downward extension of apparatus in the well adjusted for operation when the oil in the well has reached a lower level than is shown in Fig. 1, the lower level of the oil being due to the fact that the oil supply has beeen partly exhausted,
- Fig. 3 is a detailed elevational view, part# ly in section, of apparatus above the well connected with the apparatus in the well.
- the numeral 7 inidicates a well extending into the strata 8 of oil bearin sands.
- the oil sands 8 are usu-l ally bounded by a superimposel layer 9 of rock or y.othersubstance which is comparatively impervious to the gas which natural- 1y accompanies the oil.
- a casing 1,0 extends through the Welland extends above the upper end thereof.
- the lower end portion of the casing 10, which extends into the oil bearing sands, is provided with a plurality of aperturesll which extend around the casing and permit oil from the surrounding sands to -flow into the casing.
- a verl tical tube 12 Within theH casing 10 is positioned a verl tical tube 12, the lower end of which may be in the oil bearing sands 8.
- the tube 12 extends upwardly through a casing head 13 which is secured to the upper end or head of the casing 10.
- the lower end portion of the tube 12 i ⁇ s ⁇ provided with a plug -or stopper 14 having peripheral male 'threads which engage-female threads .formed in the tube 12.
- a pipe 15 is positioned within the tube 12, the lower end portion "of said pipe passing through the plug 14 and extending below the oil level.
- the pipe 15 is slidable through i the packer 17 and through the stopper 14.
- the upper end of the pipe 15 is connected to a usual cage 19 perforated axially and laterally. To the upper end of the cage 19 is connected a pipe 21 extending upwardly through the casing lhead 18 and through an assemblage of apparatus 22, known to oil men as a Christmas tree.
- the pipe 21 ex-l tends above the Christmas tree and is provided with lateral apertures 23 which iti Fig. 1 is shown above and in Fig. 2 below 00 the tree 22.
- a rod 2liL is screwed into the y
- the Christmas tree or assemblage of apparatus 22 comprises a valve 24 secured to the upper end of the tube 12.
- l A fitting 25 cruciform in longitudinal section Vis connected to the valve 24; and comprises arms 26. and 27 and a vertical branch 28, said arms and said branch being outwardly threaded.
- a valve 29 is connected to the arm 26 and a Vnipple 30-is connected to the valve 29.
- a T 31 having yavertical stem 32 is connected to the nipple 30.
- a valve 35 is connected to the arm 27 and a nipple ⁇ 36 is connected/to the valve 35.
- 'A T 37 having a vertical stem 38 is connected to the nipple 36 and a closed pipe 39 is connected to the outer end of the T37 to act as a stopper or plug.
- a member 41 threadedly engages the upper end of the branchy 28 of the itting 25, and is provided. with a stuling box 42. in which is ⁇ fitted a *follower or gland 43.
- a nipple 45 thread edly engages the upper end of the member 41 and is connected at its upper 'end to a gate valve 47.
- the gas pressure developed p in the oil sands 8 is s'ulicient to lift the oil to 207 ln some the surface but is vinsullicient to lift the col- .umn of mud or Watewhich'is-in the well hole and f'within the set Well casing after the f same has been cemented off and the drilling operations have been completed. It will be understood that when'the drilling operations have been completed,t he circulating mud or water ⁇ in the wellhole is disposed above the well fluid and above the oil sands 8U .
- mud or water or otherioreign matter constitutes a fluid which is-heavier than oil andyin certain fields the gas pressure developed is insuflicient to force the mud and. circulating fluid out of the welll hole.
- the pipe 21 connected at its lower end to pipe 15 is suspended by a solid rod 21a by a sofcalled traveling block suspended from the yderriek of the oil well, not shown.v It shouldbe re- -membered that there is'the enormous weight of pipe 21, which may be from one to three thousand feet or longer. In this position. of
- a pump not shown, is connected to the vertical stem 30 of theT 37 and a displacing ⁇ fluid, such as. oil, steam, gasoline,'compressed air or the like, is pumped through a valve .35 into the tube 12 occupying the annular space between tube A12 and pipe 21.
