DE1009128B - System for drilling deep oil or gas wells - Google Patents

Description

GERMAN

The invention relates to a system for drilling deep oil or gas wells, in particular for directional drilling along a line that deviates significantly from the vertical.

Using already known deep drilling rigs for drilling in a predetermined direction, it is possible to move the bottom of a borehole to a point that is 300 m in the horizontal direction and is further away from the starting point of the hole. However, these systems prove to be in the case of boreholes that be carried out in a direction which deviates significantly from the vertical, as inexpedient or unsuitable. In such bores, a large part of the weight of the drill string is from the Added side wall of the hole drilled with the aid of the drill pipe. Measurements of the voltages in the suspension rope of the drill string or the thrust force exerted on the drill string therefore give no accurate or uniform picture of the magnitude of the force acting on the drill bit during drilling.

In deep drilling rigs for vertical drilling, it is already known to use a telescopic one in drill rods to use sliding connection. However, in these systems, the bit pressure becomes essentially solely on the weight of the part of the drill rod located below the mutually displaceable parts exercised. The pressurized fluid flowing in the drill string is useful here no influence on the chisel pressure. When drilling holes horizontally or slightly In the inclined direction, therefore, such a drill pipe cannot be used for the same reasons as above.

In another known device for vertical drilling, the drill bit is arranged such that it can be telescoped out at the lower end of the drill string. At the upper end of the hollow drill bit, a valve is provided which is urged in the closing direction by a relatively strong spring. This valve has the task of providing a resistance to the drilling mud supplied to the drill bit, so that the latter tends to push the drill bit downward out of the rod. In this device, the drilling pressure is normally mainly dependent only on the unbalanced weight of the string which rests on a shoulder of the drill bit during drilling. Only when the drill bit suddenly breaks through a hard formation is the drill bit pushed out of the drill pipe by the fluid pressure acting in the valve in order to continue drilling during the time until the pipe is lowered again. Although this is not provided for in the known device, it could also be used as an attachment for drilling
deeper oil and gas wells

Applicant:

NV De Bataafsche Petroleum
Maatschappij, The Hague

Representative: Dr.-Ing. F. Wuesthoff, patent attorney,
Munich 9, Schweigerstr. 2

Claimed priority:
V. St. v. America June 10, 1952

Charles Alfred Yeatman

and James Nathaniel Gregory, Emeryville (V. St. Α.), have been named as inventors

apply the way that you constantly balance the whole Ge rod weight and the drilling pressure only by means of of the fluid pressure acting on the valve. A disadvantage here, however, is that the relaxation the liquid pressure already takes place in the valve, and another disadvantage that the valve the Drill bit complicated and can give rise to malfunctions.

It is the object of the invention to create a system for deep drilling, which is particularly suitable for carrying out of low slope boreholes where the drill bit is simple and the one out the jet of liquid emerging from it has a powerful flushing effect.

In the case of the deep drilling rig, which is intended in particular for drilling boreholes with a slight incline with a telescopic piston-cylinder arrangement that transmits the torque According to the invention, the outlet opening for is present on the drill bit within the drill pipe the drilling mud as well as that associated with the outer end of the hollow drill string Pump device dimensioned such that between the space in front of the piston and the bottom of the borehole a differential pressure is created which propels the drill bit into the ground along the axis of the hollow rod. Preferably, the drill bit is directly connected to a piston, which is in a End of the drill pipe provided tubular member slides.

With the deep drilling rig according to the proposal of the invention "the above are particularly with regard to

709 546/128

on the execution of bores with low inclination mentioned disadvantages eliminated in a simple manner. By suitable choice of the size of the openings provided in the drill bit for the exit of the Drilling mud can be a differential pressure across the openings, i. H. a pressure difference between that hydraulic pressure within the drill string and the pressure within the borehole space at which Achieve outside of the rod, which has a considerable-The drilling tool shown in FIG tubular component 11 which is connected at 12 to the lowermost member of the drill pipe or casing 13 is and in its lower axial closure piece 14 has an axial opening 15. In the component 11 is a tubular shaft 16, the length of which can be about 9 meters or more, arranged in the opening 15 can slide back and forth axially. The shaft 16 may be square, hexagonal, or other

