CN1629446A

CN1629446A - Coring tool with retention device

Info

Publication number: CN1629446A
Application number: CN200410081823.8A
Authority: CN
Inventors: L·E·小雷德; R·拉沃尔; D·劳普
Original assignee: Schlumberger Overseas SA
Current assignee: Services Petroliers Schlumberger SA; Schlumberger Overseas SA
Priority date: 2003-12-18
Filing date: 2004-12-17
Publication date: 2005-06-22
Also published as: MXPA04012369A; GB0426231D0; US20050133267A1; RU2004137057A; GB2409219B; NO20045149L; CA2490492A1; AU2004231265A1; FR2864140A1; NO20045149D0; FR2864989A1; GB2409219A

Abstract

In some embodiments, the invention relates to a sidewall coring tool that includes a tool body, a hollow coring shaft extendable from the tool body, and a formation cutter disposed at a distal end of the hollow coring shaft. The coring tool includes a retention member segmented into a plurality of petals and disposed proximate a distal end of the internal shaft. An internal sleeve may be disposed inside the hollow coring shaft.

Description

Coring tool with holding device

Technical field

The present invention relates to have the coring tool of holding device.

Background technology

Usually well is pierced underground oil gas and other desired material with the crude sedimentation of extraction trap in earth's crust stratum.Well is pierced underground and directly arrives destination layer from ground drill.

In case the arrival target zone, the driller is usually by obtaining the formation rock sample and analyzing rock sample and study stratum and composition thereof.Usually, sample utilizes hollow core bit to core from the stratum and obtain, and the sample that utilizes this method to obtain is generally known as " core sample ".In case taken core sample to ground, just can analyze to assess it, especially, the fluid ability (permeability) of reservoir reserves (degree of porosity) and formation formation material, mineral deposit in the chemistry of fluid and mineral constituent and the formation pore, and the content of the irreducible water in the formation material.Be used for design and implement completion and production equipment by the information that analytic sample obtained.

" routine is cored " or axially core and comprise from the shaft bottom and obtain core sample.Usually, this is used to receive the rotation core bit with hollow interior of core sample at the bottom of drill string G.I.H from well drill string taking-up or " tripping out " being carried out afterwards.Some drill bits have core bit near the middle part of drill bit, and core sample can obtain under the situation of drill string not being taken out.The routine core sample that is obtained of coring is cored along well track, that is to say along the rock of axis below drill bit of well and cores.

General axial core diameter is 4-6 inch (about 10-15cm) and can surpasses 100 feet (about 30m) length.Rotatablely moving generally produces on ground, and core bit enters the stratum by the weight-driven of the drill string that elevates above the soil.By upwards lifting the core bit that contains sample simply core sample is separated with the stratum.

By contrast, in " sidewall coring ", core sample is to obtain from the borehole wall of institute's drilling well eye.Sidewall coring will carry out after drill string takes out from well usually.The wire line coring instrument that will have core bit is lowered to well, and obtains a fritter core sample from the borehole wall.

In sidewall coring, drill string can not be used to rotate core bit, and the gravity that makes drill bit enter the stratum can not be provided.What replace is that coring tool must produce the rotation of core bit and drive drill bit and enter the necessary axial force in stratum.

In sidewall coring, available space is limited by borehole diameter.Must there be enough spaces to take out and store sample.Because this reason, conventional sidewall coring sample diameter is about 1 inch (about 2.5cm) and its length approximately less than 2 inches (about 5cm).Undersized sample can not produce enough frictional force can core sample being fetched by simple withdrawal core bit between core bit and core sample.But core bit generally can tilt so that core sample ruptures and separates with the stratum.

The other problem that may run into is, because the length of sidewall coring sample is shorter, institute is so that core sample remains on the difficulty that becomes in the core bit.Therefore, core bit also has just in sample breakage or with the stratum after separating and makes core sample remain on mechanism in the core bit.

Sidewall coring destination layer really the cutting-in degree be not to be advantageous in the known well.Logging tool comprises coring tool, can be lowered to the stratum that well is passed with the assessment well.Can obtain a plurality of core samples so that obtain the formation information at different depth place by the different depth in well.

