Development Status and Optimization Path of Oilfield Fracturing Technology
1. Brief description of oil field fracturing technology
In the oilfield development stage, for oil and gas reservoirs with complex geology, low permeability, and low porosity, to further improve the oilfield production efficiency, most mining companies will use fracturing technology to complete oilfield production tasks. In areas with low porosity and permeability and relatively large burial depths of oil and gas resources, the effect of fracturing technology is significant due to other mining technologies. In addition, with the continuous advancement of fracturing technology, water-based fracturing fluids have emerged, which can not only reduce the frictional resistance of fracturing fluids but also improve the working efficiency of fracturing pumps. However, since the research and development of fracturing fluid are still in their infancy, the application effect still needs to be further tested.
To meet the development needs of my country's oil fields, my country has successively purchased fracturing units and equipment from foreign countries, and fracturing technology has also developed rapidly in my country. With the continuous acceleration of my country's economic and scientific and technological development, my country's fracturing technology is also quite mature. Whether it is fracturing technology or fracturing fluid research and development, there has been a leap forward than ever before.
2. Status Quo of Oilfield Fracturing Technology
1. Shot avoidance technology
In the early stage of Bonan Oilfield development, after analyzing the radioactive logging curves and the good temperature curves of multiple oil wells, it was found that there was a lack of good fractures in the oil layers, and most of the fractures occurred in the underground interlayers, which increased the difficulty of oil production. In addition, after analyzing the sonic logging parameters, it is found that there are differences in the geological conditions between the interlayer and the oil layer. The harder geology is mostly distributed in the oil layer, and the geological hardness in the interlayer is smaller than that in the oil layer so that the fracture-making phenomenon is manifested in the interlayer. It is more obvious, and the thickness of mudstone is relatively small in the interlayer, which hinders the tendency of fracture extension and strengthens the fluctuation of fractures accordingly.
Therefore, mining companies need to use fracturing and shooting avoidance technology, that is, take measures to prevent the interlayer from being squeezed apart, and ensure that the upper and lower parts of the underground oil layer can avoid shooting for a certain distance. After using the shot avoidance technology, the fracture height can be well controlled, and the oilfield production efficiency and production are significantly improved. When applying shot avoidance techniques, pay attention to the following:
①If the thickness of the mudstone interlayer is small and the strength is low, and the lithological strength of the underground oil layer is high, the shot avoidance technology can be used at the bottom and top of the underground oil layer respectively. In addition, if the flat mudstone cannot limit the fluctuation of fractures due to its small thickness, the shot avoidance technology can be used directly on the top and bottom to improve the oilfield production efficiency, which has a significant effect on increasing production.
② When using fracturing technology, due to the high permeability at the bottom of underground oil and gas reservoirs, mining companies should measure the thickness of the bottom of underground oil and gas reservoirs, and use water flooding to increase production in the process of developing the bottom. During the fracturing construction stage, the cracks can be moved down through continuous cracking, which will cause the mudstone interlayer with a certain thickness to be pressed open, reducing the difficulty of oil extraction.
2. Pre-liquid treatment technology
If there is a high fracture pressure in the oil production block, the oil production unit needs to use acid substances in the pretreatment process, and then the fracturing construction can be officially started. Before construction, squeezing acidic substances into the wellbore can help reduce the fracturing pressure, which can be reduced by up to 6MPa, and can dredge the wellbore, improve the seepage effect of the channel, and reduce the difficulty of fracturing construction.
3. Current-limiting fracturing technology
The application of current-limiting fracturing technology can adjust the number of perforations in the subterranean layer so that there is a certain difference in the pressure difference of each hole in the subterranean layer, which is helpful to increase the injection volume of fracturing fluid and improving the performance of surface fracturing.
