Advanced Technology Completion Strategies for Marginal Tight Gas SandReservoirs: A Production Optimization Case Study in South Texas

Abstract

Advanced Technology Completion Strategies for Marginal Tight Gas Sand Reservoirs: A Production Optimization Case Study in South Texas D. L. Fairhurst; D. L. Fairhurst Schlumberger Search for other works by this author on: This Site Google Scholar S. Indriati; S. Indriati Schlumberger Search for other works by this author on: This Site Google Scholar B. W. Reynolds; B. W. Reynolds Schlumberger Search for other works by this author on: This Site Google Scholar J. W. Lewis; J. W. Lewis Schlumberger Search for other works by this author on: This Site Google Scholar M. W. Holcomb; M. W. Holcomb Crimson Energy Partners Search for other works by this author on: This Site Google Scholar F. F. Starr F. F. Starr Crimson Energy Partners Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, Anaheim, California, U.S.A., November 2007. Paper Number: SPE-109863-MS https://doi.org/10.2118/109863-MS Published: November 11 2007 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Fairhurst, D. L., Indriati, S., Reynolds, B. W., Lewis, J. W., Holcomb, M. W., and F. F. Starr. "Advanced Technology Completion Strategies for Marginal Tight Gas Sand Reservoirs: A Production Optimization Case Study in South Texas." Paper presented at the SPE Annual Technical Conference and Exhibition, Anaheim, California, U.S.A., November 2007. doi: https://doi.org/10.2118/109863-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search Abstract In this case study we address the problems associated with fracturing tight gas sands when nearby water sands are present. Often times the problem is that the created fracture might intersect the water sands which can impede the gas production and in extreme cases can kill the well. Production forecasts based on calibrated permeability values can be performed to show the impact of water production to gas production. If the production forecast indicates that there is enough gas to unload and carry the water to surface then an optimized larger fracture treatment based on effective and relative permeabilities can be performed across both gas and water intervals. If there is not enough gas present to unload the water then the fracture treatment must be carefully designed such that the fracture length is still optimized and water penetration does not occur.A process is described to optimize completion and stimulation design decisions while reducing uncertainty. Production forecasts are made based on a petrophysically advanced reservoir characterization and stimulation design based on a rock mechanical model adjusted for thin laminations. The actual production results have been compared with the forecasts and the process has been calibrated. These calibrations have led to improved economic results in the field. This production optimization process will apply where there are stacked and laminated tight gas sand sequences in close proximity to water sands. Field production can be increased by fracturing gas sands that are normally thought to be too close to water sands as well as gas sands with high interstitial water that would normally be bypassed. Within this case study, several wells were completed that produced a mixture of gas and water which normally would have been plugged or bypassed. Some wells produced more water than predicted and were not economical. Two wells were completed within 20 ft of obvious water sand by adjusting the job size and water was avoided completely. Six wells were stimulated within 30 ft of water and resulted in economical gas and negligible water production. The combination of magnetic resonance acquired permeability estimates and rock mechanical models adjusted by image enhanced petrophysics provided effective input to modify the stimulation design and enable economic completions for gas sands that were very close to stacked water sands.Around the world, strands of tight natural gas resource lie unproduced next to and within water bearing sands. The production optimization process that is described combines several completion techniques that incorporate currently available technology to give the completion engineer one more tool to gain access to these reserves. This technique is not geographically limited and applies to any tight gas sand resource. Keywords: hydraulic fracturing, flow in porous media, Artificial Intelligence, Reservoir Characterization, optimization problem, Upstream Oil & Gas, reservoir pressure, structural geology, stimulation, permeability estimate Subjects: Hydraulic Fracturing, Reservoir Characterization, Reservoir Fluid Dynamics, Exploration, development, structural geology, Flow in porous media Copyright 2007, Society of Petroleum Engineers You can access this article if you purchase or spend a download.