Since the 1990s, in order to enable China's oil industry to meet the growing needs of the national economy, Shandong Walsh Petroleum Equipment Co., Ltd. has also set a grand goal of developing the petroleum machinery industry. The country has proposed a development strategy of "utilizing both domestic and foreign resources and developing both domestic and foreign markets.". According to these two development strategies and the guidelines of "stabilizing the east and developing the west", "developing both oil and gas, tilting towards gas", and "developing blue land and developing offshore oil", China's oil drilling rigs have made significant improvements and development in terms of standardization, technology and manufacturing levels, research and development capabilities, product quality, and varieties. This article mainly introduces the development and application status of domestic oil drilling rigs.

AC variable frequency electric drive oil drilling rig

AC frequency conversion speed regulation electric drive oil drilling rig (AC GTO AC oil drilling rig) is an advanced electric oil drilling rig newly developed abroad. This type of drilling rig has unparalleled superior performance in meeting the requirements of oil drilling technology compared to current mechanical drive drilling rigs and DC drive drilling rigs. The core technology of this drilling rig is the adoption of AC frequency conversion speed regulation technology. AC variable frequency speed regulation technology is a comprehensive cross technology involving motor theory, automatic control theory, circuit topology theory, power electronics technology, microelectronics, and computer technology. Experts believe that AC variable frequency electric drive drilling rigs are an organic combination of modern high-tech and oil drilling machinery, with strong vitality, and are the development trend of contemporary oil drilling rigs.

In recent years, due to the rapid development and application of the above technologies and self turn-off full control technology, pulse width modulation (PWM) technology, motor control technology, vector control technology, and direct torque control technology, the rapid development of AC frequency conversion speed regulation technology has been promoted. The AC frequency conversion dispatching capability has fully met the requirements of oil drilling technology for the speed regulation performance of the drilling rig drive transmission system.

In order to make the fixed power frequency (50I-Iz) output from the oilfield power grid become a variable frequency, rectification technology is usually used to convert the power frequency into DC through rectification, and then inverter technology is used to convert the DC into adjustable AC. The original use of non self switchable semi control devices requires forced commutation to achieve inversion, while forced commutation requires an auxiliary DC power supply. The power supply devices, inductors, and capacitors used for commutation cause problems such as large volume, increased investment, high commutation losses, low inverter efficiency, poor reliability, and difficulty in adopting pulse width modulation technology due to the low switching frequency of the semi control device. After the application of turn-off fully controlled technology, due to the superior performance of turn-off devices that do not require auxiliary commutation circuits, the fully controlled devices have high switching frequency, high reliability, voltage control, low driving power, and easy implementation of driving circuits, a series of problems caused by the use of non turn-off semi controlled devices in the inverter circuit have been overcome. The application of PWM technology reduces the torque ripple and harmonic components of the motor, meeting the power supply requirements of AC motors. In addition, PWM technology adjusts the output frequency and voltage simultaneously by controlling the width of the output voltage pulse and adjusting the amplitude of the output AC voltage while adjusting the frequency. Vector control technology decouples the three-phase quantities into excitation components and torque components similar to those of a DC motor through 3/2 conversion of the three-phase motor, and controls the quantities independently. After 2/3 conversion, the three-phase quantities are converted into AC powered three-phase quantities to control the motor, ensuring the linear relationship of torque control, thereby achieving the control characteristics of a DC motor. With the development of microelectronics and computer technology, French companies such as AL-STON have introduced mature vector controlled AC converters and successfully applied them to oil drilling systems. The AC variable frequency oil drilling rig produced by ALSTON Company represents the first-class level of AC variable frequency drilling rigs in the world today. The drilling rig control system is distributed, and its main control system can process various operating instructions in real time, monitor the operation of each subsystem, timely handle faults, exchange data with each subsystem through the network, and complete information exchange with the outside world through the Internet. The drilling rig has the following subsystems: torque control system (top drive or rotary table control system), brake control system, balance control system, traveling block control system, filling control system, drilling pump, and energy feedback control system. Each subsystem and the master control system jointly implement advanced control strategies. Each subsystem adopts closed-loop system control, and each subsystem has intelligent and adaptive functions. Each subsystem ensures the optimal operation of the drilling rig under various complex working conditions through various algorithmic programs. For example, the structure of the torque control system is: AC motor, AC frequency converter, programmable controller (ALSPAl800k photoelectric encoder). When the system is closed loop, this control can ensure the stability of the drilling tool, reduce drilling tool vibration (soft torque control), and ensure that the drilling tool achieves full torque output at zero rotational speed, At the same time, real-time data/command/status transmission with the main control system is implemented to achieve on-site control. The distributed control system of the drilling rig is easy to operate. High precision, high reliability, artificial intelligence, automation, and controllability. When the control system of the drilling rig is running, the driller can understand the changes in various parameters through a TV display (video, graphical interface), and conduct real-time self inspection of the working status of each system. When a fault occurs, it can give an alarm in a timely manner. At the same time, it can detect the subsystem and module code where the fault occurs, and perform intelligent hierarchical processing of the fault at the same time. In the event of a serious fault, the auxiliary system can be automatically started to ensure the normal operation of the drilling rig, and at the same time, the system can be quickly recovered according to the fault code.

