胜利油区砂岩成岩作用及油层保护措施研究

胜利油区不同埋藏成岩带的砂岩储集层的成岩矿物、孔隙类型、储集性以及敏感性矿物不同 ,造成储集层的潜在伤害类型的差异。浅埋藏砂岩储集层的潜在伤害是粘土膨胀和出砂 ,油层保护的重点措施是机械筛网、屏蔽暂堵和添加防膨剂 ;中埋藏砂岩储集层中微粒运移、粘土膨胀和孔喉堵塞是主要伤害形式 ,其保护措施主要是添加稳定剂和防膨剂 ;深埋藏砂岩储集层潜在伤害类型主要是固相颗粒堵塞、无机结垢等引起的渗透率下降 ,其保护措施主要是添加稳定剂及铁螯合剂、复合酸酸压和屏蔽暂堵等。同一埋藏深度的砂岩储集层 ,由于沉积特征、成岩演化和储集层特征的差异 ,决定了其潜在伤害类型的差异。应有针对性地采取措施 ,以获得最佳的经济效益。

SANDSTONE DIAGENESIS AND FORMATION DAMAGE PREVENTION IN SHENGLI OILDOM

The reservoir spaces, reservoir characteristics of diagenetic minerals and the distribution of sensitive minerals are changable according to burial diagenesis belts of sandstone reservoir in Shengli oildom. It leads to the differences of latent formation damage. The latent formation damage pattern of shallow seated sandstone reservoir includes clay swelling and sand flow problem. The prevention methods for formation damage are mechanical sand control, temporary screen blocking measures and using anti clay swelling agent. Clay stabilizer and anti clay swelling agent can be used respectively for preventing clay fine migration and clay swelling in middle seated sandstone reservoir which may suffer to many formation damages, mainly including solid grain shutoff and inorganic scale. The main measures for damage prevention of this type of formations in deeply seated sandstone reservoir can use stubilizer, temporary screen blocking, iron chelating agent and acids for fracturing. The latent formation damage of sandstone in the same depth varyies with the sedimentary environments, diagenetic evolution and reservoir characteristics. Methods selected for damage prevention of this type of formation should be in accordance with formation situation to obtain the maximum economic results with minimum costs.