摘要
本文介绍了松辽盆地东部砂岩中自生石英内气液包裹体均—温度和盐度测定结果以及包裹体形态和温度分布特征,讨论了包裹体均—温度与盐度的关系,利用盐度数据确定盆地东部早白垩世沉积属于淡水—半咸水大型湖泊沉积,利用均—温度确定生油门限深度、排烃深度及勘探下限等,并推算出盆地东部的大致古地温梯度和朝阳沟地区的抬升高度。
The measurement results of homogenization temperature and salinity of gas-liquid inclusions in authigenic quartz of deep sectional sandstone in eastern Songliao Basin are presented, and the mechanism of the authiqenic quartz forming, the application of the mentioned results are discussed in this paper.
Authigenic quartz is one of the main diagenitic minerals in sandstone, the homogenization temperature and salinity of gas-liquid inclusions in which may approximatly stand for the diagenitic temperature and salinity of pore fluid. The index of secondary growth, which is one of the main forms of authigenic quartz forming, reaches to 46 in Songliao Basin. It is shown by electronic probe that the enlarged quartz were fromed in different stages and controlled by buried diagenese. The inclusions in the secondary enlarged quartz may represent partially the changing of temperature (76t - 173℃) and salinity (0- 4g/ 100ml) of pore fluid during the forming of the secondary enlarged quartz. The normal relation between homogenization temperature (135-150℃ ) and salinity has been set up according to Well Chao N0.2.
Temperature (℃) = 128.85+5.04 × Salinity, with the coofficient of 0.5932.
Based on the comparison of homogenization temperature in different depth of several wells, the palaeothermal gradient of eastern Songliao Basin can be estimated as 4.66℃/ 100m which is a little higher than the average thermal gradient 4.2℃ / 100m of present, this kind of differences may be caused by the difference between palaeo- burial depth and the modern depth. The relative risen height of Chaoyanggou area is calculated as about 400- 500m when compared with Sanzhao aera.
The functional relation between depth and palaeotemperature in Sanzhao area can be deduced according to the data of palaeothermal qradiend and the present thermal qradient:
Hb=21.46Tb-137
it can be calculated based on this formula that: The large amount of authigenic quartz formed in 1494.0m (Tb= 76℃ ); the t
出处
《沉积学报》
CAS
CSCD
北大核心
1991年第3期106-115,共10页
Acta Sedimentologica Sinica
