Based on the development practice of volumetric fracturing in shale oil horizontal wells in Ordos Basin

and the method of combining laboratory research and field production data analysis

the paper systematically summarizes the overall production decline law of shale oil horizontal wells and differences in the estimated ultimate recovery (EUR)of single well in different types of reservoirs

as well as the variation patterns of water content

salinity

pressure

gas-oil ratio and liquid production in horizontal well intervals during different development stages. On this basis

a production system featurin

g "reasonable shut-in periods to promote reservoir equilibrium

controlled flowback for sand control in early stage

and pressure-stabilized production to preserve reservoir energy" has been developed

along with a suit of remediation technologies and processes including "sand washing

wax removal

scale removal

gas content control

and eccentric wear prevention". Under the primary energy replenishment development in shale oil horizontal wells

Type Ⅰ and Ⅱ

1

reservoirs demonstrate the average estimated ultimate recovery (EUR)of over 3.0×10

4

t and approximately 2.4×10

4

t per well

respectively

achieving economically viable large-scale development. Besides

in response to the problem of low single-well production in mid-to-late development stages of shale oil horizontal wells and the demand for enhanced oil recovery (EOR)

the method of refracturing in existing horizontal wells in mature areas to create new fractures is proposed to increase EUR and EOR of single well

which is built based on preliminary field implementation analysis in combination with numerical simulation studies on reservoirs

and is predicted to increase the recovery rate by more than 5 %.