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大庆油田深部砂岩储气层岩性胶结致密,孔隙度为5％—10％,渗透率为0.01×10~(-3)—10×10~(-3)μm~2,粘土矿物绝对含量在5％—28％之间。在实验条件下,两性复合离子聚合物钻井液体系对该储层的渗透率损害程度为60％—95％。储层损害以钻井液滤液损害为主,固相损害极小甚至不存在,滤液损害又以水锁损害为主。减小储层渗透性损害的有效途径是:控制静液柱压差低于3MPa,选用优质降滤失剂,将高温高压滤失量控制在10mL以内,并将瞬时滤失量降到最小值。控制滤液性质,降低滤液表面张力,减小水锁损害,将是研究致密砂岩储气层损害的重点。
The lithology of deep sandstone reservoirs in Daqing Oilfield is cemented tight with a porosity of 5% -10% and a permeability of 0.01 × 10 -3 -10 × 10 -3 m 2. The absolute content of clay minerals is between Between 5% -28%. Under experimental conditions, the permeability of the amphoteric composite ionomer drilling fluid system to this reservoir is between 60% and 95%. Damage to the reservoir is mainly caused by the filtrate of the drilling fluid, with little or no solid-phase damage. The filtrate damage is mainly water-lock damage. The effective way to reduce the damage of reservoir permeability is to control the pressure drop of hydrostatic column to be less than 3MPa, to select high-quality filtrate reducer, to control the loss of high temperature and high pressure within 10mL and to minimize the instantaneous filtrate loss . Controlling the properties of the filtrate, reducing the surface tension of the filtrate and reducing the water lock damage will be the focus of research on the damage of tight sandstone gas reservoirs.