Shale oil is a tight reservoir and has low conventional fracturing production, it is difficult to achieve efficient development. As a new technology, multi-stage multi-cluster fracturing engineering technology has become an important measure to increase production of shale oil and low permeability reservoirs, and is an important means to realize the economic development of shale oil. Multi-stage multi-cluster fracturing has large scale and costs, so it is important to evaluate and analyze the effect. Well testing technology is an important means to determine the fracture half length, fracture conductivity, formation permeability, formation pressure and so on. It has been widely applied for its low cost and simple process.

There are many researches on conventional fracturing well test technology at home and abroad, and the well test method is relatively perfect, but the research on large volume staged fracturing well test technology in shale reservoir is still in the initial stage, the understanding of seepage characteristics is not deep enough, and the mature interpretation method has not been formed. Research and development of well test evaluation technology for fracturing effect, determination of fracture half length, fracture conductivity, formation permeability and formation pressure in the reconstruction area become important problems to be solved for fracturing design optimization and efficient development.

Aiming at the multi-stage fracturing technology of horizontal wells in the development process of shale reservoir, the wellhead pressure drop model of multi-stage volume fracturing and single-stage fracturing is established. The main technical contents include:

Study on the establishment of physical model and mathematical model of single-stage fracturing evaluation, study on the theoretical method, study on the solution method of mathematical model, and establish the pressure response characteristic curve.

By analyzing the influencing factors of pressure response characteristics, the main controlling factors of pressure curve shape characteristics were identified, and the analysis chart was established.

Research on conversion method of wellhead-bottomhole pressure, calculation method of wellbore vertical pipe flow under variable flow rate, variable density and variable viscosity; mathematical solution of complex vertical pipe flow equation; research on elimination method of pressure data fluctuation caused by water hammer based on filtering theory.

The influence of wellhead pressure accuracy and stop pump time on the corresponding characteristics of the model is analyzed.

Study on inversion of measured data and formation parameters method.