Rift Hydrocarbon Accumulation Elements Space Matching And Control Function Of Fangzheng Fault Depression

Fangzheng rift located in the northern section of Yishu graben where at the east side of the Songliao Basin, the reservoir is distribution in EW direction, however, the reason of differences between East and West accumulation is not very clear,neither the factors which influence the accumulation in different structure of different layers.Therefore, it is important to analysis how the accumulation factors in Fangzheng to control hydrocarbon accumulation,And it has important guiding significance for understanding the gas distribution and exploration in the Fangzheng rift.On the basis of using of the Fangzheng rift geological, seismic, logging and drilling data,analysis the accumulation factors, The three main aspects are rock, trap and migration channels. By reservoir anatomy, specifically the hydrocarbon accumulation factors in the relationship and type of match between space and time. The space matching relation, divided into 3 types: ①inner source ring is Xin’an village + Wu’yun group fault block trap which is in Xin’an village + Wu’yun group source rocks. The sand side connecting Xin’an village +Wu’yun group source rocks and its inner trap; ②in the up of source ring, is the trap of Baoyi which above the Xin’an village + Wu’yun group source rocks,Xin’an village + Wu’yun group source rocks and trap of Baoyi are connected by a vertical fracture Ⅵ; ③ source underside ring, is the bedrock fault nose traps or Cretaceous trap beneath the Xin’an village + Wu’yun group source rocks. Because Xin’an village + Wu’yun group source rocks and trap of Baoyi are connected by a vertical fracture Ⅵ and docking bedrock or by the unconformity lateral connection Xin’an village + Wu’yun group source rocks or the trap of Cretaceous.the relationship of time match is divided into two kinds: ①A large number of source rock expulsion with faulting period; ②The relation between petroleum migration and trap formation. By studying between East and West through the distribution of oil and gas in Fangzheng rift, Showed that the eastern part is in the Baoquanling grou, Xin’an village,Wu’yun group and basement strata are as the main layer of oil and gas accumulation, while the western oil and gas mainly in Xin’an village,Wu’yun group and Cretaceous aggregation;By contrast the distribution of oil and gas on the East and West, come to western oil and gas is better than the east. Based on the distribution of oil and gas, Combined hydrocarbon accumulation elements and matching relationship,find that there have two aspects impact Oil and gas accumulation factors matching relationship between spatial and temporal control of reservoir: ① Hydrocarbon Accumulation Elements in matching relation control of the scopeand location of hydrocarbon accumulation, 1) Source rock distributed control hydrocarbon accumulation and distribution, and 2) trap type control reservoir type, 3) Transporting pathway control specific parts of the oil and gas accumulation; ② Hydrocarbon Accumulation Elements and time matching control the degree of oil and gas accumulation.