塔河油田原油甾藿烷系列化合物地球化学再认识

Geochemical Characters Recognition for Steranes and Hopanes from Oils of Tahe Oilfield

生物标志化合物是油气油源、成熟度、运移等领域研究中的一项得力工具。运用生物标志物色谱质谱技术,对比研究了塔河油田各油区原油生物标志化合物中甾、藿烷系列化合物特征。研究表明,塔河油田为一由晚期成熟高、轻微改造的原油与早期成熟度低、遭受较强降解原油混合而成的复合油藏,该油藏各区原油C27—C29甾烷同系物以及C27—C29重排甾烷特征反映出该区不同成熟度原油来自同一母源,原油Ts/(Tm+Ts)、重排甾烷/规则甾烷和ββ/(ββ+αα)C29比值关系立体图指示出原油的充注方向,印证了“塔河地区的油气主要来自于南部的满加尔坳陷”这一论点。

Biomarker is one of the most effective tools in the study of oil-source correlation gas-oil maturity and gasoil migration. By using biomarker GC, GC-MS analysis techniques, the geochemical characters of steranes and hopanes from crude oils of Tahe oil field were investigated in this paper. The study shows Tahe oilfield is a compound oil reservoir, which is composed of later generated oils with high maturity lighter biodegradation and earlier generated oils with low maturity stronger biodegradation. The characters of C27-C29 steranes and hopanes series indicate oils with varied maturities generated from the same sort of mother materials. The three-dimensional diagram formed by Ts/ （Tin ＋ Ts）, rearranged-sterane/sterane and ββ/（ ββ ＋ αα）C29 shows that the migration direction of crude oil is from south to north, which confirms the opinion that oil and gas of Tahe oilfield mainly came from Manjiar Depression-an area to the south of Tahe oilfield.