Carbide containing cobalt is definitely a good choice.
Take the following measures: increase the top angle, grind the included angle between the two edges to 135-140, and increase the back angle at the outer edge of the bit to 12- 15. Trim the cross blade length by 0. 08 - 0。 1 to reduce the axial force of drilling. Cobalt titanium alloy drill is the best.
If a high-speed steel drill is used, the cutting speed is 7- 12m/min and the feed speed is 0.05-0.2mm/r; if cemented carbide is used, V = 25-60m/min and f = 0.050.15m/r. When drilling shallow holes, the cutting fluid can choose electrolyte, which 7%- 10% of boric acid, 3%-5% of sodium nitrite and the rest of water. When drilling deep holes, 30 # mechanical oil and kerosene can be selected, and the ratio is 3: 1 or 3: 2, and vulcanized oil can also be used.
Extended data
a little
In the process of drilling, the drill bit is the main tool to break the rock, and drilling is formed by the drill bit breaking the rock. Whether a well is completed or not and the length of time required are not only related to the characteristics of the rock in the drilled formation and the performance of the bit itself, but also related to the matching degree between the bit and the formation. Reasonable bit selection plays an important role in improving drilling speed and reducing comprehensive drilling cost.
Bit is one of the important tools for oil drilling. Whether the drill bit can adapt to the rock properties and its quality plays a very important role in the selection of drilling technology, especially in drilling quality, drilling speed and drilling cost. PDC bit is a widely used tool in oil and gas exploration and development industry, which effectively improves mechanical drilling tools and shortens drilling cycle.
introduce
Bit is the main part of drilling equipment, and its main function is to break rocks and form holes. Rotary drill bit is commonly used in petroleum industry at present. Driven by machinery, the rotary drill bit will rotate, which will drive the whole drill bit to move centripetally, and crack and break the rock through cutting and grinding, thus playing the role of downward drilling.
Bit is one of the main drilling equipment. According to the different working environment and regional environment, the specifications and shapes of drill bits should also be different. When using diamond oil, the drill bit should be selected reasonably and scientifically according to the specific needs and specific design scheme. Scientific selection of drill bit and reasonable determination of drilling fluid in specific drilling work can improve the efficiency and quality of oil drilling, make oil drilling play its own value better and make certain contributions to the development of petroleum industry.
Classification and selection
At present, there are many kinds of drill bits used in petroleum industry, which are based on different drilling methods.
According to the classification of bits, they can be divided into diamond bits, roller bits and drag bit, which are the most basic types of bits. Among these three kinds of bits, roller bit is the most common and widely used in oil drilling, and its application degree is also relatively deep. Comparing these three kinds of drills, drag bit has the smallest application range. This paper mainly introduces diamond bit and roller bit.
diamond
The cutting edge is a drilling tool made of diamond material, that is, a diamond bit. The main advantage of diamond bit is that it can adapt to the stratum with high abrasiveness and hard geology, and its cutting performance is also excellent. It has a very significant advantage in high-speed drilling.
According to the different strata, diamond bits can be divided into two categories: ordinary diamond bits and polycrystalline diamond compact bits. Among these two types, ordinary diamond bits are suitable for strata with high abrasiveness, hard geology and complex geology; Polycrystalline diamond compact bit can be widely used in hard stratum, soft stratum and stratum with moderate hardness, and its application range is very wide. The difference of blades is the main difference between these two kinds of diamond drills.
Polycrystalline diamond compact bit is mainly composed of four parts, namely diamond compact, nozzle, matrix and bit body; The common diamond bit is mainly composed of diamond particles, nozzle, matrix and bit body. Because of the excellent cutting performance of diamond bit, when diamond bit is selected as an oil drilling tool, it can drill at high speed and expand the drilling depth to a certain extent. In the process of drilling oil with diamond bit, we should pay attention to the following aspects:
First, the price of diamond bit is relatively high, so we should operate it carefully to reduce the damage;
Secondly, the diamond bit has some defects in thermal stability, so the cooling performance and clean conditions of the bit should be ensured when it is used;
Thirdly, its texture is brittle, so the impact resistance of diamond bit will be poor, and strict and standardized operation should be carried out in strict accordance with the relevant regulations of diamond bit.
