川西龙门山前雷口坡组四段白云岩储层孔隙结构特征及储层分类

通过岩心观察、铸体薄片、物性测试、毛管压力曲线和CT扫描等技术，对川西龙门山前雷口坡组四段上亚段潮坪相白云岩储层孔隙结构特征进行了研究，划分了孔隙型、裂缝—孔隙型、孔洞型和裂缝—孔洞型4类储集空间组合类型。分析发现，排驱压力、分选系数、连通孔隙数量占比、配位数和孔隙纵横比能够较好地区分4类储集空间组合类型。结合前期物性分类标准和储集空间组合类型，建立了该区储层分类标准，其中Ⅰ类储层（Φ≥12%）中裂缝—孔隙型为好储层，孔隙型为较好储层；Ⅱ类储层（6% ≤ Φ < 12%）中裂缝—孔隙型和裂缝—孔洞型为好储层，孔隙型为较好储层；Ⅲ类储层（2% ≤ Φ < 6%）中裂缝—孔隙型和裂缝—孔洞型为较好储层。

Pore structure characteristics and reservoir classification of dolomite reservoirs in fourth member of Leikoupo Formation,Longmen Mountain front,western Sichuan Basin

The pore structure characteristics of the tidal-flat dolomite reservoirs of the fourth member of Leikoupo Formation in the Longmen Mountain front in the western Sichuan Basin were studied through core observation, casting thin films, physical property tests, capillary pressure curves and CT scanning. There are four types of reservoir:pore, fracture-pore, pore-vuggy and fracture-pore-vuggy type, which can be distinguished by displacement pressure, sorting coefficient, proportion of connected pores, coordination number and pore aspect ratio. A reservoir classification standard was established combined with reservoir space combination type. For type I reservoirs (Φ ≥ 12%), the fracture-pore type reservoir is the most favorable, while the pore type was second. For type Ⅱ reservoirs (6% ≤ Φ < 12%), the fracture-pore type and fracture-pore-vuggy type reservoirs are the most favorable, while the pore type was second. For type Ⅲ reservoirs (2% ≤ Φ < 6%), the fracture-pore type and fracture-pore-vuggy type reservoirs are favorable.