摘要
塔巴庙地区位于鄂尔多斯盆地北部伊陕斜坡构造带上,构造平缓,地层倾角仅1°左右,一般认为不具备裂缝发育条件。指出,由大量钻孔岩心观察、薄片分析、测井及试井等资料证实,研究区发育以垂直或高角度裂缝为主的区域性分布的构造裂缝系统,其次为与地层局部挠曲变形有关的低角度构造裂缝系统。根据裂缝几何学、运动学和动力学特征,以及区域裂缝系统的成因及其在天然气运移聚集中的作用,在实测古应力和岩石力学性质基础上,采用三维构造裂缝预测模拟技术,对研究区主要目的层盒2+3段裂缝发育程度和发育规律进行了合理预测评价。
It is very hard to explore and develop the Upper Paleozoic low pressure tight sand gas reservoir effectively in north ordos basin. However, the existence of natural fractures in tight gas sand will change the situation dramatically by providing good conditions for gas migration and accumulation. The Tabamiao block is located in the north of ordos basin, and its tectonic setting is monoclinal structure, which stratigraphic dip is only 1 degree and is not commonly deemed good conditions for natural fracture growth. However, many vertical fractures and high-angle fractures have been found through core analysis and thin- section analysis as well as well testing and imaging logging interpretation. Further investigation in building the tectonic fracture system has been conducted on the drilling cores with paleomagnetic method and sound wave imaging technology. The result reveals that the NWW-EW oriented tectonic fractures are primary, the NEE, NE and NW NNW-SE ones are subsidiary, respectively. The local and regional fractures, which are respectively related to flexibility deformation and regional stress field, are two types of natural fractures in Tabamiao area. Based on the analysis of tectonic fractures/geometry, kinematics and dynamics, and the causes of formation of regional fracture system and its major function of gas migration and accumulation, we properly predict and evaluate the fracture distribution law and development degree for major layer (He 2+3 segment)in this area by use of detailed three-dimensions fracture predictive simulation methods. It makes clear that a majority of high producing gas wells in this area are commendably corresponding to predictive fracture development regions.
出处
《天然气地球科学》
EI
CAS
CSCD
2005年第5期575-580,共6页
Natural Gas Geoscience
基金
中石化华北分公司项目"鄂北塔巴庙地区构造应力场
裂缝系统定量预测及天然气有利靶区评价"(编号:P02077-2)资助
关键词
致密砂岩
区域性裂缝系统
定量预测
上古生界
塔巴庙气田
鄂尔多斯盆地
Tight gas reservoirs
Naturally regional fracture
Quantitative prediction
Upper Paleozoic
Ordos basin
Tabamiao area.