Due to the superior performance of AC GTO AC oil drilling rigs, foreign drilling contractors have developed AC GTO AC oil drilling rigs. From the second half of 1997 to September 1998, many offshore platforms in the British North Sea oilfield selected AC frequency conversion oil drilling rigs, and the DC drive devices of many platforms have been converted to AC drive. In the first half of 1998 alone, ALSTON's CEGELEC BAUTAIL DIVISION subsidiary in the United Kingdom undertook five sets of AC GTO AC oil rigs from Schlumberger Oil Company, and was also responsible for the transformation of the North Sea platform AC SCR De rigs.

Compared with mechanically driven oil rigs and AC SCR DC oil rigs, AG GTO AC oil rigs using AC frequency conversion and speed regulation technology have outstanding characteristics.

Laser oil drilling rig

According to information, the United States plans to use laser drilling in the 21st century. The Chicago Institute of Natural Gas Research (GRI), in collaboration with the Colorado Institute of Mines, the Massachusetts Institute of Technology, the Redwood Company, Phillips, and the United States Air Force and Army, has jointly conducted a research project on laser drilling rigs, which was completed around 2000. Richard K, the main technical director of GRI, said that laser drilling will revolutionize oil and gas drilling in the 21st century. Laser drilling will bring about a complete technological breakthrough like rotary drilling replacing conventional drilling at the beginning of this century. The advantages of laser drilling technology are: it can reduce drilling costs, improve mechanical penetration rate, improve well control, and reduce the average working days of the drilling rig, bit wear, and trip time. Laser drilling can accurately control the wellbore, and can form a hard glass coating around the wellbore, minimizing or eliminating concentric casing.

The laboratory research work for this project will be completed in the High Energy Laser System Laboratory of the United States Army and the Directional Energy Laboratory of the United States Air Force. The test will use two powerful and effective high-energy lasers developed by the US Department of Defense's Star Wars program.

One is a Medium Infrared Advanced Chemistry (MIRACL) megawatt level laser. The energy emitted by the laser can penetrate tactical and strategic targets several miles away, and can burn through soft rock, mineral, and solid materials. Phillips uses a MIRACL laser to conduct drilling tests. The laser beam can penetrate a 60mm thick sandstone shale sandstone interlayer within 1 second, with a penetration speed of at least 100 times that of current conventional drilling.

The other is a chemical iodine oxide laser (COIL), which is a high-energy laser used for air to air defense and can track and destroy missiles. Using this laser for drilling and completion with a depth exceeding 4500m can solve problems such as well control, sidetracking, and directional drilling. Due to its high accuracy, wide range, high output power, and ability to couple in optical fibers, COIL is suitable for drilling deep oil and gas wells with low cost. GRI claims that there are also two types of lasers: a high-energy discharge coaxial iodine laser, which is used to study the effects of laser beams on various materials in various environments; The other is an LDD laser, which is used to study the relationship between intense laser light and different soft rock minerals. LDD has been conducted for 4.5 × More than 104s of laser material testing, and the operating cost of LDD is relatively low. GRI experts believe that the research on laser drilling will promote the development of downhole laser drilling machinery, laser drills for drilling conventional and slim hole wells (coiled tubing), laser perforating tools, sidetracking, and directional laser drilling tools.

New type hydraulic oil drilling rig

In the early 1990s, Norwegian Mari Time Hydraulic Equipment Company and BP jointly developed a new type of hydraulic oil drilling rig. The drilling rig uses a hydraulic cylinder as the lifting mechanism, eliminating conventional equipment such as a winch, derrick, and traveling block. The entire drilling rig is composed of dual hydraulic cylinders, a floating yoke, lifting wire ropes, a balancer assembly, a hydraulic cylinder guide frame, a top drive device, and hydraulic systems.

The double acting hydraulic cylinder is supported by a separable flange on the drill floor. After the flange is removed, the holes in the platform can allow the hydraulic cylinder to descend through or undergo maintenance. The piston rod is coated with a corrosion resistant, wear resistant, and durable ceramic layer.

The traveling yoke is composed of a yoke body, 4 pulleys with a diameter of 2.8m, and 2 guide seats. The guide roller moves on the guide rail of the hydraulic cylinder guide frame, and the piston rod is fixed at the top of the guide seat. The main body of the traveling yoke is equipped with a pulley, which is pinned to the high position of the guide seat. The shaft on the pulley is positioned at the bottom of the yoke main body to ensure the balance of the entire assembly. Even during acceleration or deceleration, even when the stroke speed is uneven, it can ensure the stable guide of the piston rod, which allows the hydraulic cylinder force to maintain balance in the new position of the yoke main body under uneven conditions. Four large diameter pulleys slide on the double roller bearings of the shaft. The pulley groove can accommodate two steel ropes, and a groove can accommodate hoses or cables for top drive devices. This not only solves the problem of hanging hoses on the derrick, but also improves the hydraulic conditions of the drilling fluid after the removal of risers and goosenecks.

