In the process of geological drilling and engineering exploration, diamond drill bits are widely used drilling accessories. How to improve the service life of drill bits is a problem that drill manufacturers have been considering. The method of prolonging its service life should be considered from the three aspects of the raw material, manufacturing process and operation technology of the diamond drill.
Ⅱ. How to improve the service life of diamond drill bits for rock?
1. Raw materials
Diamond drill bit manufacturers and sales purposes are closely related. If it is a technology-based enterprise pursuing quality, they will strictly control the procurement of production materials. Only high-quality raw materials can ensure that the quality of the drill bit stands out among many brands. This is also the fundamental way to improve the service life of diamond drill bits.
2. Production process
Electroplated diamond drill bits have been developed for many years, and their production process has undergone many major changes. The production processes of different manufacturers are very different. Due to their respective operations, there is currently no complete system of diamond drill production processes that have been made public. To be sure, the production process is a direct factor in determining the quality of diamond drill bits.
3. Operation technology
If the choice of drill bit is the primary reason for its service life, then the actual operation is the secondary reason. No matter how good a diamond bit is, if there is no proper operation method, not only the ideal footage efficiency cannot be achieved, but it will also affect the wear of the bit. For example, in normal drilling, if the cleaning fluid cannot circulate normally, then the bottom of the generated high-temperature and high-speed rotation of the drill bit cannot be taken out, which can easily lead to drill bit burning accidents, not to mention the service life problem.
Steel body PDC bit can be customized for oil well, water well, mining, explorer well drilling.
Suitable Formation: Various hardness rocks or mud except for the hardest hardness or ununiform rocks like cobble.
Application: Water well, Petroleum & Gas, Water well, mining and tectonic.
The diameters of these PDC drill bits for sale range from 3″ to 36″ with a variety of cutters and optional back-out cutters as well as various blade counts.
Features of Steel Body PDC Drill Bit GS1606T
Spiral blade, directional drilling design.
6 Curved Blades
16 mm Cutters
Force-Balance Design
The layout of different patented PDC cutters enhances the capability to drill hard stringers.
CFD Technology Is Applied In Optimizing Hydraulic Efficiency.
Hard alloy hydraulic sleeves are installed to increase the service life of the hydraulic components of the bit. The use of bits without hydraulic nozzles may cause the sleeves to fall to the bottom of the well and lead to wear of the cutters.
This is a 6 blade with 1613mm cutters PDC bit, which is used for vertical drilling. After optimizing the design, this bit has achieved 1.5 times higher ROP than our competitors.
Quality Inspection of Steel Body PDC Drill Bit GS1606T
As one of the most professional drill bit manufacturers in China, GREAT has strict quality inspections on every drill bit we produce. Here is the inspection process.
We, Cangzhou Great Drill Bits Co. Ltd., specialized in R&D, design, production, and sales of various best drill bit for rock. The drill bits size from 3″ to 26″, HDD Hole opener from 8“- 48“, Such as PDC bit, Roller bit, Tricone bit, PDC Coring bit, Bi-center bits, Hole opener, etc. The Company consistently adheres to the concept of industrial development to promote energy development, adhered to innovative drive, scientific development, and is one of the largest scale companies in Asia for PDC bit and Tricone bit, Hole opener manufacturer.
Our PDC bit production line includes Matrix body PDC bit and Steel body PDC bit. Tricone bit is mainly Three cone bits, and according to the drilling formation different, we have TCI bit and Steel tooth bit available. In some HDD(Horizontal directional drilling ) project, we have Rock reamers for hard formation. Our Roller bit core barrel is widely used for piling foundation too.
We offer different types of rock drill bits for sale and can recommend the right type according to your drilling request.
Two manufactures: New manufacture with 40,000 square meters in Hebei Province, very near to Beijing, and build our own R&D Exchange Center in Beijing.
Government gives us a High-tech Firm Authories Certification, we got API Spec7-1 Quality Control Standard. ISO9001:2008 Quality Management System.ISO14001:2004 Environment Management System.
Mazark machines are imported from Japan.
Strong designs, engineers, production, sales and after-sales service team.
OEM&ODM service with confidentiality agreement.
