OA10965A

OA10965A - Logging method

Info

Publication number: OA10965A
Application number: OA9900016A
Authority: OA
Inventors: Douwe Johannes Runia
Original assignee: Shell Int Research
Priority date: 1996-07-24
Filing date: 1999-01-22
Publication date: 2003-03-04
Also published as: DE69711890D1; ID17559A; EA199900157A1; CO4700562A1; AR007947A1; DE69711890T2; EA001781B1; SA97180332B1; TR199900077T2; MY132524A

Abstract

1. A method of operating a logging tool in a wellbore formed in an earth formation, the wellbore having at least a section which is to be provided with a wellbore component (9) the method comprising: - arranging the logging tool (15) in a selected relationship relative to said component (9) so that the logging tool is guided by the component (9) through the wellbore (1) during lowering of the component into the wellbore; - lowering the component (9) with the logging tool (15) in said selected relationship, through the wellbore (1) to said section of the wellbore; - operating the logging tool (15) so as to provide logging data of the earth formation (3) surrounding the wellbore; and - transferring the logging data to surface, characterized in that the logging tool (15) is retrievably arranged relative to said component (9), and that after operating the logging tool, the logging tool is retrieved to surface while the wellbore component is left downhole. 2. The method of claim 1, wherein the logging tool (15) is operated during lowering of the component (9) with the logging tool in said selected relationship, through the wellbore (1) to said section of the wellbore. 3. The method of any one of claims 1 or 2, wherein the logging tool (15) is operated when the logging tool is located in said section of the wellbore (1). 4. A system for operating a logging tool in a wellbore formed in an earth formation, the wellbore having at least a section which is to be provided with a wellbore component (9), the system comprising means for logging tool, said logging tool is retrievably arranged relative to said component, said component forms a tubular element, wherein and the logging tool is at least partly arranged within the tubular element. 5. The system of claim 4, wherein the logging tool (15) is connected to the inner surface of the element (9) at a selected side thereof, said side corresponding to a section of the earth formation (3) to be logged. 6. The system of claim 4 or 5, wherein the logging tool (15) is arranged within a retaining device attached to the inner surface of the tubular element. 7. The system of claim 6, wherein the retaining device (27) is a tube made of a fibre-reinforced material. 8. The system of claim 7, wherein the fibre-reinforced material is selected from glass fibre-reinforced epoxy and fibre-reinforced cement. 9. The system of any of claims 4-8, wherein the logging tool (15) is selected from the group comprising one of a gamma ray logging device (17), a density logging device (21), a neutron logging device (19), an NMR logging device, a resistivity logging device, a micro resistivity/calliper logging device, a sonic logging device and any other suitable logging device. 10. The system of claim 9, wherein the logging tool (15) includes a plurality of said logging devices arranged in a stacked manner. 11. The system of claim 9 or 11, wherein the component (9) is provided with a window (25) opposite a selected one of said logging devices. 12. The system of claim 11, wherein said window (25) is filled with a material suitably transparent to the logging tool signal. 13. The system of claim 12, wherein said material is selected from fibre reinforced plastic, glass fibre reinforced epoxy and fibre reinforced cement. 14. The system of claim 11, wherein said logging device forms a pad type device extending though the window so as to contact the wellbore wall. 15. The system of any of claims 4-14, wherein the logging data are stored in the logging tool (15) and are transferred to surface by lowering a pump-down latching device (33) into the wellbore (1), the latching device being connectable to the logging tool (15) and being provided with logging data retrieving means (37), pumping the latching device (33) through the wellbore until the latching device is connected to the logging tool, and transferring the logging data via the logging data retrieving means (37) to surface. 16. The system of claim 15, wherein the tubular element (9) is provided with a guide funnel so as to guide the latching device to the logging tool during connecting the latching device (33) to the logging tool. 17. The system of claim 15 or 16, wherein the latching device (33) is provided with logging tool retrieving means, and wherein the logging tool is retrieved to surface using said logging tool retrieving means after measuring said parameter. 18. The system of any of claims 4-17, wherein the wellbore component (9) is selected from a wellbore casing, a wellbore liner, a slotted wellbore liner, an expandable slotted liner, a pre-perforated liner, a wellbore screen, a wire-wrapped screen, and a gravel pack screen. 19. The system of claim 18, wherein the wellbore component (9) forms a wellbore casing having a casing shoe track (11), and wherein the logging (15) tool is at least partly arranged in said casing shoe track. 20. The system for operating a logging tool in a wellbore formed in an earth formation, the wellbore having at least a section which is to be provided with a wellbore component, the system comprising: - means (27) for arranging the logging tool (15) in a selected relationship relative to said component (9) so that the logging tool is guided by the component through the wellbore during lowering of the component into the wellbore; - means (5) for lowering the component with the logging tool (15) in said selected relationship, through the wellbore (1) to said section of the wellbore; - means (23) for operating the logging tool so as to provide logging data of the earth formation surrounding the wellbore; and - means (37) for transferring the logging data to surface, characterized in that the means for arranging the logging tool (15) relative to said component (9) includes means for retrievably arranging the logging tool relative to said component, and that the system further comprises means (33) for retrieving the logging tool to surface while the wellbore component is left downhole.