Fig. 1 shows the example of existing side wall coring tool 101, and this coring tool is suspended in the well 113 by rope 107, as transfers assignee's of the present invention U.S. Pat 6,412,575 disclosed coring tools.Utilize core bit 103 to obtain core sample, core bit 103 stretches into stratum 105 from coring tool 101.Coring tool 101 can rest in the well by one or more support arms 111.A kind of example of commercial available coring tool is also in U.S. Pat 4,714, is described in 119 and US5,667,025, and these two patents have all transferred assignee of the present invention.

Fig. 2 shows existing coring apparatus 201 obtains core sample 2 07 from stratum 203 phantom drawing.Core bit 205 is connected on the coring apparatus 201, and this coring apparatus can have a motor, so that core bit 205 stretches out and transmit rotation to core bit 205.Core bit 205 stretches into stratum 203, and core sample 207 is captured on the inside of core bit 205.Should be noted that coring apparatus 201 is arranged on coring tool interior (as 101 among Fig. 1) usually to use in the down-hole.Core bit 205 stretches out and enters stratum 203 from coring apparatus 201 and instrument (as 101 Fig. 1).

The rotation coring tool uses the hollow cylinder core bit that has the stratum cutting tool at the far-end of core bit usually.The core bit rotation is also born against on the borehole wall.When the core bit earth penetrating, the hollow interior of drill bit receives core sample.The rotation core bit utilizes the axle of mechanical connection to stretch out from instrument.Described axle is typically connected on the motor, and described motor is to core bit transmission rotation and drill bit is leaned against on the borehole wall.The rotation core bit is usually by the opposite side of arm rests at the borehole wall.The cutting edge of rotation core bit generally is inlaid with tungsten carbide, diamond or other hard material with the incision stratum.

Fig. 3 shows the example of conventional rotation core bit 301, and it can use with side wall coring tool, as the coring tool among Fig. 1 101.A kind of similar core bit is in U.S. Pat 6,371, and open in 221, this patent transfers assignee of the present invention.Core bit 301 comprises the axle 303 with hollow interior 305.The stratum cutting members 307 that is used to hole is positioned at an end of axle 303.When core bit 301 earth penetratings (illustrating), the core sample (not shown) can be contained in the hollow inside 305 of drill bit 301.After sample is contained in hollow inside 305, core sample is separated with the stratum by mobile or inclined drilling system.Then core bit 301 and the core samples that remain in the hollow inside 305 of core bit 301 are taken out from the stratum.Other the known cutting members that is used to rotate core bit also can be used, and the example of these stratum cutting members is US09/832 at the application number of same application, is described in 606 the patent application, and this patent application has transferred assignee of the present invention.

Though existing coring tool is useful, still need effective more coring tool to guarantee taking out good core sample to analyze.

Summary of the invention

In one or more embodiments, the present invention relates to a kind of side wall coring tool, it comprises body of tool, the hollow axle of coring that can stretch out from body of tool, be arranged on the stratum cutting tool of a hollow far-end of coring, be divided into one group of lobe and be arranged on the hollow interior keeper of axle of coring.In certain embodiments, described one group of lobe comprises three lobes.

In certain embodiments, the present invention relates to a kind of method that obtains core sample, it comprises core bit is stretched into the stratum, and core sample is contained in the inner sleeve, this inner sleeve has the keeper that is divided near one group of lobe the far-end of inner sleeve, and regains core bit from the stratum.

In some other embodiment, the present invention relates to a kind of side wall coring tool, it comprises body of tool, the hollow axle of coring that can stretch out from body of tool, be arranged on the stratum cutting tool of a hollow far-end of coring, be arranged on the inner sleeve in the hollow axle of coring, and at least one maintaining body of from the group that piston and flap valve constituted, selecting, wherein said piston is arranged in the inner sleeve and can moves with respect to inner sleeve, and described flap valve is arranged in the inner sleeve.

In certain embodiments, the present invention relates to a kind of method that obtains core sample, it comprises core bit is stretched into the stratum, core sample is contained in the inner sleeve, described inner sleeve has the piston that sets within it, described piston can move with respect to inner sleeve, and regains core bit from the stratum.

In certain embodiments, the present invention relates to a kind of side wall coring tool, it comprises body of tool, and the hollow axle of coring that can stretch out from body of tool is arranged on the stratum cutting tool of a hollow far-end of coring, and is arranged on the inner sleeve in the hollow axle of coring.Described inner sleeve can comprise inner bag, and it is configured to apply radial pressure to core sample when inner bag optionally is full of fluid.

