Comparison of INPEFA technology and wavelet transform in sequence stratigraphic division of mixed reservoir: a case study of lower Es3 of KL oilfield in Laizhouwan Sag

Abstract Sequence identification and division is an important basis for oil gas exploration research. In view of the complex sedimentary environment, based on previous element logging correction lithology, through combination curve lithology data, in this paper, two methods maximum entropy spectrum analysis wavelet transform are used to identify divide interface, high-resolution sequence migmatite study area was completed. Compared with AC SP curves, overall local trend inflection points INPEFA-GR can improve accuracy medium-term short-term cycle interface identification; time–frequency different scale factors realize comparison interfaces. The results show that more suitable determining third-level fourth-level Wavelet fifth-level sequences. By comparing adjusting methods, lower Es3 KL Oilfield Laizhouwan Sag be divided into 1 long-term base-level cycle, 3 8 cycle. This has certain reference significance construction stratigraphic framework helps better describe reservoir.