鄂尔多斯盆地铝土岩储集层测井评价

铝土岩气藏是近期在鄂尔多斯盆地发现的一种非常少见的非常规气藏,测井评价在其勘探和开发中发挥着重要作用。前期测井评价中将铝土岩作为风化壳盖层,未将其作为储集层,没有形成系统的测井评价方法,不能满足铝土岩气藏勘探开发的需求。立足盆地西南部陇东地区太原组含铝岩,从岩性、矿物组分、储集层物性、含气性、成像模式-孔隙结构特征五大方面,开展铝土岩气藏的测井评价方法研究。明确了含铝岩层的测井响应特征,建立了声波时差—自然伽马含铝岩识别图版,根据岩石物理实验构建了铝土岩气藏孔渗饱评价模型,结合微电阻率扫描成像和核磁共振测井资料,提出了铝土岩储集层识别标准,形成铝土岩气藏的测井评价方法。

Well Logging Evaluation of Bauxite Reservoirs in Ordos Basin

Bauxite gas reservoir is a kind of very rare unconventional gas reservoir recently discovered in the Ordos basin, and well logging evaluation plays an important role in its exploration and development. In the early well logging evaluation, bauxite was considered as the weathering crust caprock, but not as a reservoir, and there was no systematic well logging evaluation method suitable for the exploration and development of bauxite gas reservoirs. Based on the aluminous rocks in Taiyuan formation in the Longdong area, southwestern Ordos basin, the well logging evaluation method for bauxite gas reservoirs was studied from five aspects, that is, qualitative lithology identification, mineral composition, reservoir physical properties, quantitative calculation of gas-bearing properties and systematic summary of imaging model-pore structure characteristics. The well logging response for identifying aluminous rock formations was clarified and the aluminous rock identification chart by acoustic time-gamma ray was established. The porosity-permeability-saturation evaluation model for bauxite gas reservoirs was constructed through petrophysical experiments, and the criteria for identifying bauxite reservoir was proposed by combining micro-resistivity scanning imaging and nuclear magnetic resonance logging data. Finally, a well logging evaluation method for bauxite gas reservoirs was formed.