RU2281370C2 - Method for vertical well drilling - Google Patents

Abstract

FIELD: mining industry, particularly to drill vertical freezing holes with the use of movable or stationary installations provided with movable rotators and hydraulic directional supply means.

SUBSTANCE: method involves predrilling strictly vertical well 14; stabilizing vertical direction with the use of centrators, calibrators and heavy-weight bottomhole assembly made of pipes by aligning thereof with well 14 axis; manually or automatically regulating vertical position of rotator 4 travel in continuous mode with the use of support adjustable jacks 2 by retaining drilling rig 13 frame in horizontal position. The frame position is controlled in two perpendicular planes by means of level sensor installed on frame 1 or mast 1 or rotator 4. Drilling is performed with extended drilling string under axial load equal to not more than 80% of heavy-weight bottomhole assembly weight.

EFFECT: increased productivity and efficiency of drilling stabilization process, possibility to drill strictly vertical wells.

3 cl, 2 dwg, 1 tbl

Description

The invention relates to the mining industry and can be used for sinking wells for various purposes, in particular for drilling vertical freeze wells, using mobile or stationary units with a movable rotator and hydraulic directional feed.

A known method of drilling straight wells using a laser beam to indicate a given direction [1]. The method includes orienting and installing the working body of the drilling machine in a given direction, drilling the well with a drill stand with a guide head. The stave is being built up by separate links with simultaneous placement of support lamps on it in a certain sequence, the diameter of which is not less than the diameter of the rock cutting tool, and a cleaning agent is fed into the well. An automatic guided guide light is located in the head of the stav. To indicate a given direction, a laser beam is used, which is directed inside the hollow drill stand coaxially with its longitudinal axis. The cleaning agent is used in conjunction with a laser beam to control the guide reference light during drilling. As a cleaning agent, compressed air or liquid is used.

The disadvantage of this method is its rather narrow application - only for drilling wells using a hollow drill stand and low adaptability, due to the complexity of the optical laser control.

There is also a method of stabilizing the direction of the wellbore by visually determining the contact point of the core pipe with the wall of the well [2]. To do this, in the process of drilling, a core is taken, it is extracted to the surface in a core set, the contact points of the core pipe with the wall of the well are visually determined, and the parameters of the core set are adjusted after visual determination of the contact point of the pipe with the wall of the well. Then, the deflection point of the core pipe at the point of contact with the well wall is calculated according to a certain relationship, after which the parameters of the core set are adjusted by bending the pipe at the point of its deflection at the point of contact with the wall of the well in the opposite direction from the point of contact by the value calculated by the formula:

F _k.n. = L _k.n. · (L _b.v. ) ^-1 · [E · I _b.v. / E · I k.s.] ^1/2 -0.5 f _p ,

where L _b.v. - the half-wave length of the bend of the drill pipe over the core set, m;

f _b.v. - the half-difference in the diameters of drill pipes and wells, m;

f _p - the half-difference of the diameters of the wells and the adapter core set, m;

E · I _k.n. , E · I _b.v. - respectively, the stiffness of the cross section of the core set and drill pipe, daN · m ² ;

L _k.n. - the length of the core set, m

Well drilling is carried out by SBTN with a diameter of 50 mm and a core pipe with a length of 4.5 m and a diameter of 57 mm at a speed of 600 rpm. After visual determination of the place of wear of the core pipe, the bending point of the core pipe is calculated, and then the value of the bending of the core pipe is determined by this formula. Then, with the corresponding bending deformation of the core pipe, at the point of its deflection at the point of contact with the borehole wall in the opposite direction from the point of contact, the set parameters are adjusted and, thus, the direction of the borehole is stabilized.

The disadvantage of this method of stabilizing the direction of drilling is the low adaptability of the process and the effectiveness of the method itself, based on fixing the consequences of the actual deviation from verticality and only after this elimination of this deviation, which significantly reduces the speed of drilling wells.

A known method and equipment for drilling freezing wells in a rotational manner with direct flushing [3]. According to the method, the rock is destroyed and drilled in the form of a core, and then removed from the bottom using a washing fluid. The technology for driving such wells is determined by their depth, design, and also from mining and geological conditions. So, for example, with the UBZSh-2-20 and UBZSh-2-30 drilling rigs, wells are drilled using the rotary method in difficult mining and geological conditions. At the same time, drilling is carried out both around the circumference of the trunk at a distance of at least 0.8 m or in a straight line with a distance of 1-2 m from each other. The rigs are equipped with a rock cutting tool (for example, a cone bit), a string consisting of core drill pipes for direction drilling tool, transmitting axial force and receiving drill core, weighted drill pipes (UBT) to create axial force on the working body, eliminate curvature of the wellbore and stabilize a given direction when drilling. At the same time, drill collars are additionally equipped with centralizers and colibrators, which are installed along their length [4]. Centralizers are installed in the place of maximum deflection of the tool; this distance is determined by calculation. Structurally, centralizers are similar to colibrators and to a large extent perform the same functions.

