千米桥潜山奥陶系储层特征及孔隙演化

千米桥潜山奥陶系的储集类型主要有孔洞型、裂缝型、孔洞缝复合型和孔隙型4类,其中以孔洞缝复合型为主要储集空间,最有利于油气的运聚.储层的分布具有纵向上分带、平面上分区的特点.在纵向上划分的4个带中,以第2、3带储集性能为好,是油气主要的聚集带.在平面上的残丘区和凹槽区中,以残丘区岩溶作用强度大、保存条件有利,储层最为发育.溶蚀孔洞的形成受控于岩性、水性质、构造运动及古气候、裂缝等因素,主要形成于加里东早海西岩溶期 ;构造裂缝的形成受控于构造运动、岩性、构造位置及埋深,主要形成期是印支和早燕山期 .印支早燕山运动对奥陶系储层的改造作用主要表现为产生大量裂缝、再次溶蚀、产生新的孔洞;中晚燕山运动主要表现为严重的充填作用,喜山运动则使孔洞缝有进一步减少的趋势.

RESERVOIR CHARACTERISTICS AND PORE EVOLUTION OF ORDOVICIAN IN QIANMIQIAO BURIED HILL

The Ordovician reservoir types of Qianmiqiao buried hill could be divided into 4 types:1.pore cave reservoir;2.fracture reservoir;3.pore cave fracture complex reservoir;4.pore reservoir.The pore cave fracture complex reservoir type is the major reservoir space type and most favourable for hydrocarbon migration and accumulation.The reservoirs are characterized by zonal distribution both vertically and horizentally.In vertical of the 4 zones,the 2nd and 3rd zones are favourable for hydrocarbon accumulation;in horizontal,residual dome is more favourable for reservoir development.The corroded pores and caves formed in Caledomian-earhy Hercynian and their formation was controlled by the characteristics of rock and water,tectonic movement,palaeoclamite and fractures;the formation of the fractures in Indo Chinese and early Yenshan epoches was controlled by tectonic movement,rock characteristics and burial depth.The Indosimian movement early Yenshan movement resulted in large amounts of fractures and recorroded pores in Ordovician reservoirs;the middle late Yenshan movement resulted in serious filling;the Himalayan movement reduced the pore spaces.