东营凹陷盐家地区沙四上亚段砂砾岩储层分类评价方法

Classified Evaluation of Sand-Conglomerate Reservoir of the Upper Section of the Fourth Member of Shahejie Formation in Yanjia Area,Dongying Depression

综合利用岩芯观察、薄片鉴定、物性测试等技术方法,以孔隙度、储集空间特征、成岩作用特征、孔喉分布特征以及含油性特征等为综合分类依据,将东营凹陷盐家地区沙四上亚段近岸水下扇砂砾岩储层划分成3大类7小类。Ⅰ-1类以中等偏弱压实—弱胶结为特征,原生孔隙相对发育;Ⅰ-2类以中等压实—较强溶蚀为特征,长石、岩屑溶孔以及晶间孔相对发育;Ⅰ-3类以中等胶结—较强溶蚀为特征,碳酸盐、长石溶孔相对发育;Ⅱ-1类以中等偏强压实—中等溶蚀为特征,长石、岩屑溶孔相对发育;Ⅱ-2类以中等偏强胶结—中等溶蚀为特征,碳酸盐、长石溶孔相对发育;Ⅲ类孔隙不发育,Ⅲ-1类以强压实为特征,Ⅲ-2类以强胶结为特征。从Ⅰ-1类到Ⅲ-2类储层孔隙含量降低,孔喉结构变差,荧光强度降低,岩芯油气显示变弱。结合试油试采资料对不同沉积亚相储层组合类型进行了评价,结果表明不同沉积相带储层组合对应的产能存在较大差异,其中扇中储层组合类型相对优越,储层组合单层厚度变化大,对应着中等—高单位厚度日产液量;扇根储层组合类型次之,储层组合单层厚度较大,对应着较低的单位厚度日产液量;扇缘储层组合类型最差,储层组合单层厚度最薄,对应着低单位厚度日产液量。

Based on the core observation,thin-section identification,physical property test and other technical methods,with porosity,reservoir space characteristics,diagenesis characteristics,reservoir pore throat size distribution characteristics and lubricity characteristics for comprehensive classification basis,the sand-conglomerate reservoir in the near-shore subaqueous fan of the fourth member of Shahejie Formation（ Es_4） in Yanjia area Dongying depression have been divided into three categories and seven small classes. Ⅰ-1 type reservoir is characterized by medium-weak compaction and weak cementation,with primary pores relative development; Ⅰ-2 type reservoir is characterized by medium compaction and strong dissolution,feldspar and debris dissolution pores and intragranular pores are relatively growing; Ⅰ-3 type reservoir is characterized by medium cementation and strong dissolution,with dissolved pores of carbonate and feldspar relative development; Ⅱ-1 type is characterized by medium-strong compaction and medium dissolution,feldspar and lithic dissolved pores are relatively developing; Ⅱ-2 type is characterized by medium-strong cementation and medium dissolution,with carbonate and feldspar dissolved pores relative development; pores do not develop in Ⅲ type reservoir,Ⅲ-1 type reservoir is characterized by strong compaction and Ⅲ-2 type reservoir is characterized by strong cementation. FromⅠ-1 type reservoir to Ⅲ-2 type reservoir,porosity reduces,pore throat structure becomes worse,the fluorescence intensity becomes low,and oil and gas shows in core become weaker. Combined testing and production test data,reservoir combinations in different sedimentary subfacies have been evaluated. The results show that reservoir combination type in different sedimentary facies and its productivity have big differences. Reservoir combination in the middle fan is relatively superior and single-layer thickness of reservoir combination is various,corresponding to the medium-high daily liquid production per unit thickness. Reservoir combination in root fan comes the second and have a larger single-layer,corresponding to the relative lower daily liquid production per unit thickness. Reservoir combination in fan edge is the worst and single-layer thickness of reservoir combination is very thin,corresponding to the lower daily liquid production per unit thickness.