AU6064999A

AU6064999A - Injection valve

Info

Publication number: AU6064999A
Application number: AU60649/99A
Authority: AU
Inventors: James Allison; Andrew Haynes
Original assignee: Baker Hughes Inc
Current assignee: Baker Hughes Holdings LLC
Priority date: 1998-11-25
Filing date: 1999-11-25
Publication date: 2000-06-01
Also published as: NO995772D0; CA2290897A1; NO995772L; GB2345075A; GB9927811D0

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Injection Valve r The following statement is a full description of this invention, including the best method of performing it known to me/us: FHPMELC699329010.1 NOU 24 1999 10:10 FR BHI-IP 713 439 8043 TO FREEHILL PATENT P.02/18 713 439 8043 Title: INJECTION

VALVE

Inventors: JAMES ALLISON AND ANDREW

HAYNES

Field of the Invention The field of this invention relates to injection valves used to stimulate production from subsurface formations into the wellbore through an injection well.

Background of the Invention Occasions can arise where the pressure in a subsurface formation is insufficient to bring the hydrocarbons to the surface.

One technique that has been used to provide the external force to get the hydrocarbons to the wellbore and additionally assist them in coming to the surface is the use of an injection well into the formation. The injection well is a separate well from the producing well into which various material can be injected. In some applications the injected material is a liquid such as water, and in others steam is injected. Injection wells typically use injection valves. In the past, injection valves have been insertable on wireline to latch and lock in the injection tubing. The functional components of an injection valve area spring loaded flapper Ri Received Time 25.Nov. 3:03 NOU 24 1999 09:23 PAGE.04 NOU 24 1999 10:11 FR BHI-IP 7 1 3 439 8043 TO FREEHILL PATENT P.03/18 713 439 8043 which is biased to close against a conforming seat coupled with a moveable flow tube. The flow tube when pushed downwardly against the force of a return spring forces the flapper away from the seat and protects the flapper behind the flow tube from the erosive effects of the flowing injection medium. When the injection flow rate is reduced or eliminated, the return spring pushes up the flow tube to allow the spring on the flapper to urge it toward the seat. This ensures that there is only one way flow downhole in the injection well. In order to overcome the force on .o the flow tube from the return spring, the flow tube in past designs of wireline retrievable injection valves has included a central orifice. One such product is the J-3 and J4 injection valves made by Baker Oil Tools. When such orifice wears due to the erosive effects of the injection fluid, the pressure drop across the flow 5 tube is reduced for a given flow rate. In an extreme case, the developed pressure drop can be reduced to below the point necessary for compression of the return spring. When this occurs, the flowing injection fluid is exposed to the flapper and proceeds to erode the edges of the flapper so that upon closure -2- Received Time 25.Nov. 3:03 NOU 24 1999 09:24 NOU 24 1999 10: 11 FR BHI-IP 713 439 8043 TO FREEHILL PATENT P.04/18 713 439 8043 a seal cannot be obtained between the flapper and seat. In these situations, the wireline retrievable injection valve needs to be pulled out with a wireline rig on the surface and disassembled for a replacement of the orifice.

s The presence of a single orifice to take the-necessary pressure drop to overcome the return spring also inhibits the passage of tools through the injection valve for further downhole operations should they become necessary. In those situations in the past, the injection valve had to be pulled out with a wireline rig .0 to facilitate the operations downhole. At the conclusion of those operations, the wireline injection valve would be reintroduced into the injection string.

There are many applications where it is undesirable to use a wireline run injection valve. It is thus one of the objectives of the present invention to provide a tubing mounted injection valve with advantages not available in prior injection valve designs which are wireline set In one embodiment of the present invention, the orifice itself in the flow tube is provided with a releasable locking system to allow retrieval to the surface with a wireline rig or -3- Received Time 25.Nov. 3:03 NOU 24 1999 B9:24 PRGE.06 NOU 24 1999 10:11 FR BHI-IP A 7 1 3 439 8043 TO FREEHILL PATENT P.05/18 713 439 8043 existing rig equipment Alternatively, if no surface facilities are anticipated to accommodate a wireline type injection valve, an alternative embodiment of the invention solves the objective of providing a tubing mounted injection valve with the ability to create a sufficient pressure drop across the flow tube while providing at the same time a larger clearance therethrough to facilitate further downhole operations. These and other advantages of the various embodiments of the present invention will become more apparent to those skilled in the art from a review of the preferred embodiment described below.

