In order to explore the beneficial development path of fault-block shale oil in Qintong Sag

a development mode for the fracturing of directional wells combined with pseudo-horizontal wells has been proposed based on the study on the geological characteristics of shale oil in the second member of Funing Formation

and two wells are successfully implemented. The results show that the east and west wings of the deep sag belt of Qitong Sag in Sube

i Basin are structural complex areas with fault-block shale reservoirs

which are with large thick

developed natural fracture network

high pressure coefficient

and good mobility and transformability. The geological conditions here is not suitable for the development of long horizontal wells but for the directional wells. For the multi-layer development of thick shale oil

the rectangular directional well pattern is conducive to the CO

2

huff and puff

while the diamond reverse nine-spot well pattern is reasonable for the CO

2

flooding. Therefore

with the fracturing technology system based on “large-scale liquid injection energy storage flow limiting perforation promotion and equalization flow adjustment and fracture-stabilizing network three-stage support and maintenance filling continuous construction with all electric pumps”

the fracturing of the directional wells took as the “pseudo-horizontal well” can achieve the transformation effect of the horizontal wells

and the transformation volume of the single stage is 28.6 % larger than that of horizontal wells. This new develop mode of shale oil has high initial productivity

early oil breakthrough time

low flowback rate

fast water cut decline

and long stable production time. The single stage has high elastic productivity

high recovery degree

and good economic benefits

realizing beneficial development of shale oil in advance. The beneficial development shows a good prospect for the evaluation of shale oil in complex structural areas by the directional wells.