In certain embodiments, the present invention relates to a kind of side wall coring tool, it comprises body of tool, the hollow axle of coring that can stretch out from body of tool, be arranged on the stratum cutting tool of a hollow far-end of coring, and be arranged near the coring tool far-end and the heart has the hole therein elastic keeper.

From following description and appended technical scheme, other aspects and advantages of the present invention will become clearly.

Description of drawings

Fig. 1 is the sectional drawing of well with coring tool of the prior art in the well of being suspended on.

Fig. 2 is the phantom drawing of the coring apparatus of prior art.

Fig. 3 is the phantom drawing of the rotation core bit of prior art.

Fig. 4 A is the sectional drawing of core bit according to an embodiment of the invention.

Fig. 4 B is the sectional drawing of core bit according to an embodiment of the invention.

Fig. 4 C is the sectional drawing of core bit according to an embodiment of the invention.

Fig. 5 A is the sectional drawing with core bit of holding device according to an embodiment of the invention.

Fig. 5 B is the sectional drawing with core bit of holding device according to an embodiment of the invention.

Fig. 6 A is the top view with core bit of holding device according to an embodiment of the invention.

Fig. 6 B is the top view with core bit of holding device according to an embodiment of the invention.

Fig. 6 C is the top view with core bit of holding device according to an embodiment of the invention.

Fig. 6 D is the top view with core bit of holding device according to an embodiment of the invention.

Fig. 7 A is the sectional drawing of core bit keeper according to an embodiment of the invention.

Fig. 7 B is the sectional drawing of core bit keeper according to an embodiment of the invention.

Fig. 7 C is the sectional drawing of core bit keeper according to an embodiment of the invention.

Fig. 7 D is the sectional drawing of core bit keeper according to an embodiment of the invention.

Fig. 7 E is the sectional drawing of core bit keeper according to an embodiment of the invention and inner sleeve.

Fig. 8 A is the sectional drawing with core bit of piston according to an embodiment of the invention.

Fig. 8 B is the sectional drawing with core bit of piston according to an embodiment of the invention.

Fig. 9 is the sectional drawing with core bit of liner according to an embodiment of the invention.

Figure 10 is the sectional drawing with core bit of core sample holding device according to an embodiment of the invention.

The specific embodiment

In certain embodiments, the present invention relates to a kind of core bit that core sample is remained on the keeper in the core bit that has.In other embodiments, the present invention has and core sample is held or remains on piston or liner in the coring tool.In other embodiments, the present invention relates to make rock core to remain on the interior method of coring tool.Now with present invention is described in conjunction with the accompanying drawings.

Fig. 4 A is the sectional drawing with core bit 401 of keeper 411 according to an embodiment of the invention.Fig. 4 A only shows core bit 401, but it will be appreciated by those skilled in the art that core bit 401 has constituted the part of the coring tool (not shown) that obtains core sample from the stratum.According to example, core bit can constitute the part of coring tool, as the coring tool among Fig. 1 101.

Core bit 401 has hollow shaft 403 among Fig. 4 A, and this has the stratum cutting tool 405 of the far-end that is arranged on hollow shaft 403.Stratum cutting tool 405, or cutting tool are made of the material that can pierce stratum 402.Stratum cutting tool 405 can be made of firm material, is coated with superhard material on it, as polycrystalline diamond or tungsten carbide.In other embodiments, stratum cutting tool 405 can have other device of cutting soft formation, as brush.Term " far-end " is used to describe the end of the core bit 401 that at first contacts the stratum.Far-end is axle 403 end, its when sampling apart from the middle part of coring tool (not shown) farthest.It is the first of core bit 401 earth penetratings.

Shown in Fig. 4 A, core bit 401 can comprise the inner sleeve 407 that is arranged in the hollow shaft 403.Inner sleeve 407 is used for receiving core sample when entering core bit at core sample (not shown at Fig. 4 A).In certain embodiments, inner sleeve is the inner sleeve of " non-rotating ".Irrotational inner sleeve is to be independent of the inner sleeve that hollow shaft 403 rotates freely.Thereby when coring tool penetrated stratum 402, the friction between inner sleeve and the core sample (as 410 among Fig. 4 B and the 4C) had prevented that inner sleeve is with respect to stratum 402 rotations.In certain embodiments, mechanical stopping piece can prevent the rotation of inner sleeve as the key (not shown).Reduced the abrasion of core sample by the friction between elimination core sample and the inner sleeve in sampling process.Core sleeve example together the application application number be US10/248, disclose in 475 the patent application, this patent application transfers assignee of the present invention.