Summary of the invention A tubing mounted injection valve for an injection well is described. In one embodiment, the orifice in the flow tube is removably mounted so that it can be retrieved from the surface .:15 with a wireline rig or other surface equipment. In another embodiment, the flow tube has a surface treatment internally which creates the necessary turbulence to overcome the resistance of a return spring while at the same thme providing -4- Received Time 25.Nov. 3:03 NOU 24 1999 as:24 PAGE.07 NOV 24 1999 10:12 FR BHI-IP ?713 439 8043 TO FREEHILL PATENT P.06zle 713 439 8043 larger clearance for passing tools therethrough for further operations downhole below the injection valve body.

D-ied pgcfion fDaWiDfcLs Figure 1 is a half section elevatioflal view of an embodiment showing internal surface roughness on the flow tube in a tubing mounted design.

Figure 2 is an alternative embodiment to Figure 1 shown in half section illustrating a removable orifice in the flow tube which can be retrieved from a tubing mounted injection valve to the surface.

Figure 3 is a detailed view of the design shown in Figure 2 illustrating the positioning of the orifice in the lock profile in the flow tube.

Detailed Description of the PrefernedEmbodirneaits Referring to Figure 1, the injection valve I has a body with a thread 12 to connect to the injection string from the surface (not shown). A bottom thread 14 connects to the segment of the injection string down to the injection valve (not shown). Thus the body 10 is made to be an integral part of the injection string which Received Time 25.Nov. 3:03 NOU 24 1999 09;2S PAGE.8 NOU 24 1999 10:12 FR BHI-IP 713 439 8043 TO FREEHILL PATENT P.07/18 713 439 8043 is advantageous where wireline equipment is not available for insertion into the tubing string of a wireline run injection valve.

The injection valve I of the present invention has a flapper 16 which pivots on pivot 18 and is biased to the closed position s shown in Figure 1 by a torsion spring 20. When the closed position of Figure 1, the flapper 16 contacts a confirming seat 22 to prevent flow uphole through the injection valve 1. A flow tube 24 is slidably mounted in body 10 and shown in the up position in Figure 1 which represents no flow of injection fluid from the surface and the flapper 16 in sealing contact with the seat 22 to prevent already injected fluid from coming back up the body The flow tube 24 is biased upwardly by a return spring 26. In the embodiment of Figure 1, the inside surface 28 has a series of parallel circumferential internal ribs 30. The purpose of the ribs 15s is to convert laminar flow of injection fluid in body 10 above the flow tube 24 into turbulent flow within the flow tube 24 to create a pressure drop across flow tube 24. The thickness and height spacing or orientation of the ribs can be varied to address the S* desired pressure drop at the anticipated flow conditions. The S-6- 1 -6 Received Time 25.Nov. 3:03 NOU 24 1999 09:25 PAGE.09 NOU 24 1999 10:12 FR BHI-IP 713 439 8043 TO FREEHILL PATENT P.08/18 713 439 8043 pressure drop across flow tube 24 urges it to move downwardly overcoming the reaction force from spring 26. Downward movement of the flow tube 24 pivots the flapper 16 away from seat 22. Flapper 16 turns 90 degrees into a parallel position with the longitudinal axis of the body 10 thus allowing the flow tub 24 to proceed downwardly in front of the flapper 16 effectively shielding it from the erosive effect of the flowing injection fluid through the body While a series of parallel circumferential ribs has been shown in Figure 1, those skilled in the art will appreciate that other techniques involving internal surface roughness can be employed without departing from the spirit of the invention One of the main objectives is to leave as large a bore clearance through the body 10 as possible for the required injection rate while at the same time generating sufficient differential pressure across the flow tube 24 to overcome the force of the spring 26. Thus, for example, a continuous or discontinuous spiral groove effect is also an alternative to accomplish the required pressure drop.

S

Another alternative would be to provide random roughening of the op. a -7- Received Time 25.Nov. 3:03 NOU 24 lSYY tLJ:;db PAGE. NOV 24 1999 10:13 FR BHI-IP

A

7 1 3 439 8043 TO FREEHILL PATENT P.09/18 713 439 8043 internal surface of the flow tube 24 sufficient to create enough turbulence at the predetermined flow rate for injection to ensure that the flapper 16 is completely behind the flow tube 24 when the flow tube 24 is shifted to its downward position. Another example is a series of protrusions in an ordered pattenmor randomly located. The various surface roughness treatments described above wind up making available a larger bore diameter through the body 10 for a given flow rate than.prior designs involving a single generally centrally located orifice in the flow tube 24.

