CN2161715Y

CN2161715Y - Steel body PDC drill bit with step diameter keeping structure

Info

Publication number: CN2161715Y
Application number: CN 93214106
Authority: CN
Inventors: 王福修; 侯庆勇; 周光荣
Original assignee: DRILLING TECHNOLOGY INST SHENGLI PETROLEUM ADMINISTRATION
Current assignee: DRILLING TECHNOLOGY INST SHENGLI PETROLEUM ADMINISTRATION
Priority date: 1993-05-23
Filing date: 1993-05-23
Publication date: 1994-04-13
Anticipated expiration: 2003-05-23

Abstract

The utility model relates to a steel body PDC drill bit with step diameter keeping structure which is the improvement of the steel body PDC drill bit structure used for oil well and geological well. Because of the adoption of the step diameter keeping structure, the problem that the diameter keeping position of the steel body of the drill bit is easy to contact with the rocks on the well wall can be avoided, the total area of the contact of the drill bit and the rocks can be decreased, the average mechanical drilling speed and the average odd footage of the drill bit can be enhanced, and the cost price of the drilling well per meter can be lowered.

Description

Steel body PDC drill bit with step diameter keeping structure

The utility model belongs to the architecture advances of oil, geological drilling usefulness steel body PDC drill bit.

Because advantages such as the PDC drill bit has the efficiency of breaking rock height, rate of penetration is fast and the life-span is long, thereby in oil, geological drilling, obtained extensive use.

At present have carcass and steel body two big classes at the PDC of usefulness drill bit.The general result of use of tyre case PDC drill is better, but owing to manufacturing process complexity, quality are difficult for reasons such as assurance, cost height, has limited its scope of application.On the contrary, steel body PDC process of drill bit manufacture is simple, reliable in quality, with low cost and be easy to carry out the secondary reparation, thereby has obtained widespread usage.Yet exist following two kinds of defectives at the steel body PDC of usefulness drill bit on gauge structure at present: the steel body of 1. protecting the position, footpath is a complete cylinder.Like this, when first order gauge teeth wore and tore on the bit diameter direction a little, the drill steel body that first and second grade protected between the footpath will directly contact rock, has increased the resistance of bit cutting rock, thereby reduced the rate of penetration of drill bit, also reduced the total footage of drill bit.2. the gauge teeths at different levels of drill bit all insert to the maximum gauge of drill bit.Like this, in drilling process, all gauge teeths all contact the borehole wall simultaneously, have increased the resistance of rotary drilling, have also increased the rotation torque of all drilling tools, and its result also is the rate of penetration that has reduced drill bit.

The utility model improves at above-mentioned defective.Guarantor's path portion of drill bit adopts staircase structural model, promptly protect two cylinders (the diameter difference is 3～5mm, and the step ［ 4 ］ of a 1.5～2.5mm is promptly arranged) that the steel body at position, footpath adopts diameter not wait, and the bit diameter that gauge teeth at different levels reaches is also unequal.The small diameter cylinders body is positioned at the drill bit bottom, and large diameter cylinder is positioned at drill bit top.The utility model adopts three grades of gauge structures, and first order gauge teeth ［ 1 ］ and second level gauge teeth ［ 2 ］ are edging column PDC cutting teeth, and third level gauge teeth ［ 3 ］ is cylindric carbide alloy flat-top tooth.First order gauge teeth ［ 1 ］ is installed in the bottom face and the intermediate location of protecting the footpath of drill steel body ［ 5 ］, and reaches the maximum gauge of drill bit; Second level gauge teeth ［ 2 ］ is installed on the small cylinder of drill steel body ［ 5 ］, the bit diameter that is reached is than the little 2～3mm of drill bit maximum gauge, third level gauge teeth ［ 3 ］ is installed on the large cylinder on drill steel body ［ 5 ］ top, the little 1.5-2.5mm of bit diameter that the bit diameter that is reached reaches than second level gauge teeth ［ 2 ］.Though second level gauge teeth ［ 2 ］ and third level gauge teeth ［ 3 ］ not insert to the maximum gauge of drill bit, but because all there is eccentric rotation phenomenon to a certain degree in drill bit in the rotary drilling process, even thereby after bit life later stage first order gauge teeth ［ 1 ］ or second level gauge teeth ［ 2 ］ mill was little, the utility model also can get out the enough big well of diameter.

Figure of description:

Fig. 1, a kind of steel body PDC drill bit schematic diagram with step gauge structure

Description of drawings:

1, first order gauge teeth 2, second level gauge teeth 3, third level gauge teeth

4, step 5, steel body 6, nozzle

Now in conjunction with Figure of description, the utility model will be further described:

In drilling process, at first the utility model and other down-hole equipment are linked together, down to the shaft bottom, begin the rotary drilling of pressurizeing then.Because steel body of the present utility model ［ 5 ］ has a step ［ 4 ］, even thereby first order gauge teeth ［ 1 ］ has bigger wearing and tearing on the bit diameter direction, the position, guarantor footpath of drill steel body ［ 5 ］ can not contact with rock yet, so during whole bit life, the cutting resistance of drill bit is almost constant.And since second level gauge teeth ［ 2 ］ and third level gauge teeth ［ 3 ］ not insert to the maximum gauge of drill bit, so reduced the gross area that drill bit contacts with the borehole wall.Like this, in drilling process, the utility model can keep higher efficiency of breaking rock always, has improved the average rate of penetration and the total footage of drill bit.Field trial proves, compares with ordinary steel body PDC drill bit, and average rate of penetration of the present utility model has improved 25%, and average single drilling depth has improved more than 15%, and every meter drilling cost has decline by a relatively large margin.And reduced the number of times that makes a trip, and reduced working strength of workers, be subjected to a line drilling implementer welcome deeply.

Claims

1, a kind of steel body PDC drill bit with step gauge structure mainly is made up of steel body, PDC cutting teeth, gauge teeth and nozzle, it is characterized in that there is a step [4] at the position, guarantor footpath of drill steel body [5], and the size of this step [4] is 1.5～2.5mm.

2, the steel body PDC drill bit with step gauge structure according to claim 1, it is characterized in that adopting three grades to protect the footpath, and first order gauge teeth ［ 1 ］ is an edging column PDC cutting teeth with second level gauge teeth ［ 2 ］, and third level gauge teeth ［ 3 ］ is cylindric carbide alloy flat-top tooth.

3, the steel body PDC drill bit with step gauge structure according to claim 1 and 2, three grades of bit diameters that gauge teeth reached that it is characterized in that being installed on the drill steel body ［ 5 ］ have nothing in common with each other.First order gauge teeth ［ 1 ］ reaches the drill bit maximum gauge; The bit diameter that second level gauge teeth ［ 2 ］ reaches is than the little 2～3mm of drill bit maximum gauge; Little 1.5～the 2.5mm of bit diameter that the bit diameter that third level gauge teeth ［ 3 ］ reaches reaches than second level gauge teeth ［ 2 ］.