考虑支撑剂嵌入和地层砂运移的支撑剂指数法

南海东部主要为疏松砂岩储层,含蜡量大,出砂严重,常采用压裂充填技术作为增产防砂一体化措施。支撑剂嵌入以及地层砂运移会对裂缝导流能力产生较大的影响,但现有裂缝设计方法没有考虑这些影响。针对这一问题,本研究提出一种考虑支撑剂嵌入和地层砂运移的支撑剂指数法,通过数值迭代求解,对裂缝几何参数进行优化设计。通过南海东部某口井实例计算发现,设定支撑剂体积为20-30m3,传统支撑剂指数法优化的裂缝宽度为2.2-2.7cm,裂缝长度为18.0-22.0m;考虑微粒运移和支撑剂嵌入时,新方法优化的裂缝宽度为3. 5-4.2cm,优化的裂缝长度为11.6-14.2m。地层砂运移和支撑剂嵌入程度越深,优化的裂缝长度有所下降,优化的裂缝宽度有所增加。新方法考虑地层砂运移、支撑剂嵌入的影响,对储层的压裂充填工艺参数设计具有一定的指导意义。

Proppant index method considering proppant embedding and formation sand migration

The eastern South China Sea is mainly composed of loose sandstone reservoirs with high wax content and serious sand production. Frac-packing is often used as an integrated measure for sand control and production. Embedding of proppant and migration of formation sand influent the fracture conductivity, which nevertheless are not considered in existing fracture design methods. To resolve this issue, a new proppant index method is proposed that considers proppant embedding and formation sand migration. The proposed method is applied in a case study for a well in the eastern South China Sea, when the proppant volume is set to 20-30m3, the fracture width optimized by the traditional proppant index method is 2.2-2.7cm, and the fracture length is 18.0-22.0m. When considering particle migration and proppant embedding, the optimized fracture width by the new method is 3.5-4.2 cm, and the optimized fracture length is 11.6-14.2 m. The deeper the sand migration and proppant embedding, the optimized fracture length decreases and the optimized fracture width increases. The new method considers the influence of formation sand migration and proppant embedding, which has certain guiding significance for the design of reservoir frac-packing process parameters.