The maximum palaeotemperature of oil-bearing sandstones in the UpperTriassic in the eastern Ordos basin has been determined by using many methods including thevitrinite reflectance, fluid inclusion, apatite fission tr...The maximum palaeotemperature of oil-bearing sandstones in the UpperTriassic in the eastern Ordos basin has been determined by using many methods including thevitrinite reflectance, fluid inclusion, apatite fission track, illite crystallinity, chlorite polytypeand diagenetic change of authigenic minerals. The thermal gradient in the Late Mesozoic wasabout 2.9-3.0℃/100m. The Upper Triassic was in a mature stage of organic matter andhydrocarbon began to be generated and migrated during this period. The palaeotemperatures ofoil-bearing sandstones were in the range of 88-110℃; those for the generation and migrationof oil ranged from 112 to 122℃. The thickness of the denuded strata overlying the UpperTriassic was 2465-2750m. The present burial depth of oil-bearing sandstones is generally from400 to 1200m. At a depth of ca. 1900m, the temperature may reach 140℃. Below this depth,organic matter was supermature and mainly generated gas.展开更多
Having a good oil-generation condition, the Lower Cretaceous Xinminbao Group is the main oil-generation bed in the Huahai Depression. Although the Huahai-Jinta Basin has an exploration history of about 21 years, and h...Having a good oil-generation condition, the Lower Cretaceous Xinminbao Group is the main oil-generation bed in the Huahai Depression. Although the Huahai-Jinta Basin has an exploration history of about 21 years, and has numerous oil indications, little advance has been made on oil exploration. Based on a synthetical study of geological data, and by using many methods such as apatite fission track, fluid inclusion, vitrinite reflectance展开更多
基金This study was supported by the cooperative research project of the Petroleum Administration of the Yanchang Oil Field,Shaanxi,and the Northwest University.
文摘The maximum palaeotemperature of oil-bearing sandstones in the UpperTriassic in the eastern Ordos basin has been determined by using many methods including thevitrinite reflectance, fluid inclusion, apatite fission track, illite crystallinity, chlorite polytypeand diagenetic change of authigenic minerals. The thermal gradient in the Late Mesozoic wasabout 2.9-3.0℃/100m. The Upper Triassic was in a mature stage of organic matter andhydrocarbon began to be generated and migrated during this period. The palaeotemperatures ofoil-bearing sandstones were in the range of 88-110℃; those for the generation and migrationof oil ranged from 112 to 122℃. The thickness of the denuded strata overlying the UpperTriassic was 2465-2750m. The present burial depth of oil-bearing sandstones is generally from400 to 1200m. At a depth of ca. 1900m, the temperature may reach 140℃. Below this depth,organic matter was supermature and mainly generated gas.
基金the Second National Oil-Gas Resources Evaluation Item of Oil-Gas General Company in China.
文摘Having a good oil-generation condition, the Lower Cretaceous Xinminbao Group is the main oil-generation bed in the Huahai Depression. Although the Huahai-Jinta Basin has an exploration history of about 21 years, and has numerous oil indications, little advance has been made on oil exploration. Based on a synthetical study of geological data, and by using many methods such as apatite fission track, fluid inclusion, vitrinite reflectance