鄂尔多斯盆地佳县-子洲地区上古生界储层特征

位于鄂尔多斯盆地的佳县-子洲地区是近期天然气勘探的重点区带之一，面积约9 000 km2 。区内上古生界石炭系至二叠系的太原组、山西组和下石盒子组是本区碎屑岩的主要勘探目的层系。对佳县-子洲地区碎屑岩储层特征综合研究表明，上古生界储层成因类型、岩石类型、储集空间类型多样，具有低孔低渗的特征。影响和控制储层发育的主要因素包括沉积作用、成岩作用和构造作用。沉积作用控制储集岩体的发育和分布，影响着储层的基本形态和所经历的成岩作用类型和强度，是控制储层发育的主导因素。成岩作用决定了储层内部储集空间特征和储集性能。沉积作用对储层的控制一方面表现在粒度和岩性的变化上，另一方面反映在沉积微相上。成岩作用对储层产生的不利因素主要为压实作用和胶结作用，有利因素主要为溶解作用和蚀变重结晶作用。模糊数学综合评判方法研究表明，太原组潮道砂体、山西组和下石盒子组三角洲河道砂体储集性能较好，区内镇川堡、大佛寺、佳县、子洲等区块是较好的勘探目标区。

RESERVIOR CHARACTERISTICS OF THE UPPER PALAEOZOIC IN THE JIAXIAN-ZIZHOU AREA OF ORDOS BASIN

Jiaxian-Zizhou area with area of 9 000 km 2 is located at the east in the Ordos Basin. It is one of key regions for recent natural gas exploration. Taiyuan, Shanxi and Xiashihezi Formations in the Carboniferous and Permian are the main objective exploration targets for clastic rocks in this area. The reservoir is of characteristics of many genetic types, rock types,reservoir interspace types, as well as low porosity and permeability. The sedimentation, diagenesis and structural process has played important roles in formation and evolution of reservoir. Sedimentation controlled development and distribution of the reservoir, and affected basic configuration of the reservoir as well as the diagenesis style and intension, which results in the change of granularity, lithology and sedimentary microfacies. The diagenesis decided the interior reservoir space and capability. The compaction and cementation are favourable process for diagenesis, while the dissolution and alteration with recrystallization are on the contrary. The comprehensive evaluation using the Fuzzy theory shows that the reservoirs in tidal channel sand bodies and delta channel sand bodies are of superior capability. The blocks of Zhenchuanpu, Dafusi, Jiaxian and Zizhou are favourable exploration targets.