- a displacing ⁇ fluid such as. oil, steam, gasoline,'compressed air or the like
- the displacing fluid should be of approximately the same density as the oil or-welliluid, or in other i words the displacing fluid should be lighter than the mud and circulating fluid above the well fluid.-
- the pressure of the displacing fluid will 4vforce the ci ⁇ reulating-lluid from Y tube 12 through cage '19:into pipe 21, displacing ⁇ the circulating lluidboth in v ⁇ pipe 21 and in tube 12 above'th'e cage 19 and forcing the same out through the lateral openings -23l above the tree 22'.
- the .pipe 15 is lowered in order 'to maintain its lower end below the oil level and'tlms constantly form a trap whfchconscrves the gas pressure by preventing t'he escape of the gas.
- the pipe 15 may be raisedabove the level through Ithe pipe 15 and flow upwardlytov in Fig. 2 'pipe 21 is supforthe well toisandl pipe 21 'are belowthe tree22, as shown' in of the sand, and then lowered gradually, following thesa'nd level down, the sand beling laidthroughf the pipe bythe pressure of gas.v .
- the well ma thus be kept, substantially clean otsan without shuttingdown production andwithout killing the-well.
- an oil production apparatus the combination of an outer casing perforated at its lower end, a casinghead lat V the upper end l of said casing, a stationary tube extending'- downwardly through said casing head ⁇ apipe 'open at the ⁇ bottom and closed at the top within said tube and extending below and above said tube, 'a packer at the lower end i of said tube encircling said pipe, a second packer above the casing head encircling said pipe, said pipe being slidable in said packers and provided with an o ening above the lower packer and a vsecon opening-near its upper end adapted to be disposed above the vsecond packer when it is des1red to displace the circulating fluid, or below said second packer when the well is producing; means for forcing a fluid between the tube andthe pipe to displace the circulating fluid therein and to force the same through said pipe and out of said second opening, and a valve controlled oil outletabove the casing head communicating with said tube
Description
www
my W, ma,
'TL l KALLMEYER APPARATUS Fon LIFTING OIL .TIN OIL WELLS Filed may 29, 1924 a, sheets-sheet '1 my E?, w23,
T., KALLMEYER vAxfwnw'us FOK LIFTING OIL 1N 'OIL WELLS 2 sneeps-snt 2 Filed May 29, 1924 Patented July 17, 1928.
THEOPHIL'US KALLHEYEB, 0F WILMINGTON, CPIFORNIA.
APPARATUS Fon LIFfriNG ou. nroIL WELLS.
Application led Hay 29,
^ This invention relates to an oil production apparatus for practicing the method of raising oil in oil wells. y r l I An object of this invention is 'the provision of anew apparatus by which 'the natural gas pressure in a well may be i'itilizedl without waste of gas pressure to raise the oil, -my method and apparatusproviding for the utilization of said gas pressure for raising the oil in the well as the level of oil falls in the oil strata.
Another object of this invention is` the provision of an apparatusv for cleaning the well of obstructive matter'while at ,the saine time maintaining production and without killing the well. L
A further object of this invention 1s .the provision of a pipe adapted to be raised and lowered in a well through regular production apparatus and without shutting off the production of fluid raised from the well.
It is well known that oil as it lies 1n the ground is stratified, that is, there are lay- ,Y
ers of oil of different gravities in an oil stratum or a plurality of contiguous oil strata, the oil of highest gravitybeing lowest. It ,would therefore be desirable to provide a method and apparatus thereforl by which the oil of different gravities may be 3o selectively taken from the well, and it is an object of my inventionto provide such method and apparatus. l
With the foregoing objects in view together with such other objects and advantages as may subsequently appear, my A1nvention consists in the method hereinafter described and claimed, and in the construction and arrangement of parts hereinafter described and claimedand illustrated in the 4o accompanying drawings, in which:
Figure 1 is a longitudinal section of a well and apparatus therein, and an elevational view ofapparatus above the well connected with the apparatus within the well. Fig. 2 is a .view similar to Fig. l, but illustrating the downward extension of apparatus in the well adjusted for operation when the oil in the well has reached a lower level than is shown in Fig. 1, the lower level of the oil being due to the fact that the oil supply has beeen partly exhausted,
Fig. 3 is a detailed elevational view, part# ly in section, of apparatus above the well connected with the apparatus in the well.
-v upper end of the pipe 21.
