基于恒速压汞技术的低渗储层孔隙结构与渗流能力——以珠江口盆地文昌A凹陷珠海组为例

PORE STRUCTURE AND PERMEABILITY OF LOW PERMEABILITY RESERVOIR BASED ON CONSTANT SPEED MERCURY INJECTION TECHNOLOGY:TAKING ZHUHAI FORMATION IN WENCHANG A SAG OF ZHUJIANGKOU BASIN AS AN EXAMPLE

目前南海西部各典型低渗透油气藏普遍存在微观渗流规律认识不清、油气开发潜力模糊的问题,严重制约了低渗油气田的后续开发部署。通过应用恒速压汞技术对珠江口盆地文昌A凹陷珠海组低渗凝析气藏储层孔隙结构及渗流潜力进行分析,结果表明:(1)渗透率不同的岩心样品孔隙半径差别很小,喉道是决定研究区储层渗透率的主要因素,主流喉道半径可以作为评价低渗透储层渗流能力和开发难度的关键物性参数;(2)在渗透率>1×10^(-3)μm^2的气藏范围内,文昌A凹陷珠海组开发难度较小;而渗透率在0.1×10^(-3)μm^2附近的特低—极特低渗透油藏范围内,文昌A凹陷珠海组(文昌WC-Y1井ZH3)开发难度很大。

Characteristics of pore structures and development difficulties of the low-permeability gas reservoirs in the Zhuhai Formation in Wenchang A Sag of the Zhuiiangkou Basin were studied with the method of constant speed mercury injection. Results show that. （]） pore radius are similar for the cores with different permeability, throat is the main factor determining the reservoir permeability in the study area. The mainstream throat radius is the key physical parameter to be used to evaluate per- colation ability and development difficulty of a low permeability reservoir; @1 × 10 ^-3μm^2 is is a critical value for a low permeability gas reservoir. While the permeability of gas reservoir is higher than 1×10^-3μm^2, the development difficulty of Zhuhai Formation in Wenchang A Sag is getting smaller; and while the permeability Of super-low permeability reservoirs near is lower than 0.1 × 10^-3μm^2 , the de- velopment difficulty of Zhuhai Formation in Wenchang A Sag （ZH3 of Wenchang WC-Y1 well） is greater.