Eight lifting steel wire ropes, fixed in length, arranged in parallel, with one end connected to the top drive device (to cancel the traveling block) and the other end connected to the balancer assembly on the drill floor. This assembly is used to compensate for the imbalance in the action of the hydraulic cylinder. Absorb the uneven elasticity of each rope to ensure uniform load. The breaking safety factor of steel rope is 4.0~4.5.

The hydraulic cylinder guide replaces the tower (or portable) derrick. This frame only serves as a guide and is not intended for lifting. It has a square hollow section and is welded by overlap welding. The guide rail is also on the guide frame, so there is no need to leave a safety gap, and there is no problem with the traveling block traveling to the crown block or drill floor in the past.

The top drive device is the same as the conventional one, with two exceptions: the lifting bail is connected with a chain, and the goose tube for feeding drilling fluid is facing upward to allow the hose to enter through the upper pulley.

The hydraulic system has four pumps that can be driven by electric motors or diesel engines to provide lifting capacity, but only 1/4 of a constant speed, saving power. The brake is controlled by a throttle valve at the bottom of the hydraulic cylinder. The accumulator is an important component of the main circulation system, which has sufficient capacity to handle volume changes, and has sufficient lift pressure and maximum speed during riser lift.

Hose oil drilling rig

As early as the 1950s and 1970s, foreign countries began to develop hose drills and apply hose drilling technology to drilling, but the actual industrial application was still in the early 1990s. In 1991, Oryx Energy Company of the United States drilled a 1062m horizontal well in Texas using a 2-inch continuous hose and downhole motor; In 1992, Dawell Company of the United States drilled a 1274.7m long well in the Paris Basin, France, using a 13/4-inch continuous hose and a 31/16-inch mud motor. Due to the superiority of hose drilling technology and the development and progress of related supporting technical equipment, it has maintained a strong and rapid development momentum since the 1990s.

According to the statistics of CTES (Continuous Hose Engineering Company of the United States), in 1991, 4 wells were drilled using continuous hose drilling technology, 14 wells were drilled in 1992, 30 wells were drilled in 1993, 150 wells were drilled in 1994, 356 wells were drilled in 1995, 410 wells were drilled in 1996, and 600 wells were drilled in 1997. In addition, Shell British Exploration and Production Company successfully sidetracked at a vertical depth of 3860m in the North Sea using hose drilling technology in 1997, A record has been created for the maximum vertical depth of sidetracking using hose drilling technology. Currently, countries around the world that apply hose drilling technology to drilling include the United States, Canada, France, the United Kingdom, the Netherlands, and other countries, among which the United States and Canada are the most active countries that apply hose drilling technology to drilling.

The reason why the hose drilling technology has developed so rapidly is mainly due to its outstanding advantages and the technological progress of hose drilling equipment and tools since the 1990s.

New development of continuous hose drilling equipment in recent years

In recent years, American companies such as XL and TSL have developed an electric continuous hose drilling system - electric downhole drilling tool assembly. This drilling tool assembly uses an electric submersible pump motor instead of conventional screw drilling tools. In order to reduce the rotational speed of the output shaft and better adapt to the drilling environment, the electric submersible pump motor is connected to a planetary gear transmission box. The motor is controlled by a computer on the ground connected to a variable speed drive. The developed control software can collect and record real-time drilling data from the motor, provide practical drilling information for technical personnel such as the driller, and improve the feedback and control ability of the drilling process. The drilling tool assembly consists of a continuous hose connector, a lubricating oil compensation system, an electric motor, a transmission box, a rotary sealing device, and a bearing set at the lower end of the drive shaft. The power of the drilling tool assembly is provided by a computer-controlled ground variable speed drive. The driller monitors the rotation speed of the drill bit through a computer display screen and calculates torque based on the motor current and the rotation speed of the drill bit. Various parameters can be quickly converted and changed according to the requirements of the drilling environment. This electric continuous hose drilling system has successfully passed the test and has shown the following characteristics:

The ultimate goal of the electric continuous hose drilling system is to develop a fully automatic drilling system that integrates downhole measurement and geological guidance.

Casing drilling rig

Casing drilling is a new drilling technology, known as one of the leading drilling technologies in the 21st century. The casing drilling rig, which is compatible with the casing drilling process, cancels the conventional drill pipe and uses casing instead of drill pipe for drilling. Since 1995, Tesco has developed a new type of drilling equipment for casing drilling - the casing drill. The drilling rig is mounted on a trailer and uses an electro-hydraulic driven top drive device to transmit torque through the casing and drive the drill bit installed on the bottom of the casing to rotate for drilling. The drill bit is fixed to the front of a special drilling tool set, which is locked at the bottom of the casing and connected to the special winch for lifting and dropping the drill bit on the drill floor with a steel wire rope. When it is necessary to change the drill bit, the locking device is opened, and the drill tool is lifted out using the winch. After replacing the new drill bit, the drill tool is sent to the bottom of the well using the winch, which is locked at the bottom of the casing. The operation is very convenient and rapid. Casing drilling