Keeper 411 is arranged on the far-end of inner sleeve 407.Can see keeper 411 and make core sample enter core bit 401 and inner sleeve 407, in case core sample 410 has been contained in the core bit 401, keeper also makes core sample 410 remain in the inner sleeve 407.

Fig. 4 B shows and is in the cross section that receives the core bit 401 in core sample 410 processes.When stratum cutting tool 405 penetrated stratum 402, core sample 410 entered core bit 401.When core sample 410 entered into inner sleeve 407, it pushed the lobe 411a of keeper 411 open, and 411b is so that core sample 410 can enter core bit 401.At lobe 411a, when 411b moved, they applied a radially inner power to core sample 410, and this power is used to guide core sample 410 and it is kept in place.

Fig. 4 C shows the cross section of the core bit 401 in the inner sleeve 407 that core sample 410 is contained in hollow shaft 403 inside that are arranged on core bit 401.By the lobe 411a of keeper (411 among Fig. 4 A), 411b is with dual mode at least and core sample 410 is remained in the core bit 401.At first,

lobe

411a, 411b inwardly push core sample 410 so that it keeps stable, and it is kept in place.Secondly, when core bit 401 is regained from the stratum, lobe 411a, 411b will be tending towards closing and clamping core sample 410.In ragstone, core sample 410 and lobe 411a, the additional friction between the 411b will be played the effect that core sample 410 is remained on the Wedge gripping in the core bit 401.

In weak rock,

lobe

411a, 411b can close fully and with core sample 410 traps in core bit 401.This is good, because loose or soft formation is easy to be scattering into outside the core bit 401.

Lobe

411a, 411b can close so that core sample 410 remains in the core bit 401, rather than lose 3/4 inch (about 1.9cm) core sample to the scall of 1 inch (about 2.5cm).The core sample of being lost 410 only is to stretch out lobe 411a, the part core sample of 411b.In certain embodiments, it is long that lobe is about 1/4 inch (about 0.6cm), thereby be about 1/4 inch core sample lost during closing lobe.This helps to capture and keep the core sample of soft formation, and when utilizing conventional core bit to core, the core sample of soft formation is easy to be scattering into outside the core bit.

Fig. 4 A, 4B, the keeper 411 shown in the 4C is preferably made by rubber, although it can be made by any material flexible and that have a Memorability.Material with Memorability will " be remembered " its initial position so that can both return motion arrive its initial position no matter when it moves.In certain embodiments, even it also can remain in the regime of elastic deformation when described material is mobile fully by core sample.Thereby, when the lobe of keeper by core sample when radially promoting outwardly, lobe has enough pliabilities allowing open position, thereby makes core sample can enter core bit easily, but they also can be easy to radially inwardly promote towards their initial position.This trend that is returned to initial position has produced pressure radially to core sample, and this pressure will guide core sample to enter core bit, and remains in the core bit when core bit is regained from the stratum.

In certain embodiments, keeper can be not continuous at the far-end of inner sleeve.For example, Fig. 5 A shows and has the core bit 501 that is arranged on the inner sleeve 507 in the hollow axle 503 of coring.Stratum cutting tool 505 is arranged on the far-end of the hollow axle 503 of coring.Keeper 511 is positioned at the mid point of the axial length of inner sleeve 507.In this position, keeper 511 provides guiding so that the core sample (not shown) will remain near the axis centre of inner sleeve 507, although make core sample remain on ability in the core bit 501 when core bit still has when the stratum (not shown) takes out.For example, in hardpan, keeper 511 has played and has made the core sample (not shown) remain on the effect of the Wedge gripping in the core bit 501.

Fig. 5 B shows another embodiment that has the core bit of keeper 521 according to of the present invention.Core bit 521 is included in the hollow axle 523 of coring that its far-end has stratum cutting tool 525.Keeper 531 is fixed in the central opening of stratum cutting tool by the ring in the cutting tool of stratum 533.In this position, keeper 531 can make the core sample (not shown) enter core bit 521, in case and core sample be received it core sample is remained in the core bit 521.

Should be noted that also have various described combination of features according to core bit of the present invention.For example, it can comprise the keeper that is in position shown in Fig. 5 A, but does not have inner sleeve.In another embodiment, core bit can comprise near the ring (as the ring among Fig. 5 B 533) that is not arranged on the core bit far-end.Those of ordinary skill in the art can design the embodiment of other core bit that does not break away from the scope of the invention.