Description

010965

LOGGING METHOD

The présent invention relates to a method ofoperating a logging tool in a wellbore formed in an earthformation, which wellbore has at least a section which isto be provided with a wellbore component, for example acasing.

In conventional wellbore drilling a plurality ofcasing sections of stepwise decreasing diameter areinstalled in the wellbore to prevent the wellbore fromcollapsing and to protect drilling equipment. Thewellbore is deepened by rotating a drill string whichextends to the bottom of the wellbore through previouslyinstalled casing sections. Before installing casing inthe newly drilled wellbore section, a logging tool islowered via a wireline into the un-cased wellbore sectionand operated in order to obtain logging data representingcharacteristics such as porosity or oil/water content ofthe earth formation surrounding the un-cased wellboresection. A drawback of such wireline logging method isthe required additional drilling rig time during loweringand operating the logging tool. A further drawback isthat there is a danger that the logging tool gets blockedin the open wellbore section. Moreover, it may not bepossible to operate the logging tool over a significantpart of the newly drilled wellbore section, as a con-séquence of which valuable information on the surroundingformation cannot be obtained.

Another proposed logging method is disclosed in Oil &Gas Journal, June 10 1996, pp. 65-66, whereby a loggingtool is pumped down a drill string and operated during 010965 - 2 - tripping of the drill string. Such method has severaldrawbacks, for example the diameter of the logging toolis limited to the inner diameter of the drill string, andthe présence of a downhole motor obstructs furtherpumping of the tool. Furthermore, drilling of a furtherwellbore section before the string is tripped isprecluded once the tool is positioned in the drillstring. Also, positioning of the tool in the drill stringat the desired location requires spécial technicalmeasures to be taken which make the System rathercomplicated.

Thus, there is a need to provide an improved loggingmethod which is reliable and which results in a signifi-cant réduction of drilling rig time.

In accordance with the invention there is provided amethod of operating a logging tool in a wellbore formedin an earth formation, the wellbore having at least asection which is to be provided with a wellbore compo-nent, the method comprising arranging the logging tool ina selected relationship relative to said component sothat the logging tool is guided by the component throughthe wellbore during lowering of the component into thewellbore, lowering the component with the logging tool insaid selected relationship, through the wellbore to saidsection of the wellbore, operating the logging tool so asto provide logging data of the earth formation sur-rounding the wellbore, and transferring the logging datato surface.

It is to be understood that the term wellbore compo-nent refers to any component which is to be arranged inthe wellbore to form a structural part thereof, andrelative to which the logging tool can be arranged insaid selected relationship. 010965 - 3 -

By applying the method of the invention it isachieved that drilling rig time is reduced since thelogging tool is lowered together with the wellborecomponent, thereby obviating the need for wirelinelogging. Furthermore, wellbore components generally hâvehigh mechanical strength so that such wellbore componentsare capable of protecting the logging tool in thewellbore. Also, the risk that the logging tool becomesblocked in the wellbore, or cannot be moved throughhighly inclined or horizontal wellbore sections, isreduced because of the wellbore component guides thelogging tool through the wellbore. A further réduction of drilling rig time is achievedif the logging tool is operated simultaneously with thestep of lowering the wellbore component into the well-bore .

Suitably the wellbore component forms a tubularelement and the logging tool is at least partly arrangedwithin the tubular element.

