准噶尔盆地阜东斜坡区三叠系韭菜园子组成岩作用特征及其对储层物性影响

Diagenesis and Its Effects on the Reservoir Property of the Triassic Jiucaiyuanzi Formation of Fudong Slope,Junggar Basin

三叠系韭菜园子组为准噶尔盆地阜东斜坡区重要含油层系之一,对其成岩作用类型及特征研究较少,影响到对油气储集认识以及后期储层开发。通过开展薄片观察、扫描电镜、物性分析、X-衍射以及电子探针等多种测试分析手段,明确韭菜园子组成岩作用特征及其对储层物性影响。结果表明:研究区韭菜园子组储层类型主要属于中孔-低渗储层,部分为中孔-中高渗储层,储层微观非均质性较强,成岩作用是造成储层微观非均质性强的关键因素。通过研究,认为韭菜园子组储层主要发育压实、胶结以及溶蚀成岩作用,储层成岩阶段为中成岩A期。压实作用强度普遍为中等,是造成储层物性差的重要因素;胶结作用强度为中等-强,溶蚀作用强度普遍为弱-中等,局部较强。其中方解石、黏土矿物以及硅质胶结进一步降低储层物性,沸石胶结以及溶蚀程度改善储层物性。

The Triassic Jiucaiyuanzi Formation is one of the main hydrocarbon-bearing strata in Fudong slope area of Junggar basin.The lack of research on the types and characteristics of the diagenesis affected the recognition and development of the reservoirs.By using such testing technology as slice observation,SEM,property analysis,X-Ray and electron probe,the diagenesis characteristics and its effect on reservoir property were clarified.Results show that reservoir types of Jiucaiyuanzi formation are mainly middle pore and low permeability reservoirs,with some types being middle pore and middle-high permeability reservoirs.The reservoirs have strong micro anisotropy caused by diagenesis.It is concluded that the diagenesis of compaction,cementation and dissolution was developed in Jiucaiyuanzi formation.The diagenesis stage is in stage A.The moderatein tensity of the compaction is the key factors to poor property;the intensity of cementation is moderate-strong and the intensity of dissolution is weak-moderate,sometimes strong.Calcite,clay minerals and siliceous cementation further decreases the property of reservoirs,while zeolite cementation and its dissolution improves the property.