Drilling Tools

Drilling tools mainly include wellhead tools and downhole drilling tools. Wellhead tools are tools for lifting and unloading drilling tools, such as tongs, elevator and slips. The tongs are used to load and unload threads of various downhole drilling tools. The elevator is used to hang, lift and lower the drill string. The slips are used to catch the drill string and hang on the rotary table.

Introduction of drilling tools

Including drill bits, drill strings, downhole power drilling tools, stabilizers, shock absorbers, jars and other tools.

Drill bit drilling essential rock crushing tools, mainly cone bit, diamond bit and drag bit 3 categories:

① Cone bit consists of drilling method bit body, claw, cone, bearing, water eye, etc. According to the cone structure, it is divided into two types: milling tooth type and insert tooth type. According to the bearing structure, it is divided into sealed (or not sealed) rolling bearing and sealed (or not sealed) sliding bearing. The cone bit is suitable for drilling various formations and is currently the most widely used.

Diamond bits, initially limited to hard formations, are expanding their variety and scope of use. Although the price of the drill bit is high, it has a long working life. If it is selected reasonably, it can achieve better economic results.

The scraper bit has simple structure, convenient manufacturing, and fast drilling speed in soft formations, but the torque is large when drilling, and it is easy to damage the drilling tools and equipment. In recent years, a new type of cutting bit is being developed, which is embedded in the bit matrix with new wear-resistant materials of different geometric shapes, which can adapt to various lithologic formations and can be drilled at high speed, and its economic effect is becoming more and more significant.

The general term for all downhole drilling tools from kelly to drill bit, consisting of kelly, drill pipe, drill collar, stabilizer joint and other accessories. Its function is to trip the drill head, transfer the mechanical energy required to break the rock to the drill bit, apply bit pressure to the bottom of the well, deliver flushing fluid to the well and perform other downhole operations.

The downhole power drilling tool is connected to the lower end of the drill pipe and runs into the power machine at the bottom of the well together with the drill pipe.

There are mainly turbine drilling tools, screw drilling tools and so on.

① The turbine drilling tool uses high-pressure liquid flow through the turbine to convert the liquid energy into mechanical energy on the central shaft and drive the drill bit to break the rock. It consists of hundreds of pairs of turbine stators and rotors installed in series in the housing, as well as bearings and central shafts. The blades of the turbine stator and rotor are bent in the opposite direction. The high-pressure mud flows along the deflection direction of the stator blades, forcefully impacting the rotor blades, causing the rotor to drive the central shaft to rotate. Turbodrills are the main drilling tools adopted by the Soviet Union. They have developed new turbodrills with various performances, which are widely used in drilling work at various depths and formations (including 10,000-meter wells that have been drilled), and other countries are also developing.

② The screw drilling tool passes through the stator and rotor channels by high-pressure mud, and drives the rotor to rotate in the stator spiral channel, generating torque and driving the drill bit to break the rock. It is composed of a spiral rotor installed in the housing, a rubber stator bushing with a spiral channel, a rotating shaft, and a bearing. It is a positive displacement downhole power drilling tool, its speed is proportional to the pump displacement, torque is proportional to the pump pressure, bit pressure, through the pump pressure can indirectly indicate the bit pressure. Due to the low speed, the use of roller cone bit drilling is more advantageous.

Other Tools

The stabilizer, commonly known as centralizer, is connected to the lower BHA of the drill string to prevent well deviation or directional well drilling and facilitate the smooth operation of the bit.

Drilling Tools

Shock absorbers are used to absorb shock and vibration loads generated during drilling to increase the service life of drill bits and other drilling tools. The key components are different types of shock absorbing elements.

The jar is a tool that can accumulate elastic energy to produce shock when the drill string is stretched elastically under tension. It can be used to deal with sticking accidents and is conducive to safe drilling.

Fishing tools are special tools used for fishing down-hole objects and handling down-hole accidents. Commonly used fishing tools include male cone, female cone, overshot, fishing spear, fishing basket, magnet fishing device, grinding shoe, safety joint, etc. In case of sticking accident, the sticking point shall be measured with the card tester, and then the screw thread of the stuck drilling tool shall be loosened by explosion. This method is very effective to deal with the sticking accident.