Fig. 6 A shows the end-view of keeper 601 according to an embodiment of the invention.Keeper 601 has the lobe 602a of three outside lobe circumference 605 cuttings in the center from keeper 601,602b, 602c.In certain embodiments, lobe circumference 605 has identical size with the internal diameter of stratum cutting tool (as Fig. 5 A, 5B, 505 among the 5C) basically.This makes core sample can be very suitable for keeper.In another embodiment, lobe circumference 605 can be greater than the internal diameter of stratum cutting tool (as Fig. 5 A, 5B, 505 among the 5C).

Lobe 602a shown in Fig. 6 A, 602b, 602c is adjacent to each other.That is to say, the edge of lobe, lobe 602a for example, with other lobe, 602b for example, 602c is adjacent.

In certain embodiments, keeper 601 comprises otch or bores a hole 607.Made by rigid material or when only having a spot of lobe to make each lobe firm, otch 607 can be lobe 602a when keeper 601,602b, 602c provide other retractility.

Fig. 6 B shows mutually the not lobe 622a of adjacency, 622b, the embodiment of the lobe 621 of 622c.In this embodiment, lobe 622a, 622b, 622c is separated from one another and turn back to lobe circumference 625.

Fig. 6 C shows the another embodiment according to keeper 631 of the present invention.Lobe 637,638,639 overlap each other.For example, lobe 637 has the edge 637a on the edge 639b that overlaps lobe 639.Other edge 637b of lobe 637 is overlapping by the edge 638a of lobe 638.Similarly, lobe 639 has the edge 639a on the edge 638b that overlaps lobe 638.

Fig. 6 D shows another embodiment of keeper 641 according to an embodiment of the invention.The keeper heart therein has hole 646.Producing hole 646 is because keeper 641 only extends inwardly to hole circle week 647.The core sample (not shown) can pass through hole 646 by mobile keeper 641.The elasticity of keeper 641 will make keeper 641 be received Shi Xiangqi at core sample and apply inside power.

But Fig. 6 D also shows another preferable feature of keeper.For example, the keeper 641 with hole 646 can not have any lobe.Core sample can only move solid keeper.In another embodiment, such as the embodiment shown in Fig. 6 D, keeper 641 can comprise one or more lobe 642a, 642b, 642c.Lobe 642a, 642b, 642c can be independently lobe, perhaps lobe 642a, 642b, 642c can be installed with perforation 643, this hole hole circle week 647 to extending between the lobe circumference 645.When carrying out the coring of core sample (not shown), core sample will destroy perforation 643, and core sample can be contained in the core bit (not shown).

In fact, should be noted that the embodiment of many above-mentioned disclosed keepers can use radial perforation so that keeper is divided into lobe.This will make keeper be used as overburden, and it is cored and bore a hole and prevent that pollutant from entering core bit before destroyed carrying out core sample.

Should be noted that radial perforation is different from circumferential perforation, this is circumferentially bored a hole and can be used for increasing the pliability of keeper.

Fig. 7 A-7E shows the embodiment of the various keepers that use with core bit of the present invention.Fig. 7 A shows has the lobe 711a that inwardly comes to a point gradually, the keeper 711 of

711b.Lobe

711a, 711b have the lobe circumference substantially the same with the internal diameter of stratum cutting tool 705.Core sample just in time passes the lobe 711a of keeper 711,711b.

Fig. 7 B shows another embodiment of keeper 721, and wherein, lobe 721a, 721b outwards come to a point gradually.In this embodiment, (not shown) when lobe 721a, 721b are driven by core sample will be uprised a little by lobe 721a, 721b institute applied pressure, and this is because they have further been driven forward from its initial position.

Fig. 7 C shows another embodiment according to keeper 731 of the present invention.Lobe 731a, the 731b of keeper 731 is circular and stretches into inner sleeve 707.In the time of in the core sample (not shown) is contained in inner sleeve 707, lobe 731a, 731b will inwardly be driven.

Fig. 7 D shows another embodiment according to keeper 741 of the present invention.Lobe 731a, the 731b of keeper 741 is circle and protruding from inner sleeve 707.In the time of in the core sample (not shown) is contained in inner sleeve 707,

lobe

741a, 741b will inwardly be driven.

