Formation Process and Distribution of Laumontite in Yanchang Formation (Upper Triassic) of Ordos Basin
- Received Date: 2001-10-08
- Rev Recd Date: 2002-01-07
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Key words:
- laumontite /
- Yanchang Formation /
- Ordos Basin
Abstract: Laumonti te cement is mainly distributed in the Yanchang 6 reservoir of the no rtheast Ordos basin.Through measuring inclusions in laumontite, we know that its is forming temperature is between 60 ℃and 70 ℃ and it formed in the B period of early diagenetic stage.How ever, in the A period of later diagenetic stage, laumontite were dissolved by organic acid which was generated in decarboxylation of kerogen, and a great quantity of secondary pores were formed.Exploration results have proved that newly found reservoirs are largely dist ributed in the laumontite secondary pore zone.Thus, the formation process and distribution of laumontite cement are very important for exploring reservoirs and hydrocarbon accumulat ion.In the paper, with the investigations of outcrop,thin section, organic inclusion, scanning elect ronmicroscope and elect ron microprobe, the relationship of the forming process, distribution of laumontite cement and sedimentary microfacies is studied on the basis of sedimentary microfacies.The purpose is that laumontite distribution is predicted by sedimentary microfacies.As a result, reservoir distribution is predicted.
Citation: | YANG Xiao ping, QIU Yi nan. Formation Process and Distribution of Laumontite in Yanchang Formation (Upper Triassic) of Ordos Basin[J]. Acta Sedimentologica Sinica, 2002, 20(4): 628-632. |