Based on the geological characteristics of the shale oil in the Kong 2 Member of the Cangdong Sag, Dagang Oilfield, and a large number of core experiments and numerical simulations, the displacement and single-stage liquid volume of the fracturing construction were simulated and optimized; in the stratigraphic shale and stratified mixed shale, the reverse mixing mode is adopted, that is, the gel is used for the rock-breaking seam, and then the low-concentration low-damage fracturing fluid system is used to form the complex seam net. Finally, the high-conductivity-producing area near the well is formed by the addition of sand and gel, forming a personalized horizontal well-cut volume fracturing technology in Dagang Oilfield. The application of this technology in shale oil shows that the output of horizontal well is stable after dense cutting volume fracturing, and industrial development can be realized. Microseismic and stable electric field monitoring confirmed the formation of complex network cracks, and achieved significant yield-increasing effects, providing a reference for the efficient exploration and development of China's continental shale oil.

The conductivity of supporting fractures is an important parameter to evaluate the hydraulic fracturing effect of shale reservoirs, and its size is affected by many factors. In this paper, the proppant is optimized and evaluated on the basis of real rock slab simulation and actual construction proppant test. The laboratory experimental study on the influence of proppant type, sand concentration, proppant embedding and fracturing fluid residue on propping fracture conductivity is carried out, the results show that the average conductivity of 40 / 70 mesh proppant is about 7.15d · cm at 5kg / m2 sand concentration under the condition of reservoir closure pressure of about 50MPa, which can basically meet the requirements of main fracture conductivity of Kong 2 shale reservoir in Dagang Oilfield; the damage of guar gum fracturing fluid and proppant embedment are two important factors that cause the great decline of conductivity of rock slab, and the damage of guar gum fracturing fluid has a great influence on the conductivity, reaching about 50%; the stronger the mud is (the higher the clay content is), the greater the embedment degree of proppant is, and the greater the loss of conductivity is; for the same lithology, the proppant particle size has little damage to the conductivity, and the sand concentration has a greater impact on the conductivity. The larger the sand concentration is, the smaller the loss of the conductivity is.

W27 oilfield is a multi-layer heterogeneous low permeability reservoir, which has entered the middle and late stage of development. The main reservoir is flooded seriously, and the remaining oil distribution is complex. If conventional fracturing technology is adopted, the risk of longitudinal fracture communication with water layer or water-flooded layer is high, which is easy to cause high water cut after fracturing and affect the fracturing effect. According to the characteristics of fractured well reservoir, the hydraulic injection fracturing technology is optimized to optimize the position of injection point and fracturing process parameters, avoid pressing water layer, and achieve accurate reconstruction of potential reservoir. The technology was applied to 4 Wells on site, and the average daily oil gain per well was 6 tons and the average accumulated oil gain per well was 2,500 tons. Hydraulic injection precision fracturing technology has an obvious effect on water control and oil increase in W27 oilfield, which has an important guiding significance for similar reservoirs to improve the fracturing effect.