Oil reserves of Chang 7 Shale, Triassic Yanchang Formation, Ordos Basin

With the successful exploration of unconventional hydrocarbons such as shale oil and shale gas, scholars paid more attention to the residual hydrocarbons within the shale. However, getting the reserves of residual hydrocarbons within the shale is still a problem faced by the petroleum geologists. Shale can act as both the source rocks and the reservoir of shale hydrocarbons, and the hydrocarbons within the shale system have not been expelled except a bit of loss during the geological times. Thus, the quantity of residual oil within the shale can be regarded as the reserves of shale oil. Using the pyrolytic parameters, such as total organic carbon, free hydrocarbons, and pyrolytic hydrocarbons, the quantity of residual oil within the shale can be calculated. Chang 7 Shale in Triassic Yanchang Formation, Ordos Basin, was selected to establish the calculating model, and the reserves of shale oil were calculated. The results show that the reserves of shale oil are 1.11 billion tons.