Many Cenozoic sedimentary basins developed in China marginal seas, of which the chief oil source rocks are lacustrine ones developed in rifting Ⅱ phase (developmental phase). Representative source rocks are the third member of Eocene Shahejie Formation in Bohai Sea, the Eocene Liushagang Formation in Beibuwan Basin, the EoceneWenchang Formation in Pearl River Mouth Basin, and the Eocene Yueguifeng Formation in the western depression of East China Sea Basin. Chief gas source rocks of many basins are source rocks in coal measure, which developed in rifting Ⅱ phase (decline phase). The representative source rocks are the Oligocene Yacheng Formation in Qiongdongnan Basin, the Eocene-Oligocene Enping formation in Pearl RiverMouth Basin, and the Eocene Pinghu Formation in eastern depressions of East China Sea Shelf Basin. The formation of high grade source rocks depends on abundant organic matter and paleoenvironment suitable for preservation and transformation of organic deposition. Research on the variations of palynoflora, algae and fragmentary organic matter that have been conserved in strata is an effective channel for investigating the paleoenvironment and distinguishing the growth of high grade source rocks. So, characteristics of paleoecospecies and fragmentary organic matter are feasible paleoecological marker for forecasting the growth of high grade source rocks. To study vertical and horizontal organic facies in suitable strata in combination with the paleoenvironment, paleobiology, and organic geochemistry when organic matter formed is reasonable methology for forecasting the distribution of high grade source rocks

Quaternary biogenic gas reservoir located in Sanhu area in Qaidam Basin features in low altitude structures, low compaction effect, high porosity, shallow burial depth and big thickness. For these reasons, gas reservoir has particular surface topography, geophysical and geochemical exploration abnormalities. On this basis, this paper explained and predicted shallow gas with remote sensing, geophysical and geochemical exploration methods. Through contrastive analysis of such gas fields as Tainan and Sebei No.1, this paper put forward the distributive characteristics that Sanhu gas reservoir agreed with negative gravity anomaly to a high degree, and the anomaly of high methane values of low-amplitude structure and chemical exploration, and predicted three zones favorable for exploration such as the W zone of Taijinar-Tuofengshan-northern Yanhu, the nearly E-W zone of Tainan-Sebei No.1-Sebei No.2, and the S-N zone of eastern Dabuxun Lake, two comparatively favorable zones such as northern Senie Lake and Dabuxun Lake as well as the western part, and three favorable targets such as eastern Sebei No.2 gas field, western Yanhu gas field and eastern Tainan gas field.

For the southern edge of Junggar Basin, because of the lack of systematic study of the Tertiary sedimentary reservoir, the favorable reservoir and size distribution is not so clearly. Therefore, the well logging data and core data are used for standardization and core location, and analyzing the correlation between core porosity and various logging response and between core porosity and permeability. Through regression analysis, the porosity and permeability model of log interpretation is set up. At last, the testing for oil shows that the lower limit of physical property of effective reservoir is that the porosity is higher than 8% and the permeability is higher than 1mD. Combined with sedimentary facies, lithology and other factors, it is pointed out that the Tertiary effective reservoirs developed well vertically in the southern edge of Junggar Basin are the second and first members of Shawan Formation and the third member of Ziniquanzi Formation. Horizontally, the effective reservoirs are mainly distributed in Chepaizi-Kayindike area, West Lake-Dushanzi- Anjihai anticline zone, and Huoerguosi-Manas-Tugulu-Hutubi anticline zone, providing important reference for next-step exploration deployment.

One of the basic tasks for evaluating hydrocarbon source rocks is calculating mud shale thickness. According to the characteristics that the shale particles can absorb radioactive substances, a mathematical relationship is built between natural gamma and shale content. The calculated results showed that the values of shale content ranged from 0 to 1. Eight typical wells were selected in Ordos Basin. Mud shale and non-mud shale values were observed in core interval of single well to confirm the shale content boundary which could distinguish mud shale and non-mud shale and the boundary was 0.7. Using this boundary, the mud shale values were read in Chang73 oil layer of Triassic Yanchang Formation in Ordos Basin and the distribution map of mud shale thickness was drawn by comparison with the existing results. The results showed that this method was feasible and accurate and layed a foundation for further evaluation of source rocks.

Precaspian Basin in CentralAsia, rich in oil and gas resources, is noted for the Kungurian significant thickness of salt bed. The structural evolution of Precaspian Basin mainly experienced three stages: inception of rifting, passive continental margin, and compression of rifting phases. The start of exploration in the Precaspian Basin dates back to the late 19th century, and the whole courses can be divided into two parts including early post-salt exploration and late pre-salt exploration. With large number, wide distribution and small scale, the quantity of post-salt reservoirs accounts for over 80% of the total. But due to good development of carbonate platform and reef complex, nine giant oil-gas fields (total recoverable Mmboe ≥ 500) have been found in the pre-salt reservoirs, where there are plenty of other large oil-gas fields. The most effective source rocks are the Middle Devonian-Middle Carboniferous relatively thin pelagic calcareous, siliceous, and argillaceous basinal facies rich in organic matter which accumulated on the slopes of the starved central deep. The Carboniferous bioherm and bioclastic limestone are the most favorable reservoirs. Besides, the most important regional seal is the Lower Permian Kungurian salt sequence. Furthermore, there are a great many Stratigraphic-Structural traps along Precaspian Basin?s verges. Focus of discovering giant oil-gas fields, hydrocarbon exploration orientation is based on òPre-salt first considering Post-saltó, and priority area is Astrakhan-Aktjubinsk Uplift Zone.