To obtain logging data from a selected side of thewellbore, suitably the logging tool is attached to theinner surface of the tubular element at a selected sidethereof in correspondence with a section of the earthformation to be logged.

Suitably the wellbore component is selected from awellbore casing, a wellbore liner, a slotted wellboreliner, an expandable slotted liner, a pre-perforatedliner, a wellbore screen, a wire-wrapped screen, and agravel pack screen. A suitable logging tool in application of theinvention includes at least one of a gamma ray loggingdevice, a density logging device, a neutron loggingdevice, an NMR logging device, a resistivity logging 010965 device, a micro resistivity/calliper logging device, asonie logging device and any other suitable loggingdevice. If a plurality of such logging devices isapplied, the logging devices are preferably arranged in astacked manner.

To improve communication of the tool with the sur-rounding formation the tubular element can be providedwith a window opposite a selected one of said loggingdevices, which window is optionally filled with amaterial suitably transparent to the logging tool signal.Examples of such materials are fibre reinforced plastic,glass fibre reinforced epoxy and fibre reinforced cernent.

In case said logging device forms a pad type device,such device suitably extends through the window so as tocontact the wellbore wall.

The invention will be described hereinafter in moredetail and by way of example with reference to theappended drawings, in which

Fig. 1 schematically shows a System for carrying outthe method according to the invention; and

Fig. 2 shows a cross-section of a wellbore in whichthe method according to the invention is applied, whereina logging tool is placed eccentrically in a casing shoetrack.

Referring to Figs. 1 and 2 there is shown a well-bore 1 which is being created by drilling into an earthformation 3 from a drilling rig 5 at the earth surface 7.An upper part of the wellbore 1 has been provided withtubular casing to prevent the wellbore from collapsing.

As is common practice in wellbore drilling, the casingincludes a plurality of casing sections of stepwisedecreasing diameter in downward direction. The wellbore 1is further deepened by drilling a new, inclined, wellbore 010965 - 5 - section 8 through previously installée! casing sections(not shown), and lowering a casing section 9 of smallerdiameter than the previously installed wellbore sectionsinto the new wellbore section 8. In this manner casingsections of stepwise decreasing diameter are positionedin the wellbore.

The lower end part of the casing section 9, named thecasing shoe track 11, is internally provided with alogging tool 15 composed of a gamma ray loggingdevice 17, a neutron logging device 19, a density loggingdevice 21, and a power/memory cartridge 23 which includesa suitable energy source for the tool 15. The casingsection 9 is provided with a window 25 which can be inthe form of an opening or an opening filled with fibrereinforced plastic material such as fibre reinforcedepoxy, the window 25 being located opposite the densitylogging device 17. Some sections of the shoe track 11 canbe made entirely of glass fibre reinforced epoxy, fibrereinforced cernent or other suitable material, in order tooptimise log response of tools affected by Steel (e.g.Resistivity / Induction and Nuclear Magnetic Résonancetype tools). In ail cases the shoe track 11 will bedesigned to allow through-pumping of mud to the shoetrack nose. The materials used are selected so as to beable to be drilled out in case further deepening of thewell is required. The logging tool 15 is retrievablylocated within an open ended retaining tube 27 made ofglass fibre reinforced epoxy by means of arms 29, whichretaining tube 27 is fixedly attached to the lower sideof the inner surface of the casing section 9. The lowerside of the casing is defined as the side that is pushedagainst the formation, either by casing eccentralisers (in vertical sections) or by the tools ex- centred 010965 - 6 - weight, using a casing swivel (for example in horizontalsections). A guide funnel 31 is located at the upper end of theretaining tube 27, which guide funnel 31 has a largediameter end remote from the retaining tube 27 and asmall diameter end adjacent the retaining tube 27. Thelarge diameter end corresponds to the inner diameter ofthe casing section 9 and the small diameter end cor-responds to the inner diameter of the retaining tube 27.

During lowering of the casing section 9 into the newwellbore section 8, the logging devices 17, 19, 21 of thelogging tool 15 are operated and the logging data repre-senting information on the earth formation surroundingthe new wellbore section 8 are stored in the power/memorycartridge 23 (i.e. the tool is operated in memory mode).Since the logging tool 15 is located inside the casingshoe track 11, the latter protects the logging tool 15from mechanical damage due to collision with the wellborewall. Furthermore, by the arrangement of the logging tool15 in the casing section 9 it is ensured that lowering ofthe logging tool 15 is not hampered by the irregularlyshaped wellbore wall. Especially in case of horizontal ornearly horizontal wellbore sections which are to belogged, the method of the invention is of particularadvantage since moving a logging tool through such newlydrilled sections would be difficult, if not impossible,if the logging tool would be lowered by wireline.

