Abstract

Abstract The objective of diagnostic fracture injection tests is to optimize multi-sand completions by estimating pore pressure and permeability in each lenticular sand. Since December 1998, over 200 diagnostic fracture injection tests have been pumped into isolated Piceance Basin Mesaverde sands in an effort to optimize well completions. The diagnostic injection tests were implemented to qualitatively identify the presence of fractures/fissures, to provide estimates of pore pressure and permeability, and to optimize the perforation scheme for effective limited entry fracture treatment diversion. This paper describes the diagnostic fracture injection test methodology, summarizes the results, and provides illustrative examples of typical Mesaverde sandstone pressure falloff response. The results from 201 diagnostic fracture injection tests show extreme differences in reservoir quality between sands with very similar openhole log signatures. While approximately half of the injection tests indicate open fractures/fissures through pressure-dependent leakoff, it is quite common to observe relatively high-permeability (kg > 0.050-md) without indications of open fractures/fissures. Permeability estimates between pay sands separated by less than 50-ft have been observed from kg < 0.001-md to kg > 0.100-md. Several examples of sands damaged by drilling mud invasion (fracturing) have also been verified with the diagnostic injection test analysis, which can differentiate between reservoir fluid permeability and fracture face damage. Since the differences in reservoir quality are identified with a pre-frac diagnostic injection test, the final perforation scheme can also be adjusted to ensure a limited entry fracture treatment will divert to the "best" reservoir rock. Although the results presented are specific to the Piceance Basin, the methodology and analytical techniques are valid in all basins.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.