Effect of multiple hydraulic fractures on gas-well performance

This paper describes the use of a single-phase 2D numerical model to study the performance of a well intersected by two perpendicular vertical fractures assumed to have either infinite or finite conductivities. Analysis of the simulated drawdown tests at a constant flow rate showed that the transient flow behavior of a well intersected by finite-conductivity (C_fD<500) perpendicular fractures does not exhibit the bilinear and formation linear flow periods. However, when fracture conductivities were infinite (C_fD <500), the formation linear flow period was observed. This period was used to determine the fracture half-length and gave a fracture half-length equal to the sum of the two fracture half-length (Xf+Yf). The beginning of the pseudoradial flow period for any conductivity was found to decrease as Yf/Xf increased and to increase as the fracture conductivities increased for a given Yf/Xf. A single hydraulic fracture gave higher productivity than two fractures of the same total length when fracture conductivity was infinite. However, when fracture conductivity was low, the two fractures gave higher productivity than the single fracture.