RU2373366C1 - Technology for development of wells and bores - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: invention is related to methods for rock tunneling by action of working agent jet energy at drilled medium under pressure and is intended for development of wells and bores of various purposes. Technology includes action at drilled medium from energy of working agent jets that flow out of working element of autonomous drilling aggregate to bottomhole under pressure, removal of drill slag to wellhead, strengthening of well wall. In process of well tunneling, consumption of working steam-gas agent is carried on in volume, which creates a flow of drill slag outgoing from bottomhole with speed that exceeds speed of soar of the main number of particles of drilled rock, size and mass of which make larger part of drill slag, separate rock particles, larger in size and mass, being detached from wellhead, are exposed to dynamic and high-temperature action of working agent due to periodic pulse increase of speed and temperature of flowing jets of mentioned working agent, therefore creating conditions for their breaking down to size and mass of particles removed from bottomhole area to wellhead in common flow of drill slag. In process of tunneling of water-saturated unstable horizons, pressure in well cavity is set as exceeding pressure of these horizons rocks to well wall by increase of working steam-gas agent flow from working element or from auxiliary flow nozzle of drilling aggregate, this excessive pressure is preserved in well cavity until process of bottom hole development is completed and well cavity is cleaned from drill slag, afterwards process of bottom hole development is interrupted, and flow of working agent from auxiliary nozzle is used to maintain specified excessive pressure in well cavity for the time of its wall strengthening process.

EFFECT: improved efficiency of well bottom hole development process.

3 cl, 2 dwg

Description

The invention relates to methods for driving rocks by exposing a drilling medium to the energy of the jets of a working agent under pressure and is intended for the formation of wells and workings for various purposes.

The technological processes of rock sinking and well formation have now been solved by certain methods and operations, of which the most representative are the methods of well formation, the essential methods and signs of which are: equipping the mouth with a preventer, drilling geological horizons by exposing the drilling medium to the energy of the working agent jets the formation of the upward flow to the wellhead for the removal of drill cuttings from the bottom zone and cavity [Dmitriev A.P. and others. Thermal and combined destruction of rocks. M .: Nedra, 1978, p.135-136; US 3917007, 175/14; FR 2232670, E21B 7/18; RU 2161245, ЕВВ 7/14].

Significant and obvious disadvantages of similar methods are: excess unit costs of the working agent for the bottom and increased energy costs for the formation of a stream of drill cuttings directed from the wellbore to the wellhead; uncontrollability of the process characteristics in terms of thermal and kinetic energies, parameters of the working agent and its effect on the bottom and walls of the well passed through. This leads to a stochastic process of selecting operations and method parameters and is reflected in the cost overruns of the components forming the volume of the working agent for drilling the well in geological horizons.

The closest in technical essence is the technology (method) of the formation of wells and workings in sedimentary rocks, including the impact on the drilling medium with the energy of the jets of a working agent flowing from the working body of an autonomous drilling unit to the bottom under pressure, removal of drill cuttings to the wellhead, wall fastening wells [RU 2168598, 10.06.2001, ЕВВ 7/14, Е21С 37/16].

Significant disadvantages of this method are similar to some of the negative characteristics of the analogous methods mentioned above, in particular, this method (technology) does not take into account the conditions of inertia of rocks for the process of thermal influence on the massif and individual inclusions of an inhomogeneous nature; there are also no techniques and operations for the formation of optimal flow rates of drill cuttings, as well as maintaining a stable pressure in the cavity of the well being drilled.

The technical task and the positive technological result of the proposed technology for the formation of boreholes and workings is to further improve the processes, operations and impact parameters on the bottom, borehole walls, formation of a drill cuttings stream by choosing the optimal operations, modes and their parameters for the process of destruction of the rock mass at the bottom, crushing individual particles, controlling the speed and temperature of the impact of the working agent and the flow of drill cuttings leading to improved efficiency and increasing the productivity of the drilling machine used.

