Fracture Hits Characterization: Application of Post-Fracture Job Analysis and Production Prediction
Authors: Bagci A. Suat 
Published: October 2023

Optimum well spacing is a key factor to improve the performance of unconventional wells within multi-well pads in the field development program. Fracture hits characterization is currently inefficient and poorly defined which impacts the learning on causation and the uncertainty of production results for newly drilled child wells or offset parents. In this paper, workflow, and methodology were developed with the combination of post-fracture job analysis of parent and child wells fracturing jobs and well modeling to predict the production. The impact of well interference on productivity can be identified by evaluating interference between producing wells and interference during the fracturing of parent and child wells and fracture hits.

Post-fracture job analysis from parent wells in the studied shale play can provide information about fracture dimensions for indicating fracture hits with proposed child wells in the pad. Post-fracture job analysis for parent and child wells was used to identify the fracture geometry parameters (fracture half-length, height, width, conductivity, dimensionless conductivity, and fracture permeability) for each stage along the lateral section of the well using digitally recorded fracture treatment data. Frac hits were identified and correlated to which stage hit the existing fractures created along the parent well with the designed fracture treatment schedule and stage spacing.

Production performances of parent and child wells are highly dependent on the fracture stage placement and properly designed fracture treatment. To predict the production of parent and child wells and for evaluation of interference on production performances, the well modeling consisting of the well deviation, fracture geometry dimensions, and completion type was applied using Inflow Performance Relationship (IPR) – Vertical Lift Performance (VLP) matching.

The optimized well spacing indicated that frac hits were observed when the offset distance is lower than 500 ft. which indicated poor spacing execution with deviated wellbores or well bore proximity at the heel. Fracture hits characterization indicated that the increasing communication between parent and child wells when wells were drilled in a depleted zone based on changes in geomechanical stresses caused the propagation of various fracture half-lengths. Perforation design impacted communication due to unreliable cluster performance and it required modification of the perforation design including the reduction in the number of shots per cluster.

Fracture hits characterization helps detect, characterize, and mitigate this communication by determining the cause of the fracture hits and offering quantified rules and recommendations for future field development plans. Post-fracture job analysis characterized fracture hits using post-stimulation jobs to deliver well-spacing rules and completion design recommendations. With developed workflow and methodology, fracture hits characterization combined with post-fracture job analysis, fracture treatment design, well modeling, and production prediction provide powerful solutions to optimize shale play pad development.