Fig. 7 E shows an embodiment of the keeper 751 that is similar to shown in Fig. 7 B.In Fig. 7 E, inner sleeve 757 has the groove 753 that provides the space for the lobe 751a that is in activation point, 751b.The inside diameter D 2 of the inner sleeve 757 in the groove 753 is greater than the nominal diameter D1 of inner sleeve 757.In an illustrated embodiment, the internal diameter with stratum cutting tool 705 is identical basically for the nominal diameter D1 of inner sleeve 757.When core sample enters inner sleeve, the lobe 751a of keeper 751,751b will be driven into groove 753.As lobe 751a, when 751b entered groove 753, it had the internal diameter substantially the same with the nominal diameter D1 of inner sleeve 757.This makes that core sample 701 can both close fit at points all on the axis of inner sleeve 757, still has the advantage of keeper according to an embodiment of the invention simultaneously.

The embodiment of the inner sleeve 757 shown in Fig. 7 E can use with the various embodiment of keeper.For example, the inner sleeve 757 with groove 753 can use with arbitrary embodiment of keeper shown in Fig. 7 A-7E.

Keeper according to arbitrary embodiment of the present invention can be specifically designed as special purpose, perhaps can be designed to capture and keep the multistage rock core.For example, some core bits can be designed to core sample is stored in the inner sleeve.That is to say that inner sleeve moves to storage area from core bit inside.In other embodiments, only have core sample can move into memory device, and inner sleeve is used to capture another core sample.

Persons of ordinary skill in the art may appreciate that Fig. 7 A-7E shows the cross section according to the specific embodiments of core bit of the present invention and keeper.Equally, accompanying drawing only shows two lobes among the embodiment.This is the effect in cross section, and it is not limited to the present invention.Can have a plurality of lobes according to keeper of the present invention.Can be preferably, keeper consistent, solid, taper or have one or more holes of passing wherein.Can imagine and other structure.Keeper can be used for tearing and/or stretching when core sample enters sleeve.Be stretched or the keeper of tearing part can be to the core sample application of force to clamp core sample.It can be withdrawn into initial position basically and close the restriction core sample and partly run out of the rock core sleeve after core sample thereby preferred keeper has elasticity.

Fig. 8 A shows the cross section according to the core bit 800 of the inner sleeve 807 with piston 802 of the present invention.Piston 802 can be with respect to inner sleeve 807 axially-movables.Piston 802 begins to be positioned near the position the far-end with inner sleeve 807.When core sample was gathered from stratum 810, core sample will be with respect to inner sleeve 807 mobile pistons 802.Piston 802 also can comprise seal 812 or bearing so that piston 802 moves more easily in inner sleeve 807.

In an illustrated embodiment, inner sleeve 807 has and the essentially identical diameter of the internal diameter of stratum cutting tool 805.In order to be fit to inner sleeve 807, piston 802 has and the essentially identical diameter of the internal diameter of inner sleeve, so that piston seal 812 can form sealing between inner sleeve 807 and piston 802.

Fig. 8 B shows the cross section with the core bit 800 that is contained in the core sample 801 in the core bit 800.Core sample 801 moves to position near the near-end of inner sleeve 807 with piston 802.Piston 802 moves in the time of in core sample 801 is contained in core bit 800.This is favourable for loose stratum, and in loose stratum, it will be cracked when the formation core sample enters core bit.Piston 802 can prevent that the stratum is cracked.

In addition, when core bit 800 was regained from stratum 810, piston 802 helped core sample is remained in the inner sleeve 807.In certain embodiments, the chamber 815 after the piston 802 comprises that flap valve or other device (not shown) are discharged from chamber 815 to allow air or fluid, but it does not allow to reflux.Thereby the vacuum after the piston 802 has prevented that piston 802 outward directions from moving.

In certain embodiments, ventilate fully in the chamber 815 after the piston.Yet core sample 801 can not be moved out of inner sleeve 807 under the situation of mobile piston 802 not.This can realize by the vacuum that is produced between piston 802 and core sample 801.Friction between piston 802 and the inner sleeve 807 will produce the additional drag that stops core sample 801 to move, and it helps core sample 801 is remained in the core bit 801.

In addition, except that simple piston 802, inner sleeve 807 also comprises pawl device or locking device.This device will prevent that piston from outwards moving.

Fig. 9 shows has the cross section that core sample 901 is held and remains on the core bit 900 of the liner in the drill bit 900.Hollow outer shaft 903 utilizes the stratum cutting tool 905 that is arranged on axle 903 far-ends to penetrate stratum 910.Core sample 901 is contained in the inner sleeve 917 that is arranged in the hollow shaft 903.

