Abstract

This study addresses many questions that operators in the Delaware basin are asking in terms of developing their fields:

  • What are the best targets to drill a horizontal well?

  • Are hydraulic fractures overlapping vertically?

  • Should wells be stacked on top of each other or should they be staggered?

  • What is the optimum staggering distance?

  • What is the best way to complete stacked and staggered laterals?

  • Should wells be completed from top to bottom or bottom to top?

The Delaware basin is one of the most prolific basins in the United States, with stacked reservoirs comprising the Avalon Shale, Bone Spring, and Wolfcamp formations. In a quest to develop these resources in an optimum manner, operators are targeting multiple reservoirs in one section, using a stacked and staggered pattern. With the expectation that this wine-rack pattern of wells is the future of the industry, we have developed workflows specific to the unconventional reservoirs, to understand the growth of the hydraulic fractures and their production interference with the offset wells. The goal is to integrate multidomain data to determine the optimum configuration.

To identify the key drivers of production, we built workflows to include high-tier logs (dipole sonic, images, magnetic resonance, and element spectroscopy), unconventional fracture model (UFM), PVT, and numerical reservoir simulations to understand the stimulated reservoir volume (SRV). Advanced geomechanical analysis was performed, which was then calibrated using results from pressure tests using a modular formation dynamics tester. The simulated hydraulic fractures seamlessly integrate into a numerical reservoir simulator to perform calibration and production analysis. The 3D model is used for predictive modeling of the various combinations of stacked laterals. With the use of 3D finite element geomechanics, vertical and horizontal stress shadow is considered between stacked wells and between stages on a single well. The workflow involves staggering wells at varying distances and depths and understanding the fracture interference vertically to optimize the wine-rack and improve hydrocarbon recovery while maximizing productivity per well.

This content is only available via PDF.
You can access this article if you purchase or spend a download.