Study Of Oil-Gas Migration And Accumulation Mechanism In Shangjia Structure Nose Region

With the detailed application of the available datas in working area ,systematically study and the research of the stucture and fault development,evolution features of Shangjia region, the conclusion of Shangjia nose structure is a long-term inherited development paleostructure and the faults of it have four types ( generated in rift stage and still activing in depression stage,generated in depression stage,generated in rift stage and still activing in structure reversal stage,generated in depression and still activing in structrue reversal stage ) has been come up with .With the target reservoirs researched , Fuyang Oil Layer Reservoir types mainly have three types,they are: fault,fracture,fault-lithology reservoir in Shangjia Oilfield. Among them the fault-lithology reservoir type is the most ,second is fracture reservoir,the least is fault reservoir,oil and gas distribution is mainly situated near or tip of the nose of Shangjia nosing structure. The relationship of oil and gas distribution is complex, dominately controled by sandbody and fault connection and the continuity of sandstone .Through oil sources comparison we abtain that crude oil of Fuyang oil layer in Shangjia region chiefly stem from k1q1 in Sanzhao Sag, secondly stem from k1q2; By means of distribution and geochemical features of sources we abtain that Qingshankou Formation source rock in Sanzhao provide hydrocarbon amount to Shangjia Region about 1.1×103t. Through the research of the relationship of time and space configuration , oil &gas migration and accumulation models of Fuyang oil layer in Shangjia Region are that oil and gas generated by Qingshankou Formation source rock in Sanzhao Sag through T2-T22 fault migrate downward to Fuyang reservoir by overpressure action. Then migrate laterally through sands connected by fault by buoyancy action to fault,fracture,fault-lithology trap of Shangjia nosing structure and accumulate reservoir; migration and accumulation models of Putaohua oil layer in Shangjia Region are that oil-gas of Fuyang oil layer in Shangjia region migrate upward through T2-T11 fault by buoyancy action to Putaohua oil layer, then migrate laterally through sands by short distance to fault,fracture,fault-lithology trap of Shangjia nosing structure and accumulate reservoir; migration and accumulation model of k1q2 in Shangjia region is that migrate through Fuyang oil layer to Shangjia region into connected with k1q2 high block trap and accumulate reservoir; Natural gas migration and accumulation model of Yang1 Formation in Shangjia region is that gas generated by Shahezi group sourcerock action migrate upward through T5-T2 or T4-T2 fault by buoyancy to fault trap of Yang1 group and accumulate reservoir. Through the study of the relations between the distribution of oil and gas and reservoir conditions, the accumulation of Fuyang oil layer in Shangjia Oil field was controled by 3 factors what are that whether the traps were development, whether the traps were located in the path of oil and gas migration and whether the sand was rich in the traps. The accumulation of Putaohua oil layer was controlled by 4 factors, what were that traps were development, the traps were located above the F oil region, the faults of between T2 and T11 (reversal stage activities) were connectivity and the sand was rich in the traps. The accumulation of K1q2 oil was controlled by 3 factors, what were that the traps were development, high block traps and the oil and gas of Fuyang oil layer migration ways were connectivity, and the sand was rich in the traps.The accumulation of the gas of Yangdachengzi oil layer was controlled by 4 factors, what were that the traps were development, the development Shahezi Formation source rock was under the traps, there were faults which connected T5 or T4 and T2, and the sand was rich in the traps.Through actual measurement, reservoil samples fluid inclusion homogenizaion temperature of Fuyang oil layer in Shangjia Region mainly distribute 115-120℃, mainly paticular period of reservoir forming of Fuyang oil layer,Putaohua oil layer and k1q2 in Shangjia Region is the end of Mingshui group sedimentation period, mainly paticular period of gas reservoir forming of Yangdachengzi oil layer is the end of Quantou group-Qingshaokou Formation sedimentation period. Synthesize main controlling factors,we obtain thatⅠt ype range of profitability of Fuyang oil layer in Shangjia region has three, that area is 52.2Km2,resources amount is 1507×104t,Ⅱtype range of profitability has five, that area is 13.3Km2,resources amount is 267×104t.Ⅰtype range of profitability of Putaohua oil layer has four, that area is 9.5Km2,resources amount is 113×104t,Ⅱtype range of profitability has three, that area is 12.5Km2,resources amount is 149×104t.Ⅰtype range of profitability of k1q2 layer has two, that area is 3.7Km2,resources amount is 107×104t,Ⅱtype range of profitability has one, that area is 3.0Km2,resources amount is 43×104t.Gas range of profitability of Yangdachengzi group has one, that area is 2.2Km2.