Chamber (shown in the mark 918) in the inner sleeve 917 is positioned at after the core sample 901, has been full of fluid in it, as water.The near-end of inner sleeve 917 comprises valve 921, passes between the other parts of inner sleeve 917 and instrument optionally to make fluid.For example, valve 921 can be flap valve, and when core sample 901 entered inner sleeve 917, this flap valve made fluid discharge chamber 918.When core bit 900 was removed from the stratum, valve 921 can be used for preventing that fluid from flowing backwards enters the room 918, and generation makes core sample remain on vacuum in the core bit 901 core sample 901 after.

In at least one embodiment, the flap valve among Fig. 9 921 can be used in combination with the core bit 800 among Fig. 8 A and the 8B.In this embodiment, piston (802 among Fig. 8 A and the 8B) will force fluid to pass flap valve (921 among Fig. 9).Flap valve (921 among Fig. 9) will prevent the refluence of fluid, thereby piston (802 among Fig. 8 A and the 8B) vacuum afterwards will make the piston-like core sample keep in position.

Figure 10 shows the cross section of core bit 1001 according to another embodiment of the present invention.Hollow shaft 1003 has the stratum cutting tool 1005 that is positioned at hollow shaft 1003 far-ends.Inner bag (bladder) 1007 is as the inner sleeve in the core bit among Figure 10 1001.When inner bag 1007 dwindled, it provided enough space to receive core sample.Then, inner bag 1007 can expand by being full of fluid.Described fluid can be the hydraulic fluid of storage, perhaps for pumping into the drilling fluid of inner bag.Employed fluid type is not limited to the present invention.

When inner bag 1007 was filled, it inwardly compressed and applies radial pressure to the core sample (not shown).Described pressure is used for providing overload stable and that keep core sample to core sample.

Embodiments of the invention can have one or more following advantages.The core bit that has according to keeper of the present invention or other holding device will remain in the core bit core sample when core bit takes out from the stratum.This will prevent in this course that core sample is damaged or loses.

What have advantage is that core bit can be included in the keeper of cutting out fully when capturing core sample in soft formation or the scall.When keeper is closed, core sample will be completely enclosed within the core bit and make it exempt from further damage and lose.

What have advantage is that the core bit with non-rotating inner sleeve can not denuded core sample by the friction between core sample and inner sleeve and the keeper.When core sample was captured, inner sleeve and keeper can not be rotated with respect to the stratum.

What have advantage is that the embodiments of the invention with the piston in the inner sleeve are received Shi Weiqi at core sample provides additional guiding.Described piston is moved by core sample, in case and core sample received fully, described piston produces in the back of core sample when core bit is removed from the stratum and makes core sample remain on vacuum or space in the inner sleeve.

What have advantage is that the embodiments of the invention with liner provide stable guiding for it when core sample enters core bit.In case core sample is contained in the core bit, core sample is kept by vacuum or the space after the core sample.

Though invention has been described in conjunction with the embodiment of limited quantity, benefits from of the present disclosure one skilled in the art will appreciate that and can design other embodiment that does not break away from this disclosed scope of the present invention.Therefore, scope of the present invention should only be limited by appended technical scheme.

Claims

1. side wall coring tool, it comprises

Body of tool;

The hollow axle of coring that can stretch out from body of tool;

Be arranged on the stratum cutting tool of a hollow far-end of coring; And

Be divided into one group of lobe and be arranged on the hollow interior keeper of axle of coring.

2. side wall coring tool as claimed in claim 1, it also comprises the inner sleeve that is arranged in the hollow axle of coring, and wherein said keeper is connected on the inner sleeve.

3. side wall coring tool as claimed in claim 2 is characterized in that described keeper is arranged near the far-end of inner sleeve.

4. side wall coring tool as claimed in claim 2 is characterized in that described inner sleeve comprises irrotational sleeve.

5. side wall coring tool as claimed in claim 2 is characterized in that described inner sleeve comprises radial groove, so that the lobe of keeper can be positioned in the groove radially outwardly.

6. side wall coring tool as claimed in claim 5 is characterized in that, described keeper comprises the lobe circumference roughly the same with the internal diameter of inner sleeve.

7. side wall coring tool as claimed in claim 2, it also comprises and being arranged in the inner sleeve and can be with respect to the axially movable piston of inner sleeve.

