CN2466335Y

CN2466335Y - Flexible drilling tool

Info

Publication number: CN2466335Y
Application number: CN 00258470
Authority: CN
Inventors: 张书明; 吴淑芳
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-10-15
Filing date: 2000-10-15
Publication date: 2001-12-19
Anticipated expiration: 2010-10-15

Abstract

The utility model relates to a flexible drilling tool for drilling horizontal wells with ultrashort radiuses by a turntable method for the exploration, development and production of petroleum. The utility model is mainly composed of a pipe type guide cylinder with an elastic bended outer shell and a flexible drill rod with a rolling bearing. The flexible drill rod is arranged in the guide cylinder with an elastic bended outer shell, the lower end of the flexible drill rod is connected with a drill bit, the upper end of the flexible drill rod is connected with a common drill rod, and inclination producing drilling with 90 DEG can be implemented. The flexible drill rod can be extended horizontally by connecting the flexible drill rod with the drill bit only to drill horizontal well eyes.

Description

A kind of flexible drill string

The utility model relates to a kind of well drilling tool field of recovery of subterranean fluid.Particularly a kind of spining disk method bores the flexible drill string of super short radial horizontal well.

Existing horizontal well drilling instrument, flexible poor because its rigidity is big, to horizontal payzone section, need creep into extremely less tens meters of hundreds of rice from vertical section, thereby the cost height, enter the poor accuracy of payzone." 95 " China National Petroleum Corporation (CNPC) tackles key problems to super short radial horizontal well, breaks into the horizontal well of a collection of radius more than 30 meters, and many with introducing hinged screw drill, cost is up to hundreds thousand of units.U.S. geophysics company has the super short radial horizontal well supporting technology of high-pressure rotary jet rock-breaking, the every well more than 200 ten thousand of service price, and well depth is only limit in 2000 meters.

The purpose of this utility model is: at cost height in the prior art, enter defectives such as payzone poor accuracy, design a kind of radius of curvature is bored super short radial horizontal well less than 3 meters spining disk method flexible drill string.

The utility model purpose is achieved in that

Bend to the elastic tube-type guide cylinder of 90 degree, the long ball key formula high pulling torque flex-stem that has the rolling alignment bearing is being adorned in the inside, and the two constitutes kick-off device.The characteristics of guide cylinder are can bend meeting directly, enough elastic force is arranged, impel drill bit to turn to, have many group guiding righting strips and Geng Duo group to prevent turning round banking stop on the guide cylinder outer wall, guarantee whole guide cylinder directional curvature, azimuthal stabilization and not turning round partially, flex-stem can be made circumference and rotate by the particular design of outer spherical key in a plurality of, gives drill bit with transfer torque, but outer spherical bond structure circumferential skewing certain angle all in every group, it is that bendable 90 degree circumferentially rotate that many groups connect.Be assembled with the ball alignment bearing on every group of spherical key, make the spherical key drilling tool of rotation not contact guide cylinder, do not contact the borehole wall when level is crept into, have only the ball of bearing on the guide cylinder inwall, to roll, the very little deficiency of friction causes the variation in guide cylinder orientation, therefore, and can directional inclination.Each spherical key of forming flex-stem is hollow, and the pneumatic hose or the composite material tube of drilling fluid carried in the inside dress.After the flex-stem that has ball bearing is installed in and finishes deflecting in the guide cylinder, also its lower end can be connected with drill bit, receive again below the common drilling rod drill collar, be lowered to and proceed level in the inclination section payzone and creep into.

The utlity model has following advantage:

1, kick-off device and flex-stem are applicable to various rig, and applicability is strong, are convenient to promote.

2, deflecting radius of curvature 2.5-3m only, can be in payzone the deflecting and the horizontal well eye of fetching water, can make full use of old well heavily bores payzone, eliminating old well payzone pollutes, 100% is effective drilling depth, farthest increases the payzone exposed surface, and output is improved, drilling cost is reduced because of the shortening of drilling period, improve the oil field ultimate recovery.

Below in conjunction with accompanying drawing the utility model is described in further detail:

Fig. 1 is the utility model overall structure schematic diagram, Fig. 2 is the utility model guide cylinder schematic diagram, Fig. 3 is the A-A sectional drawing of Fig. 2, Fig. 4 is the B-B sectional drawing of Fig. 2, Fig. 5 is the anti-partial enlarged drawing of turning round position-limit mechanism 4, Fig. 6 is the utility model flex-stem schematic diagram, and Fig. 7 is the C-C sectional drawing of Fig. 6, and Fig. 8 is the D-D sectional drawing of Fig. 6.

Fig. 1 is overall structure signal of the present utility model, and it is made up of the flex-stem of guide cylinder that does not rotate and inner rotation.Set upright gib block 1, slot 2, aperture 3 and the anti-position-limit mechanism 4 of turning round on the guide cylinder; Flex-stem is respectively by screw thread 5, internal slip 6, and external slips 7, high-pressure rubber pipe 8, interior spherical key 9, outer spherical key 10, bearing bracket stand 11, steel ball 12 and screw thread 13 are formed.Screw thread 5 connects common drilling rod, and screw thread 13 connects drill bit, but guide cylinder and flex-stem are united just deflecting of use, uses flex-stem to finish horizontal well separately and creeps into.

