OA12086A

OA12086A - Wellbore system having non-return valve.

Info

Publication number: OA12086A
Application number: OA1200200142A
Authority: OA
Inventors: Wilhelmus Hubertus Pau Heijnen
Original assignee: Shell Int Research
Priority date: 1999-11-16
Filing date: 2000-11-15
Publication date: 2006-05-04
Also published as: AU765867B2; DE60007779T2; MXPA02004815A; DE60007779D1; CN1390274A; AU1703701A; RU2002115865A

Description

1 2086

The présent invention relates to a wellbore Systemcomprising a borehole formed in the earth formation, theborehole being provided with a valve having a passage fora stream of fluid flowing from an upstream side of the 5 valve to a downstream side of the valve. In the practice of production of hydrocarbon fluid from a wellbore valvesare generally applied to control the flow rate of theproduced fluid or to shut off the wellbore in case of anemergency. Such valves generally allow flow of fluid 10 through the borehole in both directions thereof.

The wellbore System according to the preamble of claim 1 is known from US patent No. 5,655,607. In theknown system a one-way valve is arranged in a drillstring to control the inflation of an inflatable packer 15 that seals of the annuiar space between the drill string and borehole wall during a pressure test of the well. US patent No. 5,293,905 discloses a pipeline plugwhich can be locked within the pipeline by a pressureresponsive locking mechanism. 20 It is an object of the invention to provide a wellbore System comprising a borehole formed in the earthformation, the borehole being provided with a valveallowing flow of fluid in one direction through theborehole and preventing flow of fluid in the other 25 direction through the borehole.

In accordance with the invention there is provided a wellbore System which is characterised by thecharacterising features of claim 1.

Suitably the valve is orientée in the borehole in a 30 manner that the closure member is biased to the open 1 2086 position thereof by the drag force exerted by the streampumped through the borehole in downward directionthereof.

Preferably the valve is oriented in the borehole in a5 manner that the closure member is biased to the open position thereof by the drag force exerted by the streamflowing through the borehole in upward direction thereof.

The invention will be described further in moredetail and with reference to the accompanying drawing in 10 which

Fig. 1 schematically shows a wellbore Systemaccording to the invention formed in an earth formation;and

Fig. 2 schematically shows an embodiment of the valve15 applied in the wellbore System according to the invention.

Referring to Fig. 1 there is shown a wellboreSystem 1 formed in an earth formation 3, the wellboreSystem including a main borehole 5 and two branch 20 boreholes 7, 9 extending from the main borehole 5 into the earth formation 3 at respective borehole junctions10, 12. The main borehole 5 is at its upper end in fluidcommunication with a hydrocarbon gas production facility14 provided with a production control valve 15 arranged 25 at surface. The boreholes 5, 7, 9 extend into respective hydrocarbon gas réservoirs 16, 18, 20 of mutuallydifferent gas pressures, whereby the gas pressure P]_ inréservoir 20 is higher than the gas pressure P2 inréservoir 18, and the gas pressure P2 in réservoir 18 is 30 higher than the gas pressure P3 in réservoir 16. Each branch borehole 7, 9 and the main borehole 5 are provided 3 10 15 20 25 30 1 2 086 with a respective wellbore casing (not shown), wherebythe casings of the branch boreholes 7, 9 are connected tothe casing of the main borehole at the respectivewellbore junctions 10, 12 in a sealing manner.

Referring further to Fig. 2, the branch borehole 7 isprovided with tubular wellbore casing 22 cemented in thebranch borehole by a layer of cernent 24. A valve 26 isfixedly arranged in the casing 22 by means of a lockmandrel schematically indicated by reference numéral 28,the valve having a central longitudinal axis 32 whichforms an axis of symmetry of the valve. In Fig. 2 thevalve 26 is shown in two different modes of operation forthe two different sides relative to the axis ofsymmetry 32. Arrow 30 indicates the direction from theréservoir 16 to the junction 10 (cf. Fig. 1). Thevalve 26 includes a tubular housing 34 having a fluidinlet 36, fluid outlets 38a, 38b, and a fluid passage 40providing fluid communication between the inlet 36 on onehand and the outlets 38a, 38b on the other hand. Thefluid inlet 36 and the fluid outlets 38a, 38b arearranged such that fluid flowing through the borehole 7in the direction of arrow 30 flows via the inlet 36 andthe fluid passage 40 to the outlets 38a, 38b. Thehousing 34 is provided with an annular valve seat 42extending around the fluid passage 40, and a closuremember 44 movable relative to the housing 34 inlongitudinal direction thereof between an open position(indicated at the upper side of axis 32) in which theclosure member is remote from the valve seat 42, and aclosed position (indicated at the lower side of axis 32)in which an end surface 46 of the closure member 44contacts the valve seat 42. The shape of the endsurface 46 matches the shape of the valve seat 42 so thatthe fluid passage is closed when the closure member is inthe closed position. A compression spring 48 is at one 35 4 1 2086 end thereof biased against the closure member 44 and atthe other end thereof against an adjustable stop ring 50arranged in the housing 34, the spring 48 exerting aforce F to the closure member 44 when the latter is in 5 the closed position.

The closure member 44 is provided with a central bore 52 having an internai shoulder 54 defining atransition between a larger diameter part 52a and asmaller diameter part 52b of the bore 52, the larger 10 diameter part 52a being doser to the valve seat 42 than the smaller diameter part 52b. The larger diameterpart 52a of the bore 52 is provided with a plug 56removable from the bore 52 in the direction of the fluidpassage 40 by application of a selected fluid back- 15 pressure in the smaller diameter part 52b relative to a fluid pressure in the fluid passage 40 when the closuremember is in the closed position.

