川东北铁山-龙会地区长兴组礁滩相储层特征及主控因素

针对铁山-龙会地区长兴组礁滩储层特征，采用岩心、薄片观察及测井解释相结合的方法研究表明，该区储集岩类型主要有礁云岩和礁灰岩，储集空间以次生孔隙为主，储集性能较差，多为低孔、低渗的裂缝－孔隙型和孔隙－裂缝型储层。长兴组储层电性特征明显，礁相储层表现为GR值低，电阻率值呈箱状，深浅双侧向具正差异；非礁相储层测井曲线表现为明显的指状或刺刀状特征，GR值低，三孔隙曲线起伏不明显，储层渗流受到裂缝影响。海平面的相对变化控制了礁滩体的规模，为优质储层的发育奠定了基础，而沉积环境决定了沉积相带的展布，沉积相带影响了储层的储集性能；裂陷槽的上升盘和古地貌高地控制了台地边缘礁滩体的分布，是有利储集相带发育的基础；白云石化作用和溶蚀作用为次生孔隙的发育提供了有利条件，改善了储层的储集性能。

Reef-beach Reservoir Features of Changxing Formation and Its Controlling Factors in Tieshan-Longhui of Northeastern Sichuan

Changxing Formation reef-beach reservoir features are studied with core,thin section observation and logging explanation.It turns out that the main reservoir rocks are reef dolomites and reef limestone,and the reservoir space is mainly secondary pore with poor reservoir property.The reservoir types are mostly fracture-pore and pore-fracture with low-porosity and low-permeability.Changxing Formation has obvious electric response.The reef shows low gamma value,box-shaped resistivity and positive difference of deep & shallow double laterologging.The non-reef shows finger-like logging curve,low gamma,positive difference of laterologging,no significant fluctuation of three porosity log curve and its flow is affected by fissures.Relative change of sea level controls the scale of reef and beach,which gives a foundation of good reservoir.And the sedimentary setting determines the distribution of sedimentary facies which has effects on reservoir property.Uplifted side of rift trough and palaeogeomorphology highland dominate the distribution of reef and beach in the platform margin,which is the basis of the development of excellent reservoir facies belts.Moreover,dolomitization and solution promoted the property of reservoir and provided advantages for the formation of secondary pores.