CO2泡沫压裂液的研究与应用

泡沫压裂液适用于低压、水敏性储集层。通过室内试验及研究，优选出CO2泡沫压裂液配方，得出对其性能测试的结果：起泡，稳泡能力强，流变性能，携砂能力好，低滤失，破胶快等，岩心实验证实具有低膨胀及低伤害特性，可以满足压裂工艺设计的要求，CO2泡沫压裂施工中，如要提高施工规模，增大砂量及砂液比，使用酸性交联压裂液体系可确保施工的顺利进行。在长庆油田等现场实施的CO2泡沫压裂液增产效果良好。

Study and application of CO2 foam fracturing fluids

Foam fracturing fluids have been used to stimulate low pressure, fluid sensitive formations. The characters of foam fracturing fluids have been recognized as leaving minimal damage to fracture conductivity, flowing back quickly, lowing leak off efficient, high efficient fluid, high viscosity and strong proppant carring capacity. Parameters studied in the laboratory include: research and development system of CO 2 foam fracturing fluid, optimization of the formulation and the properties of CO 2 foam fracturing fluid being tested. In the end, conclusion drawn are (1) CO 2 foam fracturing fluid have a strong foamability and foam stability, predominate rheological and proppant carring capacity, lowing leak off and quick breakdown as well, which are satisfied to fracturing technology and it has been confirmed by the experimental results of reservoir cores that CO 2 foam fracturing fluid is characterized by lower expanding and damage for reservoir rock. (2) In the process of CO 2 foam fracturing, CO 2 foam fracturing crosslinked foam by acidity of agent have such capacities as improving dimensions of fracturing, increasing quantity of proppant and sand fluid ratio. Increasing production of CO 2 foam fracturing fluid has been testified in Changqing oil field.