This in the proposed technology for the formation of wells and workings in sedimentary rocks is achieved due to the fact that the process includes exposure to the drilling medium with the energy of the jets of the working agent flowing from the working body of the autonomous drilling unit to the face under pressure, removal of drill cuttings to the wellhead, wall fastening wells, in the process of drilling a well, the consumption of a combined-cycle gas agent is carried out in a volume that creates a stream of drill cuttings extending from the bottom with a speed exceeding the speed of the main the number of particles of drilled rock, constituting most of the drill cuttings in size and mass, separate larger particles and larger mass of rock particles, separated from the bottom, are subjected to dynamic and high-temperature action of a combined-cycle working agent due to periodic pulse increase in the speed and temperature of the flowing jets the specified working agent, thereby creating conditions for their destruction to the size and mass of particles removed from the bottom zone to the wellhead in the total flow of drill cuttings, when this, the speed of the drill cuttings leaving the bottom of the face is determined by the dependence

V _PB = V _RF + ΔV _RF , m / s,

where V _pb - the speed of the outgoing stream from the bottom of the stream, sufficient to remove the bulk of the drilled particles;

V _HF - the rate of movement of particles of rock of the main quantity in the exhaust stream of drill cuttings;

ΔV _rf is the added value of the flow rate of the working agent for exceeding by 5-10% the speed of coarse particles in the flow of drill cuttings,

and during the drilling of water-saturated unstable horizons, the pressure in the well cavity is set to exceed the pressure of the rocks of these horizons on the well wall due to an increase in the flow rate of the working steam-gas agent from the working body or from the auxiliary nozzle of the drilling unit, this overpressure is maintained in the well cavity until the completion of the bottom hole development process and cleaning the cavity of the well from drill cuttings, then stop the process of developing the face and the consumption of the working agent from the auxiliary nozzle under hold the specified overpressure in the well cavity for the duration of the process of fixing its wall.

The technology of well formation provides for the impact on these larger particles in the form of pebbles, gravel with a steam-gas working agent with its temperature of about 700 ° C and a periodic pulse increase in speed, 2-3 times higher than the speed of these large particles, with pulse repetition in 5-10 s and a pulse duration of 2-3 s.

In this technology of well formation during the drilling of water-saturated unstable horizons, the pressure in the well cavity due to the consumption of the agent from the auxiliary nozzle can withstand 1.5-2.0 times the pressure of the rocks of this horizon on the well wall.

The technology of well formation is illustrated by reference to the drawings, in which Fig. 1 shows a general view of a drilling assembly located at the bottom; figure 2 - the basic design of the drilling unit.

The drilling unit 1 with its working body 2 is placed on the bottom 3 of the well 4 having a wellhead 5. The unit 1 also has an auxiliary nozzle 6 in the front upper part, designed to supply an additional volume of the working vapor-gas agent to the well cavity and form an additional upward flow to remove it from the bottom and removal of drill cuttings to the wellhead. Unit 1 has in its case a gas-vapor mixture generator 7 for feeding the working body 2 into the cavity and its working nozzle nozzles 8 and 9 of the working agent, as well as for supplying a part of the gas-vapor mixture into said nozzles 6 with its nozzle 10 oriented to the wellhead. Unit 1 is equipped with a programmed control device 11, initially operating on a command transmitted along the wellbore from its wellhead using directed acoustic waves, then the device 11 operates in the well 4 depending on the actual pressure in the well cavity created by the drill cuttings discharge from the bottom and given the changing pressure in the well.

The technology of formation of wells and workings in sedimentary rocks is as follows. Using a drilling unit 1 and its working body 2 destroy the rock at the bottom 3, passing the geological horizons and forming a well 4, starting from its mouth 5; rock destruction is carried out by impact on the face with jets of a gas-vapor agent under pressure and with a predetermined temperature, while the working agent is consumed in a volume that creates an upward flow of drill cuttings with its speed exceeding the rate of soaring of more rock particles, which are the main - most of them the size and mass that make up the upward flow of drill cuttings, so for particles having a nominal diameter of 10-20 mm and a size across 5-10 mm, it is necessary to create an upward velocity of about 24 m / s; for particles of a smaller size it is enough to create a flow of 10-15 m / s, which is carried to the day surface (to the mouth 5) by raising the worked-out flow of the working agent from below, filling its volume, limited by the diameter and length of the well.

When developing a face, separation of rock particles with sizes of 25 ÷ 50 mm × 10 ÷ 20 mm is possible. It is more efficient to crush such large particles in a targeted manner, subjecting them to dynamic and high-temperature effects by applying to the face 3 of the working body 2 a pulsed high-speed flow of the working agent, with a pulse duration of 2-3 s, repetition after 5-10 s, with a speed of more than 100 m / c and an agent temperature of about 700 ° C (in the range of 650-750 ° C); this causes a destructive thermogasdynamic effect on large particles (pebbles, gravel), crushing them to the size of the bulk of the particles and ensures the removal of drill cuttings to the mouth. At the same time, the speed of the drill cuttings leaving the bottom is set by the dependence:

V _{PB =} V _RF + ΔV _RF , m / s,

where V _pb is the velocity of the outgoing stream from the bottom of the bottom, sufficient to remove the main amount of particles of the drilled rock from the bottom zone;

V _HF - the rate of movement of particles of rock of the main quantity in the exhaust stream of drill cuttings;

ΔV _rf is the added value of the flow rate of the working agent to exceed by 5-10% the speed of coarse particles in the flow of drill cuttings.

