Case Histories of Integrating DAS Fiber-based Microseismic and Strain Data for Monitoring Horizontal Hydraulic Stimulations

Abstract

The industry is currently utilizing a fairly new technology called Distributed Acoustic Sensing (DAS) to obtain downhole geophysical and geomechanical measurements. This technology uses a fiber optical cable to characterize the hydraulic fracture stimulation. This paper will cover several case studies where data was acquired from a vertical observation well during the stimulation of offset horizontal wells. We have utilized this instrumented well to record several stimulations over a period of many years. Each offset stimulation of a pad, separated by some significant time, is considered an individual case study. The observation well was also equipped with pressure gauges, tiltmeters, and geophones. Each experiment recorded: strain based on acoustics measurements and tiltmeters, temperature, formation pressures, and microseismic. All of these data were then integrated to characterize the stimulation geometries. In addition, the fiber optic cable was used to record 3D vertical seismic profiles, which tie conventional 3D seismic to well logs. Multiple seismic profiles, collected before and after the well is stimulated, have been collected to further enhance our understanding beyond what can be obtained by the measurements made during the stimulation. By integrating each of these datasets we recognized relationships between pressure, temperature, strain, presence of proppant, fluid, and microseismic activity. These new data types have improved our understanding of the hydraulic stimulation process and have altered the way we interpret common historic datasets like microseismic. In addition, the collected surveillance data has been used to update our forward models, so that new designs can be vetted prior to field implementation.

AAPG Datapages/Search and Discovery Article #90343 ©2019 AAPG Southwest Section Annual Convention, Dallas, Texas, April 6-9, 2019