松辽盆地南部烃源岩生烃时效性及天然气富集

The Time Effect of Hydrocarbon Generation of Source Rocks and the Natural Gas Enrichment in Southern Songliao Basin

松辽盆地南部的深层断陷历经多期构造运动,这些构造运动的不平衡使得各断陷深层烃源岩演化有较大差异,进而控制了深层天然气富集。依据深层烃源岩生烃对油气成藏贡献的大小,其时效性可以划分为持续沉降高效型、明水组沉积期末抬升中效型、嫩江组沉积期末抬升低效型和营城组沉积期末抬升无效型等4种类型,根据天然气成藏研究,可划分出中部断陷带深断陷富集气区、周缘高含气区、东部断陷带残留气区和西部断陷带贫气区等4个区域。其中,中部断陷带深层是最现实的大型天然气藏勘探领域。

The deep depressions in southern Songliao basin underwent multistage tectonic movements, of which the unbalance caused the great differences of source rock evolution in each deep depression, resulting in controlling the deep natural gas enrichment in this region. According to the contribution size of the deep source rock hydrocarbon generation to the hydrocarbon accumulation, the time effect of hydrocarbon generation could be divided into four types such as the continuous subsidence high efficiency type, the Late Mingshui period uplift middle efficiency type, the Late Nengjiang period uplift low efficiency type and the Late Yingcheng period uplift inefficiency type, which can be accordingly classified as the deep fault depression gas enrichment area in its middle part, the surrounding high gas-beating area, the remained gas area in the east part and the poor gas area in the west part. It is considered that the deep fault depression gas enrichment area in the middle fault depression zone is the most realistic large scale domain for natural gas exploration in Songliao basin.