火山岩优质储层定量预测技术及应用

Quantitative Prediction Technology of High Quality Volcanic Reservoir and Its Application

目前,火山岩储层预测还处于火山岩体外观几何形态的定性描述阶段。针对准噶尔盆地乌夏地区夏72井钻遇的气孔未充填熔结角砾凝灰岩这套优质储层开展定量储层预测技术探讨,旨在推动火山岩储层预测技术向定量化方向发展。通过乌夏地区二叠系火山裂隙式喷发模式的建立,认为其分布受火山口、喷发断裂和古地貌的控制。首先,通过火山口识别、喷发断裂刻画和古地貌恢复以及多属性聚类分析,预测熔结角砾凝灰岩的分布;其次,建立气孔充填程度与速度和振幅之间的定量关系,通过正演模拟和反演加以相互验证;最后,在熔结角砾凝灰岩的分布范围内,预测均方根振幅和速度平面分布,根据上述的定量关系,得到气孔未被充填的熔结角砾凝灰岩这套优质储层的分布。预测结果得到钻探证实,证明这种定量预测技术是适用的,值得在类似地区推广应用。

The prediction of volcanic reservoir is still in the qualitative description stage of the appearance geometry. In this paper, we discuss the qualitative prediction of high quality volcanic reservoir which is mainly welded breccial tuff with unfilled pores in the drilled well Xia 72 of Wuxia area,Junggar basin,to promote the volcanic reservoirs prediction technology in the direction of quantification. After the fissure eruption of Permian volcano in the Wuxia area is described,we consider that the distribution of high quality reservoir is controlled by the volcanic vent, eruption fracture and the ancient landform. The prediction methods of the high quality volcanic reservoir are documented as follows： firstly, the distribution of welded breccial tuff is determined by crater identification,eruption fracture description,ancient palaeogeomorphology restoration as well as multiattribute clustering analysis. Secondly, the quantitative relationship between pore filling degree and velocity is established by result verification of both forward modeling and inversion. Finally,the flat RMS amplitude and velocity distribution is predicted in the scope of the fused tuff breccia distribution. According to quantitative relationship, the distribution of the high quality reservoir is gotten. The predicted result has been confirmed by drilled hole, indicating the quantitative prediction of this technology applicable,and it is valuable to be promoted in the similar areas.