Prestack inversion identification of organic reef gas reservoirs of Permian Changxing Formation in Damaoping area, Sichuan Basin, SW China

ZHOU Lu,ZHONG Feiyan,YAN Jiachen,ZHONG Kexiu,WU Yong,XU Xihui,LU Peng,ZHANG Wenji,LIU Yi

Table 4 Comparison of coincidence rate of gas-bearing property of Changxing Formation reef reservoir predicted by different parameters.

Well name Fluid property of reef reservoir Detection effect Prestack P-S wave velocity ratio Prestack fluid factor Poststack P-wave impedance High frequency attenuation Angle gather Yun’an 12_12 Gas layer Coincident Coincident Coincident Coincident Not coincident Yun’an 6 Gas layer Coincident Coincident Coincident Coincident Coincident Yun’an X7 Gas layer Coincident Coincident Not coincident Coincident Coincident Yun’an X8 Gas layer Coincident Coincident Coincident Not coincident Coincident Yun’an X9 Gas-bearing water layer Coincident Coincident Coincident Not coincident Coincident Yun’an_X11_ce Undrilled reef Not coincident Not coincident Coincident Coincident Coincident Yun’an_X11_2ce Gas layer Coincident Coincident Not coincident Coincident Not coincident Yun’an_X11 Undrilled reef Coincident Coincident Coincident Coincident Coincident Yun’an 012 Gas layer Coincident Coincident Coincident Not coincident Coincident Yun’an 012_1_C Gas layer Coincident Coincident Not coincident Coincident Not coincident Yun’an 012_1_Z Gas-bearing layer Coincident Coincident Coincident Coincident Coincident Yun’an 012_2 Gas layer Coincident Coincident Not coincident Coincident Coincident Coincident rate 91.7% 91.7% 66.7% 75% 75%