We are strictly quality control our PDC bit, Tricone bit, Hole opener quality, The precision of CNC lathes is ±0.01mm, it can meet all the turning requirements. And after turning a certain numer of pieces, we must change the tool of lathes to make sure the precision of machines.
According to the manufacturing standard the quality department tests every process strictly and carefully.
As one of most professional drill bit manufacturers in China, we strictly control the whole production process, and we inspected the finished drill bits, we can also make several design changes according to the customer’s feedback, and finally, ensure the customer’s excellent drilling effect.
Meanwhile, we can provide our engineer service in the field.
Ⅰ. The basic requirements of roller cone bit teeth
For the teeth of roller cone bits, the basic requirements are high rock breaking efficiency and long life. In order to meet this requirement, first, the geometric shape of the teeth must be reasonable; second, the material of the teeth must be wear-resistant and have sufficient strength.
Ⅱ. Common tooth types of roller cone bits
According to the type of teeth, roller cone bits can be divided into milling teeth (also called steel teeth) and cemented carbide teeth (referred to as inserts).
1. Milling tooth profile
The teeth of the milling cone bit are integrated with the cone shell. It is formed by milling the cone blank. In order to improve the wear resistance of the teeth, cemented carbide powder is applied on the tooth surface.
The tooth profile of milling teeth is mainly wedge-shaped teeth. The outer gauge gears can be made into P, T, and L shapes.
2. Insert tooth profile
a. Wedge-shaped teeth: suitable for crushing soft formations with high plasticity and medium-hard formations, with tooth tip angles ranging from 65 to 90 degrees, small tooth tip angles are suitable for soft formations, and large tooth tip angles are suitable for harder formations.
b. Scoop chisel: There is also a kind of wedge tooth with asymmetrical sides, one side of which is concave, called scoop chisel, suitable for drilling soft formations.
c. Conical tooth: There are two kinds of single cone and double cone. The rock is crushed by crushing method. The medium cone tooth of 60°-70° is used to drill medium and hard formations, such as limestone and dolomite. 90° cone and 120° double cone teeth are suitable for hard formations with high abrasiveness, such as hard sandstone and quartzite.
d. Triangular tooth: a plane is cut every 120° on the cone surface of the double cone tooth, which is suitable for the interlaced layer of hard and brittle stratum and soft and plastic stratum.
There are many manufacturers of tooth bits, and these drill bit factories provide bits of various types and structures. In order to facilitate the selection and use of roller cone bits, the International Association of Drilling Contractors (IADC) has developed a unified worldwide classification standard and numbering method for roller cone bits.
IADC stipulates that each type of drill bit is represented by three digits, and the meaning of each number is as follows:
The first digit indicates the type of tooth and the formation suitable for drilling:
1 – Milling teeth, soft ground;
2 – Tooth milling, medium to medium hard formation;
3 – Milling teeth, hard, abrasive or semi-abrasive formations;
4 – Spare;
5 – Insert teeth, soft to medium stratum;
6 – Insert teeth, medium-hard stratum;
7 – Insert teeth, hard, abrasive or semi-abrasive formation;
The second digit indicates that the drilled formation is subdivided into four hardness grades 1, 2, 3, and 4.
The third digit indicates the structural characteristics of the drill:
1 – Unsealed rolling bearings;
2 – T-shaped outer row tooth gauge;
3 – There are insert teeth on the gauge diameter;
4 – Sealed rolling bearing;
5 – Sealed rolling bearing, with insert teeth on the gauge diameter;
6 – Sealed sliding bearing;
7 – Sealed sliding bearing, with insert teeth on the gauge diameter;
8 – Directional well deflection bit;
9 – Other.
Advantages of roller cone bits:
1. The double action of impact and shearing breaks the rock, both the impact of the teeth and the shear caused by sliding, the rock breaking efficiency is high.
2. It is suitable for a wide range of formations and is suitable for drilling in all formations.
3. The self-washing effect of the drill bit is good, and it is not easy to mud pack.
In the process of drilling, drill bit is the main tool to break rock, and borehole is formed bya drill bit breaking rock. The formation of a well is good or bad, and the length of time it takes is not only related to the rock characteristics of the drilled formation and the performance of the bit itself, but also related to the matching degree between the bit and the formation. The reasonable selection of bit plays an important role in improving the drilling speed and reducing the comprehensive cost of drilling.
