Experimental and theoretical study of fracture conductivity with heterogeneous proppant placement

Proppant distribution patterns play a significant role in the improvement of stimulated well performance. Multiple studies indicate that an uneven proppant distribution within fractures can considerably reduce well productivity. However, fluid flow is not necessarily restricted by a non-uniform proppant distribution. A novel technique called channel fracturing greatly increases fracture conductivity by creating open channels inside fractures that are caused by heterogeneous proppant placement. In this study, an effective experimental model was established to measure the flow capacity with heterogeneous proppant placement. A series of experiments on a discontinuous proppant distribution and conductivity was conducted by considering the formation temperature. The fracture conductivities of a heterogeneous proppant placement and uniform proppant distribution were compared. The effects of the fibre concentration, proppant properties, rock properties, proppant mass placement patterns, and fluid damage on the fracture conductivity and proppant embedment were also investigated to quantify the key factors affecting the effectiveness effectivity of the propped fracture. In addition, new analytical models were derived to calculate the proppant embedment and fracture conductivity with a discontinuous proppant distribution. The creeping deformation model was adopted to predict the changes in the proppant embedment and fracture conductivity over time. This study contributes to the optimization of channel fracturing treatments and elucidates the effect of a heterogeneous proppant placement on fracture conductivity.