川东北飞仙关组鲕粒滩储层特征研究

川东北下三叠统飞仙关组鲕粒滩储层发育规律是勘探部署的重要依据。通过露头、钻井资料以及实验室内各项分析，研究了飞仙关鲕粒滩储层特征，认为鲕粒滩优质储层岩石类型为 (残余)鲕粒白云岩；储集空间主要为粒间溶孔、粒内溶孔、超大溶孔晶间(溶)孔，构造缝、构造溶蚀缝将各种溶孔连通；孔隙结构分为3类，Ⅰ类粗-中孔大喉型、Ⅱ类粗孔中喉型或中-细孔中喉型、Ⅲ类粗孔小喉型或中-细孔小喉型；储层物性以中-高孔隙度及中-低渗透率储层为主；通过储层评价分出3类储层，其中一类储层为已发现气藏的优质储层，储层类型以裂缝-孔隙型为主，二类储层在研究区较为常见，储层类型以孔隙型为主。建议以鲕粒白云岩岩性圈闭为部署原则，寻找孔隙型二类储层。

CHARACTERISTICS OF FEIXIANGUAN FORMATION OOLITIC SHOAL RESERVOIRS IN NORTHEAST SICHUAN BASIN

The development law of the Feixianguan Formation oolitic shoal reservoirs of Lower Triassic is an important basis for exploration deployment. Through investigating the characteristics of the reservoirs according to the outcrop observation, drilling and lab analysis data, it was considered that the excellent oolitic shoal reservoir rocks are the (residual) oolitic dolostones; the reservoir rooms are mainly composed of intergranular and intragranular solution pores, over size solution pores, intercrystalline (solution) pores, and pore connecting structural fissures and structural solution fissures; the pore structure may be divided into three categories, i.e. coarse medium pores and large throats (category Ⅰ), coarse pores and medium throats or medium fine pores and medium throats (category Ⅱ) and coarse pores and small throats or medium fine pores and small throats (category Ⅲ); and the reservoirs are mainly the medium high porosity and medium low permeability ones. In light of reservoir evaluation, the reservoirs can be classified as three types, in which the type Ⅰ excellent reservoirs are mainly the fractured porous ones in which the gas reservoirs have been discovered; and type Ⅱ reservoirs are commonly found out in research region and mainly composed of porous ones. It is suggested that the lithological traps of oolitic dolostones may be taken as the exploration targets to survey the type Ⅱ porous reservoir. (financed by the 973 Program project, No.1999043311)