This invention relates to a method for evaluating the
escape rate of
shale gas reservoirs with different dip angles, employing the following technical solution: including the following steps: Step (1) Calculate the drilling angle θ of the
plunger sample based on the shale
bedding type, calculate the length L of the
plunger sample based on the
plunger diameter d, and
drill the plunger sample based on the drilling angle θ and length L; Step (2) Test the minimum starting pressure P0 of the plunger sample using
methane gas; Step (3) Calculate the
fluid pressure P of the formation where the plunger sample is located. 流
hydrostatic pressure P 水 Minimum starting pressure P0 and static
rock pressure P 岩 Calculate the test pressure Δ for permeability testing p and confining pressure P 围 Step (4) is performed according to the test pressure P determined in step (3). 测 and confining pressure P 围 The permeability of the plunger sample is tested to obtain the permeability k; step (5) calculate the gas
escape rate R; step (6) evaluate the
shale gas escape capacity of the layer where the sample is located based on the gas
escape rate R. The larger the escape rate R is, the stronger the
shale gas escape capacity is. Then calculate the shallowest burial depth H where the layer where the sample is located can be effectively preserved.