The bit is one of the important tools for oil drilling. Whether the bit adapts to the rock property and its quality plays a very important role in the selection of drilling technology, especially in the aspects of drilling quality, drilling speed and oil drill bit cost. PDC bit is a rock breaking tool widely used in the oil and gas exploration and development industry today which effectively improves the mechanical drilling tools and shortens the drilling cycle.
Bit is one of the main drilling equipment. According to the different working environment and regional environment, the specification and shape of bit should also be different. When drilling oil, the bit should be selected reasonably and scientifically based on the specific needs and design scheme.
At present, there are many kinds of bits used in the petroleum industry. According to different drilling methods, the bits can be classified into diamond bits, roller bits and scraper bits. These three kinds of bits are the most basic ones.
Because of the excellent cutting performance of diamond drill bits rock, the diamond bit can drill at high speed and enlarge the drilling depth to a certain extent when being selected as oil drilling tool. In the process of drilling oil with diamond bit, the following aspects need to be paid attention to:
First, the price of diamond bit is relatively high, so we should operate it carefully to reduce the damage degree;
Secondly, the diamond bit has some defects in thermal stability, so the cooling performance and cleaning condition of the bit should be guaranteed when it is used;
Thirdly, its texture is relatively brittle, so the impact resistance of the diamond bit will be relatively poor, so we should strictly follow the relevant rules of the diamond bit to carry out strict and standardized operation.
When selecting oil drilling bits it is necessary to select the bit according to the actual situation of the drilling equipment, the actual conditions of the formation, the geological data of the adjacent oil wells and the formation data. During the drill bit selection, the following issues need to be considered:
First of all, we need consider whether there is soft and hard interlacing in the drilling formation;
Secondly, it should consider whether anti deviation drilling and curve operation are needed in the oil drilling work;
Thirdly, the actual depth of different drilling sections in the same well should be considered;
Finally, drilling geology, formation abradability and hardness should be considered.
(1) According to the lithology of the drilled formation, the following principles should be followed when selecting the type of tricone bit drilling:
a. In the shallow well section where the rock is cemented and loose, the drilling speed of the drill bit and the prevention of mud packs should be considered;
b. In the deep well section where the trip is long, the footage of the drill bit should be considered;
c. When the outer row teeth of the drill bit out of the well are severely worn, a bit with gauge teeth should be used;
d. In the easy deviating well section, a bit with small slip and many short teeth should be used;
e. Wedge-shaped tooth drills should be used when selecting insert drills;
f. For diamond limestone, it is advisable to use double-cone-tooth and projectile-shaped tooth drill bits;
g. When there is more shale in the formation or the density of drilling fluid is higher, a bit with a larger slip amount should be selected;
h. When the stratum is limestone or sandstone, and a bit with a smaller slip amount should be selected;
i. When drilling hard and highly abrasive stratum, it is advisable to use pure rolling button and double bevel bit.
(2) In order to optimize the hydraulic parameters of bit, the longer nozzle and unequal diameter combined nozzle bit should be preferred.
2. Inspection of a drill bit before drilling
(1) Check whether the model and diameter of selected bit meet the requirements;
(2) Carefully check whether the thread, weld and teeth of the drill are in good condition;
(3) Check whether the nozzle is installed firmly and the water hole should be unblocked; when rotating the cone of the rock bit by hand, the bearing seal should be intact; the pressure compensation system of the drill bit should be intact, and the pressure relief hole should not be blocked.
3. Matters needing attention when a drill bit enters the well
(1) After cleaning the drill thread, apply special thread oil;
(2) Choose a suitable loading and unloading device, and do not jerk when the drill bit is put into the loading and unloading device;
(3) Tighten according to the specified torque;
(4) The drilling operation should be stable, and no hard pressure should be encountered in case of resistance. Drilling of the insert bit should be slow to avoid damage to the alloy teeth in the hard formation and irregular hole;
(5) When drilling down and encountering an obstruction, the depth of the well, the situation and time of the obstruction should be noted, so as to determine the cause of the obstruction and control the working time;
(6) Drill down to a certain distance to the bottom of the well (a single root). The pump should be turned on and the turntable should be slowly lowered. It is strictly forbidden to go down to the bottom to open the pump.
