Numerical simulation of the distribution of invading fines in packed proppant

Abstract Fine particles from residual slurry and the mobilized clay particles from the shale formation will invade into the proppant-supported fracture and cause porosity reduction. Understanding the distribution of these fine particles in the packed proppant is significant for preventing undesired formation damage and achieving expected engineering targets in the development activities of oil and gas. A numerical model considering particle expansion, size, and shape was proposed to predict the distribution of invading fines. In the prediction by the non-expandable particle flow model, particles either gathered at the entrance due to too large size or formed bridge plugging by multiple small fines. It led to the plugging in the deep region of packed proppant were ignored and difficult to predict. The prediction by this model found that the expansion resulted in a different distribution pattern and more serious plugging compared with the conventional big or small particle. The invasion distance of the main plugging area increases with expansion timing but decreases with the expansion ratio. The plugging degree of the main plugging area decreases with expansion timing but increases with the expansion ratio. The aspect ratio of particle shape after inhomogeneous expansion influences the invasion as well. A slight inhomogeneous expansion (AR 3) will weaken the process of invasion into porous media. This work simulated the distribution of invading fines in proppant-supported fractures. It will provide the necessary data for future more accurate fracture conductivity prediction.