Modeling of Inter-well Fracture Driven Interaction Between Parent and Child Well Fractures

ABSTRACT: Inter-well Fracture Driven Interaction (FDI) plays an important role in the development of unconventional reservoirs as well density has increased over time due to infill drilling of child wells after a period of production from the initial parent wells. The FDI can lead to a performance hit on both parent and child wells. It is important to be able to simulate the potential impacts of the child well fractures on the overall production performance of these wells, as well as understand the expected pressure response in the parent wells during fracturing of child wells so proper diagnoses and actions can be taken. The current modeling capability of FDI is still limited due to the complex modeling workflow and demanding computation required for simulating the life cycle of fracturing and depletion of parent wells and the associated stress field changes, as well as the new child well fracture propagation and interaction with the existing parent wells. In this work, the unconventional fracture model (UFM) that has been in use commercially for simulating complex hydraulic fracture networks in naturally fractured formation is extended by coupling the propagation of child well fractures with Darcy flow in the existing closed propped parent well fractures. Special handling of moving tips along the existing parent fracture cells are implemented. An example case of a single child frac interacting with a parent frac, based on a previous work by Wu et al. (2022), is presented to illustrate comparable FDI responses. Significant pressure diffusion to the parent well is seen when the parent fracture has sufficiently large conductivity. Contrarily, pressure response is small if the fracture has low conductivity, unless the child well fracture directly intersects the parent well. A more complex case of simulating multiple stages with multiple perforation clusters is also presented.