A significant drawback of this method of drilling is the unreliable stabilization of the direction of drilling, the curvature of which is prevented only by using the pendulum effect characteristic of a heavier bottom, which significantly reduces the stability of the stabilization and the cost-effectiveness of freezing wells.

Closest to the proposed invention is a method of adjusting the mode of drilling for the magnitude of the axial load on the bit with a fixed upper end of the drill string, which is selected as a prototype [5]. At the same time, for the implementation of the method, for example, a mobile drilling rig is placed in the usual place at the drilling site, and a well-mounted techniques are installed over the wellhead with adjustable supports with a drill mast, which is equipped with the appropriate equipment: a movable rotator with a hydraulic drive, a set of drill pipes with a weighted layout bottom and centralizer. Next, vertical drilling and subsequent drilling is carried out, including lowering the drill string with a rock cutting tool into the well and supplying a flushing agent. Through the drill pipe from the movable rotator to the rock cutting tool - the drill bit transmit torque, axial load and flushing agent. Then, according to the method, during drilling, the upper end of the drill string is fixed from axial movements and the value of the axial load on the bit, torque, amplitude and frequency of natural bending vibrations of the weighted bottom are measured. Next, axial loads corresponding to the extremes of the measured parameters are determined. The rotation of the column around its own axis or around the axis of the well is prevented to a large extent by adjusting the magnitude of the axial load on the bit. It was experimentally established that this load should correspond to Pi or 0.5 · (P _i + P _{i + 1} ), where Pi is the value of the axial load on the bit, corresponding to the i-th number of touches of the compressed part of the weighted bottom of the drill string (UNBK) with the walls of the well. The load Pi is determined by calculation or by the method of drilling with a braked winch drum, which correspond to extrema depending on the rate of change of the load on the bit and the load value or in the relationships between the torque on the bit (on the rotor) or the amplitude (frequency) of the column vibrations and the load on the bit . At high probability wellbore curvature, as judged by the previously drilled wells, prevent or reduce a curvature while maintaining the axial load equal one of the values 0,5 · (P _{i + Pi} + ₁₎ or near thereto. The most optimal in this case is to maintain the load equal to P _i , with a periodic increase or decrease to 0.5 · (P _i + P _{i + 1} ). In this case, the rotational speed of the bit is maintained outside the frequency of the natural bending vibrations of the UNBK, which prevents the risk of accidents with UNBK elements and bits.

The disadvantage of this method of drilling vertical wells is its unreliability, due to the empirical calculation approach to adjust the verticality of penetration, and, as a result, low efficiency and adaptability of drilling.

The aim of the invention is to remedy these disadvantages: increasing the productivity and efficiency of the process of stabilization of drilling, in particular when driving freezing wells, where it is especially important to ensure maximum vertical drilling.

This goal is achieved by the fact that in the method of drilling vertical wells, including mounting above the wellhead on support adjustable jacks of the bed of a rotary drilling rig with direct washing, containing a mast rigidly connected to it with a movable rotator, vertical drilling and drilling by immersing a heavier bottom assembly in the well with centralizers and drilling tools, as well as adjustment, control and stabilization of the verticality of the drilling process, according to the invention, the verticality of the drilling process they are heated strictly by vertical drilling of the well and stabilization of the gained vertical direction by means of centralizers and colibrators of the weighted bottom layout by rigidly centering it with the axis of the well, while additionally, by means of support jacks, the vertical rotation of the movable rotator is continuously or automatically controlled by maintaining the horizontal position bed rig, which is controlled in two mutually perpendicular planes level sensors mounted on a bed or mast or rotator, and drilling is carried out on an extended drill string with an axial load of not more than 80% of the weight of the weighted bottom assembly.

Strictly vertical drilling of the well is provided by preliminary adjusting the vertical position of the mast and the axis of the movable rotator during installation of the bed of the drilling rig by adjusting level sensors in two mutually perpendicular planes by means of a theodolite functionally associated with them, which is additionally mounted on the earth's surface regardless of the drilling rig.

