鄂尔多斯盆地西南缘演67井烃源岩评价及油源对比

Evaluation of Source Rocks and Oil-Source Correlation of Well Yan67 in Southwest Margin of Ordos Basin

近年来，鄂尔多斯盆地西南部彭阳地区侏罗系石油勘探取得重大突破。石油预探不断加强盆地西南边缘的勘探力度，2010年位于盆地西南边缘甘肃平凉地区的演67井和演65井等井不但在长8钻遇油层而且在长7钻遇平均厚度达10m的暗色泥岩。针对勘探中出现的新情况，选取暗色泥岩进行地球化学精细定量分析研究．揭示了该区域暗色泥岩具有有机质丰度高、类型好、成熟度高的特点，与盆地内部长7优质烃源岩具相近似的电性、岩性和地球化学特征，为一套优质的烃源岩。同时，对演67井长8油藏原油从物性、母源性质、沉积环境、成熟度等方面展开精细油源对比分析，揭示了该油藏的油源。该研究成果不仅扩大了盆地的生烃范围，拓展了勘探新领域，而且有效地指导了盆地西南缘勘探部署。同时,对进一步评价天环坳陷南段资源潜力提供了重要依据。

In recent years, Jurassic oil exploration in Pengyang region of southwestern Ordos Basin has obtained a major breakthrough. Oil pre-exploration continues to be strengthened in the southwest margin of the basin. In 2010 in Pingliang region, located in the southwest edge of the basin, Yan67 and Yan65 wells were not only drilled down to oil reservoir （s） of ChangS, but also drilled down to average thickness of 10m of mela-mudstone of Chang7 reservoirs. In the light of the new situation in the exploration, the authors select the mela-mudstone to analyze quantitatively in detailed of geochemical studies. It revealed characteristics of high abundance of organic matter, good type, and high maturity of the mela-mudstone in the region. It＇s a set of high-quality source rocks, with similar quality of electricity, lithology and geochemistry to that of high- quality source rocks of Chang7 in the basin. Meanwhile, for the crude oil from Chang8 reservoir of well Yan67, fine oil-source correlation analysis has been conducted on the properties, the kerogen types, the depositional environment, and maturity. This revealed the kerogen typeof the oil reservoir. The results not only expand the range of hydrocarbon-generating in the basin, expanding the new exploration areas, and effectively guide the exploration deployment in the southwest margin of the basin. It provides an important basis for further evaluation of the resource potential of the southern section of Tianhuan depression.