1.introduction
Fracturing is one of the most common ways to increase production in shale oil and gas development. By injecting high pressure fluid into the oil-bearing rock layer, cracks are created in the rock layer, so that the previously unrecoverable oil and natural gas resources can be safely discharged. Once a shale oil and gas resource is found in an area, the drilling team first works on the site, and then the rig is built to drill, log, cement and perforate the well.
When all of this is done, the fracturing process begins, which is done by injecting fracturing fluid into the well. There are many types of fracturing fluids, and the treatment method is appropriate for the specific situation. The existing fracturing equipment is mainly divided into two kinds: wood drive and electric drive. The conventional driving mode has the problems of environmental pollution, high noise and low power density, but the electric drive fracturing is better than the traditional wood drive in environmental protection and economy. FGI Company proposed a set of system schemes for variable frequency speed regulation and gas turbine power generation and energy storage suitable for fracturing sites. The system schematic diagram of fracturing construction sites is as follows:
2. Overview of electric drive control systems
Main loop structure
skid in fracturing site, a design scheme of one tow and two main circuits is proposed. The frequency converter can run separately, and can pull two motors separately, and can also run in parallel, and pull a larger motor, which greatly improves the flexibility of the frequency converter and the pump.
3.Gas generator and high pressure energy storage system.
(1)The energy storage system is applied at the fracturing site
Shale oil is distributed in remote areas, such as basins and mountains, where electricity is often unavailable. Therefore, in fracturing construction, gas turbine is usually used to generate electricity, and natural gas can be generated by LNG, CNG and other gas supply methods. Compared with conventional diesel generators, gas turbine has the characteristics of small size, light weight, large single power and less pollution. In order to improve the reliability and stability of the power supply in the fracturing operation area, promote energy conservation and environmental protection, and support the development of clean energy, high voltage energy storage devices play an important role in the fracturing site.
(2)High voltage energy storage system architecture.
High voltage energy storage system mainly includes battery, EMS system, BMS, energy storage converter and so on. At present, the lithium iron phosphate battery is used in the high-voltage energy storage device, which is composed of a group of battery packs, and then the battery PACK is formed in different combination forms. EMS is an important part of the power system, it plays an important role in the power system. BMS system is also a battery management system, its role is to carry out intelligent management and maintenance of each battery unit, avoid overcharge and overdischarge of the battery, thereby improving the service life of the battery, and monitoring the status of the battery. Energy storage converter (PCS) is a conversion device between power grid AC and battery DC, AC/DC is the charging process, DC/AC is the discharge process.
4.TAG
Electric drive, fracturing is the inevitable direction of the future development of fracturing industry, FGI with its self-developed frequency control and energy storage system, the application in the field of fracturing is becoming more and more mature. Through the continuous field application, the energy saving and emission reduction of China's shale gas fracturing industry will be strongly promoted. Create fracturing equipment with wisdom and cast fine products with heart. The continuous innovation of business mode is a strong driving force for the development of new scenery, making it a leader in the industry in high quality and high-quality service.