闭合酸化工艺在高钙储层中的应用

大庆长垣西部齐家南探区高台子油层由于含钙、含泥量高导致储层孔渗条件变差，常规的压裂和酸化改造工艺易引起地层中粘土矿物的膨胀和颗粒运移，使流动孔隙减小，形成桥堵，造成储层伤害。在对储层物性、酸压工艺、酸液、压裂液等进行实验分析基础上，针对西部高泥高钙储层，开发了相应的酸液、压裂液体系和配套添加剂，提出了适合该区措施改造的新工艺。通过3口井11层的现场试验结果表明，闭合酸化后增液显著，储层物性明显改善。试井解释结果表明，储层综合有效渗透率提高3．30～4．84倍，与常规压裂相比，表皮系数由-1．65下降到-3．99。通过现场试验证明闭合酸化工艺作为大庆油田长垣西部高含泥高含钙储层主要改造工艺是可行的。

Application of Closed Acid Fracturing Technique in High Calcium Reservoir

In the west of Daqing placantioline, Gaotaizi layer has properties of poor porosity and permeability due to high calcium and mud content. The conventional fracturing and acidizing methods would cause clay .swelling and granule migration, which will reduce the effective porosity and make the bridge block, harm the layer. Based on the analysis of the layer' s physical properties, the acid fracturing technique, acid liquid and fracturing liquid, we have developed a new acid liquid, fracturing liquid and additive for the layer in the west of Daqing placanticline, a new technique is provided for this area. The result of 1 1 layers and 3 wells showed the closed acid fracturing increased the producing liquid and reservoir physical properties greatly, the well testing reports have shown that the layer' s effective permeability Increased by 3.3- 4.84 times, Comparing with the common fracturing, 5 (skin factor) reduced from - 1. 65 to -3. 99. The on-site test verified that the acid fracturing technique could be applied as the main stimulating technique in the west of Daqing placanticline.