Abstract

This paper presents a unique process for deriving reservoir properties (i.e., minimum horizontal stress, kh/µ and reservoir pressure) in isolated reservoir layers intersected by the same wellbore.  It is based on simultaneously performing multiple diagnostic fracture-injection tests (DFIT) with extended multi-day shut-in periods using downhole shut-in tools and bottomhole memory gauges.

A case study of 58 wells completed in the Mesaverde and Dakota sandstones of the San Juan Basin is used to describe and assess the above application.  These intervals are gas productive, slightly to significantly sub-pressured, and possess a very low permeability pore network enhanced by natural fracture networks.  As many as seven individual intervals per well were tested using the simultaneous process in an area spanning the entire San Juan Basin.  Large scale, multi-stage hydraulic fracturing is necessary to establish commercial production from these intervals.  The diagnostic tests were done prior to the large-scale fracture treatments, yet did not impede the subsequent implementation of the treatments.  In the Dakota interval, the diagnostic testing results agreed well with the kh derived from post-frac production analysis and led to a process of treatment design optimization.  In the Mesaverde interval, less agreement was found between diagnostic test and production analysis results.  Despite the lack of validation, fluid leak-off rates measured during the diagnostic testing provided insight into fracture half-length differences documented in a previous study of microseismic mapping.  As part of the case study, procedural guidelines and best practices developed in the process of doing over 200 tests will be discussed.

Biography

Ross Martin joined ConocoPhillips in 2007 after receiving a BS degree in mechanical engineering from Texas Tech University.  Mainly focused in Completion Engineering, Ross has completed well in Texas, Oklahoma, Louisiana, and New Mexico.