Gear/gear
According to the structure, roller bit can be divided into five parts: water hole, bearing, palm, roller and bit body. If it is a sealed jet roller bit, it usually includes an oil storage compensation system. Generally, the thread will be in the upper part of the roller bit, and the drill string and thread are connected with each other. There will be a cone with three legs at the lower part of the drill bit. Roller cones will be installed on bearing shafts, and bearings will be installed between the bearing shafts and each roller cone. The cone will break the rock through its own cutting teeth.
The channel of drilling fluid is the water hole of the drill bit. In the process of oil drilling, through the transverse shear and longitudinal vibration during drilling, the roller bit will achieve the purpose of breaking the rock, thus improving the drilling speed.
When selecting roller bit as oil drilling tool, it is necessary to select roller bit according to the actual situation of drilling equipment, the actual situation of formation and the geological data and formation data of adjacent oil wells. When making a choice, you should consider the following questions:
First of all, we should consider whether there is soft and hard interleaving in the drilling formation; Secondly, it is necessary to consider whether deviation prevention drilling and curve operation are needed in oil drilling;
Thirdly, the actual depth of different drilling sections of the same oil well should be considered;
Finally, drilling geology, grindability and hardness of formation should be considered.
Diamond compact
PDC bit is a widely used tool in oil and gas exploration and development industry, which effectively improves mechanical drilling tools and shortens drilling cycle? .
PDC (polycrystalline diamond compact) is a kind of composite superhard material, which is made of diamond powder and cemented carbide matrix by ultra-high pressure and high temperature sintering. It has both the hardness and wear resistance of diamond and the strength and impact toughness of cemented carbide. It is an excellent cutting tool and wear-resistant tool material, and has been widely used in many fields, such as metal and nonmetal cutting tools, wood processing tools, oil and gas drills and so on.
It has been 35 years since the research and development of PDC and its application in oil and gas bit. During this long journey, many researchers have made outstanding contributions to it.
In terms of PDC research and development, Compax, which was announced by GE in 1970 and officially commercialized in 1972 ~ 1973, is of epoch-making significance. In 1976, the company launched a PDC series product-PDC for-Stratapax bit, which is specially used for oil and gas, to research and develop the bit.
Since then, many PDC manufacturing companies have also made great progress in technological innovation. Among them, PDC with thicker diamond layer and better impact resistance made by Synthetic in the United States entered the drilling market in the mid-1990s, which significantly improved the drilling effect of PDC bits. From 65438 to 0997, the company became the market leader.
China Zhengzhou Sanmoyu 1987 successfully developed PDC and gradually entered the drilling market. Although the product performance is not perfect, it has won the favor of China's nascent bit manufacturing industry at a very low price.
After 1992, Zhengzhou Xinya composite superhard material co., ltd was completed and put into operation, and the manufacturing technology of PDC was continuously improved, and the performance of PDC was greatly improved.
The development and application of PDC oil and gas bit can also be traced back to more than 30 years ago. The initial plane PDC bit design carried out by the Drilling Research Center of Tulsa University and GE Company in 1973 and many field drilling tests carried out in several major oil fields in the United States are of groundbreaking and milestone significance.
Since then, bit manufacturers have made unremitting efforts and continuous improvement in the design, manufacture and use of bits, which has made PDC bits widely popularized in oil and gas drilling and brought rich economic returns to PDC and its bit manufacturing industry and oil and gas exploration industry.
1985 Ishikawa-Christensen Diamond Bit Company was established by Sichuan Petroleum Administration Bureau of China and Christensen Company of the United States.
