Recognition methods of lithologic traps in #2370 horizon of lower Zhujiang Formation in Lufeng South area

At present, the sandstone pinch-out is identified primarily at sand-mudstone interbedding section through seismic amplitude variation and seismic attribute analysis. However, there is less research on the identification method of sandstone pinch-out under the influence of high velocity and high density limestone, under which the reflections of thin sandstone and surrounding rock beneath limestone are often smeared. Thus, it is difficult to effectively judge the shape of pinch-out line of sandstone by conventional methods, which then affect the implementation of lithologic traps. We developed a method of identifying the #2370 sand pinch out line from geophysical and geological perspective by means of 3D seismic data. The method is a comprehensive description of pinch out line by means of statistical reflection characterization, forward modeling, seismic attributes and inversion, and geological model analogy. Results show that through this method, the sand pinch-out line matches the lithology of surrounding wells. In addition, combined with local tectonic background and sand pinch-out line, we have clearly located the #2370 sand lithologic trap in the southern area of Lufeng Sag. This method shall have important reference for implementation of lithologic trap below limestone in the areas of widely developed limestone.