Seismic Inversion And Interpretation Of Eocene In Tangyuan Fault Depression

Tangyuan Fault Depression is northernmost secondary tectonic unit of Yi-Shu Garben, which boundary is controlled by two discordogenic fault that parallel trends NE. Totally it is an east-faulting and west-overlapping half fault depression controlled by eastern boundary fault, which area covers about 3320km2. The exploration foreground of this research area is very good. Aiming to Xinancun-Dalianhe Formation, applying the theory of sequence stratigraphy and seismic exploration, based on the drilling and seismic materials, utilizing the new technique and method of constrained inversion of drilling and attribute extraction, we do the lithologic identification and forecast of Tangyuan Fault Depression.By collecting the materials of regional geology, seismics and drilling in the research area, this paper identifies the sequence interface using the traditional seismic materials and certain the stratigraphic identified marks of lithology, drilling curve and seismic reflection characteristics. Utilizing the method of wave impedance inversion, we establish initial geological model, get the section of wave impedance inversion of high resolution, and educe many kinds of instantaneous seismic property, using the method of drilling constrained inversion based on model and multi-attribute extraction. Uniting the sequence interface of traditional seismic material, we further do the identification of sequence surface, do the mathematical statistics to the relationship between drilling material and lithology, then fit the mathematic relationship between lithology and rate, depth and property. Combination gamma ray neutron laterolog, SP and dual laterolog are main methods to divide sand shale, SP is very useful for the sand shale section of fresh mud, combination gamma ray neutron laterolog is very useful for the sand shale section of salt mud, specitic resistance and other curves are usually taken as references. Using the lithologic fitting formula, we calculate the lithologic space distribution, forecast the distribution of sandstone and mudstone, estimate the ratio of sand and mud, and draw the relationship between the depth and rate of sand shale, isopach map of sandy ratio and sandy shale. Utilizing the new method and technique, this paper studies the treatment of seismic material of Tangyuan Fault Depression, forecast the favorable sandbodies and discuss the petroleum accumulation regular in sequence stratigraphic framework. This research not noly has important geological significant for basic geological research, but also has important actual significant for further stratigraphic study and oil and gas exploration.