Preliminary prediction and evaluation on source rock in low exploration basin—A case study from the northeast depression, South Yellow Sea basin, East China

Abstract

Low exploration activity fields (e.g., deep formation, deep water, and new exploration areas) are of great importance for petroleum exploration. The prediction of source rocks is critical to the preliminary evaluation of low exploration activity fields, which will determine the early strategic electoral district and decision of exploration activity. The northeast depression is a new exploration area at the South Yellow Sea basin at present. Based on lots of seismic data in the study area and a few of well data in adjacent homologous depression, the early evaluation of source rock in the northeast depression was finished by comprehensively using the techniques of geological analogy, geophysical inversion and basin modeling, and an integrated methodology about preliminary evaluation of source rocks to low exploration activity fields is also presented. The methodology consists of three aspects: (1) prediction of the main formation of major source rocks, based on analogy analysis of seismic reflection characteristics and quality of source rocks in adjacent homologous depression; (2) method of seismic attribution to determine the thickness of source rocks; and (3) prediction of vitrinite reflectance, based on basin modeling technique to determine the maturation of source rocks. The results suggest that the source rock of the Taizhou (泰州) Formation is the most important interval for hydrocarbon generation in the northeast depression, which is characterized as high TOC, fine OM type, huge thickness, and high maturity. The western subdepression is the most important hydrocarbon kitchen in the northeast depression.

Geochemical characteristics and hydrocarbon generation modeling of the Paleogene source rocks in the Qinnan Depression, Bohai Bay Basin, China

“…The Qinnan Depression is fully covered by high-quality 3D seismic data, which can complement the sporadic well control. Therefore, geological analogy method was used to compare seismic facies/sedimentary facies and geological conditions (Cao et al, 2009). After that, the high-exploration slope zone was employed as reference to determine geological conditions of the low-exploration depression zone.…”

Distribution Prediction of Middle‐deep Lacustrine Source Rocks in Eocene Wenchang Formation in the Kaiping Sag, Pearl Mouth Basin

“…Source rocks can only be evaluated using regional geological and seismic data (Mi et al, 2007;Liu et al, 2007;Cao et al, 2009;Gu et al, 2011), applied sequence stratigraphy (Liu et al, 2007;Huang et al, 2015;Lai et al, 2020), seismofacies and seismic attributes (Cao et al, 2009) in regions without wells. Previous studies showed that middle-deep lacustrine, high quality source rocks were developed in Wenchang Formation of Kaiping sag (Pang et al, 1995;Li et al, 2013Li et al, , 2014.…”

“…Rock physics and seismic data were also used to study the spatial distribution of source rocks (Løseth et al, 2011). For regions with a few well, sedimentary facies, seismofacies, seismic attributes and dynamic modelling were used to predict the characteristics and distribution of source rocks (Cao et al, 2009;Gu et al, 2011). If geochemical data were obtained, the relationships between TOC and logging curves, TOC and seismic response could be used for fitting the relationships of source rocks on well and seismic data.…”

Identification and Distribution of Lower Cretaceous Source Rocks in Ying’er Sag, Jiuquan Basin

“…Seismic response of source rocks. Tracing and predicting favorable facies of major source rocks based on the seismic reflection characteristics have been proved available by lots of practical exploration activities [4,5]. According to the analysis of the sedimentary facies and the calibration of well, three major seismic facies were recognized (Fig 2 ).…”