Recognizing method and device for effective reservoir of compact oil and gas deposit

The embodiment of the invention provides a recognizing method and device for an effective reservoir of a compact oil and gas deposit. The method includes the steps that tri-porosity logging values of the effective reservoir and a non-reservoir are read in a single-layer formation testing section; natural gamma characteristic values of the effective reservoir and the non-reservoir in the single-layer formation testing section are read, a natural gamma characteristic value of a mudstone section adjacent to the single-layer formation testing section is read, and a natural gamma characteristic value of a sandstone section which is adjacent to the single-layer formation testing section and highest in lithological purity is read; according to the read natural gamma characteristic values, a natural gamma relative value of the single-layer formation testing section is determined; according to the tri-porosity logging values, the natural gamma relative value of the single-layer formation testing section and the natura