This provides the necessary speed of lifting drill cuttings and the removal of particles of drilled rock from the wellbore to the mouth.

When driving water-saturated unstable horizons, where water discharges, collapses of the wall of the well are possible, the pressure in the wellbore (cavity) of the well 4 is set to be 1.5-2.0 times higher than the pressure of the rocks of these horizons on the wall of the well due to an increase in the flow rate of the working vapor-gas agent from the working body 2 and / or from the auxiliary consumable nozzle 6 of the unit 1; this excess pressure prevents disturbance of the borehole wall, which (pressure) is maintained until the completion of the bottom hole development process, maintaining the flow rate of drill cuttings of about 50 m / s, until the well cavity is cleaned of drill cuttings and incoming water; maintain the specified overpressure in the well for the duration of the process of fixing its walls.

Such a fundamental method of well formation allows the use of autonomous drilling units and apparatuses (by A.Plugin's design and technology) with independent power equipment for working in the well without using metal-intensive drill pipes for sinking geological horizons (and structures). This allows you to use this method in unprepared sites and in the absence of stationary sources of energy supply (tundra, deserts, mountains, swamps, etc.).

The efficiency of the face mining process is increased by 10-12% due to the supply of a working agent in a pulsed mode with a temperature elevated during a pulse, which allows finer crushing of rock particles and their removal in the total sludge stream; in addition, the ability to control pressure with a gas-vapor mixture (products of the consumption of fuel components in a mixture with evaporated water and evaporated solid carbon dioxide, setting the conditions for constant expansion of volume) prevents disturbance of the well wall during the passage of unstable and water-saturated horizons. These advantages of the method determine the progressiveness of the technology of rock sinking and formation of wells for various purposes.

Claims (3)

1. The technology of formation of wells and workings in sedimentary rocks, including the impact on the drilling medium with the energy of the jets of the working agent flowing from the working body of an autonomous drilling unit to the face under pressure, removal of drill cuttings to the wellhead, fixing the wall of the well, characterized in that when driving a well, the consumption of a combined-cycle gas agent is carried out in a volume that creates a stream of drill cuttings extending from the bottom with a speed exceeding the speed of the main quantity of particles of drilled rock, constituting in size and weight most of the drill cuttings, separate larger particles and larger mass of rock particles, separated from the bottom, are subjected to dynamic and high-temperature effects of combined-cycle working agent due to periodic pulse increase in the speed and temperature of the outflowing jets of the specified working agent, creating these conditions of their destruction to the size and mass of particles removed from the bottom to the wellhead in the total flow of drill cuttings, while the speed of the outgoing from the bottom ovogo slurry define the relationship:
V _PB = V _RF + ΔV _RF , m / s,
where V _pb - the speed of the outgoing stream from the bottom of the stream, sufficient to remove the bulk of the drilled particles;
V _HF - the rate of movement of particles of rock of the main quantity in the exhaust stream of drill cuttings;
ΔV _hf is the added value of the working agent flow rate for exceeding by 5-10% the speed of coarse particles in the flow of drill cuttings, and when sinking water-saturated unstable horizons, the pressure in the well cavity is set to exceed the pressure of the rocks of these horizons on the well wall due to an increase in the consumption of combined-cycle gas agent from the working body or from the auxiliary nozzle of the drilling unit, maintain this excess pressure in the well cavity until the development of the face and cleaning strips these wells from drill cuttings, then the bottom hole development process is stopped and the specified excess pressure in the cavity of the well is maintained by the flow of the working agent from the auxiliary nozzle during the process of fixing its wall. 2. The technology of well formation according to claim 1, characterized in that the impact on these larger particles in the form of pebbles, gravel is driven by a gas-vapor working agent with a temperature of about 700 ° C and a periodic pulsed increase in speed 2-3 times faster than the speed of movement of these large particles, with a pulse repetition after 5-10 s and a pulse duration of 2-3 s. 3. The well formation technology according to claim 1, characterized in that during the drilling of water-saturated unstable horizons, the pressure in the well cavity by the agent flow rate from the auxiliary nozzle is maintained to exceed the pressure of the rocks of this horizon on the wall of the well by 1.5-2.0 times.

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