SU1691489A1 - Method for drilling hole complicated conditions - Google Patents

Abstract

The invention relates to a well drilling technique and can be used to create a local flush in the zone of well complications. The purpose of the invention is to increase the effectiveness of coping with complications in the process of drilling wells and simplify the method. To do this, in the complicated zone, a local area is created with a pressure equal to the reservoir pressure. At the same time, a screw pump will be included in the drill string layout, the stator of which soitsik -ot with a rock-breaking element (bit) directly or through the bottom part of the drill string layout and rotates the latter with a greater number of revolutions than is necessary to rotate the bit. , dg -teio last turn over and create a hydraulic resistance to flow by setting the maximum hydraulic resistance in the bit of the nozzle. In this case, drilling is carried out with local circulation of the drilling fluid, adjusting the rotational speed of the bit and the production rate. 1 з п. Ф-лы, 3 Il. cl

Description

The invention relates to a well drilling technique and can be used to create a local flush in the zone of well complications.

The purpose of the invention is to increase the efficiency of dealing with complications in the process of drilling a well and to simplify the method.

Figure 1 shows the upper portion of the lower part of the drilling unit; figure 2 - respectively, its lower portion; on fig.Z - parameters of drilling.

The drilling rig contains a chisel 1 associated with a pump stator 2, the rotor 3 of which is associated with a drill string 4. For example, a downhole screw motor can be used as a pump,

inverted by 180 °. Chisel 1 is equipped with a nozzle 5 maximum hydraulic resistance. On the drill string 4, there is a sludge catcher 6 and a circulation coupling 7. The position 8 denotes a zone of complications (absorbing layer).

The circulating coupling ensures the flow of drilling fluid from the annulus into the inside of the pipe; her columns. It can be done, for example. in the form of a hole in the drill string of the calculated size in the estimated km Gerwele

The method is carried out as follows.

The method of drilling a well in difficult conditions leads to the creation of a local

f &

flushing in the zone of complications of the well with the creation of a local area with a pressure equal to the reservoir.

Local flushing is created by a pump embedded in a drilling rig. For this, the stator 2 of the pump is connected to the bit 1, the rotor of the 3rd drillstring 4 and the drill string 4 is rotated from a surface with a rotational speed exceeding the desired rotational speed of the bit 1, and the pumping rate and rotational speed of the bit 1 the flow of flushing fluid in the bit 1 by installing the nozzle 5 of the limiting hydraulic resistance.

Consider three possible options for the operation of the drill string 4. If the flushing fluid flow is completely blocked, turning the rotor 3 relative to the stator 2 in the screw pump will become impossible (we ignore leaks in leakages). This will correspond to the maximum moment of rotation that transmits the bit, and the rotor speed of the pr, stator ps and chisel pd will be equal to the number of revolutions of the drill string Pb.k., i.e.

M Mmax, k.

If on the way to the bottom, including chisel 1, to remove all obstacles for the free passage of fluid, then all conditions will exist for the maximum flow rate, the minimum moment on bit 1, which, when creating resistance, will be in place 0, 0max,

,

If we create resistance to the flow, but leave the possibility for its existence, i.e. leave free, for example, one hydraulic nozzle in bit 1, then O Q Omax; Mmin M Mmak.

About Pbk.

Thus, in the latter case, conditions are created to maintain local circulation and well deepening.

In the proposed method, a chisel with a diameter of 90 mm, a downhole motor D2-172 M equipped with a spindle section ШШ 0-01-172 is used. The known methods determine the efficiency of the regime, for which during drilling it is necessary to maintain the minimum flow rate of the drilling fluid p / s, the minimum number of revolutions of the bit at the bottom of rpm. Taking into account the load on the bit, the last should, when drilling, overwhelm the KGM torque. On the diagram fmg.2 on the right in the coordinates P - M their ratios are shown, in the left part with fire 0

five

0

five

nor n-Q. In the n-Q diagram we find that for a volumetric engine, the flow rate l / s corresponds to ob / min. In the right diagram, we determine that the moment KMM corresponds to a pressure differential of 26 MPa and an engine speed of 135 rpm. In order for the bit to rotate at rpm, the drill string must be rotated at rpm. 1335 rpm. In this case, the shaft (rotor) of the screw engine - the pump will rotate relative to the casing (stator) of the screw engine with a speed of 135-52 83 rpm. Then the pump will pump the drilling fluid through the nozzle at a flow rate of l / s, and the resistance to movement of the solution in the nozzle should be at least 2.6 MPa. By knowing the flow rate (8 l / s) and pressure (2.6 MPa), the nozzle diameter, which is set in the bit, is calculated using known methods.

When the mud density is 1200 kg / m3, the flow rate is 0.008 m3 / s and the pressure drop is 2.6 MPa, the total area of the bit in the bit

f SE uPget-gu

and.

  flsijiLa-gctLL

0.9

26

1.36cm

Driving in this mode is carried out before filling the sludge trap or controlled by a pressure gauge on the rotor until the bit is fully drained if the drilling is accompanied by the discharge of the sludge into the absorbing formation.

Claims (2)

1. A well drilling method under complicated conditions, including the creation of local circulation of the flushing fluid in the zone of complications with a pump integrated into the drilling assembly, is also distinguished by the fact that, in order to increase the effectiveness of combating complications in drilling process, pump stator connect with a chisel, the rotor - with a drill column and rotate the drill string from the surface with a frequency rotation, exceeding the required frequency of rotation of the bit, and pump performance and frequency of rotation of the bit are controlled by the value of the flow resistance of the flushing fluid in the bit by setting the nozzle of the maximum flow resistance. 2. A method according to claim 1, characterized in that, with the whole simplifications of the method, a downhole motor is used as pumps. 4 6 Thebes 1 2 300 that 155 wo 52 About 8W 10 SOSrfffO 100110200 300 400 M, kg # U8.t