Abstract:

To identify shale oil exploration potential of Shahejie Formation from Liaohe west sag and the controlling factors of shale oil, focused on Es3 Formation, combined with seismic and logging data, based on an emphasis on organicrich shale hydrocarbon potential, reservoir property and oilbearing assessment by the FIB - SEM, automatic helium porosity determination and BET - BJH tests, the shale oil resource calculation methods of Es3 are analyzed. The results show that, (1) the organic carbon content has a range of 1.0%8.54% with a public value of 2.15%; Ro ranges from 0.32% to 1.57% with a public value of 0.65%, corresponding to the oil window; (2) variety of six micropores such as intergranular pores, grain pore and microfracture with mesopores between 3.9 and 20 nm are rich in shale; (3) Es3 Formation has 1 industrial oil flow, 2 oilenriched layers and 16 oil spots; (4) the shale oil resource calculation methodsunit calculation method were analyzed by probability and statistics, analogy, weight assignment principle and in unit divisionstep calculationcumulative sum manner. It is concluded that Es3 Formation has a good exploration prospect and should be selected as an area with abundant organic matter, moderate thermal evolution, high porositypermeability and oiliness. In contrast, formations with too low thermal evolution or too high content of clay, will be avoided.

Key words: Liaohe west sag, Shahejie Formation, shale oil, oilbearing, unit calculation method, exploration prospect