borrowed feed pressure on the drill bit results. The cross-section should be suitable for a rotation against the feed pressure is to be prevented by changing the hydraulic over component 11. The tubular ■> Chen pressure in the drill pipe in a simple manner carries a piston-shaped head 17 and a shaft adjustable and can continuously without difficulty over-stop collar 18, which together the back and forth be awake. Limit float by reducing the amount required. There is one on head 17 the outlet cross-section for the drilling mud occurs 15 sealing device 19 provided to a Überdieser as a powerful jet that emerges at the bottom of the drilling mud from the space within Drilling to prevent a good flushing effect on the cuttings of the drill pipe in the annulus 20, exercises. The shaft 16 carries a at its lower end

The invention is based on hand schema drill bit 21, depending on the requirements as table drawings can be executed on several examples, 20 stone chisels or spade chisels, len explained in more detail. On the drill bit 21 are for the purpose of

Fig. 1 shows a schematic representation of a sludge circulation openings 22 provided as a vertical section through a bore that can be formed on the nozzle. By a suitable choice of surface in an essentially horizontal direction of the size of the openings 22 can be started at the beginning and later at the desired target point 25 with a at the upper end of the bore is brought, which in the horizontal direction from the hydraulic pressure slightly along the openings a differential pressure , ie a pressure difference between the hydraulic pressure inside the drill pipe and the pressure inside the drill hole space, achieve on the outside of the pipe in the order of about 35 to 70 kg / cm ² .

Using 7 inch OD tubing like them is common today, it follows that on

has begun and the direction of which is gradually changing hydraulically, a force of the order of magnitude changes until the desired slight inclination is reached from about 4.5 to 9 t exerted on the drill bit is. This final direction of the hole can then be used to cause this to be retained in the for until the bottom of the hole in question penetrates mation.

Starting point is away, and

Fig. 2 shows a schematic representation of a preferred embodiment of a drill bit arrangement according to the invention.

The sectional view in FIG. 1 shows the course of a typical bore 2 with a slight inclination a point 3 located on the surface in a substantially or nearly horizontal direction

has been brought to the desired destination (to a point 4), the point 4 for example within boundaries 6 and 7 of an area to be investigated and located outside the coastline 8 and below the upper edge 9 of an oil-bearing formation is, in turn, by geological or geophysical work or by correlating drilling profiles.

Surface casing of suitable length (in the example shown in FIG. 1, the length is this section about 2000 English feet) up to a point 10 is laid so that the shoe follows this The piping is located more than about 600 feet below the surface of the earth for the facility the occurrence of eruptions along the circumference of the casing. This surface piping preferably has a length such that it extends over the entire curved section of the Bore extends, d. H. over the length of that section within which the bore gradually from their original, essentially horizontal, direction to their final, more inclined Direction passes; the purpose of this measure is to pipe up this section to prevent to prevent splined longitudinal grooves.

In order to be able to regulate the feed force actually acting on the drill bit, the drill rod is necessary formed in the manner shown in Fig. 2, here the telescopic connection at the end of the drill string is provided.

Claims (2)

Patent claims: 1. Deep drilling rig with in the hollow drill pipe provided telescopically displaceable against each other by differential pressure of the flushing liquid, not Piston-cylinder arrangement that can be rotated against one another, especially for drilling boreholes low slope, characterized in that the cross-sectional area of the drill bit provided outlet opening (22) for the drilling mud and with the outer end of the hollow drill pipe in connection pump device are dimensioned such that between the space in front of the piston and the bottom of the borehole creates the differential pressure that propels the drill bit into the ground along the axis of the hollow rod (13). 2. Deep drilling system according to claim 1, characterized in that the drill bit (21) directly is connected to the piston (17), which is located within one at the end of the hollow drill pipe (13) provided tubular component (cylinder 11) slides. Documents considered: German Patent No. 562 151; French Patent No. 492,296; British Patent No. 611,340; U.S. Patents Nos. 1,767,350, 1,844,257, 565 794, 2 588 068. 1 sheet of drawings © 709 546/128 5.