Evaluation method for shale quality based on organic porosity and total content of organic carbon

The invention relates to an evaluation method for shale quality based on organic porosity and the total content of organic carbon. Logging data of shale of a to-be-evaluated well of a work area is acquired; shale layer section of the to-be-evaluated well is determined; an evaluation criterion of the shale quality is built according to logging data of an actually-drilled well in the work area, the shale total content of organic carbon TOC is taken as the X axis, the shale organic porosity POR is taken as the Y axis, a TOC-POR evaluating chart is formed, and different symbols are used for labeling the classifications of the shale quality on the evaluating chart; a determined partition criterion of the quality classifications of the work area is drawn on the evaluating chart, and values of the shale organic porosity POR and the shale organic carbon TOC of the shale layer section of the to-be-evaluated well are projected on the evaluating chart in a point mode, and corresponding reservoir layer quality classifica