4. Precautions for drilling of a drill bit
(1) The new drill bit should be run-in lightly for about half an hour, and then gradually increase to the specified WOB, and it is strictly forbidden to pressurize to start the turntable;
(2) Concentrate and deliver the drill evenly when operating the brake lever to prevent accidents of slipping and sudden drills;
(3) During roller bit drilling, the changes in lithology and the working conditions of the bit should be analyzed at any time according to the change of the drill pair and the operation of the bit, and the drilling parameters should be adjusted in time.
5. Determine the starting time of a drill bit
(1) Determine according to the wear of the bearing and teeth, the phenomenon of bearing damage:
The turntable has periodic jumps. If the bit pressure is small, the jump is light. If the bit pressure is big, the jump is heavy; the drilling speed drops; the pump pressure is normal but the pointer of the weight indicator swings.
(2) The phenomenon of cone jamming:
The load on the turntable increases; the turntable chain jumps; the kelly rod is crappy; the turntable is stopped and the car is reversed; the drilling speed drops; the weight indicator pointer swings severely.
(3) The phenomenon of tooth grinding (stripping):
The load of the turntable is reduced; the kelly does not jump; the drilling speed is significantly reduced or there is no footage; the weight indicator indicates smooth and no swing; the pump pressure is normal.
Cangzhou Great Drill Bits Co.,Ltd., as an excellent oil and gas drill bit manufacturer, offers a wide range of drill bit for you to choose from
what is a pdc bit? PDC bit is the abbreviation of Polycrystalline diamond compact bit, also known as polycrystalline diamond cutting block bit or composite chip bit. Because of its advantages of fast drilling speed, long service life and high footage, PDC bits are widely used in oil drilling.
Structure Characteristics of Drilling PDC Bits
PDC bit is composed of the a bit body, PDC cutting teeth and a nozzle. According to different structures and drill bit manufacturing processes, the drilling PDC bits are divided into two series: steel body and matrix body.
The whole bit body of rigid drilling PDC bit is made of medium carbon steel and formed by the machine manufacturing process. Drill holes on the working face of the bit, and fix PDC cutting teeth on the bit crown by pressing in and tight-fitting. The crown of a pdc rock drill bit is treated by a surface hardening process (spraying tungsten carbide wear-resistant layer, carburizing, etc.) to enhance its erosion resistance. The main advantage of this kind of pdc rock drill bits is a simple pdc bit manufacturing process, but the disadvantage is that the bit body is not erosion resistant and the cutting teeth are difficult to be fixed, so it is seldom used at present.
The upper part of the pdc bit components is made of steel and the lower part is made of WC wear-resistant alloy. The PDC bit is made by powder metallurgy sintering process. The PDC cutting teeth are welded on the preformed groove of the carcass with low-temperature solder. Tungsten carbide matrix has high hardness and erosion resistance, so the matrix PDC bit has long service life and high footage, which is widely used at present.
Working Principle of PDC Drilling Bits
Drilling PDC drilling bit breaks rocks by cutting. The self-sharpening cutting teeth can easily cut into the formation under the action of WOB and move the shear rock forward under the action of torque. When multiple PDC cutting teeth work at the same time, and there are many free faces of the bottom rock, the rock is easy to be broken under the shear action. That’s way PDC drilling bit has higher rock-breaking efficiency ans faster drilling speed.
Correct Use of PDC Rock Bits
Diamond PDC bit has the best effect in large homogeneous soft to medium-hard formation. It is not suitable for drilling gravel layer and soft hard cross formation.
Before the PDC rock bit is put into the well, the bottom of the well shall be clean to ensure that there is no metal falls.
When the PDC rock bit is just put into the well, it should adopt small bit pressure and low rotation speed to run, andresume normal drilling until the bottom of the well is formed.
PDC drilling bit is an integral bit without any moving parts, suitable for high-speed turbo drilling.
Drilling PDC bits produced by Great Drill Bit, a leading pdc cutter manufacturer, are featuring good drilling effects like low WOB, high rotation speed and large displacement.
