SU1643735A1 - Method for hydraulically working productive strata - Google Patents

Abstract

The invention relates to the mining, industrial and allows to increase the safety of mining operations, intensive extraction of the working fluid (RJ) and gas from the well (C) and cost reduction: to remove the products of destruction of the horizontal part of the trunk C. T is directed C with an oxBaia angle of less than 90 ° C, the horizontal portion of which is drawn in the soil of the seam raerab. Then, point-firstly, the productive stratum (PT) is opened and, starting from slab C, the AF is introduced and injected into them. Each previously processed interval zones PT overlap and disconnect. After completion of the hydrotreatment of the last interval of the zone, the PT produces slit perforation C at the level of the dome of the rocksliding orientally along the axis of the horizontal part of the trunk C. In the plane of the dome of the rockslining and along the horizontal part C form trunk cracks. Then I pump out aerated methane gas from C. After working out the horizontal section With gas cleaning, gas is extracted from the collapse dome. Moreover, the cleaning work is carried out in the direction from Zabo to the mouth of C. 2 s. f-ly. with SS (L oe 4 with J SO JV

Description

The invention relates to the mining industry and can be used in the preparation of a mineral deposit.

The purpose of the invention is to increase the safety of mining operations, the intensity of extraction of the working fluid and gas from the well and reduce the cost of removing the destruction products of the horizontal part of the wellbore.

The sequential execution of technological operations during the implementation of the method consists in that a well is drilled from the day surface with an angle of coverage less than 90 °, i.e. so that the horizontal wellbore of this well is traversed in the soil of the reservoir under development. The well is surrounded with pipes for the entire length, plugging the annulus. Beginning from the bottom in the direction to the well head at the design elevations, the casing stone is perforated interlinally. Then the working fluid is injected into the perforated zones, each interval of the productive unit is blocked and separated. After completion of the hydrotreatment of the last interval, the spruce perforation of the well at the level of the caving of the rock fall is oriented along the axis of the horizontal wellbore. The main cracks are formed in the plane of the dome of the collapse of rocks and the body of a horizontal well; the working fluid is pumped out of the well; after cleaning the well, gas is extracted from the dome of the collapse of rocks. Moreover, the cleaning work is carried out in the direction from the bottom to the wellhead.

The method is carried out as follows.

Within the limits of the sloping floor, the central panel of the mine floor is subjected to a force action through a Donbass-1 type well, but the angle of coverage is less than 90 °. The horizontal wellbore must be drilled in the soil of a coal seam, the thickness of which varies in the range of 1.4-1.6 m. plot of stabilization of the angle of inclination, the so-called horizontal trunk (1400-18MO m). The casing of the well is provided with pipes and the plugging of the annulus for the entire length. The horizontal barrel is drilled with a diameter of 216 mm, surrounded with pipes with a diameter of 146 mm and a wall thickness of 10.7 mm.

Maximum intensity is curved, about no well bore limited 4

on 10 m of penetration.

The opening of the casing and cement stone sections is provided by a PNKT-89 type cumulative perforator, which is lowered into the well on the tubing. The location of the punch in a horizontal wellbore is determined by the length of the tubing tubing. The slit perforation of the well in the plane of the dome of the rock fall is carried out using a hydraulic sandblasting perforator.

Perforation of the horizontal wellbore is envisaged at seven sites, the distance between which

five

0

five

It is assumed equal to 70–80 m. The pumping of the working fluid into the coal-mass mass is carried out by a group of pumping units of type 4AN-700. The parameters of the force action are as follows: the injection rate is 40-80 l / s, the expected pressure at the bottom of the well is 35-40 MPa, the volume of working fluid injected into the perforation interval is 12 thousand m3. After the project volumes have been injected, the working fluid is kept in the carbon-rock massif for 24 hours. Then, pressure is released at the wellhead by opening the latter to the spout. Insulating elements are installed in a horizontal well bore, for example, explosive packers over each perforation zone, excluding the latter.

After complete hydroprocessing of the experimental section, slit perforation of the well is carried out at the dome level of rock caving oriented along the axis of the horizontal wellbore. The upper boundary of the zone of collapse of rocks is determined by the formula of SG Avershin

0 where h 5

m KR & I

1 3m.,

h - (K; -THGOGO 16 m

the distance from the roof of the coal seam to the upper boundary of the dome of the collapse of rocks (vertical), m; reservoir thickness, MJ rock loosening coefficient (, 1-1.4) j dip angle, deg.

five

0

five

0

For the formation of trunk cracks in the plane of the dome of the collapse of rocks in the direction of the axis of the horizontal wellbore and along the body of the latter, the working fluid is pumped in hydraulic fracturing mode. This mode is determined by the flow rate of the fluid, repeatedly interrupting the natural pickup of the coal mass array, and throughput of opening cracks, which is accompanied by an abrupt increase in pressure to a value sufficient to break (destroy) the roof rocks of the coal seam in the directions of the fluid forces. After the fracture (destruction) of rocks, the pressure abruptly drops due to a multiply increased hydraulic conductivity, determined mainly by hydraulic fractures. Feed rate

fluid can be found from the expression up 0.25N-p "l + (Gy 0.25-100-90 + 80 Ј 270 kgf / cm2,

where up is the pressure drop, kgf / cm2; (j. - temporary resistance of the fracture, kgf / cm2; H - well perforation depth

(vertical) m; pnft- reservoir pressure, kgf / cm2

Thermogaschemical exposure (TGHV) can be used as a working agent for the formation of trunk cracks, the essence of which is the burning of a powder charge at the well bottom. When the latter is quickly burned, the pressure at the bottom reaches 30-100 MPa. After self-curing of the working fluid, the latter is forcedly pumped out at the beginning by a compressor airlift according to a ring pattern with a small flow rate - using an IC type rocker pump.

The coal cleaning pit was made in the direction from the bottom of the horizontal shaft to the mouth. After the well has been refined, the gas is extracted from the dome of the rock formation and partially from the soil of the coal seam by self-expiration and forcibly vacuum by pumping units.

Claims (3)

1. Hydroprocessing method of the productive stratum, including drilling from the surface of a directional well, the horizontal part of the borehole of which is carried out in the soil of the reservoir under development, interval interval opening production, injection and injection into them, starting from the bottom of the well, working fluid, overlapping and dissociating each previously treated interval of the zone and after complete hydrotreatment of the experimental section, pumping the working fluid from the previously treated producing zone, gas extraction and cleaning so that, in order to increase the safety of mining operations, the intensity of extraction of the working fluid and gas from the well and reduce the cost of removing the destruction products of the horizontal parts of the wellbore, after completing the hydrotreatment of the last interval of the productive zone, slit perforations are made at the level of the dome of the rock fall oriented along the axis of the horizontal part of the wellbore, forming main fractures 5, in the plane of the dome of the rock break and along the horizontal part of the well, the methane-aerated liquid is pumped out of it, then after the part-time part of the well has been processed, gas is extracted from floor collapse of rocks. I 2. The method of pop. 1, excluding the fact that the well is drilled from the surface with an angle of coverage less than 5 90 ( 3. Method pop. 1, characterized in that the cleaning work is carried out in the direction from the wellhead to the wellhead.