Clastic rock trap oil-gas possibility evaluation method based on risk probability

The invention discloses a clastic rock trap oil-gas possibility evaluation method based on a risk probability. The method comprises the following steps: analyzing possible factors affecting a trap oil-gas possibility, wherein possible factors include trap conditions, hydrocarbon sources and charging conditions, reservoir conditions and storage conditions; analyzing continental facies clastic rockdrilling success and defeat traps according to four aspects of the trap conditions, the hydrocarbon source and the charging conditions, the reservoir conditions and the storage conditions, dissectinga gas reservoir, and determining a risk evaluation assignment standard of each possible factor; based on the actual parameters of an oil and gas drilling target, assigning each possible factor according to the risk evaluation assignment standard obtained in the step 2; and calculating an oil and gas containing probability of the oil and gas drilling target, wherein the oil and gas containing probability p is equal to p1*p2