8. side wall coring tool as claimed in claim 2, it also comprises the flap valve that is arranged in the inner sleeve.

9. side wall coring tool as claimed in claim 8 is characterized in that described flap valve is arranged on the near-end of inner sleeve.

10. side wall coring tool as claimed in claim 9 is characterized in that, described flap valve can make fluid flow out inner sleeve.

11. side wall coring tool as claimed in claim 1 is characterized in that, the internal diameter of the inner sleeve internal diameter with the stratum cutting tool basically is identical.

12. side wall coring tool as claimed in claim 1 is characterized in that, the internal diameter of inner sleeve is greater than the internal diameter of stratum cutting tool.

13. side wall coring tool as claimed in claim 1 is characterized in that, described inner sleeve comprises inner bag, and it is configured to apply radial pressure to core sample when inner bag optionally is full of fluid.

14. side wall coring tool as claimed in claim 1 is characterized in that, described one group of lobe also has three lobes.

15. side wall coring tool as claimed in claim 1 is characterized in that, described one group of lobe is overlapping.

16. side wall coring tool as claimed in claim 1 is characterized in that, described one group of lobe is opened by separated.

17. side wall coring tool as claimed in claim 1 is characterized in that, described keeper has perforation.

18. side wall coring tool as claimed in claim 17 is characterized in that, described perforation is the circumferential perforation that is arranged on the lobe periphery.

19. side wall coring tool as claimed in claim 17 is characterized in that, described perforation is for being arranged on the radial perforation of lobe inside circumference to small part.

20. side wall coring tool as claimed in claim 1 is characterized in that, described one group of lobe is adjacent.

21. side wall coring tool as claimed in claim 1 is characterized in that, described keeper is made by rubber.

22. side wall coring tool as claimed in claim 1 is characterized in that, described keeper is circular and stretches out to hollow far-end of coring axle.

23. side wall coring tool as claimed in claim 1 is characterized in that, described keeper is circular and stretches out to hollow near-end of coring axle.

24. a method that obtains core sample, it comprises:

Core bit is stretched into the stratum, and described core bit has the keeper that is divided into one group of lobe;

Core sample is contained in the core bit; And

When from the stratum, regaining core bit, core sample is remained in the core bit with keeper.

25. method as claimed in claim 24, it also comprises and utilizes fluid optionally an inner bag to be full of to apply radial pressure to core sample.

26. method as claimed in claim 24, its spy is that described keeper is connected on the inner sleeve that is arranged in the core bit, and described core sample is accommodated in the inner sleeve.

27. a side wall coring tool, it comprises:

Body of tool;

The hollow axle of coring that can stretch out from body of tool;

Be arranged on the stratum cutting tool of a hollow far-end of coring; And

Be arranged on the inner sleeve in the hollow axle of coring.

28. side wall coring tool as claimed in claim 27 is characterized in that, described inner sleeve has an inner bag, and it is configured to apply radial pressure to core sample when inner bag optionally is full of fluid.

29. side wall coring tool as claimed in claim 27, it also comprises the maintaining body that at least one is selected from the group of piston and flap valve formation, wherein said piston is arranged in the inner sleeve and can moves with respect to inner sleeve, and described flap valve is arranged in the inner sleeve.

30. side wall coring tool as claimed in claim 29 is characterized in that, described at least one maintaining body is a piston.

31. side wall coring tool as claimed in claim 30, it also comprises the seal that is arranged between piston and the inner sleeve.

32. side wall coring tool as claimed in claim 30 is characterized in that, the internal diameter of the inner sleeve internal diameter with the stratum cutting tool basically is identical.

33. side wall coring tool as claimed in claim 30, it is connected to the flap valve of inner sleeve with also comprising operability.

34. side wall coring tool as claimed in claim 27, it also comprises and is arranged near the coring tool far-end and the heart has the hole therein keeper.

35. as claim 27,29 or 34 described side wall coring tools, it also comprises near the keeper that is arranged on the inner sleeve distal openings and is divided into a plurality of lobes.

36. a method that obtains core sample, it comprises:

Core bit is stretched into the stratum;

Core sample is contained in the inner sleeve, and this inner sleeve has piston disposed thereon, and described piston can move with respect to inner sleeve; And

From the stratum, regain core bit.

37. method as claimed in claim 36, it also comprises and utilizes fluid optionally inner bag to be full of to apply radial pressure to core sample.