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塔里木盆地是世界上勘探程度较低的大型盆地之一。近年来在该盆地中进行了大规模的油气勘探 ,发现了一系列的油、气田 ,其油、气资源量近似 1∶1,说明在该盆地中天然气资源非常丰富。该盆地已发现的天然气主要分布在塔里木盆地东部地区的塔北隆起、塔中隆起和库车拗陷。天然气主要与凝析油及原油伴生。该盆地天然气组分分析表明 ,已发现的天然气藏绝大多数烃类气体含量大于 6 5 % ;非烃气体CO2 含量小于 5 % ,N2 含量小于 10 %。一些天然气中N2 含量达 2 5 %到 35 %。在塔北隆起油气藏中天然气的干湿指数 (C1/C2 +比值 )具有从东到西降低的趋势 ,天然气中N2 含量具有从东到西升高的趋势 ,天然气甲烷的碳同位素组成也具有由东到西变轻的趋势 ,结合该区的地质背景可知造成这一趋势的主要因素可能是由于该区下古生界烃源岩热演化程度具有东高西低的特征。
The Tarim Basin is one of the largest exploration basins in the world. In recent years, large-scale oil and gas exploration has been carried out in this basin and a series of oil and gas fields have been discovered. The amount of oil and gas resources is approximately 1: 1, indicating that natural gas resources are abundant in this basin. The natural gas discovered in this basin is mainly distributed in Tabei uplift, Tazhong uplift and Kuche depressions in the eastern part of the Tarim Basin. Natural gas is mainly associated with condensate and crude oil. Analysis of natural gas components in this basin shows that most of the discovered natural gas reservoirs have a hydrocarbon content greater than 65%, non-hydrocarbon gas with CO2 content less than 5% and N2 content less than 10%. Some natural gas N2 content of 25% to 35%. The wet-dry index (C1 / C2 + ratio) of natural gas in Tarim uplifted reservoirs tends to decrease from east to west, the content of N2 in natural gas tends to increase from east to west, and the carbon isotope composition of natural gas methane also has From the east to the west, the main reason for this trend may be the combination of the geologic setting of the area and the low-east-low thermal evolution of the Lower Paleozoic source rocks.