克拉玛依油田克75井区上乌尔禾组沉积特征及砂体连通性

Sedimentary Characteristics and Connectivity of Upper Wuerhe Formation in Wellblock Ke 75,Karamay Oilfield

准噶尔盆地克拉玛依油田克75井区上乌尔禾组非均质性强,连通性差异大,砂体展布特征与早期认识有较大差异,需对沉积相及砂体连通性进行研究,明确储集层展布规律。运用沉积学原理,探讨碎屑流与辫状水道共同控制的冲积扇各亚相4级构型要素特征及构型样式,分析各构型样式的沉积特征及其砂体连通性。研究结果表明:当扇根片流带相邻井的电性及沉积旋回特征较一致时,砂体连通性较好;当漫流砂体或漫流细粒沉积发育时,砂体连通性差,不易形成有效储集层。落实了克拉玛依油田克75井区1个Ⅰ类有利开发气藏区。

The upper Wuerhe formation in Wellblock Ke 75 in Karamay oilfield,Junggar basin has strong heterogeneity and varying connectivity between adjacent wells,and the understanding of sand body distribution in the formation is greatly different from the previous one.It is necessary to study the sedimentary facies and sand body connectivity to clarify reservoir distribution.Taking the upper Wuerhe formation in the Wellblock Ke 75 as an example,the characteristics and styles of the 4th-order architectural elements for each subfacies belt of alluvial fan controlled by both debris flow and braided channel were discussed according to the principles of sedimentology,and the sedimentary characteristics and sand body connectivity of each architectural style were analyzed.The research shows that when the electrical properties and sedimentary cycle characteristics of neighboring wells in the sheet flow zone at fan root are consistent,the sand body connectivity is good,and when the cross flow sand bodies or cross flow fine-grained sediments are developed,the sand body connectivity is poor,leading to difficulties in forming effective reservoirs.The research confirmed a Class I favorable gas reservoir area in the Wellblock Ke 75 in Karamay oilfield.