1924. serial '110,716,697'. i
Referring the drawings for a more detailed description thereof, the numeral 7 inidicates a well extending into the strata 8 of oil bearin sands. The oil sands 8 are usu-l ally bounded by a superimposel layer 9 of rock or y.othersubstance which is comparatively impervious to the gas which natural- 1y accompanies the oil. A casing 1,0 extends through the Welland extends above the upper end thereof. The lower end portion of the casing 10, which extends into the oil bearing sands, is provided with a plurality of aperturesll which extend around the casing and permit oil from the surrounding sands to -flow into the casing.
Within theH casing 10 is positioned a verl tical tube 12, the lower end of which may be in the oil bearing sands 8. The tube 12 extends upwardly through a casing head 13 which is secured to the upper end or head of the casing 10. The lower end portion of the tube 12 i`s\provided with a plug -or stopper 14 having peripheral male 'threads which engage-female threads .formed in the tube 12.
A pipe 15 is positioned within the tube 12, the lower end portion "of said pipe passing through the plug 14 and extending below the oil level. A packer 17, positioned just above the, stopper 14, encircles a portion' of the pipe 15 and fills the spacebetween said portion and the opposing portion -of 'the tube 12. The pipe 15 is slidable through i the packer 17 and through the stopper 14. The upper end of the pipe 15 is connected to a usual cage 19 perforated axially and laterally. To the upper end of the cage 19 is connected a pipe 21 extending upwardly through the casing lhead 18 and through an assemblage of apparatus 22, known to oil men as a Christmas tree. The pipe 21 ex-l tends above the Christmas tree and is provided with lateral apertures 23 which iti Fig. 1 is shown above and in Fig. 2 below 00 the tree 22. A rod 2liL is screwed into the y The Christmas tree or assemblage of apparatus 22 comprises a valve 24 secured to the upper end of the tube 12. l A fitting 25 cruciform in longitudinal section Vis connected to the valve 24; and comprises arms 26. and 27 and a vertical branch 28, said arms and said branch being outwardly threaded. A valve 29 is connected to the arm 26 and a Vnipple 30-is connected to the valve 29. A T 31 having yavertical stem 32 is connected to the nipple 30. A closed pipe 433-"issecured to one end of the T to close the same. A valve 35 is connected to the arm 27 and a nipple`36 is connected/to the valve 35. 'A T 37 having a vertical stem 38 is connected to the nipple 36 and a closed pipe 39 is connected to the outer end of the T37 to act as a stopper or plug. A member 41 threadedly engages the upper end of the branchy 28 of the itting 25, and is provided. with a stuling box 42. in which is `fitted a *follower or gland 43. A nipple 45 thread edly engages the upper end of the member 41 and is connected at its upper 'end to a gate valve 47. ,y
` fields the gas pressure developed p in the oil sands 8 is s'ulicient to lift the oil to 207 ln some the surface but is vinsullicient to lift the col- .umn of mud or Watewhich'is-in the well hole and f'within the set Well casing after the f same has been cemented off and the drilling operations have been completed. It will be understood that when'the drilling operations have been completed,t he circulating mud or water` in the wellhole is disposed above the well fluid and above the oil sands 8U .This
. mud or water or otherioreign matter constitutes a fluid which is-heavier than oil andyin certain fields the gas pressure developed is insuflicient to force the mud and. circulating fluid out of the welll hole. With the-appa ratus in position, as'shown in Fig. 1, the pipe 21 connected at its lower end to pipe 15 is suspended by a solid rod 21a by a sofcalled traveling block suspended from the yderriek of the oil well, not shown.v It shouldbe re- -membered that there is'the enormous weight of pipe 21, which may be from one to three thousand feet or longer. In this position. of
the apparatusit lshould be noted thatf'the lateral opening's23n pipe 21 are freelyexposed and above the tree 22. A pump, not shown, is connected to the vertical stem 30 of theT 37 and a displacing `fluid, such as. oil, steam, gasoline,'compressed air or the like, is pumped through a valve .35 into the tube 12 occupying the annular space between tube A12 and pipe 21. The displacing fluid should be of approximately the same density as the oil or-welliluid, or in other i words the displacing fluid should be lighter than the mud and circulating fluid above the well fluid.- The pressure of the displacing fluid will 4vforce the ci`reulating-lluid from Y tube 12 through cage '19:into pipe 21, displacing `the circulating lluidboth in v`pipe 21 and in tube 12 above'th'e cage 19 and forcing the same out through the lateral openings -23l above the tree 22'.- Y
It will be understoodthat a length of pipe may be inserted in pipe 21 and the same may be lowered so that the cage 19 will `be at a' point below the one shown in 1 in order to remove an additional amount of the cir f 8 is-now sulicient'to allow the oil to enter y the top. of the well and thewell is now ,brought in. lAt this stage the traveling ,bloc'lgafrom which pipe 21 issuspended, is i' lowered so that the. lateral apertures 23 in Fig. 2; though it will be understoody it will be sufficient it these apertures are below the stuiiingbox 42.' The displacing fluid pump having been stopped, 'the gate valve 35 is closed and the gate valve 29 is opened.' The ,gas pressure will force the oil upwardly through tube 12. and the samewilll HOW.
