考虑裂缝宽度及压差的裂缝-孔隙型储层屏蔽暂堵实验研究

孔隙型储层的屏蔽暂堵技术研究应用较成熟，而裂缝一孔隙型储层的研究不够深入，未充分考虑裂缝宽度及正压差的影响，因此有必要研究不同缝宽及压差条件下的屏蔽环暂堵效果。对川东北区改性后的钻井液进行评价，以碳酸盐岩为实验岩心，进行了裂缝宽度分别为10m、20m、50m的岩样的屏蔽暂堵实验及同一岩样在正压差为1MPa、2MPa、3MPa和4MPa的屏蔽暂堵实验。研究结果表明，改性浆对裂缝宽度在10～50m的岩样暂堵和返排效果好，强度高，并且和该钻井液粒度峰值相匹配的裂缝宽度为50m左右的岩样，暂堵和返排效果最好。裂缝宽度在10m左右的岩样，合理的正压差为2MPa。

RESEARCH ON THE TEMPORARY SHIELDING PLUGGING EXPERIMENT IN CONSIDERING FRACTURE- PORE RESERVOIR OF FRACTURE WIDTH AND PRESSURE DIFFERENCE

The temporary shielding researches of fracture - pore reservoir are less than pore reservoir. And it doesn t consider the influence of the fracture width and positive differential pressure. So it is necessary to research difference fracture wide and pressure to keep shielding temporary. This paper appraises the modified mud in the Northeast in Sichuan basin. Regarding carbonate rock as experimental core, the temporary shielding experiment is done when fracture width of core is 10 m,20 m,50 m and pressure difference is 1 MP,2 MPa,3 MPa and 4 MPa. The research indicates: the effect of temporary shielding rate in the transformed mud is well to the fracture width from 10 m -50 m. When the mud is matching to granularity peak value, the temporary shielding effect is the best. If the fracture width of core is about 10 m, the rational pressure difference of temporary plugging is 2 MPa.