After the casing section 9 has been installed andprior to cementing of the casing section in the wellbore,a latching device 33 provided with suitable dises 35 (so-called swab cups) for pumping the latching device 33through the wellbore 1 is inserted into the wellbore 1.The latching device 33 is connectable to the logging 010965 - 7 - tool 15 and is connected to a wireline 37 or a coiledtubing (not shown) extending from surface into thewellbore 1. The wireline 37 or coiled tubing is providedwith electric conducting means for transferring electricsignais representing the logging data to surface, theconducting means at surface being connected to suitabledata reading equipment at a logging truck 39. Thelatching device 33 is pumped down the wellbore 1 to theretaining tube 27. Upon arrivai of the latching device 33at the retaining tube 27, the guide funnel 31 guides thelatching device 33 to the open upper end of the retainingtube 27 until the latching device becomes connected tothe logging tool 15.

In a next step the logging data stored in thepower/memory cartridge 23 are transferred to the datareading equipment via the electric conductor. Subse-quently the logging tool is retrieved to surface 7 usingthe wireline 37 or the coiled tubing. Alternatively thelogging data could be read from the logging tool 15 afterthe logging tool 15 has been retrieved to surface 7 orduring retrieval of the tool to surface. Such wireline orcoiled tubing can also be used to check the depth of thelogging tool. The optimum method for depth control wouldbe to leave the tool on during retrieval while measuringcable (or coiled tubing) depth at surface thus creatingan optimal depth match curve.

The casing is then cemented, including the retainingtube 27 which can be drilled out of the casing section 9using a conventional drill string if the wellbore is tobe further deepened.

In case of temporary latching of the latching deviceto the logging tool, for example during taking of pres-sure testing measurements or logging while allowing full 010965 - 8 - interactive data acquisition, the latching System 33 canbe controlled from surface to either retrieve the tool 15or to dis-latch from the tool.

Instead of the logging tool being arranged entirelyeccentrically in the casing shoe track, the tool can bepositioned partly eccentrically and partly centralised,depending on the type of tool and tool sensor or padgeometry applied.

In the above described procedure the logging data arestored in the power/memory cartridge and transferred tosurface thereafter. However in an alternative mode ofoperation the logging data can be transferred to surfacein a real-time mode using full interactive connectionwith a logging unit, for example during formationpressure testing at selected depths.

To establish a real time check that the logging toolis functioning properly while in memory mode, without thetool being connected to surface by a wireline, an inter-nai check System providing intermittent puises (e.g.pressure or electromagnetic) can be included in the toolstring. The intermittent puises can also be used toobtain real time data while running the wellbore component into the wellbore.

In the event of a tool failure, the tool can beretrieved by the pump down latch on a cable and bereplaced by a back-up tool, whereafter logging operationscan be resumed. If the logging tool is to be placed inthe shoe track of an open liner (e.g. a slotted liner, apre-drilled liner or a wire-wrapped screen) a wash pipecan be positioned in the open liner to close off theopenings in the liner so as to allow the latching deviceto be pumped through the open liner, or alternatively the 010965 tool can be connectée! to the wash pipe and retrievedtogether with the wash pipe.