Cangzhou Great Drill Bits Co.,Ltd., as an excellent oil and gas drill bit manufacturers, offers a wide range of drill bit for you to choose from
The oil well drill bit is a widely used drilling bits adapting to a wide range of formations and featuering high drilling speed. The oil well drill bit is composed of more than 20 parts such as cutting structure, bearing structure, locking element, oil storage seal installation and nozzle installation. The current motor is repeatedly used in the wellbore, forming a front part of that has greater rigidity, smaller relative discharge area, and higher relative return velocity. The upper annulus is taken to form a vortex that affects the cuttings at the front. The formation of accumulation affects the drilling speed, and further formation of the repeated fragmentation of those cuttings by the PDC drill bit, which is easy to form a mud pack of the bit remover.
(1) The steel ball is used in the wellbit to lock the roller, suitable for relatively high speed.
(2) The O-ring seal adopts a wear-resistant, highly saturated nitrile rubber, which increases the cross-section of the seal ring. And the outer end of the seal area adds a small sealing boss to improve the sealing performance.
(3) The oil well drill bit uses high-strength and high-toughness alloy teeth, which improves the ability of resisting impact and reducing the probability of tooth breakage. Soft formations are inlaid with spoon-shaped teeth.
(4) The bearing of the palm of the oil well bit is covered with a layer of hard alloy, and there is also a silver-plated layer on the roller shaft to improve the anti-bite and load-bearing capacity.
(5) The oilfield bits use a grease that can withstand a temperature of 250°C, and low wear improves the ability of the drill bit.
(6) The optimized number of teeth of the oil well bit and the equipment such as exposed teeth and alloy teeth can uplift the bit cutting speed at a larger height.
Sometimes when you use a PDC drill bit for a long period of time, you will find it there is something wrong about it, like the follwing;
The footage is obviously slower or higher when drilling;
Increasing or reducing WOB has no obvious effect on drilling speed;
It has little effect on the drilling rate when the formation changes;
Drilling tool puncture and the circulation short circuit occur during the drilling, and the drilling speed obviously slows down after treatment.
The teeth of the drill bit cannot effectively penetrate into the formation, showing that the torque is reduced or the torque fluctuation range is reduced;
The phenomenon of “piston pulling” occurs during tripping and drilling.
Causes of PDC Bit Balling
Above phenomenon occurs because that your PDC bit is balling ,and here Great Bit, a professional drill bit manufacturer, listed four main reasons may cause balling of PDC bit:
Geological Factors:
The drilled stratum is soft mud with non-diagenetic upper part, which is very easy to stick to the surface of the drill bit, which will cause balling of the drill bit after compaction.
Although the shale in the stratum is diagenetic, it is easy to hydrate and disperse, making the mud or solid phase in the wellbore greatly increases, which is adsorbed on the surface of the drill bit and causes the bit balling.
Or the formation contains dispersed gypsum, which causes mud pollution, and the harmful solid phase in the mud is difficult to remove, which greatly increases the probability of formation of bit balling.
Under the action of the pressure difference, the harmful solid phase in the wellbore and the cuttings that are not carried out in time are absorbed to form a thick mud cake, which accumulates under the diamond PDC bit when starting the drill, causing the bit balling.
Mud Performance Factors:
Poor mud inhibition, unable to control the hydration and dispersion of shale;
Too high solid content and sticky cut, the drilled cuttings are difficult to remove and are easily adsorbed on the surface of the drill bit.
If a solid-free phase drilling fluid is used, the drill bits will never have mud packs;
The proportion of mud is too high, the water loss is large, and thick mud cakes are easily formed;
The lubrication performance is poor, the surface of the drill bit cannot form an effective protective film, and the inferior solids in the drilling fluid are easily adsorbed on the drill bit.
Engineering Technical Factors:
The drilling displacement is small, the bottom hole and the drill bit cannot be cleaned effectively, and the upward and backward speed is insufficient.
The cuttings stay in the well for a long time and adhere to the well wall to form a thick mud cake, especially in the upper part of the drill.
It is more serious when the speed is high; in the soft mudstone formation, the drilling pressure is too high, the formation or the drill cuttings and the surface of the drill bit form direct contact, causing the bit balling;
The long open hole drilling does not carry out halfway circulation, and the mud cake scraped from the well wall or drill cuttings will cause the drill bit balling.
Drill Bit Selection Factors:
The water eye design cannot meet the chip removal requirements;
The channel chip removal angle prevents the drilling cuttings from smoothly leaving the bottom of the well.
Cangzhou Great Drill Bits Co.,Ltd. 