Carbonatite and dolomite stratum oil well wire-line coring tool

Abstract

The utility model provides a carbonatite and dolomite stratum oil well wire line coring tool, including drill stem, outer tube, inner tube, inner tube assembly, winch and fisher, drill stem bottom end is connected with outer tube, inner tube assembly is connected with inner tube top end, the free end of rope on winch is connected with fisher top end, outer tube bottom end is connected with PCD drill bit, and the outer tube bottom end is connected with the PCD drill bit. A through hole is formed in the central axis of the PCD drill bit, and the through hole is in butt joint with the rock core containing channel in the inner pipe; the PCD drill bit is provided with six straight blades, the width of each straight blade is 1 / 20-1 / 16 of the circumference of the PCD drill bit, each straight blade is provided with a plurality of cutting teeth, and on the same straight blade, the cutting teeth at the most front end are arranged on the end face of the bottom end of the through hole. The oil well wire-line coring tool for the carbonate rock and dolomite formations has the advantages of being high in drilling efficiency for the carbonate rock and dolomite formations, high in core yield rate for the unconsolidated sand shale of the Nadisk group and capable of being suitable for deep coring operation.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of oil exploration, and more particularly to a carbonate rock and dolomite formation oil well rope coring tool. BACKGROUND

[0002] The rope coring tool is mainly composed of a drill pipe, an outer pipe, an inner pipe, an inner pipe assembly, a winch, a fishing tool and other accessories, the outer pipe is connected to the bottom end of the drill pipe, the bottom end of the outer pipe is connected with a drill bit, the top end of the inner pipe is connected with the inner pipe assembly and is sleeved in the outer pipe, the winch is wound with a rope, and the end of the rope is connected with the fishing tool; during drilling, the rope with the fishing tool passes through the center channel of the drill pipe, the fishing tool hooks the hook at the top end of the inner pipe assembly, the inner pipe filled with the core is fished up, and the new inner pipe is put into the hole bottom to continue drilling, and the core is not taken out during drilling, so that the influence of tripping on drilling efficiency is minimized.

[0003] The traditional rope coring tool has the following disadvantages: (1) the rock hardness is concentrated in 1.5-2, while the hardness of the carbonate rock and dolomite formation is 3.5-4, when the traditional equipment is used, the attack of the drill bit on the rock formation is weak, and the rock powder discharge capacity is poor, which leads to low drilling efficiency of the drill bit; (2) the impact force of the water eye of the traditional drill bit is large, when it is used in the Gidike group loose sand shale, the core is easily eroded, which leads to low core recovery rate; (3) it is mainly suitable for shallow coring, due to the weight of the rope and the overall weight of the tool, it cannot be used for deeper coring operation.

[0004] In order to solve the above problems, people have been seeking an ideal technical solution. SUMMARY

[0005] The utility model discloses to the deficiency of prior art, and provides a carbonate rock and dolomite formation drilling efficiency is high, and the core recovery rate of Gidike group loose sand shale is high, and the carbonate rock and dolomite formation oil well rope coring tool can be applied to deep coring operation.

[0006] In order to achieve the above object, the utility model adopts the technical scheme: a carbonate rock, dolomite formation oil well rope coring tool, including drill rod, outer tube, inner tube, inner tube assembly, winch and fisher, the bottom end of the drill rod is connected with the outer tube, the inner tube assembly is connected in the inner tube top, the free end of the rope on the winch is connected with the fisher top, the fisher bottom is used for grabbing the inner tube assembly, the bottom end of the outer tube is connected with PCD drill bit, the center axis of the PCD drill bit is equipped with through -hole, the through -hole is connected with the core receiving channel in the inner tube, six straight blades are provided on the PCD drill bit, the width of each straight blade is 1 / 20-1 / 16 of the PCD drill bit circumference, a plurality of cutting teeth are provided on each straight blade, and the frontmost cutting tooth on the same straight blade is arranged on the bottom end surface of the through -hole.

[0007] Based on the above, the spacing of the adjacent two cutting teeth is not less than 1 / 3 of the radius of each cutting tooth.

[0008] Based on the above, the rake angle of each cutting tooth is 3-8 °.

[0009] Based on the above, the PCD drill bit is provided with a large aperture water hole between each adjacent two straight blades, the large aperture water hole is inclinedly arranged towards the periphery of the PCD drill bit, the large aperture water hole is arranged close to the cutting side of the straight blade, and the diameter of the large aperture water hole is 1 / 3-1 / 2 of the spacing between the two straight blades.

[0010] Based on the above, the rope diameter of the winch is 9.3mm, and the motor power of the winch is 11kw.

[0011] The utility model has substantial features and progress compared with the prior art, specifically, the utility model has the following advantages:

[0012] (1) compared with the spiral blade and cutting tooth layout of the conventional drill bit, the utility model sets up six straight blades, sets up the frontmost cutting tooth on the bottom end surface of the through -hole, sets up the spacing of the adjacent two cutting teeth, reduces the cutting tooth density, sets up the smaller rake angle of the cutting tooth, makes the PCD drill bit have stronger aggressiveness, and improves the drilling efficiency.

[0013] (2) compared with the water hole structure of the conventional drill bit, the utility model sets up the narrower width of the blade, sets up the larger water hole aperture, and the large aperture water hole is inclined towards the periphery of the drill bit, effectively reduces the impact force on the core, improves the rock powder discharge capacity, and further improves the drilling efficiency and core harvesting rate.