1994, Xinjiang Yidi Aisi Bit Tool Company was established by Xinjiang Petroleum Administration Bureau and secarity DBS Company of Halliburton Company. Both companies made use of the mature PDC bit manufacturing technology abroad, which effectively promoted the progress of PDC bit manufacturing and application technology in China and promoted the promotion and popularization of PDC bits in major oil fields in China? [6]。
Brief history of drill bit development
Before the PDC production technology was not mature, or before the PDC bit was just developed, some manufacturers used polycrystalline synthetic diamond without cemented carbide matrix to replace natural large-particle diamond to manufacture surface mount bits. Polycrystals have a variety of shapes, such as cylindrical, triangular block, disk, rectangular and one-end conical block, such as Geoset and Fomset of GE, Syndax3 of De Beers, TSP of Zhengzhou No.3 Rolling Mill, etc. Their * * * characteristics are high thermal stability, that is, resistance to1000℃ ~1100.
During the period of 1969 ~ 1975, several kinds of JR20SN-2 polycrystals with different diameters were produced in Zhengzhou No.3 Rolling Mill, which were first used to manufacture gauge impregnated drill bits and reamers, and then used to manufacture petroleum drag bit in mines below Grade 7, and were tested in Shengli Oilfield. Taking the same well with a drilling depth of 2400 meters as an example, the polycrystal and each well in cemented carbide drag bit and drag bit are compared. Compared with roller bit, polycrystalline drag bit saves more than 50% cost and shortens drilling time by 5 ~ 8 days.
In addition, geological coring bits, reamers and 2.5×5mm polycrystals made of 1.8×5mm polycrystals are used to protect the diameter of impregnated drill bits in metallurgy, coalfield and geology, and their effects are similar to those of natural diamonds.
Before the PDC independently developed by China failed in the early 1980s, 6×6mm polycrystalline was widely used in coring bits and watermelon peel all-around bits for oil and gas drilling. Triangular block polycrystals have also been widely used to manufacture coring bits or all-around bits in medium-hard to hard formations (such as limestone and dolomite) and slightly worn formations. After the large-scale production of domestic PDC in 1990s, polycrystalline synthetic diamond gradually withdrew from the drilling market and was completely replaced by PDC.
The development and application of PDC bit for oil and gas drilling have gone through a long time. The impact resistance of PDC bit in the early stage is not high, and there is delamination phenomenon. In addition, there are also problems in the design and manufacture of drill bits, and oil and gas drilling is very risky. The manufacturers of roller bits, which occupy a large share of the drilling market, are not active, so the development and application of PDC bits have encountered great difficulties and resistance.
During the period of 1973 ~ 1975, the PDC(Compax) produced by GE Company, with a thickness of 8.38×2.8mm and a diamond layer of 0.5mm, was used in the United States to weld the cemented carbide tooth column and then installed on a steel drill. A large number of original test data show that PDC can replace natural diamond for ground-mounted drills for drilling the hardest and highly abrasive rocks.
However, considering the structure and performance characteristics of PDC, and the oil and gas layers are mostly soft-medium hard layers, bit manufacturers have turned their attention to the oil drilling market with huge market prospects. The Drilling Research Center of Tulsa University participated in the preliminary design of the planar PDc bit, and carried out key tests on PDC itself. During this period, GE conducted four PDC bit tests in South Texas, Colorado, Utah and Upper Michigan, which exposed some problems in the design and manufacture of PDC columns and bits.
After the problems in the initial trial were solved, GE Company introduced Stratapax series products for PDC bit in February 1976, which improved the performance, had stronger impact resistance and was easier to fix on the bit body. At the same time, Diamant B0art Company has also conducted some successful PDC bit tests in the salt rocks in the Persian Gulf and the North Sea and East.man Christensen Company in the North Sea.
After the above preliminary exploratory tests, PDC manufacturers have made a series of improvements and innovations to PDC since the end of 1980s, which greatly improved the performance of PDC. With the prosperity of energy market and the continuous innovation of crude oil price, major drill companies and oil companies have actively developed a series of new PDC drills, which have improved the use effect and expanded the application field.
