After years of exploration, the buried hill in Raoyang sag now is characterized by high degree of exploration and great difficulty in exploration. But the buried-hill exploration is inhomogeneous, so the buried hill has great exploration potential. Since 2006, based on secondary acquisition and merging processing of three-dimensional seismic data, in the light of the buried-hill exploration area in Raoyang sag, the buried-hill reservoir-formation conditions have been reconsidered by new ideas and new perspectives, the controlling mountain fault structure has been summarized again, the buriedhill reservoir-forming modes have been reestablished, the original data of old wells have been reviewed, the existing conclusions and cognitions have been reexamined. Buried-hill reservoirs including Chang-3, Ninggu-8, and Hu-8 buried-hill reservoirs have been discovered one after another in Changyangdian, Suning, and Sunhu buried-hill structural belts. New breakthroughs have been achieved in buried-hill exploration

Salt-related structure modeling is an important link in seismic data processing and interpretation of Kuche Depression. Because of the different starting points of research, structure modeling varies a lot in methods and purposes, such as modeling of salt morphology, modeling of structural movement patterns, and modeling of oil and gas reservoir models. On seismic profiles distortion of structural feature of Kuche Depression is serious, so failure drilling wells often occur when arraying wells according to seismic results. 80% failure drilling wells are related to the unascertainment of traps. The degree of ascertainment of traps depends on velocity accuracy and structure modeling. Starting from the exploration practice in Kuche Oilfield, to correct the distortion of salt-related structure in time domain, new comprehensive classification methods are used to combine the velocity structure, the structural configuration, and the lithology of the formation rationally. And 10 new models of salt-related structure are established, which plays a positive role in improving trap accuracy and arraying wells.

In recent years, the widely distributed Fuyu Oil Layer of low abundance has become a focus for increasing reserves in Songliao Basin. However, some features of the layer have seriously block the exploration progress, such as the poor reservoir conditions, the heterogeneity, the complex controlling factors and the difficulty to determine favorable areas of high abundance. By a detailed study on the reservoir geological conditions and the forecasting techniques of petroleum spatial distribution based on the integrated method of multiple factors, the controlling factors of the accumulation are confirmed, an effective discriminant analysis template is established, and the probability of exploration success in Zhaozhou-Chaoyanggou Area is predicted. Furthermore, the distribution of the oil and gas-rich region is studied by fractal simulation of petroleum abundance. The results reveal that the low-risk exploration area is mainly distributed in the Fanshentun Anticline, the Bohetai Nose Structure, the south of Zhaoyuan, the Zhaozhou Oilfield, and Zhou39-Zhou391 area in south of Zhaozhou Oilfield. Besides the discovered resources, the remaining resources are approximately 80 million tons and mainly enriched in the southern area of Zhaozhou Oilfield, the west of Bohetai Nose Structure and southern Zhaoyuan.

The sequence boundary of Paleogene in Jiyang Depression could be divided into six construction styles, i.e. the truncated overlap style, the truncated parallel style, the parallel overlap style, the top overlap style, the parallel style, and the compound style. Taking T6', one of the Paleogene sequence boundaries in Jiyang Depression, as an example, genetic model of lithologic traps is established based on the sequence boundary construction styles, and favorable zones of lithologic traps under the control of sequence boundary construction styles are predicted by using the criterion of “six factors” (the changes dynamics of sequence boundary, sequence boundary sand control, the properties of reservoir sandstones, hydrocarbon generation and expulsion, sedimentary environment, and sequence boundary reservoirs control). The practical application indicates that this method has obvious technology advancement and it will definitely increase the accuracy of prediction and improve the ability and level of exploration deployment

Oil & gas reservoir has been discovered in Carboniferous and Devonian Systems in Maigaiti slope. Recently, it is found that Ordovician buried hill has favorable conditions for reservoir formation. This is a set of potential oil & gas strata, and it has great significance for exploration. The Ordovician has oil & gas source conditions for forming large-scale oil and gas reservoir. Two-dimensional and three-dimensional fine calibration, integration interpretation, and predictive analysis show that karst reservoir developed in Yingshan Formation buried hill of Ordovician, favorable reservoircap rock assemblages are formed by the karst buried hill of Ordovician Yingshan Formation and the shale in lower part of overlying Kepingtage Formation, Maigaiti slope has been in a favorable position of oil and gas migration and accumulation during the structural adjustment from north to south, oil and gas migration and accumulation match well

The technology of seismic attribute has been improved a lot in the past few years, and has been widely used to structure interpretation, reservoir prediction, reservoir description, etc. However, it does not perform so well in lithology identification quantitatively. Taking Dafeng-Xinghua Area as an example, drilling and three-dimensional seismic data are used for fine calibration, some lithologic attributes are selected for lithology identification quantitatively by attribute collection and analysis on the basis of fine structure interpretation. It is found that amplitude attribute could be used to identify volcanic rock, marl, sandstone and mudstone, and their boundary lines in terms of amplitude attribute are confirmed, which matches well with actual drilling, providing very good evidence for sand prediction and reservoir prediction.

T3x2 gas reservoir is a typical “tight sandstone gas” reservoir, which features in low porosity and ultra-low permeability. The basin modeling results shows that T3x2 gas reservoir has gone through four processes: burial, uplift, re-burial and re-uplift. T3x2 was compacted and became tight sandstone before the Cretaceous. T3x1, which lies beneath T3x2, started to generate gas in late Jurassic. The peak of gas generation started in late Cretaceous and ended in Paleocene. The critical moment of gas migration and accumulation was in late Cretaceous, that is early than the age when T3x2 became tight sandstone. Based on the geological models and the characteristics that the buoyancy of gas in water is not the main drive of gas flow in tight sandstone, this paper proposes the method of modeling gas migration and accumulation, and then uses it to predict the gas distribution in T3x2. As a result, the modeling is consistent 88 percent with the actual data of the discovered resources at Hechuan1 Block and Tongnan2 Block. It confirms the predicting model is rational. Furthermore, the modeling results show there are half of natural gas undiscovered in the Hechuan area, located at the northeast of Hechuan, and north and southeast of Tongnan.

