济阳坳陷渤南—孤北地区深层天然气成藏期分析

Timing of Deep Gas Accumulation in Bonan and Gubei Areas of Jiyang Depression

通过气源岩热演化生烃史、储层流体包裹体均一温度、天然气轻烃及构造活动综合分析,探讨了济阳坳陷渤南—孤北地区深层天然气藏的形成时间和期次。研究表明,孤北潜山带存在2期不同成因天然气的充注过程:煤成气于新近纪馆陶沉积晚期充注、油型气于新近纪明化镇中期充注;渤南洼陷油型气藏存在沙一末至东营末期和明化镇期至现今的2次充注过程,以第二期充注为主。不同构造部位、不同层系的成藏期有明显差异,构造低部位气藏形成时间早于高部位。

The formation time and stage of the deep gas reservoirs in the Bonan and Gubei Areas of Jiyang Depression are ascertained by a set of analysis techniques, including the hydrocarbon generation history, fluid inclusion homogenization temperature, light hydrocarbon characteristic and structure movement analysis. Two periods of different original gas charging are established in the Gubei buried hill belt, coalformed gas charging in late stage of Ng and oil-formed gas charging in middle stage of Nm. At the same time, there are two accumulation periods which include from late stage of Esl to late stage of Ed and from the stage of Nm to nowadays in oil-associated gas reservoirs in Bonan sub-sag, the late stage accumulation plays an important part. There are different periods at different structure location and strata. The formation period of gas reservoir at downstructure location is earlier than that of gas pool at upstructure location.