RU192852U1 - Shoe Chisel - Google Patents

Abstract

The utility model relates to the mining industry and can be used as a rock cutting tool, that is, drill bits for casing drilling in the construction of oil and gas wells. The technical result consists in increasing the reliability and efficiency of the drilling process in complicated geological conditions, preventing emergencies, expanding the functionality of the device by improving the control of the shoe-shoe, which can be used as a rock cutting tool and centralizer during subsequent cementing of the casing . The casing shoe consists of a body with a connecting thread, a central channel and an assembly of easy-to-drill material, with flushing fluid openings, steel blades and PDC polycrystalline diamond cutters that extend apart under pressure. The shoe-shoe body is made with guide screw grooves, and the sliding steel blades are made with the possibility of opening along the guide screw grooves to significantly reduce the effort expended when the sliding steel blades of the shoe-shoe are fully open, the sliding and moving steel blades are moved and oriented along the guide screw grooves of the case.

Description

The utility model relates to the mining industry and can be used as a rock cutting tool, that is, drill bits for casing drilling in the construction of oil and gas wells. The technical result consists in providing the possibility of penetration of wells in soft and medium rocks with simultaneous casing.

Prerequisites for creating a utility model.

Analysis of the current level of technology in this field showed the following.

One of the elements of technological equipment for casing strings is shoes, which are used for successful descent of casing strings and normal subsequent operation of wells. There are shoes of different designs and applications: vibratory shoes used in the construction and repair of wells, such as cementing, preventive flushing, for installing profile shutoffs and shanks. For selective operation and processing of reservoirs, valve shoes of various designs are used. Column shoes of type BK, formerly called columnar guide plugs, are designed to equip the bottom of the casing strings, guide them along the wellbore and protect against damage during descent.

Casing drilling technology offers one of several alternatives. This system reduces the number of hoisting operations (STR), which, in turn, speeds up the drilling process. The main advantage of casing drilling is to reduce the time spent, in particular, the time spent on hoisting operations with drill pipes and lowering casing, including flushing, is reduced. When drilling with casing, the need for elements of the standard layout of the bottom of the drill string (BHA) is reduced and the need for one or more drill pipe columns can be eliminated.

Fields of application of casing drilling technology:

- the range of application conditions from soft rocks of 1-3 hardness categories to deep operational oil and gas reservoirs;

- drilling with a guiding column or conductor in a single shutdown, which reduces downtime;

- casing drilling at complicated intervals, such as loss of circulation zones, zones with different conditions and unstable rocks.

The casing drilling technology can be used when drilling complicated intervals with catastrophic absorption zones, transition zones with alternating pressure, and also ensures the stability of an open wellbore, eliminating partial shedding or destruction of its walls when drilling crumbling clays, by reducing the time spent on the walls of the well in open state and exceptions for tripping during well construction.

Known drill shoe (US patent No. 7096982 McKay et al.), The casing of which is made of relatively soft material, in which the blades are made of solid material. The blades, usually steel, are additionally equipped with PDC cutters (Polycrystalline Diamond Compact). When the required drilling depth is reached, the moving element is activated to push the soft material and bend the blades to the side walls of the annular space. Then the moving element can be drilled with a subsequent bit. The drill shoe provides the supporting mechanism of the cutting structure with steel blades strong enough to impact loads during drilling.

A disadvantage of the known drill shoe is the occurrence of accidents with incomplete opening of the drill shoe, due to the fact that there is not enough effort to push and bend the blades.

In the prior art, a shoe is known with an expansion chisel element and a nose made of aluminum or zinc alloy to enable the nose to be drilled (US Pat. Nos. 6,401,820 and 6,659,173 to Kirk et al.).

The disadvantage of these devices is the need to drill the shoe with a big loss of time and money, since you have to drill the blades with PDC cutters, which are made of very durable materials.

The closest in technical essence to the claimed utility model is a 295.3 mm drill bit with sliding blades manufactured by BURINTECH LLC (RF patent for utility model No. 156923, IPC Е21В 10/64. "Casing drill bit" from 04/20/2015 Propulsion: November 20, 2015, Bull. No. 32), selected as a prototype.

The casing drill bit is used for casing drilling in rocks of hardness category 1-3. The features of this design are as follows: the bit contains a central unit made of easily drilled material, steel blades sliding apart under pressure, and PDC cutters of a premium class.

The disadvantage of the prototype is the possible occurrence of accidents with incomplete disclosure of the blades of the shoe-shoe.

The main goal of this utility model is to increase the reliability and efficiency of the drilling process in complicated geological conditions, to prevent emergencies, to expand the device’s functionality by improving the control of the shoe-shoe, which can be used as a rock cutting tool and centralizer for subsequent cementing casing string.

The goal is achieved by the claimed technical solution.

The casing drill shoe consists of a body with a connecting thread, a central channel and an assembly of easy-to-drill material, with flushing fluid openings, steel blades and premium PDC polycrystalline diamond cutters that extend apart under its pressure.

What is new is that the shoe-shoe body is made with guide screw grooves, and the sliding steel blades are made with the possibility of opening along the screw helical grooves to significantly reduce the effort expended when the sliding steel blades of the shoe-shoe are fully open, the sliding and moving steel blades are guided and guided along the guide screw grooves of the housing.

Also new is the fact that the chisel shoe is used as a centralizer during subsequent cementing of the casing string.

The inventive utility model is illustrated by drawings, where:

- FIG. 1 shows a chisel shoe in a transport position;

- FIG. 2 shows a chisel shoe with centralizer function.