Through the study on drilling data and gas test case in Qingxichang Area in northeastern Sichuan, it is found that the fractured gas reservoir is distributed unevenly in Feixianguan Formation. High-pressure fractured gas reservoir is drilled in Well QX1 and Well XQX1, but Well QX2 and Well QX3 are in vain. Therefore, it is necessary to study the distribution of fractures in the area. Firstly, the logging data of Well QX2 are used for rock physical forward model study and it is found that the fractured gas reservoir exhibits AVO response. Secondly, based on the anisotropic theory of subsurface media in seismic wave propagation, pre-stack seismic data are used to study the azimuthal attribute and pre-stack gathers of different angles of incidence of seismic data. Starting with the analysis of the variation of pre-stack seismic attribute with the azimuth and the angle of incidence, the distribution characteristics of fractured reservoir at top of Feixianguan Formation in Qingxichang structure are characterized and described. Thirdly, post-stack coherence attribute slice is used to analyze the fractured reservoir in the area, and numerical simulation for tectonic stress field is applied to verify the fracture system in the area. The results show that fractures developed in top reservoir of Feixianguan Formation, detection of anisotropic characteristics has good effect on fracture prediction in the area, and abnormal low FVO gradient on plane is consistent with anisotropic detection. But the results of numerical simulation of coherence attribute slice and tectonic stress field are relatively poor. Comparative study is conducted on the fractured reservoir drilled at top of Feixianguan Formation, and it is shown that anisotropic detection results correspond well to the data of drilled wells in the area, the fracture strike predicted at the drilling site is identical with that interpreted based on log data.

The Yanan sag of Qiongdongnan Basin is located in pressure transition zone, and it is characterized by complicated reservoir-forming conditions and oil & gas accumulation rules, deeply buried targets, great lateral variation of reservoir, and strong physical heterogeneity. On the basis of fully study of reservoir characteristics and selecting the technology for reservoir prediction and oil & gas detection, the spatial distribution of lithologic reservoir of Sanya Formation is described, the distributed areas of effective reservoir are confirmed, and favorable zone and targets for oil and gas reservoir exploration are identified, by using the acoustic impedance inversion technology, the spectral imaging analysis technology, the technology for analysis of attenuation by absorption and other technologies.

CH-2 area is located in beach area of Dagang Oilfield, where the special geological environmental results in difficulty in data acquisition and only a few wells scatter. To build model on this condition, this paper puts forward the geological modeling idea based on seismic data. It mainly depends on the three-dimensional seismic data and the predicting results of logging reconstruction and constrained inversion, using stochastic modeling, to predict distribution of reservoir sand bodies between wells and variation of reservoir properties, and to establish high-precision three-dimensional geological model of reservoir. This approach greatly reduces uncertainty of cross-well reservoir prediction and risk in development, and simultaneously provides good reference for precise reservoir evaluation in similar work area.

Typical meandering stream deposits developed in Tertiary Minghuazhen Formation on the north slope of Gangxi Oilfield, of which channel lag deposit and point bar deposit (point bar) combination are important reservoir types in the area. In order to detect the sands ofMinghuazhen Formation, the generalized S transform is applied to frequency-divisional processing of post-stack seismic data, and precise time window analysis is used to collect seismic attributes on the amplitude tuning dominant frequency spectrum data volume along the layer, so as to show the distribution characteristics of the channel. The results show that channel characteristics are clear and natural and fully consistent with the drilling results, achieving the desired purpose.

Based on the seismic and drilling data and the provenance-supply mode, the sedimentary sequence, provenance features and oil-gas exploration prospects are analyzed. The study area has the typical double-layer geologic structure of rift-depression, and has double provenance supply in the north and south. The provenance supply in rifting period was mainly from the southern Darwin shelf, and was also from the northern Sahul Platform, while the provenance supply in depression period was mainly from the southern Darwin shelf. In the rifting period, the southern sediment formed a large-scale progradation body, and encountered the delta formed by the northern provenance in the central depression; in the depression period, large-scale neritic deposits developed in Cretaceous, and relatively large-scale platform limestone developed in Sahul Platform and its surroundings in the study area. The seismic data and basin data indicate that, the multi-stage reservoirs of delta, fan delta and shore of Jurassic-Cretaceous could be the good exploration targets

Oil shale is distributed all over China, concentrating in Mesozoic and Cenozoic basins. It is mainly distributed in extensional basins, flexure basins, strike-slip basins and cratonic basins in accordance with basin type, and extensional oil shale basins are in the majority. Through the study on the extensional oil shale basins in Northeast China, this paper emphasizes on the formation law of oil shale in Songliao Basin and Dalianhe mining area of Yilan Basin, sums up the factors controlling the formation of oil shale deposits in the extensional basins in Northeast China. The formation of oil shale deposits is mainly affected by the sedimentary environment, paleostructure, paleoclimate, organic matter sources, redox conditions, paleotopography, paleosalinity, etc. The study on the formation law of oil shale deposits in extensional oil shale basins has promoted the development of China's geological theory of oil shale and the exploration and development of similar oil shale basins