自由膨胀比测定新方法在胜利油区砂岩储层评价中的应用

Application of the Relative Free Swelling Ratio Testing of Clay Minerals in Sandstone Reservoirs Evaluation in Shengli Oil Field,China

粘土矿物的"水敏效应"是引起砂岩储层伤害的最主要原因之一。本文应用自由膨胀比试验的新方法,测定了胜利油区27个砂岩储层岩心样品,并通过X衍射对样品中粘土矿物含量的测定,建立了储层自由膨胀比与蒙脱石含量之间良好的正相关模型。该方法可以更直观、准确地描述出油气储层中粘土矿物的自由膨胀行为,并定量地反映出粘土矿物水敏性导致的储层潜在伤害,也可以用于油田防膨剂的研制,因此在油气田开发中具有较广泛的应用前景。

The water sensitivity of clay minerals is one of the primary causes of reservoir damage in oil fields. As a new testing method of expansive soil, the relative free swelling ratio is defined as the ratio of the equilibrium sediment volume of 10 g ovendried soil in distilled water to that in coal soil （or CC14）. This paper applied this new testing method in swelling property analysis of clay minerals in sandstone reservoir. The relative free swelling ratios of 27 sandstone core samples with argillaceous contents of 10-50% in Shengli Oil Field were measured, the clay minerals contents were also identified by X-Ray, and then the positive correlation model between montmorillonite contents and free swelling ratios of sandstone reservoirs was established. The results showed that the free swelling ratio measurement can more directly and accurately describe the free swelling properties of clay minerals in sandstone reservoirs, and quantitatively reflect the potential swelling damage of reselwoirs caused by water sensitivity of clay minerals, and consequently can be applied in the development of clay antiswelling agents for reservoirs, which is important and significant for adjusting the development plans of oil fields.