The proposed bit shoe for drilling wells on the casing string (Fig. 1, Fig. 2) consists of a housing 1 with a connecting thread (for connection with elements of a standard BHA), an assembly of easily drilled material and a central channel (not shown in Fig.), flushing holes 2 for flushing fluid and sliding steel blades 3 equipped with polycrystalline diamond cutters PDC 4. The housing 1 contains guide screw grooves 5 (Fig. 1), which serve to orient and fully open the sliding steel blades 3 according to the grooves 5. The chisel-shoe works as follows.

The body 1 of the shoe shoe is connected with the BHA elements (not shown in Fig.) Using the connecting thread at the wellhead and the BHA is smoothly lowered into the well, being careful when passing through the rotor table and wellhead equipment, since the protruding edges can damage the calibration surface and the armament of the bit, while the sliding steel blades 3 are in the closed state (Fig. 1).

After reaching the bottom, when the chisel-shoe touches the bottom, the torque usually sharply increases, while the chisel-shoe is raised above the face by 1.5-2 meters, while maintaining full circulation and low speed for about 5-10 minutes to clean the bottom of the well.

Then they start drilling with a load of no more than 1000 kg until a new bottom profile is formed - 30-60 cm. The shoe-shoe is worked out at gentle drilling modes at a distance of 2-3 m. The load on the bit is added to 0.5-1 ton to the permissible, save constant load in equal time intervals (5 ... 10 minutes). The optimal parameters of the drilling mode are selected: the load on the chisel-shoe, the supply of flushing fluid, the number of revolutions in order to obtain maximum mechanical speed. The load on the chisel-shoe is optimal, at which the maximum number of meters was drilled in a certain time interval, in particular, these loads on the chisel-shoe and the rotational speed of the drill string are determined only for specific drilling conditions and can be continuously applied only in similar mining and geological conditions. The initial value of the rotational speeds of the drill string is usually taken from the data on the previous wells in similar mining and geological conditions, or the minimum value of the operating characteristics specified in the specification is taken.

The maximum value of the load on the chisel-shoe is usually taken from the highest values of the operating characteristics specified in the specifications or based on the actual weight of the used drill pipe (UBT), or from the maximum allowable values determined by other drilling conditions (barrel bending, vibration). So, for example, in the conditions of PJSC Tatneft, drilling is carried out with the following parameters:

- mechanical speed of 20 m / h;

- load 2 ... 10 tons;

- rotational speed 40 ... 120 rpm;

- flow rate of flushing fluid 30 ... 55 l / s.

After opening the zones with complete absorption of the flushing fluid, the fluid flow rate is reduced to 16 l / s.

Under the action of axial load and torque, the PDC 4 cutters destroy the rock, which is brought to the surface through the gaps between the walls of the borehole and the outer surface of the casing 1 by flushing fluid injected through the flushing holes 2 in the casing 1. In this case, the rock cutting tool - sliding steel blades 3 are in contact with the walls of the well, providing reliable alignment of the tool in the well and maintaining a given direction of drilling.

The technology for using the proposed shoe-shoe after reaching the design bottom of the well consists in activating the shoe-shoe by relieving the plastic ball and raising the pressure using the CA-320 unit to expand the steel blades of the 3 shoe-shoe. Sliding steel blades 3 are moved and oriented along the guide screw grooves 5, which significantly reduces the effort and facilitates the opening of the shoe-shoe. Subsequently, during subsequent cementing of the casing string, the chisel shoe is used as a centralizer. The process of cementing the column is carried out according to traditional technology. After waiting for the hardening of cement (OZZ) and the installation of the preventer, the assembly is launched on drill pipes with a PDC bit for drilling cement stone and subsequent drilling.

Casing drilling technology offers one of several alternatives. This system reduces the number of hoisting operations (STR), which, in turn, speeds up the drilling process. The main advantage of casing drilling is to reduce the time spent, in particular, the time spent on hoisting operations with drill pipes and lowering casing, including flushing, is reduced. When drilling with casing, the need for elements of the standard layout of the bottom of the drill string (BHA) is reduced and the need for one or more drill pipe columns can be eliminated.

Fields of application of casing drilling technology:

- the range of application conditions from soft rocks of 1-3 hardness categories to deep operational oil and gas reservoirs;

- drilling with a guiding column or conductor in a single shutdown, which reduces downtime;

- casing drilling at complicated intervals, such as loss of circulation zones, zones with different conditions and unstable rocks.

The casing drilling technology can be used when drilling complicated intervals with catastrophic absorption zones, transition zones with alternating pressure, and also ensures the stability of an open wellbore, eliminating partial shedding or destruction of its walls when drilling crumbling clays, by reducing the time spent on the walls of the well in open state and exceptions for tripping during well construction.

The advantages of the proposed shoe bit are the reliability and durability of the structure, in increasing the efficiency of well construction in complicated geological conditions, in particular: intervals with partial or complete loss of circulation due to fracturing of permeable or fractured formations, zones of unstable rocks, intervals of permafrost soil.

The chisel shoe is made in strict accordance with the regulatory requirements for fire and explosion safety and meets the requirements of labor safety and environmental protection.

This claimed technical solution reflects the specifics of oil production, leads to a comprehensive positive scientific and technical result and the expansion of the functionality of the device.

Claims (2)

1. The chisel shoe for drilling wells on the casing string, comprising a body with a connecting thread with a central channel and an assembly of easily drilled material, with flushing holes, steel blades and PDC polycrystalline diamond cutters, expandable under pressure of the flushing fluid, characterized in that the casing of the bit is the shoe is made with guide screw grooves, and the sliding steel blades are made with the possibility of opening along the guide screw grooves to significantly reduce costs efforts to fully open the sliding steel blades of the shoe-shoe, the movement and orientation of the sliding steel blades along the guide screw grooves of the housing. 2. The device according to claim 1, characterized in that it is used as a centralizer during subsequent cementing of the casing string.

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