金湖凹陷阜宁组砂岩储层敏感性分析

Analysis of Sensitivities for Sandstone Reservoir, Funing Formation in Jinhu Depression

储层的速敏性主要与岩石的固结程度及微粒矿物的类型,含量和产状有关;水敏性主要与蒙脱石的含量及其他粘土矿物的含量和产状有关;酸敏性(盐酸)与碳酸盐充填物及含铁矿物的含量、产状有关。通过实验分析表明,金湖凹陷阜宁组阜三段具有较强的速度敏感性和水敏性。阜二段及阜一段则以酸敏性和水敏性为主。建议:①在注入水中加入粘土稳定剂或提高水的矿化度以减小或消除储层水敏性;②为减小或消除酸敏性,应避免将氧化剂或空气带入井内,或在酸液中加入还原剂以控制返出残酸的pH值,或在注入水中加入Fe^(3+)络合剂以抑制Fe(OH)_3沉淀。

The velocity sensitivity of a sandstone reservoir, Funing formation in Jinhu depression, situated in Jiangsu province, is related to the degree of rock consolidation and to the type, content and attitute of clay minerals, and its water sensitivity concerned mainly to the content of montmorillonite, the content and attitute of other clay minerals. The acid sensitivity(HCI) is relevant to carbonate filling in and iron minerals. It is shown by experiments that there are more intensive velocity sensitivity and water sensitivity in the third member of Funing formation in Jinhu depression and acid and water sensitivity in the second and the frist members. From this, proposals are presented: a) to put clay-stabilizer into injection water or to increase the salinity of injection water in order to decrease or eliminate the water sensitivity; b) to prevent oxidant or air from entering into a well or add a certain amount of reductant for limiting the pH value of the return acid solution or Fe^(3+)complexing agents in order to decrease or eliminate the acid sensitivity.