Bohai LD5-2 heavy oil reservoir has strong heterogeneity and low rock cementation strength. It has formed a dominant channel due to long-term water injection. At present

it is difficult to meet the requirements of greatly improving oil recovery by single profile control

flooding or oil displacement measures. The combined use of profile control

displacement and other measures has become a new way to solve this bottleneck. In order to meet the actual demands of LD5-2 reservoir

in-room experimental study of profile modification measure of “profile control+profile modify+oil displacement” is carried out by the longitudinal three-layer heterogeneous core and a new model of “injection and production separately” and the means of electrode measurement. The results show that

compared with the vertical well network

the hydraulic pressure difference of the mid-low permeability layer is larger after the horizontal well network profile adjustment

the effect of expanding the spreading volume is better

and the recovery rate increases by 28.50 %. For the heterogeneous cores

the remaining oil in the longitudinal direction is mainly distributed in the mid-low permeability layers. On the plane

the vertical well pattern is mainly distributed in the two wings away from the main stream line

while the horizontal well network oil-water interface is parallel to the well trajectory. The composite gel in the slug combination of “composite gel+microsphere/high efficiency oil displacing agent” has a strong retention effect in the high permeability layers. The liquid flow steering effect is better

which makes the synergistic effect in the subsequent “microsphere/high efficiency oil displacing agent” composite system better. It takes into account the technical requirements of expanding the volume and improving the washing efficiency

and the effect of increasing oil and precipitation is obvious

with the increase of recovery rate by 26.50 %. Profile modification is the key to increase oil recovery greatly.