Workflow Development and Sensitivity Investigation of Offset Well-to-Well Interference Through 3-D Fracture Modeling and Reservoir Simulation in the Denver-Julesburg Basin

Abstract

The objective of this research was to construct a calibrated multi-well 3D fracture model to evaluate well-to-well interference, also known as well "bashing", in the Niobrara and Codell formations of the Denver-Julesburg (DJ) Basin. Hydraulic fracturing is a vital component to produce in unconventional resource plays economically. In the early stages of development in all unconventional resource plays, including the DJ Basin, single well pads were common for either exploratory drilling or lease retention. Initially many shale plays across the world were not fully developed and in order to capture the resources originally left behind, infill drilling is taking place to access additional resources to create a greater effective stimulated rock volume (SRV) and achieve better recovery. Unfortunately, many previously drilled, producing "parent" wells and newly drilled "child" wells are actually yielding a reduction in recovery rates in short and long-term cases due to interference. Research has shown that one of the main contributors to the variability in production is the presence of pressure depletion from production around the parent wells and the impacts it has on subsequent child well completions. As a means of examining well-to-well interference, the focal point of this study was a nine well pad consisting of six wells in the Niobrara and three wells in the Codell. This pad showed evidence of interference measured using bottom hole gauges installed in the two "parent" wells, one in each formation, during the stimulation of the child wells. Oil and water flowback tracers utilized during the treatment of the child wells also supported the presence of communication. A multi-well, multi-stage (total of 500 stages) 3D hydraulic fracture model was developed using offset vertical well logs and geologic interpretation of mud logs to define the variation in rock properties that best represent the reservoir in which these wells were drilled. vi TABLE OF CONTENTS

Status and Outlook of Oil Field Chemistry-Assisted Analysis during the Energy Transition Period

“…Another issue is that many horizontal wells are drilled in stacked mode and developed as “three-dimensional.” , Infill wells are drilled among many old wells to improve recovery efficiency. , Well-to-well interaction and communication are easy to occur, so the accurate development of unconventional oil and gas reservoirs needs a high-resolution fluid origin tracing technique with very fine stratigraphic intervals between 3 to 6 m. , …”

“…299,300 Infill wells are drilled among many old wells to improve recovery efficiency. 301,302 Well-to-well interaction and communication are easy to occur, 303 so the accurate development of unconventional oil and gas reservoirs needs a high-resolution fluid origin tracing technique with very fine stratigraphic intervals between 3 to 6 m. 304,305 The Delaware basin belongs to the Permian basin, 306 the most productive in North America. 307,308 Take a case with two-row well development, for example, in Figure 19, in terms of dynamic reservoir volume (DRV) and well-to-well communication using a geochemical-based method.…”