In order to clarify the main principal factors that affect the initial productivity during the development of shale oil reservoirs

a comprehensive data analysis method involved both the hierarchical cluster analysis and the principal component analysis in data statistics is presented; and then the deta of the static formation parameters

fracturing operation parameters and the oil productivity of 51 wells in Block Li-151 are analyzed quantitatively. At first

the wells in the block are divided automatically into two types

Type A and Type B

by the hierarchical cluster analysis method. Then

a principal component analysis method is used to analyze the principal productivity factors for different types of wells. Analysis results show that

when the well shut-in time is less than 125 days

the oil production decline rate can be reduced effectively by the well shut-in measures; however

when it is greater than 125 days

the effect of well shut-in measures on oil production decline rate becomes negative. The production decline rate of Type A wells is highly negative with the amount of injected fracturing water; the main principal factors for the production decline rate of Type B wells are the moving liquid level and the porosity of shale matrix. The principal factors for the production rate of Type B wells are the number of fracturing sections. All in all

for the production optimization of shale oil development in Block Li-151

the differences of principal production factors between Type A wells and Type B wells should be considered and the different analysis results of the principal factors that affect the initial shale oil productivity under different well types should be fully utilized. Some guidance can be provided specifically for the formulation of a reasonable shale oil efficient development plan.