| Tazhong area of the Tarim basin is rich in oil and gas resources. Shun9well block is located at the exploration area in Shuntuoguole low uplift of Tazhong north slope. The Shun9well has been got oil and gas discoveries in sandstones located in lower Kepingtage formation of Silurian, which shows good exploration prospects. But the reality is that the oil-bearing sandstone bodies in the Kepingtage formation of Silurian are low porosity and low permeability sandstone reservoir, which have the characteristics of buried depth and thin thickness. At the same time, the lack of effective technical method cause the base study of sedimentary facies and sand body distribution is weak. The situation makes it difficult to describe the distribution of favorable sand bodies. The oil and gas reservoir evaluation process is slow, and has not formed a production capacity construction field with a certain scale.This paper aims at the technical bottleneck problem of sandstone reservoir prediction in Kepingtage formation of Silurian in Tazhong area. The study carried out with comprehensive analysis of geological, seismic, well logging, mud logging and other various static and dynamic testing data, and also using the method of combination of seismic and geology to focus research on stratigraphic division and correlation, sedimentary facies division and reservoir characteristics study in shun9well block. Based on the research, the thesis establishes structure model, sedimentary micro-facies model and reservoir parameter model of the purpose layers by Petrel modeling software. These three geological models make the favorable reservoir zone clearly and provide an important basis in the next exploration well deployment. The main research contents and results as follows:(1) The paper carried out seismic-geological integrated studies in Silurian of Tazhong northern slope. In this paper, we confirmed the tectonic framework of this area is nose structure pattern which is high in south and low in north and the fault distribution characteristics of NE-trending en-echelon Strike-slip normal fault through comprehensive research of thin layers division and contrast, fine seismic data interpretation, sedimentary facies and reservoir study. The sandstone of Kepingtage Formation of Silurian in shun9well block belongs to low porosity and low permeability pore type and fracture-pore type reservoir by the analysis of reservoir characteristics. Based on the analysis of main controlling factors of reservoir development, we think the sedimentary facies is the most important control factor of the reservoir development of Kepingtage formation in study area.(2)Seismic facies controlled modeling method is used to solve problems in Silurian of Tazhong northern slope. The study results show that RMS amplitude is the sensitive attribute of reservoir prediction by correlation analysis of RMS amplitude and sedimentary micro-facies types. Based on the plane distribution of sedimentary facies according to the RMS amplitude, the sedimentary facies distribution model is established through wells data and crosswell constrained by seismic attribute. The sand body porosity model is established by sequential Gaussian simulation method. The permeability and water saturation models are established according to the relationship between permeability and porosity.(3)Three models are high reliability in study area by the test of new drillings, the consistency analysis of data structure before and after modeling and the inspection of model visualization. The study has divided some favorable reservoir zone according to the geological modeling results. The research results provide an effective technical means for the next exploration target of Silurian in Tazhong area. |
PDF Full Text Request