-through the tree. 22 out at'the outlet'32.l It is sometimes advisable in a case where there is a tremendouspressure developed and the stulingboX 42 is leaking, toput a cap 50 on top of the tree22, as shown in Fig. 2, .to conx fn'e any seepage of'oil within thetree. lIn A the position shown ported above the' stuliing b oX. 42 by means-of a collar or joint which rests on the st ulliug box; and the supporting structure.
As the level ofthe oil in the well falls during production, the .pipe 15 is lowered in order 'to maintain its lower end below the oil level and'tlms constantly form a trap whfchconscrves the gas pressure by preventing t'he escape of the gas.
If there is a tendency up1 the pipe 15 may be raisedabove the level through Ithe pipe 15 and flow upwardlytov in Fig. 2 'pipe 21 is supforthe well toisandl pipe 21 'are belowthe tree22, as shown' in of the sand, and then lowered gradually, following thesa'nd level down, the sand beling laidthroughf the pipe bythe pressure of gas.v .The well ma thus be kept, substantially clean otsan without shuttingdown production andwithout killing the-well.
. "In order toiwithdraw from the. Well a` layer of oil having a desired specific gravity, the pipe 15may be lower end desired gravity', f'which actionfis readily permitted by my construction. l
It will thus .be seen that I have provided a new methodot` raising oil in a well; which comprises conserving the natural supply of gas and utilizing such gas to force' theoil out cfa well and continuously so as the oil level goes down, and I have alsoif-)p-rovided appar-altus for carrying out the new method of oil production.' "31' It will also be appreciated-that the method diierent in part from the prior art by the oloil production hereinbefore,v described is. t
Y `lus ositionedv1 so that its is in.' the layer of voil -having the conservation of natural supply of gas done for the purpose of providing natural motive power for 'raising oil in, a well, the methods of the prior art having allowed gas to escape 5 and thus natural motive power to be wasted This invention has been described, but 'modifications thereof maybe devised without departing from the spirit thereof, and itis to be understood that such modications come within the scope of this invention.
What is claimed is:
l. In `an oil production apparatus the com? bination of an outer casing perforated at A the lower end, a casing head at the upper end of said casing, la stationar tube extendingdownwardly through sai casing head, a Christmas tree mounted at the upper end .of said tube, a pipe o en at the bottom and closed at the top wit in said tube andex- 0 tending below and above said tube, a packer at the lower end of said tube encircling said pipe, a second packer in said Christmas tree encircling said pipe, said pipe being slidable i in said packers and provided with an open- 5 ing above' said lower packer and a second opening near its upper end andadapted to be disposed above said second packer when it is desired to displacethe circulating fluid, or below said second packer when the well i is producing means for forcing a fluid be-l tween the tube and the pipe to displace theV circulating fluid therein andforce the same `throuvh said pipe and Aout through said second opening, and a valve controlled oil outlet in theChristmas'tree communicating with said tube. y
2. 'In an oil production apparatus the combination of an outer casing perforated at its lower end, a casinghead lat V the upper end l of said casing, a stationary tube extending'- downwardly through said casing head` apipe 'open at the `bottom and closed at the top within said tube and extending below and above said tube, 'a packer at the lower end i of said tube encircling said pipe, a second packer above the casing head encircling said pipe, said pipe being slidable in said packers and provided with an o ening above the lower packer and a vsecon opening-near its upper end adapted to be disposed above the vsecond packer when it is des1red to displace the circulating fluid, or below said second packer when the well is producing; means for forcing a fluid between the tube andthe pipe to displace the circulating fluid therein and to force the same through said pipe and out of said second opening, and a valve controlled oil outletabove the casing head communicating with said tube.v
3. In anoil production apparatus the combinationfof a stationary tube, a pipe open at the bottom and closed at the top slidably disposedwithin said tube, means closing the lower end of the tube about said pipe, said pipe being provided with an opening above said closing means and a second opening-near the upper end, means for forcing a fluid' into said tube to displace the circulatory' fluid therein and force the same through said pipe upwardly andout through the openingat the upper endnofsaid "tube, .v
4. In an oil production apparatus thecombination of an outer casing perforated at the A lower end, a stationary tube within said casing, a pipe within said tube and mounted for bodily slidable movement and extending above and below said tube, a packer between the lower end of said tube and said pipe, a second packer encircling the upper end of said pipe, therelbeing an opening in the pipe above said first packer and a second opening` near the upper end of said pipe adapted to be disposed abovesaid second packer when it is desired to displace the circulating fluid,v or below said second packer when the well is producing, means for forcing a fluid into said tube and pipe to displace the circulatory; fluid therein, and means connected to said tube for conducting oil out of the well.
