Abstract:
The existing conventional bridge slurry plugging materials have problems such as weak fracture adaptability, shallow plugging layer and low plugging success rate. For this reason, different specifications of elastic mesh materials were selected for evaluation tests of compressive resilience, tensile strength and temperature resistance, and the one with the optimal performance was identified. In addition, we investigated the influence of sizes, shapes and concentrations of the elastic mesh material on plugging efficacy. Experimental results indicate that elastic mesh material marked No.1 is suitable for plugging, due to its low permanent compressive rate of 10% at 50% of its compressive strength, high tensile strength of 150 kPa and high temperature resistance of 150 °C. The cubic elastic mesh material can remain in fractures, and thus presents excellent performance in plugging. The elastic mesh material in the size of 5.0 mm×5.0 mm×5.0 mm has the best plugging performance in wedge-shaped fracture in the size of 5.0 mm × 4.0 mm. In addition, the optimal concentration of the elastic mesh material is 0.08%, and the success rate of one-time plugging has reached 86.7% after the elastic mesh material has been applied in multiple wells. The research demonstrated that the elastic mesh material has good adaptability and plugging effect for fractured formations, and can solve the problem of lost circulation.