Lithologic Trap Study Of Paleogene Formation In Chunguang Block, Junggar Basin

The oil and gas exploration in Chunguang block，Chepaizi area，Junggar Basinhas not made a breakthrough. Previous researchers have made a lot of work aboutShawan formation and point out that the block is the favorable areas for hydrocarbonmigration, and a large number of oil and gas were found in the Shawan formation.However, previous research was rarely focused on the Paleogene stratum. In this paper,we start with the sedimentation controlled by tectonic factors; and draw the isopachmaps in the paleogene. Through the research, we think that the source direction of theChunguang block in Paleogene is northwest or north，which make a preparation forthe depositional system research.In this paper, we are guided by the standardization of sequence stratigraphytheory and the research approach is the integrated study of drilling data, well loggingdata and seismic data. By the application of bedding flattening methods, Paleogene isdivided into a three-order sequence. Furthermore, Paleogene is divided into a TST anda RST, four parasequence (groups).Based on the sequence stratigraphic framework, we use the waveform analysistheory and seismic facies analysis to explain the target layer sand body of the studyarea. Subsequently, we make an analysis on the depositional system. At last, weconclude seismic response characteristics of the known oil and gas wells, and make aprediction on the favorable traps in the favorable sedimentary facies.The main achievements obtained in this paper are as follows:1、Recognition technology of sand body has preliminarily formed, which isestablished on the research flow of sedimentary tectonic background analysis-sequence stratigraphic frame-velocity analysis-seismic facies analysis-lithofacies analysis by the application of waveform analysis.2、Seismic response of most sand bodies of Paleogene in Chunguang block isshown as that wave trough represent the top interface, and seismic responsecharacteristic of a few sand bodies with thick layer is shown as the blank factes withlow frequency and weak amplitude, the similarity between seismic traces is bad.3、A delta-lacustrine sedimentary system develops on the Paleogene E-s-1sandgroup.4、Sum up the basis for Paleogene favorable trap prediction.5、The Chunguang block is the favorable areas for hydrocarbon migration;Paleogene Es-1sand group has great exploration potential, and the sand body of updippinch out zone is regarded as an important exploration. In this paper, we predict twofavorable traps located in the southwest of the study area.