Abstract: Based on a study of the source rocks in the HLR basin, this paper suggests a numerical and comprehensive index named as source rock index (SRI)to evaluate the hydrocarbon source rock quantitatively.The value of SRI lies in a range of 0 to 100.It is indicated that the rock is unsaturated by hydrocarbons and didn't come to a critical point of expulsion of hydrocarbon significantly if its SRI is less than Ol.ts quality or grade is compara ble to or better than Daqing source rock if SRI value is greater than 100.The greater the SRI is, the better the source rock and the more the amount of hydrocarbon expelled.The average critical depths of the expulsion of methane(CH₄), heavy hydrocarbon gas(C2-4)and liquid hydrocarbon(C₅ or higher)of the source rocks in the HLR basin are 400m, 600m and 1870m respectively.Their methane source rock index(SRIgl), heavy hydrocarbon gas source rock index(SRIgn)and liquid hydrocarbon source rock index(SRIo) are less than 100, 50 and 25 respectively.This means that the prospect of the natural gas in HLR basin is better than that of the oil.

摘要： 根据海拉尔盆地源岩排油气量的研究,提出了对源岩进行综合定量评价的源岩指数-SRI,海拉尔盆地源岩指数SRI的数值分布于0～100范围。SRI<0说明源岩还没有大量进入排油气门限。SRI≥100说明源岩的品质较好,SRI数值越大,源岩品质越好,排出的烃量越多。海拉尔盆地油气源岩平均排甲烷、重烃气和液态烃的临界门限分别为<400m、600m和1870m。它们的甲烷气源岩指数(SRIg₁)、重烃气源岩指数(SRIgn)和液态烃源岩指数(SRIo)分别小于100、50和25,表明海拉尔盆地的天然气勘探前景较好。

关键词: 海拉尔盆地, 生油岩评价, 生油气量