A method for evaluating paleo hydrocarbon pools and predicting secondary reservoirs:a case study of the Sangonghe Formation in the Mosuowan area,Junggar Basin

Taking the Jurassic Sangonghe Formation in the Mosuowan-Mobei area of the Junggar Basin as an example, this paper provides a method that evaluates paleo hydrocarbon pools and predicts secondary reservoirs. Through Quantitative Grain Fluorescence （QGF） experiments, well-tie seismic correlation, and paleo structure analysis, the scale and distribution of paleo hydrocarbon pools in the study area are outlined. Combining current structural features and fault characteristics, the re-migration pathways of paleo oil and gas are depicted. Based on barrier conditions on the oil re-migration pathways and current reservoir distribution, we recognize three types of secondary reservoirs. By analyzing structural evolution and sand body-fault distribution, the major control factors of secondary reservoirs are specified and, consequently, favorable zones for secondary reservoirs are predicted. The results are mainly as follows. （1） In the primary accumulation period in the Cretaceous, paleo hydrocarbon pools were formed in the Sangonghe Formation of the Mosuowan uplift and their size and distribution were extensive and the exploration potential for secondary reservoirs should not be ignored. Besides, paleo reservoirs were also formed in the Mobei uplift, but just small scale. （2） In the adjustment period in the Neogene, traps were reshaped or destroyed and so were the paleo reservoirs, resulting in oil release. The released oil migrated linearly northward along the structural highs of the Mobei uplift and the Qianshao low-relief uplift and then formed secondary reservoirs when it met new traps. In this process, a structural ridge cooperated with sand bodies and faults, applying unobstructed pathways for oil and gas re-migration. （3） The secondary hydrocarbon pools are classified into three types： low-relief anticlinal type, lithologic pinch-out type and fault block type. The distribution of the first type is controlled by a residual low uplift in the north flank of the paleo-anticline. The second type is distributed in the lithologic pinch-out zones on the periphery of the inherited paleo uplift. The third type is controlled by fault zones of which the strikes are perpendicular to the hydrocarbon re-migration pathways. （4） Four favorable zones for secondary reservoirs are predicted： the low-relief structural zone of the north flank of the Mosuowan paleo-anticline, the fault barrier zone on the western flank of the Mobei uplift, the Qianshao low-relief uplift and the north area of the Mobei uplift that parallels the fault zone. The study above effectively supports the exploration of the Qianshao low-relief uplift, with commercial oil discovered in the Qianshaol well. Besides, the research process in this paper can also be applied to other basins to explore for secondary reservoirs.

Extensional Tectonics, Rifting, Formation of Sedimentary Basins, Cretaceous Volcanism, Emplacement of Dyke Swarms and Development of Hydrocarbon Pools: Case Studies from Peninsular India and Indian Ocean Region

Prolonged extensional regime in peninsular India resulted in formation of rift and grabens,elongated basins and Gondwana sedimentation along them.Downward progression of rift related faults caused decompression

Enhancement of catalytic and anti-carbon deposition performance of SAPO-34/ZSM-5/quartz films in MTA reaction by Si/Al ratio regulation

In order to further improve the catalytic performance of zeolite catalyst for methanol to aromatics(MTA)technology, the double-tier SAPO-34/ZSM-5/quartz composite zeolite films were successfully synthesized via hydrothermal crystallization. The Si/Al ratio of SAPO-34 film was used as the only variable to study this material. The composite zeolite material with 0.6Si/Al ratio of SAPO-34 has the largest mesoporous specific surface area and the most suitable acid distribution. The catalytic performance for the MTA process showed that 0.6-SAPO-34/ZSM-5/quartz film has as high as 50.3% benzene-toluenexylene selectivity and 670 min lifetime. The MTA reaction is carried out through the path we designed to effectively avoid the hydrocarbon pool circulation of ZSM-5 zeolite, so as to improve the aromatics selectivity and inhibit the occurrence of deep side reactions to a great extent. The coke deposition behavior was monitored by thermogravimetric analysis and gas chromatograph/mass spectrometer, it is found that with the increase of Si/Al ratio, the active intermediates changed from low-substituted methylbenzene to high-substituted methylbenzene, which led to the rapid deactivation of the catalyst. This work provides a possibility to employ the synergy effect of composite zeolite film synthesizing anti-carbon deposition catalyst in MTA reaction.

The Formation Conditions and Distribution Regularities of Lithologic Reservoirs in the Songliao Basin

The geological background of the fluvial and lacustrine depository system in the large mid-shallow layered depressed lake in the Songliao Basin has been proven to have the geological conditions for the formation of lithologic reservoirs over a large area. Because the rise and fall of the base level caused considerable differences in the space at different periods, the types of sand bodies varied in different geologic periods; but at the same time, because of the differences in burial depths and the relative differences in positions of the siltstones and source rocks, the formation conditions and distributive regularities for oil-bearing groups of subtle reservoirs also vary accordingly. In view of the reality of the thinly-interbedded lithologic reservoir in the deltaic frontal facies belt, we have conducted a series of research to study the thinly-interbedded subtle reservoirs with the help of high resolution sequence stratigraphy, pattern recognition and the geophysical recognition and prediction techniques for thinly-interbedded subtle reservoirs, thus achieving a better effect and optimizing several exploration target areas, each of which has an oil reserve of about 100 million tons. This has shed light on further exploration of new subtle reservoirs.

Understanding Zeolites Catalyzed Methanol-to-Olefins Conversion from Theoretical Calculations

Zeolites catalyzed methanol-to-olefins （MTO） conversion provides an alternative process to produce light olefins such as ethene and propene from nonpetroleum resources. Despite of successful industrialization of the MTO process, its detailed reaction mechanism is not yet well understood. Here we summarize our work on the hydrocarbon pool reaction mechanism based on theoretical calculations. We proposed that the olefins themselves are likely to be the dominating hydrocarbon pool species, and the distribution of cracking precursors and diffusion constraints affect the selectivity. The similarities between aromatic-based and olefin-based cycles are highlighted.

Confinement effects in methanol to olefins catalysed by zeolites： A computational review

Small pore zeolites, containing 8-rings as the largest, are widely employed as catalysts in the process of methanol-to-olefins （MTO）. Reactants and products dif- fuse with constraints through 8-rings and this is one of the reaction bottlenecks related to zeolite micropore topology. Small pore zeolites and silicon-aluminophosphates （SAPOs） containing cavities, where olefins are mainly formed through the hydrocarbon pool （HP） mechanism, are frequently tested for MTO. Shape selectivity of transition states within the side-chain methylation will be reviewed as this is one of the controlling steps of the MTO process, with particular attention to the role of hexam- ethylbenzene （HMB） and heptamethylbenzenium cation （HeptaMB~）, which are the most tipically detected reaction intermediates, common to the paring and side-chain routes within the HP mechanism. The relative stability of these and other species will be reviewed in terms of confinement effects in different cage-based zeolites. The role of the different alkylating agents, methanol, dimethyl ether （DME）, and surface methoxy species （SMS） will also be reviewed from the computational viewpoint.