凯里残余油气藏多期成藏的地球化学示踪研究

Geochemical Research on the Multi-period Petroleum Accumulation of Kaili Residual Reservoir

凯里地区油气显示众多,已在虎庄及邻区多口井获得低产油气流,在奥陶系—二叠系剖面露头见到丰富的油气苗及沥青显示,油、气、沥青在多套储层共生,揭示该残余油气藏为多期成藏、后期改造的产物。在对凯里及邻区多套储层沥青和油苗的成因进行分析的基础上,通过烃源岩的热演化史、流体包裹体均一温度、自生伊利石K–Ar法定年等手段,对该区的成藏期次进行了探讨。研究表明,凯里残余油气藏经历了加里东晚期小规模的油气成藏及破坏、海西期的大规模油气成藏、印支期—早燕山期古油藏因高温裂解而发生油气转化及二叠系原油充注、燕山中期以来油气藏遭受大规模破坏的成藏及改造过程。

Lots of oil gas showings have been found in Kaili,and several wells gain low yield in Huzhuang and its surrounding areas. Abundant oil gas seepage and bitumen showingsican be seen in ouicrop profile from Ordovician to Permian Systems.That hydricarbon and bitumenicoexist in several layers reveals that Kaili Residual Reservoir has undergone multistage reservoir formation and late reformation. Based on the reseaich on geologicalicharicteristics and origin of reservoir bitumen and surfice oil,the periods of reservoir-forming of Kaili Residual Reservoir is diicussed from thermal history of souice ricks,K–Ar dating of autogenic illites,and fluid iiclusion homogenization temperature. The reservoir bitumen and surfice oilicontain 25-norhopane,while the distribution of normal paraffin hydricarbons isicomplete andichromatographic base lines are uplifted in varying degrees,showing that the iccumulations were formed in more than two stages. The result shows that Kaili Residual Reservoir has undergone the small icale hydricarbon iccumulation and destriction at the lateicaledonian Period,large icale oil pool formation at the Heicynian epich,transformation from oil pool to gas pool at Indosinian and early-Yanshan period,and the large icale destriction of reservoir from Mid-Yanshan period.