Based on the studies of petrology and sedimentology, the petrologic characteristics of Moogooloo reservoir are clarified through the analysis of clastic constituents, structural feature and pore types. Similarly, the sedimentary characteristics are elaborated via the research of sedimentary structure, well-logging data and grain size accumulation curve. The research results show that the lithology of the Moogooloo reservoirs in the research area is quartz sandstone and subarkose, with residual primary intergranular pores and intragranular dissolution pores. The Moogooloo Formation was deposited in middle Artinskian and the sedimentary environment was braided river accompanied with weak hydrodynamic environment. Based on the above research, the factors affecting the physical property of reservoir are analyzed from the perspectives of sedimentary process and diagenesis, while the latter one mainly includes compaction, cementation and denudation. More specifically, the sedimentary process controls the development of the primary pores and, to a great extent, the physical property of the reservoir, while the quartz overgrowth is the most significant factor which triggers the decrease in the reservoirs porosity. The systematic research of main factors of Moogooloo Formation in Southern Carnarvon Basin is helpful for the assessment and exploration of next step, while the elementary discussion of the regulation between stratigraphic sequence and physical property of reservoir exerts a positive influence on further application of stratigraphic sequence

Block A is located in the middle of Waipogah Basin which is a backarc sag basin. The major source rocks are limestone and mudstone of Mamberamo, Darante and Makat Formations.The intra-formational sandstone and limestone are reservoir rock. Darante- Makats play, Mamberamo B-C-D member play, and Mamberamo E member-Koekoendoeri play developed in the block. The northern zone in the block has good hydrocarbon accumulation conditions and good exploration potential. This is the key zone for next exploration

The deepwater turbidite sandstone in northern Gabon Basin of West Africa has become a very important oil and gas storage medium, which consists of turbidite channel, slump turbidite sandstone, turbidite lobe and some other elements. However, this kind of turbidite sandstone reservoir is distributed limitedly, and is difficult to be predicted. The author analyzed and summarized the sedimentary model based on the feature of the sedimentary geology, did some research on the seismic forward modeling, and set up the seismic reflection recognition model of the turbidite channel and the slump turbidite. The former seismic reflection has a protruding top and a concave bottom, which form a trough-shaped appearance, with a clear border and a weak internal reflective structure. The latter has a wedge-shape appearance, a better seismic reflection continuity of axis between top and bottom, strong amplitude, and a weak internal reflective structure. In addition, the author analyzed the multiple seismic attributes, optimized the sensitive parameters, and used the amplitude, phase and the attributes of strata body to predict the distribution of the sandstone. Furthermore, by gathering the accumulation characteristics of oil and gas and analyzing the potential of the oil and gas resources in different turbidite sand body, the author cleared the significance of the turbidite sands in oil and gas exploration

Shale gas play is a continuous gas play, which is a closed natural gas system with combination into one body of source rock, reservoir and cap rock. And there are four characteristics of shale gas accumulation and distribution conditions, i.e. uniqueness of gas generating, diversity of gas storage, variation of gas enrichment, and transformation of gas supply. The uniqueness of gas generating means that the source rock of shale gas play is organic-rich shale, and only roots in mature organic matter hydrocarbon generation; the diversity of gas storage shows that free gas and adsorbed gas are main modes of occurrence as to shale reservoir. The content of natural gas of the two modes of occurrence varies a lot. Gas accumulates in microfracture and micropore of organic matter and pore and fracture of shale. The variation of gas enrichment refers to multiple geological indexes, i.e. òfive-parameteróindexes affect the formation of shale gas play. The òfive parametersóinclude depth, thickness, TOC, Ro and brittleness, and appropriate parameters can make the formation of shale gas play that could be exploited commercially. The transformation of gas supply highlights the biggest characteristic of shale reservoir?nano-darcy permeability, affecting single well production. So production is low, declines slowly and the production period is long. Based on above reasons, only systematic fracturing technology is key to get industrial airflow. The analysis of four characteristics provides major technical basis for shale gas exploration in Huangboling Formation of Lower Cambrian in Lower Yangtze area. Combined with regional geology and geochemical characteristics, it is regarded that the southeastern edge of Lower Yangtze and the Huangboling Formation are most favorable for the formation of shale gas play, and they could be exploited commercially

Lithology of Jiulaodong Formation in Lower Cambrian, Sichuan Basin is mainly dark shale mixed with siltsone and fine sandstone. In particular, the western part of the Basin which features in big thickness, abundant organic matter and high gas generating intensity has always been regarded as a good source bed. In recent years, due to the introduction of the concept of shale gas, people began to realize that shale was not only oil source bed, but also reservoir, involving the participation of siltstone, fine sandstone and even interbedded sand, which could make the generated gas accumulate and form reservoir at source bed. Based on previous research on clay shale of Jiulaodong Formation, the author further studied the formation and evolution, migration and reservoir formation of natural gas here, and believed that the block favorable for exploration was mainly Block Weiyuan of which the gas generating intensity reached 23 billion cubic meters per square kilometer, the Deying Formation of Sinian system was also a source bed and supplied natural gas continuously, and the mud shale of Ordovician -Silurian was sealed well. Second is Block Nanjiang located at the border of Sichuan and Shaanxi, with the intensity of gas generation between 3 and 6 billion cubic meters per square kilometer. Rock of Jiulaodong Formation has shown in the block, which features in shallow burial depth and low cost. It does not only save labor power, material resources and time, but also fast to be verified.