塔中62区块上奥陶统碳酸盐岩储层非均质性影响因素

Influencing factors of the Upper Ordovician carbonate reservoir heterogeneity in Tazhong 62 area

塔中奥陶系碳酸盐岩储层主要以礁滩相颗粒灰岩为主,储集空间类型主要为孔洞型和裂缝-孔洞型,储集层缝洞系统发育,储层非均质性很强。充分认识此类储集层非均质性的影响因素对于油藏的有效开发至关重要。研究表明,同生期大气成岩环境中形成的横向连续性差的透镜状礁滩沉积岩体,是影响储层平面非均质性的主要因素之一;受岩溶作用影响在垂向和横向上孔洞集中发育段,导致储层物性在横向和垂向上的变化难以评价;不同尺度的裂缝网络系统是影响储层渗流能力非均质的一个重要因素;岩性隔夹层、沉积微界面、成岩致密胶结带等一系列的渗流屏障,对流体的运移起到了阻隔作用,加大了储层非均质性的严重程度。

The carbonate reservoir of Ordovician in central Tarim area is mainly grained limestone of reef flat facies and has pore-cave type and crack-pore-cave as its space.The reservoir has a developed fracture-hole system and strong heterogeneity.Understanding the development and influencing factors of heterogeneity,which has a seriously impact on the de-velopment of reservoir.h is showed that lens shaped reef flat deposits, which was formed in the syngenetic atmospheric enviromnent and had a poor lateral continuity,is the main influ- encing factor of the heterogeneity.Effected by the Karst, the holes mainly developed together, which made the prediction of reservoir property in vertical and horizontal very difficult,frac- ture network of different scales is the main factor influencing the heterogeneity of reservoir permeability.Flow barrier, such as interlayer, sedimentary micro interface and dense cement zone,resisted the migration of oil and gas and increased the reservoir heterogeneity.