In testimony whereof I have signed my 90 name to this specification.
THEOPHILUS KALLMEYER.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US716697A US1677349A (en) | 1924-05-29 | 1924-05-29 | Apparatus for lifting oil in oil wells |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US716697A US1677349A (en) | 1924-05-29 | 1924-05-29 | Apparatus for lifting oil in oil wells |
Publications (1)
Publication Number | Publication Date |
---|---|
US1677349A true US1677349A (en) | 1928-07-17 |
Family
ID=24879060
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US716697A Expired - Lifetime US1677349A (en) | 1924-05-29 | 1924-05-29 | Apparatus for lifting oil in oil wells |
Country Status (1)
Country | Link |
---|---|
US (1) | US1677349A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3066737A (en) * | 1959-02-24 | 1962-12-04 | Isaac B Barrett | Flue gas well casing pressure cycling system and apparatus |
FR2505397A1 (en) * | 1981-05-06 | 1982-11-12 | Elf Aquitaine | Quick-disconnect coupling for gas injection piping - for oil wells protected by blowout preventers |
-
1924
- 1924-05-29 US US716697A patent/US1677349A/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3066737A (en) * | 1959-02-24 | 1962-12-04 | Isaac B Barrett | Flue gas well casing pressure cycling system and apparatus |
FR2505397A1 (en) * | 1981-05-06 | 1982-11-12 | Elf Aquitaine | Quick-disconnect coupling for gas injection piping - for oil wells protected by blowout preventers |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3011548A (en) | Apparatus for method for treating wells | |
US3386508A (en) | Process and system for the recovery of viscous oil | |
CN104533356B (en) | The method and oil production by layer method of a kind of two-layer automatic control oil production by layer | |
US1677349A (en) | Apparatus for lifting oil in oil wells | |
US2120132A (en) | Method and apparatus for cleaning wells | |
US2016919A (en) | Method for cementing and testing wells | |
US2193144A (en) | Method and apparatus for forming mud seals | |
US1834946A (en) | Method and apparatus for operating wells | |
US2179033A (en) | Method and apparatus for performing fishing operations | |
CN108952672A (en) | The drillstem test tubing string and application method of motionless drilling tool | |
US2674201A (en) | Well swab | |
US3486558A (en) | Apparatus for setting liners in boreholes of wells | |
US2087297A (en) | Method of shutting off water sands in wells | |
US2531258A (en) | Dual flowing device | |
US3195631A (en) | Method for perforating a well | |
US2743905A (en) | Improved sealing valve assembly | |
US2050289A (en) | Wall washing bailer | |
US2360200A (en) | Method for gravel packing | |
US1758156A (en) | Method and means for cementing oil wells | |
US1662336A (en) | Well packer | |
US2173119A (en) | Means for graveling oil wells | |
US2101640A (en) | Method and apparatus for cementing wells | |
RU96167U1 (en) | WELL WASHING DEVICE | |
US2008114A (en) | Air or gas lift pump | |
CN107762459A (en) | Separate layer water injection string |