The Study Of Forming Condition Of Tight Oil & Gas And The Resource Potential In Bo Li Basin

Tight oil and gas as unconventional oil and gas,is gradually becoming the key point of exploration and developing.Bo Li basin is located in eastern Jiamusi-Yitong graben,it's one of the Mesozoic Sanjiang Residual basin of Late Mesozoic reformed coal bearing sedimentary basin.It can be proved from the existence of effective source rocks,tight reservoirs and the spatial configuration of the reservoir that certain scale of tight oil and gas existed in the basin.However,due to the low degree of exploration and limited available files,and the lack of appropriate methods for calculating the amount of resources,making the knowledge of the tight oil and gas is little and same situation as the uncertainty of resource potential.Aiming to these questions above,making potential of tight oil and gas resources and optimization of favorable areas as research emphasis,according to existing research,comprehensively using seismic,logging,core data,reservoir characteristics to have a thoroughly detailed study of the Bo Li basin,determining the main dominating factors of tight oil and gas.The results show that the main formation of hydrocarbon source rocks of Bo Li basin is the Chengzihe layer;The reservoir are Chengzihe layer and Muling layer,the physical properties are mainly low porosity and low permeability sandstone(including siltstone,fine sandstone and coarse sand);The type of organic matter is type II to III,which means it is in the mature stage;Mudstone from and Chengzihe and Muling layer and tuff are the main cover in the basin;The source,reservoir and cap assemblage is good.But the late-reformation is strong,the preservation condition of tight oil and gas is complex,besides regional cap rocks,faults also play an important role;According to the law of tight oil and gas accumulation,according to the principle of "generation,storage,transportation and preservation",and combining the multi-factor superposition method to select the favorable area of oil and gas.Two more favorable areas are optimized from the east and west sides of central depression.Finally,based on the analysis of oil and gas geology,combining three math methods: hydrocarbon generation,analogy and volume to calculate the amount of oil and gas in the basin: The oil resource is 3521×104t and the gas resource is about 322.7×108m3.