夏9井区克下组成岩相及其对油水分布的控制作用

Diagenetic Facies of Kexia Formation in Well Xia9 and Its Control to the Distribution of Oil and Water

夏9井区地处准噶尔盆地西北缘,其三叠系油藏和下侏罗统八道湾组油藏是夏子街油田的组成部分。通过对三叠系克下组储层的成岩作用阶段及各阶段中的成岩作用类型的研究,识别出3个成岩相,即压实成岩相、铝硅酸盐及碳酸盐溶解成岩相、碳酸盐及自生粘土胶结成岩相,后者又分为深埋胶结亚相和复合成因的胶结亚相。成岩相的分布不仅控制了研究区的含油区带,同时也是造成区内南西段的背斜低部位含油,而东北段的背斜高部位仅含水或为干层的主导因素。

The area of Well Xia9 was located in the northwest margin of Junggar Basin. Its reservoirs of Triassic and Badaowan Formation of lower Jurassic were the compositional parts of Xiazijie Oilfield. Based on the study of diagenetic stages and diagenetic types at each stage of the reservoirs of Kexia Formation of Triassic, three diagenetic facies were identified, which included compaction diagenetic facies, aluminosilicate and carbonate dissolution diagenetic facies, carbonate and authgentic clay mineral cement diagenetic facies, and the latter could be subdivided into deeply buried cement subfacies and multiple genesis cement subfacies. The distribution of diagenetic facies not only controls the oil bearing zones, but also is the dominant factor which causes oil only being contained in the lower position of the southwest anticline section, while the higher position of the northeast anticline section contains only water or dry layer.