【摘要】 碳酸盐岩烃源岩的资源评价是油气领域的热点和难点问题,而总有机碳含量(TOC)又是一个非常重要的参数,通常在测定总有机碳含量时,对赋存于碳酸盐岩的烃都未加以计算。通过对鄂尔多斯盆地西峰油田三叠系延长组6个油砂样品中游离烃、封闭烃、碳酸盐胶结物烃、束缚烃和石英颗粒包裹体烃的分步分离和抽提,并用盐酸(10%)处理碳酸盐胶结物后,从酸液中萃取的碳酸盐胶结物烃(相当于氯仿B)的C29甾烷20S/(20S+20R)和ββ/(αα+ββ)比值明显小于其他赋存形式的烃,它可能是碳酸盐沉淀(胶结)时赋存于其中的“原生”烃。更多还原

【Abstract】 Resources assessment of carbonate source rocks is a hot spot and also a difficulty for petroleum industry. Total organic content (TOC) is a very important parameter for resources assessment. However, the hydrocarbons contained in carbonates usually are neglected when calculating TOC. Fractional separation and extraction are performed on 6 oil sand samples taken from the Triassic Yanchang Formation of Xifeng oilfield in the Ordos Basin to test free hydrocarbons, sealed hydrocarbons, carbonate cement hydrocarbons, included hydrocarbons and quartz inclusion hydrocarbons, and the carbonate cements are treated with hydrochloric acid (10%). The C29 sterane 20S/ (20S + 20R) and ββ/(ββ+αα) ratios of the carbonate cement hydrocarbons (corresponding to chloroform B) extracted from the acidizing fluid is significantly lower than that of hydrocarbons occurring in the other forms. The carbonate cement hydrocarbons may be the "primary" hydrocarbons trapped in the carbonate during precipitation (cementation). It is believed based on the preliminary study that a real and reliable result of resources assessment can be obtained only when the hydrocarbons occur in carbonate (calcite) crystals.更多还原