Claims

010965 - 10 - AME N DEP CLAIMS

1. A method of operating a logging tool in a wellboreformed in an earth formation, the wellbore having atleast a section which is to be provided with a wellborecomponent, the method comprising: arranging the logging tool (15) in a selectedrelationship relative to said component (9) so that thelogging tool is guided by the component (9) through thewellbore (1) during lowering of the component into thewellbore; lowering the component (9) with the logging tool (15)in said selected relationship, through the wellbore (1)to said section of the wellbore; operating the logging tool (15) so as to providelogging data of the earth formation (3) surrounding thewellbore; and transferring the logging data to surface,characterized in that the logging tool (15) isretrievably arranged relative to said component (9), andthat after operating the logging tool, the logging toolis retrieved to surface while the wellbore component isleft downhole.
2. The method of claim 1, wherein the logging tool (15)is connected to said component (9) in said selectedrelationship.
3. The method of claim 1 or 2, wherein the loggingtool (15) is operated during lowering of thecomponent (9) with the logging tool rn said selectedrelationship, through the wellbore (1) to said section ofthe wellbore. 010965
4. The method of any one of daims 1-3, wherein thelogging tool (15) îs operated when the logging tool islocated in said section of the wellbore (1).
5. The method of any one of daims 1-4, wherein saidcomponent (9) forms a tubular element and the loggingtool (15) is at least partly arranged within the tubularelement.
6. The method of claim 5, wherein the logging tool (15)is connected to the inner surface of the element (9)· at aselected side thereof, said side corresponding to asection of the earth formation (3) to be logged.
7. The method of claim 5 or 6, wherein the loggingtool (15) is arranged within a retaining device attachedto the inner surface of the tubular element.
8. The method of claim 7, wherein the retaining device (27) is a tube made of a fibre-reinforced material.
9. The method of claim 8, wherein the fibre-reinforcedmaterial is selected from glass fibre-reinforced epoxyand fibre-reinforced cernent.
10. The method of any of daims 1-9, wherein the loggingtool (15) includes at least one of a gamma ray loggingdevice (17), a density logging device (21), a neutronlogging device (19), an NMR logging device, a resistivitylogging device, a micro resistivity/calliper loggingdevice, a sonie logging device and any other suitablelogging device.
11. The method of daim 10, wherein the logging tool (15)includes a plurality of said logging devices arranged ina stacked manner.
12. The method of claim 10 or 11, wherein the component (9) is provided with a window (25) opposite aselected one of said logging devices. 010965 i ί_
13. The method of ciaim 12, wherem said window (25) isfilled with a material suitably transparent to thelogging tool signal.
14. The method of ciaim 13 wherein said material isselected from fibre reinforced plastic, glass fibrereinforced epoxy and fibre reinforced cernent.
15. The method of ciaim 12, wherein said logging deviceforms a pad type device extending though the window so asto contact the wellbore wall.
16. The method of any of daims 1-15, wherein the loggingdata are stored in the logging tool (15) and aretransferred to surface by lowering a pump-down latchingdevice (33) into the wellbore (1), the latching devicebeing connectable to the logging tool (15) and beingprovided with logging data retrieving means (37), pumpingthe latching device (33) through the wellbore until thelatching device is connected to the logging tool, andtransferring the logging data via the logging dataretrieving means (37) to surface.
17. The method of ciaim 16, wherein the tubular element (9) is provided with a guide funnel so as toguide the latching device to the logging tool duringconnecting the latching device (33) to the logging tool.
18. The method of ciaim 16 or 17, wherein the latchingdevice (33) is provided with logging tool retrievingmeans, and wherein the logging tool is retrieved tosurface using said logging tool retrieving means aftermeasuring said parameter.
19. The method of any of ciaims 1-18, wherein the wellbore component (9) is selected from a wellborecasing, a wellbore liner, a slotted wellbore liner, anexpandable slotted liner, a pre-perforated liner, awellbore screen, a wire-wrapped screen, and a gravel pack screen. 010965 - 13 -
20. The method of claim 19, wherein the wellbore component (9) forms a wellbore casing having a casingshoe track (11), and wherein the logging (15) tool is atleast partly arranged in said casing shoe track.
21. A System for operating a logging tool in a wellboreformed in an earth formation, the wellbore having atleast a section which is to be provided with a wellborecomponent, the System comprising: means (27) for arranging the logging tool (15) in aselected relationship relative to said component (9) sothat the logging tool is guided by the component throughthe wellbore during lowering of the component into thewellbore; means (5) for lowering the component with the loggingtool (15) in said selected relationship, through thewellbore (1) to said section of the wellbore; means (23) for operating the logging tool so as toprovide logging data of the earth formation surroundingthe wellbore; and means (37) for transferring the logging data tosurface, characterized in that the means for arrangingthe logging tool (15) relative to said component (9)includes means for retrievablv arranging the logging toolrelative to said component, and that the System furthercomprises means (33) for retrieving the logging tool tosurface while the wellbore component is left downhole.
22. The method substantially as described hereinbeforewith reference to the drawings.
23. The System substantially as described hereinbeforewith reference to the drawings.