高成熟碳酸盐气源岩定量评价标准的探讨

随着全球性石油天然气勘探的商业风险性日益增大,烃源岩的商业评价越来越受到重视,但对于高成熟碳酸盐岩一直没有一个很好的评价方法,尤其是气源岩的评价更缺乏手段。从有效气源岩的概念入手,利用岩石等温吸附仪求取岩石最大吸附气量,再利用热模拟分析仪测定岩石的热解气量,热解气量大于岩石最大吸附气量即为有效气源岩,通过大量实验,建立了高成熟碳酸盐岩作为有效气源岩的评价标准,认为产气率等于151/t为碳酸盐岩有效气源岩的下限值,并将该标准应用于塔里木、鄂尔多斯和四川3个含气盆地,验证了该评价方法的可靠性和有效性。

DISCUSSION ON QUANTITATIVE EVALUATION CRITERION FOR HIGH-MATURED CARBONATE GAS SOURCE ROCKS

As commercial risk of oil and gas exploration of the world increases, commercial evaluation on source rocks has become more and more important. Till now there isn' t a good method to evaluate high matured carbonate source rocks, especially of gas source rocks. Quantitative evaluation criterioa for gas source rocks is introduced in this paper.According to the conception of effective gas source rock, rock isothermal absorber is used to abtain maximum of absorptive gas, then use thermal analogy analyzer to measure the pyrolytic gas amount of the rock. If the pyrolytic gas amountis greater than the maximum of absorptive gas of the rock, the rock then could be considered as available gas sourcerock. The criterion of high-matured carbonate rocks is established as effective gas source rocks by a lot of experiments.Gas generation rate of l5 l/t is considered to be the lower liwit of the carbonate. source rocks. This criterion is appliedto evaluate the available carbonate source rocks in Tarim, Ordos and Sichuan basins, and is proved to be effective.