STUDI SIKUENSTRATIGRAFI BERDASARKAN HASIL ANALISIS DATA PALINOLOGI PADA SUMUR Y, CEKUNGAN SUMATERA SELATAN

Abstract

Palynology is a study of biostratigraphy for determining relative age and depositional environment based on the abundance of palynomorf. Palynology study develompent in Indonesia is still could be more increased along with more oil and gas exploration moved to transitional environtment. Study of palynology in stratigraphy is aiming to determine relative age and depositional environment. Besides, palynology could also determine sequence stratigraphy in a large scale of study based on palynomorf percentage. The study of sequence stratigraphy based on palynomorf percentage has been done in WellY, South Sumatra basin. The method of this research is descriptive method through the microscopic observation on sample 1 - 14 from 1400 m depth Y-Well’s cutting and quantitative method calculation and analysis method from this observation and calcuation could determine the percentage of each palynomorf. This percentage lead to a trend then interpretated into several sequencestratigraphy. From this observation, it can be determined characteristic zone of this well. The characteristic zone of palynology in this well is divided into 3 zones of palynology; Proxapertites operculatus Zone, Flocshuetzia meridionalis Zone, and Stenoclaeniidites papuanus Zone. Each zone shows the characteristic of age from Eocene to Pliocene and also depositional environment from delta plain to pro delta. From palynomorf percentage trend, we may also see the pattern of sequece stratigraphy works in this depth. The percentage trend shows the time whether sea level fall at the minimum percentage of palynomorf and sea level rise at the maximum percentage of palynomorf. The trend shows the sequence with sequence boundary lying in the start and the end of the sequence and also transgressive surface indicates the sea level start rise. Overall, this well has 5 sequences based on this trend; sequence a, sequence b, sequence c, sequence d, and sequence e and all the sequences are bordered by sequence boundary. Keyword: Palynostratigraphy, Quantitative Method, Palynology ZoneandSequencestratigraphy