Since 1990s, from the point of view of bit hydraulics, by improving drilling mud, the bit mud pack in shale has been successfully controlled, and a breakthrough has been made in solving the problems existing in drilling shale interlayer. The biggest development of PDC bit is that Amoco discovered that the main cause of bit damage is bit rotation deviation (rotation), and then developed the design technology to prevent bit deviation. From the point of view of bit design, various bit manufacturers have adopted a series of design techniques to prevent bit deflection in order to minimize the degree of rotation deflection.
In addition, Eastman Christensen Company commercialized Amoco's deviation prevention products, adopted stable bit working device to reduce the serious deviation load that caused PDC damage during drilling, and formally introduced the anti-rotation deviation prevention bit, which is more beneficial in multi-layer (heterogeneous interlayer) rock drilling. In addition, the crown shape of the drill bit has changed from a plane shape to a watermelon skin shape with 3-8 or even more pieces (spiral).
Another reason for the continuous improvement and innovation of PDC bit is the development and application of more modern and complex computer data model system (CAD/CAM), which is combined with laboratory verification, thus increasing the guarantee of successful application of bit.
Due to the influence of PDC localization in China, the development of PDC bit is about 15 years later than that in the United States. In the mid-1980s, Jianghan Bit Factory, Drilling Research Institute of Dagang General Machinery Factory and Beijing Petroleum University began to develop PDC bits. 1985 Ishikawa-Christensen Diamond Bit Company and 1990 Xinjiang Yidibi Aisi Bit & Tool Company introduced foreign mature PDC bit technology and subsequent new technology, respectively, and adopted PDC with stable and reliable quality produced by GE, DeBeers and USS companies, all of which performed well in drilling.
It paves the way for the development and application of PDC bits in China and shows the bright prospect of PDC bits in the oil and gas drilling market. However, due to the high cost and high price of drill bit, its application is mainly promoted in Xinjiang oilfield and offshore oilfield drilling.
From 65438 to 0988, the low-priced PDC independently developed by Zhengzhou No.3 Mill was put on the market, which accelerated the pace of localization of PDC bits in China. A number of PDC bit manufacturers, such as Drilling Research Institute of Jianghan Bit Factory, Dagang Petroleum General Machine Factory, Shengli Oilfield Drilling Institute and Daqing Petroleum Administration Bit Factory, have appeared one after another, and all domestic PDC bits have been popularized and popularized in Daqing Oilfield, Zhongyuan Oilfield, Dagang Oilfield, Shengli Oilfield, Liaohe Oilfield and Jilin Oilfield.
Due to the unsatisfactory performance of domestic PDC in the early 1990s and the relatively low level of bit design and manufacturing in some bit manufacturers, the drilling effect is not satisfactory. Until Zhengzhou Xinya Composite Superhard Material Co., Ltd. was put into production, unremitting research and innovation were made in PDC manufacturing technology. The product specifications were consistent with those of foreign products, which improved the quality and reliability of products and basically met the technical requirements of domestic and foreign drill customers for drilling soft and medium hard formations. At present, the company is mainly committed to developing drill bits suitable for hard formations, interlayers and hard formations.
In addition, in terms of bit manufacturing, besides Ishikawa-Christensen Diamond Bit Company and Xinjiang Dipi Aisi Bit Tool Company, a number of high-quality bit manufacturing companies have emerged, such as Chengdu Best Diamond Bit Company, Wuhan Yida Tool Company, Chengdu Dipi Diamond Bit Company and Sichuan Ishikawa Diamond Bit Company. It is believed that in the near future, with the improvement of PDC quality and the improvement of bit design and manufacturing level, the use effect and application field of domestic PDC bits will make great progress.
At present, in the world drilling market, there are four well-known companies that dominate the manufacturing technology and output of drill bits: Baker Hughes, DBS (Secarity DBS of Lihai Burton Company), Smith International and Hycalog Tool—Reed.
Reference source: Baidu Encyclopedia-Diamond