As shown in Figure 2, guide cylinder time body has two row's aperture 3 and slots 2, and the effect of aperture 3 is to reduce stress to concentrate, and the effect of slot 2 is guide cylinder to be bent can directly be convenient to rountrip.Guide cylinder 80% part under normal conditions bends to 90 degree, and 20% part is linearly.90 degree bending are needs of deflecting, can provide enough lateral forces for drill bit, and 20% the preparing less than designing build angle rate in order to supply actual build angle rate of straight section.Can see that from figure guide cylinder is eccentric, that is to say that one side is thick, on one side thin, the thickest part accounts for 1/5th to 1/3rd of girth, is continuous, plays a part big spring, and remainder is cut off respectively, and cut-off is just easy like this, and elastic force is also big.Many groups are set upright gib block 1 and are distributed in barrel outer surface, every group have three circumferential uniform, their effect be in elastic force effect lower support on the borehole wall, can only be along the well axial slip, and can not circumferentially rotate, guarantee towards an orientation deflecting.In addition, also have on the guide cylinder that a row is anti-to turn round position-limit mechanism 4, they are positioned at the most inboard of cylindrical shell, and per three same T-shaped hollow sheets are formed one group and anti-ly turned round position-limit mechanism 4, play a part to prevent turning round spacing.

Can see that from two profiles of A-A, B-B guide cylinder is eccentric as shown in Figure 3, Figure 4, that is to say that one side is thick, on one side thin, the thickest part accounts for 1/5th to 1/3rd of girth.

Anti-ly as shown in Figure 5 turn round position-limit mechanism 4 and forms, be welded on every cross cut seam both sides, play a part to prevent turning round spacing, guarantee to be drilled to the well of radius of curvature 2.5--3 rice by enlarged drawing by three same T-shaped hollow sheets.

Fig. 6 is the spherical key ten tooth high pulling torque flex-stem schematic diagrames that have ball bearing, its lower end screw thread 13 is connected with drill bit, upper end screw thread 5 is connected with conventional rigidity drilling rod, and the later borehole length of flex-stem length and deflecting is complementary, and can be made up of many flex-stems.High-pressure rubber pipe 8 is worn in the centre of drilling rod, two ends respectively by after 7 lockings of internal slip 6, external slips again with screw thread 13, screw thread 5 welding at two ends, carry high pressure drilling liquid with this, drilling fluid is through ground high pressure pipe joint, standpipe, hose, water tap, kelly bar, conventional drilling rod, flex-stem, from bit nozzle, spray, in order to take bits, lubricated, cooling, retaining wall, blowout prevention or the like, finish deflecting and creep into.So flex-stem can transmit tension and compression and moment of torsion is the effect of interior spherical key 9 and outer spherical key 10, their head and the tail welding respectively, and have ten spherical key teeth to be meshed, so owing to be that spherical key tooth can along the circumferential direction crooked certain angle, a plurality of combinations just can be spent more than or equal to 90 by circumferential skewing.The ball alignment bearing is made up of bearing bracket stand 11 and steel ball 12, they are installed in each outer spherical key 10 minor diameter place respectively, its diameter is greater than outer spherical key 10, when flex-stem rotates, have only the steel ball 12 that is rolling to contact with the guide cylinder (during deflecting) or the borehole wall (when level is crept into), like this, flex-stem and outer wall friction are little, also make when creeping into moment of torsion less, help effective progress that deflecting and level are crept into.

Be illustrated in figure 7 as the ball alignment bearing and be made up of bearing bracket stand 11 and steel ball 12, its diameter is greater than outer spherical key 10.

As shown in Figure 8, flex-stem is made up of interior spherical key 9 and outer spherical key 10, their head and the tail welding respectively, and have ten spherical key teeth to be meshed.

Claims

1, a kind of flexible drill string is made up of with the flex-stem two parts that have rolling bearing the curved shell guide cylinder of tubular type, and flex-stem is positioned at guide cylinder, last stacks, lower drill.It is characterized in that: the screw thread (5) that has the flex-stem of rolling bearing spins with common drilling rod, screw thread (13) spins with drill bit, internal slip (6), external slips (7), locking internal high pressure sebific duct (8), and with the welding of screw thread (5), screw thread (13), interior spherical key (9) and outer spherical key (10) have ten teeth to be meshed, each ball key is welded to each other, and with the welding of screw thread (5), screw thread (13), transfer torque, bearing bracket stand (11) and steel ball (12) are formed the rolling alignment bearing, and the diameter maximum is installed on each outer spherical key (10).

2, flexible drill string according to claim 1, it is characterized in that: the curved shell guide cylinder of tubular type has slot (2) and aperture (3) all over body, they can bend cylindrical shell can be straight, flexible when straight, and the cylindrical shell outside weld is connected to many group guiding righting strips (1) and the anti-position-limit mechanism (4) of turning round.