Formation And Evolution Of JiaoLai Basin And Formation Condition Of Combination Gas

Jiaolai basin is a fault-strike slip basin of Cretaceous in the east of China, it has abundant hydrocarbon resources, its formation and evolution was controlled mainly by the activity of Tanlu, Muping-Jimo and Wurong fracture and the function of deep mantle's uplift. In this paper, we use new theories and methods of structural Geology, Geophysics and Geochemistry to study structural geometry, kinematics and formation condition of combination gas of jiaolai basin, the outcome and recognition are underneath:(1)By the structural analysis and results of information of Geology and Geophysics, we can draw conclusions that the activity of extension occurred mainly in Laiyang and Wangshi stage, the direction of Laiyang stage is north east-south west ang Wangshi stage is south-north, the main stage of extension is Laiyang stage in Zhucheng seg, the main stage of extension is Wangshi stage in Gaomi and Laiyang seg. By the information analysis of fold, reverse fault, angular unconformity contact relation, jointing, scratch, microstructure and acoustic emission testing, we can know that compression activity of Jiaolai basin has three stages. The compression activity of end of Laiyang and Qingshan stage is north west-south east, after Wangshi stage is close to south-north. The compression after Wangshi stage can divide into three stages: end of Cretaceous, end of Tertiary and end of Quaternary. By the structural metastatic intensity, compression of the end of Wangshi stage is most deep. (2) From the compositive outputs of inclusion homotemperature, vitrinite reflectivity and acoustic time, we know that the largest denuded thickness lies in the north of Zhucheng seg and east of Laiyang seg, numerical value exceeds 6,000 meter. The second is Chaigou horst, Dayetou horseback, north of Muping-Jimo fracture zone and west of Haiyang seg, numerical value generally exceeds 3,000 meter. The smallest zone is the center of Jiaoxian seg and south-west of Laiyang seg, the smallest value is less than 1,000 meter.(3)With the constraint condition of research of structural analysis, count of jointing, measurement of scratch, microstructure and testing result of acoustic emission, we use finite element method to process numerical simulation with palaeotectonic stress field of all stages of formation and evolution of Jiaolai basin. The results are below: the direction of the maximal principal compressional stress of Laiyang stage is north west-south east and the value is above 75Mpa;In Qingshan stage the activity is integral pull apart, the direction of the maximal principal stretch stress is north west-south east and the value is about 60Mpa; the direction of the maximal principal compressional stress of end of Qingshan stage is north west-south east and the value is above 80Mpa; the direction of the maximal principal stretch stress is close tosouth-north and the value is about 50Mpa;after Qingshan stage, the direction of the maximal principal compressional stress is north east-south west and the value is about 60-75Mpa.(4)By geochemistry analysis of abundance of organic carbon, content of chloroform asphalt "A", thermal decomposition and gas chromatograph, Shuinan member was formed in relative hydrogenant environment, its organic material was mainly derived from offgrade onganism, the abundance of organic material is high and type is favorable and thermal evolution of organic material have already arrived maturation stage, it is the main hydrocarbon source rock of this region and have favorable genetic potential, the abundance of organic material of Xiaoxianzhuang member is medium, the type is mixed type and thermal evolution is more high and have definite genetic potential .Generalizing oil-forming condition, container rock condition and preservation condition, together with analysis of evidences of oil and gas show, we can concluded that outskirts of Dayetou horseback and north-west of Zhucheng seg belong to the most beneficial region of oil and gas prospect, Chaigou horst, Jiaoxian depression and Laiyang district belong to more benef...