The curve of vitrinite reflectance(RO)-depth(H)is successive across the unconformity on top of Carboniferous-Permian strata in Zhaoyuan area,which means the Carboniferous-Permian buried deep during the later sedimentation.The maximal paleogeothermal gradient of the study area is the CarboniferousPermian paleogeothermal gradient analyzed by R.P.Suggate standard plate.Based on the occurring positions and homogenization temperatures of fluid inclusions,there are twice hydrocarbon charges.The results show that the Carboniferous-Permian source rocks have a secondary hydrocarbon-generation after later deep burial,and Zhaoyuan area is the favorable area for secondary gas-generation.

松辽盆地石炭系—二叠系烃源岩经历了较为复杂的构造演化,不同地区烃源岩的埋藏史、热演化史及生烃史不相同.通过对收集的资料和采集的上古生界烃源岩样品进行地球化学分析,探讨了松辽盆地不同地区石炭系—二叠系烃源岩演化特征及其有效性.结果表明:松辽盆地上古生界烃源岩有机质丰度低,有机质类型较差(主要为Ⅲ型和Ⅱ2型),现今热演化程度高(已达到成熟和过成熟阶段),后期生烃潜力有限,但不代表地质历史时期生烃贡献小;肇源、长岭地区上古生界烃源岩为后期深埋藏型,存在二次生烃,为上古生界有效烃源岩主要分布区,对天然气资源有贡献;杜尔伯特地区由于受周边侵入岩烘烤、后期浅埋深等因素的影响,古地温远高于现今地温,不能发生二次生烃,烃源岩基本无效.因此,松辽盆地肇源、长岭地区为上古生界烃源岩有利生气区.

The basic principle of using gas chromatographic finger print technique in reser-voir development was that the changes of full hydrocarbon gas chromatographic fingerprint were representations of heterogeneity of oil. The gas chromatography fingerprint technique was applied to understanding of oil layers connectivity of chang 6 oil of a certain area in Ordos Basin. According to the chromatographic fingerprint parameters, the oil of studied area can be divided into five types: Ⅰ-Ⅳ types and the special type. Except for the special type oil, the oil of same type was basically in agreement with reservoir sand distribution charac-teristics and was in good connectivity. There was difference in oil layer connectivity and preservation condition among different sandbodies. The results of the well logging, testing for oil, and layering data shows that crude oil chromatographic fingerprint technology was a re-liable method in researching connectivity of layers.

The type of organic matter from Upper Paleozoic source rock in Songliao Basin is typeⅢ,and the thermal evolution is generally in high-over mature stage.A long-term exposure and erosion happens during Triassic in Songliao Basin,and then rapid deep burial happens,causing secondary hydrocarbon generation in Upper Paleozoic source rock.So,the comprehensive evaluation of gas generation potential in Upper Paleozoic source rock should include the first hydrocarbon generation and the secondary hydrocarbon generation.Based on the hydrocarbon generation thermal simulation experiment and the recovery of vitrinite reflectance and organic carbon content,it is confirmed that the hydrocarbon generation potential of Upper Paleozoic source rock in Songliao Basin is limited nowadays,but the characteristic of hydrocarbon generation potential in geological history is obviously different in each region.The first hydrocarbon generation is mainly in the western and northern parts of Songliao Basin,and the secondary one is mainly in the eastern part.According to the above recovery of key parameters,the first gas generation and secondary one are respectively calculated by the means of thermal degradation rate.The calculated results show that the first gas generation from Upper Paleozoic source rock in Songliao Basin is about 566.24×1012 m3,and the gas resources produced by secondary gas generation is(0.97-1.29)×1012 m3;secondary hydrocarbon generation of Upper Paleozoic source rock in Songliao Basin mainly happens in Daqing-Zhaozhou and Da'an-Nong'an areas,while there is no gas generation in the western part of Songliao Basin,the scope of gas generation is small in the northern part,and the generation is efficient in the eastern part.

Based on the reservoir geochemistry theory and taking the lower third member of Shahejie formation in Xia 502 block,the second member of Dongying formation in Shang 546 block and the second member of Guantao formation in Dalujia block in Linyi sag as examples,the reservoir and fluid connectivity were researched by using traditional oil chromatographic fingerprint and nitrogen compounds distribution technologies.The results show that the similar distribution characteristics of crude oil nitrogen compounds reveal a good connectivity between different reservoirs and fluid in the same well field,on the contrary,the connectivity is poor.Because of the high ability to resist biodegradation,nitrogen compounds distribution is more suitable to predict the connectivity of reservoirs biodegraded in some degree.The fine recognition and identification characteristics of the nitrogen compounds can be used for the repeated and comparative analysis on the reservoir connectivity for different scholars.

Analyses of geochemical characteristics of oil fractions,C-isotope and biological markers of well cores and crude oil from the Hongqiba area in the northwestern margin of Junggar Basin reveal that the source rock has low abundance in organic matter and poor kerogen.Oils from Hongqiba and its adjacent areas show a certain degree of correlations with the source rocks of the Fengcheng Formation in the Mahu sag with regard to the distribution of C 20,C 21,C 23 tricyclic diterpanes,Pr/Ph,and carbon isotope.Therefore,we suggest that oils mainly originated from the Fengcheng Formation of the Mahu sag.

The Hongqiba area in northwestern margin of Junggar basin is in low degree of prospecting and no commercial hydrocarbon flow has been found up to now.However,there are a lot of petroleum reservoirs found in Xiazijie area nearby.By comparison with the hydrocarbon accumulation conditions in Xiazijie area,it is recognized that there are such similar conditions as reservoir and cap rocks,trap type,hydrocarbon charging periods and hydrocarbon preservation for these two areas.The differences are that Hongqiba area is far from the Mahu sag(hydrocarbon-generated center) and it is not on the favorable direction of hydrocarbon migration.It is concluded that exploration in this area should be more careful because the condition of hydrocarbon accumulation in Hongqiba area could be poorer than that in Xiazijie area.