[0014] (3) Compared with the traditional winch, the rope diameter is thicker, the motor power is larger, and the rope coring operation of deeper formation can be applied. BRIEF DESCRIPTION OF DRAWINGS

[0015] Fig. 1 is the structure diagram of the carbonate rock and dolomite formation oil well rope coring tool in the utility model.

[0016] Fig. 2 is the top view of the PCD drill bit in the utility model.

[0017] Fig. 3 is the side view of the PCD drill bit in the utility model.

[0018] In the figure: 1. Drill pipe; 2. Outer tube; 3. Inner tube; 4. Inner tube assembly; 5. Winch; 6. Fish; 7. Rope; 8. Motor; 9. PCD drill bit; 10. Through hole; 11. Straight blade wing; 12. Cutting tooth; 13. Large aperture water eye. DETAILED DESCRIPTION

[0019] The technical scheme of the utility model will be described in further detail below through specific embodiments.

[0020] As shown in Figs. 1-3 A carbonate rock and dolomite formation oil well rope coring tool, comprising a drill pipe 1, an outer tube 2, an inner tube 3, an inner tube assembly 4, a winch 5 and a fish 6, the bottom end of the drill pipe 1 is connected with the outer tube 2, the inner tube assembly 4 is connected at the top end of the inner tube 3, the free end of the rope 7 on the winch 5 is connected with the top end of the fish 6, and the bottom end of the fish 6 is used for grabbing the inner tube assembly 4; this part of structure is a common structure in the prior art and does not need to pay creative labor.

[0021] In order to be suitable for carbonate rock and dolomite formation coring operation, the bottom end of the outer tube 2 is connected with a PCD drill bit 9, a through hole 10 is formed at the center axis of the PCD drill bit 9, the through hole 10 is butt jointed with the core receiving channel in the inner tube 3, and six straight blade wings 11 are arranged on the PCD drill bit 9, the width of each straight blade wing 11 is 1 / 20-1 / 16 of the circumference of the PCD drill bit 9, and the width is relatively narrower than that of the traditional drill bit.

[0022] A plurality of cutting teeth 12 are arranged on each of the straight blades 11, and the frontmost cutting tooth 12 is arranged on the bottom end surface of the through hole 10 in the same straight blade 11; the interval between two adjacent cutting teeth 12 is not less than 1 / 3 of the radius of each cutting tooth 12, and the back rake angle of each cutting tooth 12 is 3-8°, so that the cutting tooth density is lower and the back rake angle is smaller than those of a conventional drill bit, thereby having stronger aggressiveness, and the drilling efficiency for carbonate rock and dolomite strata can be increased by nearly 50%.

[0023] The PCD drill bit 9 is provided with a large-aperture water eye 13 between each two adjacent straight blades 11, the large-aperture water eye 13 is arranged obliquely towards the periphery of the PCD drill bit 9, and the large-aperture water eye 13 is arranged close to the cutting side of the straight blade 11; compared with the water eye structure of a conventional drill bit, the large-aperture water eye 13 has larger aperture and more dispersed water outlet, thereby effectively reducing the impact force on the core, improving the core powder discharge capacity, and further improving the drilling efficiency and the core recovery rate for the loose sandstone and mudstone of the Jidike group.

[0024] In order to adapt to the wire line coring operation of deeper strata, the diameter of the wire rope 7 of the winch 5 is 9.3 mm, and the power of the motor 8 of the winch 5 is 11 kw.

[0025] In specific use, the carbonate rock and dolomite strata oil well wire line coring tool is assembled, and in the drilling process of the PCD drill bit 9, the core gradually fills the inner tube 3, at this time, the wire rope 7 carries the fisherman 6 through the central passage of the drill rod 1, the fisherman 6 hooks the hook at the top end of the inner tube assembly 4, and the inner tube 3 filled with the core is fished up, and at the same time, the new inner tube 3 is put into the hole bottom to continue drilling.

[0026] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalent ones; without departing from the spirit of the technical solutions of the present application, they should be covered in the technical solution range of the present application claimed.

Claims

1. A wireline coring tool for oil wells in carbonate rock and dolomite formations, comprising a drill pipe, an outer tube, an inner tube, an inner tube assembly, a winch, and a retrieval device, wherein the bottom end of the drill pipe is connected to the outer tube, the inner tube assembly is connected to the top end of the inner tube, the free end of the rope on the winch is connected to the top end of the retrieval device, and the bottom end of the retrieval device is used to grab the inner tube assembly, characterized in that: The bottom end of the outer tube is connected to a PCD drill bit. A through hole is opened at the central axis of the PCD drill bit, and the through hole connects to the core receiving channel in the inner tube. The PCD drill bit is provided with six straight blades. The width of each straight blade is 1 / 20-1 / 16 of the circumference of the PCD drill bit. Each straight blade is provided with several cutting teeth. On the same straight blade, the foremost cutting tooth is located on the bottom end face of the through hole. The distance between two adjacent cutting teeth is not less than 1 / 3 of the radius of each cutting tooth. The back slope angle of each cutting tooth is 3-8°. The PCD drill bit is provided with a large-diameter water eye between each pair of adjacent straight blades. The large-diameter water eye is inclined towards the periphery of the PCD drill bit and is located close to the cutting side of the straight blade. The diameter of the large-diameter water eye is 1 / 3-1 / 2 of the distance between the two straight blades.

2. The wireline coring tool for oil wells in carbonate rock and dolomite formations according to claim 1, characterized in that: The winch has a rope diameter of 9.3 mm and a motor power of 11 kW.

Images