辽河曙光油田杜84块超稠油油藏的储集层胶结非常疏松，原油中沥青质、胶质含量高达45.7%，原油黏度对温度敏感性强，油藏温度45℃时原油黏度高达22×104mP*s。用包封洗油、风干的松散储集层样品制作实验样品，据实验压力要求，在三轴岩心夹持器上将其压实成型，使实验样品的物性参数与区块参数平均值一致。应用由加拿大DBL公司稠油相态平衡装置改装而成的热模拟实验设备，共进行12个样品的热模拟实验，实验温度为100℃、200℃、300℃，实验压力为3.5 Mpa、7.5 Mpa、11.5 Mpa、14.5MPa。热模拟实验结果表明：沥青质沉积与温度及压力关系明显，沥青质主要呈孤岛状、薄膜状、丝片状、星点状、网络状、星云状等形态充填孔隙或在喉道处形成桥塞。沥青质沉积会引起润湿性反转及在孔喉处形成堵塞，在沥青质沉积与微粒迁移堵塞共同作用下渗透率严重降低、毛细管压力增加、喉道变窄。照片1图1参2（张人雄摘）%Du-84 block of Shuguang oil field in Liaohe is an unconsolidated super heavy oil reservoir, with oil viscosity of 22×104mPa*s, and asphalt and gelatinoid content up to 45.7%. The cleaned and unconsolidated core samples are packed to make the porosity and permeability of core samples equal to the average value of the block. A specific heavy oil phase behavior simulation equipment is used, and the thermal recovery experiment of 12 core samples has been carried out. Experiment temperature is divided into three levels (100, 200, 300℃), and pressure four levels (3.5,7.5,11.5,14.5MPa). The principle conclusion of thermal recovery experiment is as follows: asphalt deposition is closely related to temperature and pressure. The asphalt-aggregated states are of island, film sheet, star point, net and cloud which fill up the pores or form bridge-plug at the pore-throat. This will result in the wettability conversion and permeability decrease, capillary pressure increase, and throat size decrease.
展开▼