As level sensors, for example, cylindrical or round bubble hydraulic levels with a division value of 1-10 seconds are used, which are adjusted during the installation of the drilling rig by means of a theodolite.

The invention is illustrated by drawings.

Figure 1 presents a schematic block diagram of a mobile drilling rig.

Figure 2 - diagram of the drill string with the layout of the weighted bottom (UNBK).

Installation 13 in a mobile version contains a frame 1 with three supporting adjustable jacks 2 (one of them is not shown in the drawing). On the bed 1 there is a mast 3 rigidly connected with it, equipped with a movable rotator 4 with hydraulic feed cylinders 5. On the mast 3, two horizontal level sensors 6 are installed in mutually perpendicular planes in the form of cylindrical hydraulic bubble levels. The sensors 6 are functionally connected to the theodolite 7, which is installed on the ground separately from the bed 1 of the installation 13 and is designed to adjust the level 6 and monitor the verticality of the rotation of the rotator 4. The rotator 4 is connected to the drill string, consisting of drill pipes, by a drive shaft (not shown) 8, the layout of the UNBK containing the bit 9, weighted drill pipe (UBT) 10, two calibrators 11 mounted at the ends of the first UBT, two centralizers 12 installed in the middle and at the upper end of the UBT string.

The method is implemented as follows.

The frame 1 of the drilling rig 13 is mounted above the wellhead 14, the mast 3 is installed in a strictly vertical position. The installation of the mast 3 and the axis of rotation of the rotator 4 are adjusted using three jacks 2. The accuracy of the installation of the mast 3 vertically and, accordingly, the axis of rotation of the rotator 4 is determined by level 6, which is pre-set using theodolite 7. During the adjustment, check that the horizontal position of the bubbles level 6 coincided with the vertical stroke of the rotator 4, while the accuracy of adjusting the verticality is determined by the division price of level 6 and is 1-10 seconds or more, depending on the set value that is required yderzhat during drilling. Then, vertical drilling of the well 14 is carried out. During the drilling process in the same way as when the mast 3 was installed, they are continuously monitored at level 6 and the jacks 2 are controlled by the vertical stroke of the rotator 4, which in the same way is constantly monitored and regulated during further drilling of the well 14. When this check that the permissible deviation of the axis of the rotator 4 from the vertical was not more than the permissible design values. Stabilization of the vertical direction during drilling and further drilling is carried out by means of a drill string of pipes 8 with a rigidly concentrated arrangement of weighted pipes 10 with two calibrators 11 and two centralizers 12, while drilling is carried out on an extended drill string so as to create an axial load on the bit 9 no more than 80% by weight of UNBK. During drilling, a flushing agent, for example, a clay flushing fluid or peat sapropelic drilling fluid, or other similar fluid (not shown) is supplied to the well 14.

Table 1 shows a fragment of the calculated data of the upward force on the drill string (to a depth of 118.3 m) and pressure in the hydraulic supply system of the rotator 4 as an example of the implementation of the method in specific production conditions.

Table 1. UBT-203, 5 m each, weight of the 1st pipe 965 kg, pcs SBT-168 4.9 m each, weight of the 1st pipe 191 kg, pcs. Weight of a drill, kg Permissible load on a bit, kgf Unloading force up, kgf (*) Pressure in a hydraulic system of supply of a rotator up, atm Drilling interval from, m Drilling interval to, m one 0 965 772 193 0.772 0,0 5,0 2 0 1930 1544 386 1,544 5,0 10.0 3 0 2895 2316 589 2,316 10.0 15.0 four 0 3860 3088 772 3,088 15.0 20,0 5 0 4825 35003500 1325 5.3 20,0 25.0 6 0 5790 3500 2290 9.16 25.0 30,0 6 one 5981 3500 2481 9,924 30,0 35.0 6 2 6172 3500 2672 10,688 35.0 39.9 6 3 6363 3500 2863 11,452 39.9 44.8 6 four 6554 3500 3054 12,216 44.8 49.7 6 5 6745 3500 3245 12.98 49.7 54.6 6 6 6936 3500 3436 13,744 54.6 59.5 6 7 7127 3500 3627 14,508 59.5 64,4 6 8 7318 3500 3818 15,272 64,4 69.3 6 9 7509 3500 4009 16,036 69.3 74,4 6 10 7700 3500 4200 16.8 74,4 79.1 6 eleven 7891 3500 4391 17,564 79.1 84.0 6 12 8082 3500 4582 18,328 84.0 88.9 6 13 8273 3500 4773 19,092 88.9 93.8 6 fourteen 8464 3500 4964 19,856 93.8 98.7 6 fifteen 8655 4600 5155 20.62 98.7 103.6 6 16 8846 4600 4246 16,984 103.6 108,5 6 17 9037 4600 4437 17,748 108,5 113.4 6 eighteen 9228 4600 4628 18,512 113.4 118.3 (*) Note: Pressure on the manometer was calculated based on the ratio: 1 atm = 250 kgf.