'o Referring now to Figures 2 and 3, the components described for Figure 1 which are again repeated in Figure 2 will not be described again. The distinction between Figures 2 and 3, as compared to Figure 1, is that in Figure 2 and orifice 32 is removably mounted in a profile 34 located in the flow tube 24'.

Known wireline equipment can be used at the surface to insert or remove the orifice 32. The embodiment shown in Figures 2 and 3 is again made integral to the injection tubing (not shown) and connected at the top and bottom respectively at threads 12' and 14'. A lock profile 34 is of a type known in the art and is located -8- Received Time 25.Nov. 3:03 NOU 24 1999 09:26 PPAE. 11 NOU 24 1999 10:13 FR BHI-IP A 7 1 3 439 8043 TO FREEHILL PATENT P.10/18 713 439 8043 in the flow tube 24'. The advantage of this design is that it allows easy removal and replacement of an orifice in the flow tube should erosion from the flowing injection fluid enlarge the opening to such an extent that the force of spring 26' cannot be overcome with the normal injection flow rate. While the design of Figures 2 and 3 requires rig equipment to remove the replace an orifice 32.

it provides some advantages in certain applications where wireline equipment is not available when the original injection string is inserted. Additionally depending on the severity of the service, occasion for replacement of the orifice 32 may only occur substantially later in time after placing the injection well in service and therefore still provide some advantage to the operator in savings related to the ability to put the injection well into service without use of wireline equipment.

5"s The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the spirit of the invention.

It will be understood that the term "comprises" or its grammatical variants as used herein is equivalent to the term "includes" and is not to be taken as excluding the presence of other elements or features.

9 Received Time 25.Nov. 3:03 NOU 24 1999 09:26 PAGE.12

Claims

1. A valve for downhole use conprisifl 3 a body; 4 ulpper rmttably mounted to selctively engage a seat in said WTdy 6 afo b aigafopt oal onoaiS ,ba 7 naesaid flapper and rotate it a*y ror said sWa; 8 said flow tube moveable against said bias by flow through its 9 flowpatli; said flowpath Aujthe comprising an interior su~rface having a 11 surface configuration that increases flow turbulence. 1 2. The valve of claim1, wherein: said interior surface configuration further comPrises a es n 3groove.

13. The valve of claim 2,wherein: :2 said groove is spirally shaped- 1 4. The valveof cflm 3,whereUi 2 said groove is continuous. 1o. 5. The valve of claimll3,whereinl: 2 said groove is discontinuous. 1 6. The valve of claim 1, Wherein: 2 said surface configuration comprises a rou*heing of said interior 3 surface. Received lime 25.Nov. 3:03 P~1 NOV 24 1999 09:2 PGE1 8 I liv 1 z, L L r m nn i i r tZ..J ~JJ UJt.J,.J C) I)W I 713 439 8043

17. The valve of Olai 1, wherein: 2 ~said surfce configUration farter rOmprises at least one rib- 1 8. The valve of claim 7, wherein: 2 said at least one rib ftrther comPrises 8-Plrality of ribs.

19. The Valve of claim 8, wherein: 2 said ribs are Parallel. 1 10. ThevaIve of claim, whrin: 2 said surface configuration furher comprises an ordered pattern of .3protusions. said surface configationi further comprises randomly located 4 .i proftusions. 12. The valveOf claim 1,wherein: *2 said surface configuration creates a comparable resistance to a predeterined Ilow through said flovipacth while leaving a larger open a 4 than a single orifice.

113. A downhole valve, comprising-. 2 a body, a pivotally mounted flapper movable with a flow tube, said 3 flow tube furtb comprising an orifice in a housing removably mounted 4 to said flow tube, whereupon wear of said orifice said housing may be remnoved from said flow tube downho1e. -11- Received lime 25-Nov. 3:03 NOV 24 1999 09:26 PAGE. 14 NOV 24 1999 10:14 FR BHI-1P A713 439 8043 TO FREEHILL PATENT P.13/18 713 439 8043 14. The dowrzibole valvc of claim 13, wherein': said housing is removable with a wfreline. The downliole valve of Claim 13, wherein: said housing is insertaole intO said flow tube by wire-line- with said body situated downhole. BAKER HUGHES INCORPORATED by Freehills Patent Attorneys Registered Patent Attorneys for the Applicant November 1999 4 U. -12- Received Time 25.Nov. 3:03 NOU 24 1999 09!27 PROE.