TX-7井加砂压裂砂堵影响因素浅析

砂堵是造成压裂施工失败的最直接原因，尤其是在四川地区致密碎屑岩气藏的压裂施工中，砂堵的几率较高，而影响砂堵的因素又较复杂，主要包括地层因素、压裂液因素、工程因素、设计因素等，如何有效避免砂堵的产生一直是压裂设计和施工作业中感到棘手的难题。针对大塔场构造TX-7井复杂的工程地质特征和砂堵特点，根据对测试压裂和主压裂施工数据及曲线进行分析处理的结果，分析评价了该井产生砂堵的多裂缝、井筒及井眼附近摩阻、压裂液效率等因素的不同影响程度，并针对大塔场构造沙-气藏为特低渗的薄互层、井眼附近摩阻高、滤失系数大等复杂的地质和工程特征，提出了优选射孔层段、段塞降摩阻、粉砂暂堵、高粘液体降滤等多 项重要枯术措旆的建议．其结论和建议对四川地区致密碎屑岩气藏的压裂改造具有重要的指导意义。

ANALYSIS OF AFFECTION FACTORS FOR SAND PLUG OF SAND FRACTURING IN WELL TX-7

Sand plug is the main cause for resulting in fracturing failure, and the probability of sand plug is higher when fracturing in tight clastic gas pool in Sichuan region. Affection factors of sand slug are manifold, including formation factor, fracturing fluid factor,engineering factor and design factor and so on. How to avoid sand plug effectively is a knotty problem in fracturing design and operation. Aiming at complicated geologic characteristics and the sand plug feature of TX-7 well in Datachang structure, and based on the analysis processing result of construction data and curve of minifrac calibration treatment and main fracturing, this paper analyzed the affection factors of sand plug, including multi-fissure, well bore, friction resistance of wellbore, fracturing fluid efficiency. And this paper offered some important technical measures, such as optimizing perforated interval, slug reduction frictional resistance, silt temporary plug, high viscosity fracturing fluid loss, and so on. The conclusion and suggestion have important guide significance for fracturing of tight clastic gas pool in Sichuan.