The main borehole 5 (Fig. 1) is provided with avalve 60 arranged between the réservoir 18 and the 20 wellbore junction 12, and the branch borehole 9 is provided with a valve 62 arranged between theréservoir 20 and the junction 12. The valves 60, 62 aresimilar to the valve 26.

During normal operation hydrocarbon fluid, for 25 example natural gas, is to be produced a) from réservoir 20 only, b) from réservoirs 20 and 18simultaneously, or c) from réservoirs 20, 18 and 16simultaneously. Before start of production the fluidpressure Ρθ in the upper part of the main wellbore is at 30 a level so that the pressure différences across the valves 26, 60, 62 is such that the closure members 44 ofthe respective valves 26, 60, 62 are in their closedposition. When it is desired to produce gas fromréservoir 20 only (option a), the pressure Pq in the 35 upper part of the main borehole 5 is gradually lowered by 5 1 2086 opening production control valve 15 until the pressuredifférence (Pj-Pq) across the valve 62 exceeds the springforce F, whereupon the valve 62 moves to the openposition and fluid is produced from réservoir 20 through 5 the production facility 14.

When thereafter it is desired to produce gas fromréservoirs 20 and 18 simultaneously (option b), thepressure Pq in the upper part of the main borehole 5 isgradually further lowered by further opening production 10 control valve 15 until the pressure différence (P2-P0) across the valve 60 exceeds the spring force F, whereuponthe valve 60 moves to the open position and gas isproduced from réservoirs 18 and 20 to the productionfacility 14. 15 When in a next phase it is desired to produce gas from réservoirs 16, 18 and 20 simultaneously (option c),the pressure Pq in the upper part of the main borehole 5is gradually even further lowered by even further openingproduction control valve 15 further until the pressure 20 différence (P3-PQ) across the valve 26 exceeds the spring force F, whereupon the valve 26 moves to the openposition and gas is produced from réservoirs 16, 18 and20 to the production facility 14.

In case fluid is to be transferred from surface into 25 one or more of the branch boreholes 7, 9 or the lower part of the main borehole 5, said fluid back-pressure isapplied at the downstream side of the respectivevalve(s) 26, 60, 62 thereby removing the plug(s) 56 fromthe bore(s) 52 so that fluid can be transferred through 30 the bore(s) 52 in the direction opposite the direction 30.

Furthermore the valves 26, 60, 62 prevent flow offluid from one réservoir into another since thevalves 26, 60, 62 prevent fluid flow in the direction 35 opposite to the direction 30. 1 2086

Production of fluid in an order different than theorder a), b), c) described above can be achieved byadapting the spring forces F of the springs 48 of therespective valves 26, 60, 62 accordingly.

Claims

7 1 2086

1. A wellbore System comprising a borehole (7, 5, 9)formed in the earth formation, the borehole beingprovided with a valve (26, 60, 62) having a passage for astream of fluid flowing from an upstream side of thevalve to a downstream side of the valve, a closuremember (44) exposed to a drag force exerted by the streamand movable relative to the passage between an openposition in which the closure member allows fluid to flowthrough the passage and a closed position in which theclosure member closes the passage, said drag forcebiasing the closure member to the open position thereof,and a spring (48) exerting a spring force to the closuremember (44) biasing the closure member to the closedposition, wherein the spring force, when the closuremember (44) is in the closed position, exceeds a selectedlower limit of the drag force; characterised in that thevalve (26, 60, 62) is fixedly arranged in the borehole (7, 5, 9) and that the closure member (44) isexposed to the drag force exerted by a stream ofhydrocarbon fluid passing through the fluid passage (40)of the valve (26, 60, 62) .
2. The wellbore System of claim 1, wherein the valve (26, 60, 62) is oriented in the borehole (7, 5, 9)in a manner that the closure member (44) is biased to theopen position thereof by the drag force exerted by thestream pumped through the borehole (7, 5, 9) in downwarddirection thereof.
3. The wellbore System of claim 1, wherein the valve (26, 60, 62) is oriented in the borehole (7, 5, 9) 8 1 2086 in a manner that the closure member (44) is biased to theopen position thereof by the drag force exerted by thestream flowing through the borehole (7, 5, 9) in upwarddirection thereof.
4. The wellbore system of claim 3, wherein said borehole (7, 5, 9) is one of a plurality of boreholesarranged to produce hydrocarbon fluid from the earthformation to a common hydrocarbon fluid productionfacility.
5. The wellbore system of claim 4, comprising a plurality of said valves, each valve being arranged in acorresponding one of said boreholes.
6. The wellbore system of claim 5, wherein the springforces of the springs of the valves are mutuallydifferent.
7. The wellbore system of any one of daims 4-6, whereinthe common hydrocarbon fluid production facility isprovided with valve means for controlling the flow rateof hydrocarbon fluid produced from each of saidboreholes.
8. The wellbore system of any one of daims 3-7, whereineach closure member is provided with an opening allowingflow of fluid from the upstream side of the valve to thedownstream side of the valve via said opening, theclosure member further being provided with a plug closingsaid opening, the plug being removable from the closuremember in the direction of the upstream side of the valveby the application of a selected fluid pressure in theborehole at the downstream side of the valve.
9. The wellbore system of claim 1, wherein the wellboresystem comprises a main borehole (5) and a plurality ofbranch boreholes (7, 9), which branch boreholes (7, 9)are each equipped with a valve (26, 60, 62) according to 1 2 086 - 8a - claim 1 for controlling transfer of hydrocarbon fluidbetween the main borehole (5) and the branch borehole (7,9) ·