The required upward force on the rotator 6 to stretch the drill string was determined by the formula:

P _in = (an + bm) -P _d

where a is the weight of one weighted pipe (UBT), t

P _in - the weight of one drill pipe, t

n is the number of pipes UBT, pcs.

m is the number of drill pipes, pcs.

R _d - axial load on the bit.

In the process of drilling, the axial load, alignment of the layout of the hard weighted bottom, bit rotation frequency, drilling fluid parameters and other technological drilling parameters are adjusted to optimal values based on actual geological conditions. These adjustments are made to the automatic control system and are subsequently used when drilling subsequent wells.

The developed method was successfully applied when drilling vertical freezing wells during the construction of mine shafts at the Krasnoslobodsky mine of RUE "PO Belaruskali" (Belarus, Soligorsk) in 2003-2004. and showed high efficiency and manufacturability. At the same time, 76 wells with a depth of 220 m and a diameter of 244.5 mm were drilled. The permissible design deviation from the vertical was 0.5 m or 7.8 minutes at the final depth. The achieved vertical verticality of the wells corresponded to design requirements by 90%, and in the remaining 10% they only slightly exceeded them. This made it possible to completely abandon the drilling of 10 additional wells, in case of a significant deviation from the vertical of the main freezing wells, originally envisaged by the project based on the results of previous similar drilling operations in the construction of 4 mines over the past 50 years, and to receive savings of about $ 180,000.

Information sources

1. Patent RU No. 2113588 C1, IPC ⁶ E 21 B 7/04, E 21 C 1/00, (22) 10.04.95., (46) 06/20/98, bull. No. 17, "A method of drilling straight wells and a device for its implementation."

2. Patent RU No. 2144619 C1, IPC ⁶ E 21 B 7/10, (22) 06/06/97, (46) 01/10/99, bull. No. 1, "Method for stabilizing the direction of the wellbore."

3. Drilling rigs for driving wells and shafts: Reference: A.T. Nikolayenko, B.Ya. Sedov, ND Terekhov, N. S. Bolotskikh, 3rd ed., Revised and ext. - M .: Nedra, 1985, p. 18, 19, 52-54.

4. Handbook of water well drilling. Ed. prof. D.N. Bashkatova, Moscow: Nedra, 1979, p. 418.

5. Patent RU No. 2016193 C1, IPC ⁵ E 21 B 45/00, 7/10, (22) 04/11/89, (46) 07/15/94, "Method of regulating the drilling mode" (prototype).

Claims (3)

1. The method of drilling vertical wells, including mounting above the wellhead on adjustable support jacks of a rotary drilling rig bed with direct flushing, containing a rigidly connected mast with a movable rotator, vertical drilling and drilling by immersing a weighted bottom assembly with centralizers and a drilling tool in the well as well as adjustment, control and stabilization of the verticality of the drilling process, characterized in that the verticality of the drilling process provides strictly vertical drilled wells and stabilization of the gained vertical direction by means of centralizers and calibrators weighted bottom layout by hard centering with the axis of the well, while additionally using support jacks continuously automatically or manually adjust the vertical stroke of the movable rotator by maintaining the horizontal bed of the rig, which is controlled in two mutually perpendicular planes additionally mounted on a bed or mast, or rotate le level sensors, and drilling is carried out on an extended drill string with an axial load of not more than 80% of the weight of the layout of the weighted bottom. 2. The method according to claim 1, characterized in that the strictly vertical drilling of the well is provided by preliminary adjusting the vertical position of the mast and the axis of the movable rotator during installation of the bed of the drilling rig by adjusting the level sensors in two mutually perpendicular planes by means of a functionally connected theodolite, which is additionally mounted on the surface of the earth regardless of the rig. 3. The method according to any one of claims 1 and 2, characterized in that, for example, cylindrical or round bubble hydraulic levels with a division value of 1-10 s are used as level sensors, which are adjusted during the installation of the drilling rig by means of theodolite.

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