SU1439215A1 - Apparatus for mud-grouting borehole walls, mounted above drilling bit with nozzles - Google Patents

Abstract

The invention relates to the oil and gas industry. The purpose of the invention is to increase the efficiency by treating the walls of the wells with a colculate fine fraction. The device has a housing (K) 1, at the inlet of which a swirler 2 is installed with radially located blades 3, V K 1 has a nozzle 4, inside which is installed a commutator section.

Description

XSW.5S

lo (C) 5. The device is installed above the drill bit from C. The input edge of the nozzle 4 is spaced from. the K axis at a distance Hz, determined from the expression ra, dK dc / 2-ijdl + nd, where dn is the inner diameter K 1; - diameter of the exit section C 5; - diameter of the output section C of the bit; n is the number of C bits. The working agent injected into the drill string is twisted at the entrance to K 1. As a result of the centrifugal forces in the center, there will be small clogging, and in the peripheral part - a large one. The small fraction is entrained inside the nozzle 4 and, passing through C 5, falls on the borehole wall. The optimal combination of the number and diameters of the C 5 as well as the C bits is established empirically. For each particular case corresponds to a certain value of the distance SC, 2 Il.

one

The invention relates to the oil and gas industry, in particular to devices for clogging the walls of a well.

The purpose of the invention is to increase the efficiency of operation by treating the walls of the well with a coarse fine fraction.

1 shows a device for clogging the walls of the well, a longitudinal section; figure 2 - section aa in figure 1 ..

The device comprises a housing 1, at the inlet of which a swirler 2 is installed with radially arranged blades 3, and a branch pipe 4 is placed in the lower part of the housing, inside which is installed a closure nozzle: 5. The device is installed above the drill bit with nozzles (not shown). The entrance to the edge of the nozzle 4 is separated from the longitudinal axis of the body at a distance determined by the formula

Hz

dK d s

inTr -

21} d + ndl where d is the inner diameter of the case

devices, m; dt is the diameter of the output section

clogging nozzle, m; d / tA diameter of output section

bit nozzles, m; n is the number of bit nozzles. This distance is selected as follows.

It is necessary to direct the working fluid to the nozzle from the central part of the total flow QI.J, where there is a ring of fines. At the same time

0

five

According to the equation of the flow nonexpertance, this central part of the total flow must pass through the nozzle and the nozzle. One side

QL ,,, (1)

where is the velocity of the central part

working fluid, m / s; Ft is the transverse size (area) of this central part of the stream, m,

On the other hand, to achieve a positive effect, it is necessary to

PS VC-FC, (2)

where Vc is the worker speed

fluid at the outlet of the nozzle placed in the pipe, m / s; FC output area

nozzles, m -. Get

Rc VtsFts VcF, from here

FM -2 Vu,

Simplify formula (1) as follows:

(3)

(four)

FC

dl

(five)

d is the diameter of the exit section of the nozzle, m.

(6)

. to.

QH total worker

fluid per unit time or pump capacity, MVc;

F - internal area of the device, m

FK

Tdl 4

where is the inner diameter of the case.

sa, m. Substituting (5), (6), (7) into (4), receive

Vt

Otherwise, expressing Hz through the radius of the central stream, have

.Yy -. ;

 16 QH

(10) At the same time, the pump capacity, i.e. The total supply of working fluid is divided into two parts. One part Qe flows through the device nozzle, the other part Qc through the bit nozzle

QM Qt + QCA. (11) Since the device for clogging the borehole walls in the bottom hole assembly (NKBC) is set in close proximity to the bit, the dynamic pressures and, accordingly, the speed of the working fluid jet at the nozzles of the device and the bits are the same.

By knowing the area of the central part of the flow FU ,, you can find its radius, which is the required distance from the entrance edge of the nozzle to the longitudinal axis of the body. It has been proved by laboratory that for effective clogging of permeable rocks, the velocity of the jet at the nozzle exit Vc 60 - 120 m / with. Then

Claims (1)

The invention of the device for wall clogging l - n 4. n - L7 / f d t 4. t,) wells, installed above the drilling site I1 ChS t I t I) 1) A bit with nozzles that includes a radially located body with a nozzle, characterized in that, in order to increase the working efficiency by treating the walls of the well with a coarse fraction, it is equipped with a swirler with radially arranged blades and placed in the lower part of the housing a branch pipe, inside of which a cloaking nozzle is installed, the input edge of the branch pipe being separated from the longitudinal axis of the housing at a Hz distance determined from the expression where dc is the diameter of the bit nozzle; n is the number of bit nozzles. Substituting (12) into (1), have gi,. . (13) + -ndlf,. The device works as follows. The housing 1 is connected to the shaft of the pipe or drill pipe, and the shaft is rotated. Pumping a working agent into the drill string at the entrance to the cavity of housing 1, which is rigidly connected to it ten 9215 The swirl theme 2 - blades 3 acquires a twisted movement. The swirler 2 serves to rigidly connect the blades, as well as to direct the agent to them. The blades 3 inform the working agent of the centrifugal acceleration, while there is a redistribution of solid particles (clogging) of the working fluid along the flow radius. In the center there is a small colmatant, and in the peripheral part - a large one. The coarsening coarse fraction is directed down the body wall, mine is nozzle 4, and the small fraction 15 remains in the central part and is entrained with clogging, jet inside the nozzle 4. Thus, in the device for well wall collation, two tasks are solved, 20 namely, separation of the coaggant contained in the working agent for the coarse and fine fractions by the rotating system housing 1 - swirler 2 - the blades 3 and the selection into the clover around 25 a jet of a working agent of its fine fraction, a system of a pipe 4 - clogging nozzle 5. Experimental field tests established the optimal combination of quantities and diameters of colletrillating x; nozzles and bit nozzles. Thus, the diameter of the nozzles varies from iI to 13 mm, and the number of bit nozzles from 1 to 3. Then the distance from the input edge of the nozzle to the longitudinal axis of the device body is 0.22 d - 0.38 d. For each specific case corresponds to a certain value of the distance. The invention of the device for wall clogging wells installed above the drill wells installed above the drill A bit with nozzles, including a radially positioned body - a nozzle, characterized in that, in order to increase the working efficiency by treating the borehole walls with a fine fraction coagulating agent, it is equipped with a swirler with radially located blades and placed at the bottom part of the housing by a nozzle, inside which the closure nozzle is installed, the input edge of the nozzle being separated from the longitudinal axis of the housing at a Hz distance determined from the expression r -. 2 + ndl where d is the internal diameter of the case, m; 6 SD is the diameter of the nozzle exit cross section and the nozzle exit cross section, respectively, m; n is the number of bit nozzles. Phie.g