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Exposing formation to Hydraulic Pressure- Technology Advancement for Horseshoe Canyon CBM Stimulation. Original Presentation by: Francois Cantaloube – Schlumberger Mike Yu – EnCana Corporation. CSUG – Nov 2008. Francois Cantaloube– Schlumberger. Agenda. The Conventional Approach
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Exposing formation to Hydraulic Pressure- Technology Advancement for Horseshoe Canyon CBM Stimulation Original Presentation by: Francois Cantaloube – Schlumberger Mike Yu – EnCana Corporation. CSUG – Nov 2008. Francois Cantaloube– Schlumberger
Agenda The Conventional Approach The ThorFRAC Approach Bottom-Hole Dynamics Tool Capabilities Case History and Results
The Conventional Approach Coal Cleat Matrix Natural path of least resistance Preferential damage path Complex stimulation requirements Low Young’s modulus Stimulation fluid Low effective viscosity of N2 Compressibility Equipment limitation at surface Inefficiency due to friction losses Bigger footprint Higher costs Reservoir conditions require High N2 pump rates for an optimized stimulation Operational constraints limit high pumping rates
Effective Pressure at the Coal Face Efficiency loss in the system N2 Pumping rate @ 1200 scm / min
Mechanisms at Coalface PressurizingBH N2 leak-off into formation as BH is pressurized prior to break down
Mechanisms at Coalface Break down
Mechanisms at Coalface Remaining volume injection
Limitations on Current Practices Significant fracture propagation is not likely to occur with low viscosity (N2) Experimental approaches have shown that ultra high-rates deliver better stimulation results than high-volumes Current “high pumping rates” are limited by friction losses CBM economics limit major operational cost increases
Changing The Game The inefficiency of the current approach has triggered the need to optimize the process of CBM stimulation Develop a Multi-zone/high-rate system that effectively transfers energy/pressure to the formation*, optimizing the volume of N2 used. * Patented process (#2 550 750)
Effective pressure at the coal face N2 Pumping rate @ 1200 scm / min
High-Energy Release at Coalface(ThorFRAC) PressurizingBHA
High-Energy Release at Coalface(ThorFRAC) PressurizingBHA No N2 leak-off into formation as BH is pressurized N2 Volume optimization
High-Energy Release at Coalface(ThorFRAC) Pressure Released at highest rate possible in a N2 CoilFRAC treatment
High-Energy Release at Coalface(ThorFRAC) Incremental surface area exposed during subsequent pumping
Bottom-Hole Dynamics Pressure loss in the system
Tool Capabilities Operation: Actuate as many times as required. Actuate at any release pressure without POOH. Follow-up pumping after pressure release. 1 meter minimum interval straddle. Real Time Depth control (CCL) and BHP & BHT enabled through fiber optics. Fluids: Nitrogen: all current cases. Foam: no cases but no apparent restrictions Slurry: Will need to determine the effects on tool. Depth: ~1,000 meters range. Casing: 114.3mm, current. 139.7mm, doable. Pressure Limitation: Tool (49,000 kPa), Cups (35,000 kPa).
Case History • Formation: Horse Shoe Canyon CBM (Belly River formation completed in some wells) • 24 wells on six 4-well pads • New completions- No re-fracs • Perform 2 High Energy Release, and 2 Conventional treatments per pad
Eight-Month Cumulative Production Comparison North Areas “Wet” Section South Areas
Statistical Analysis Completion by Pad Belly River Completed BLRV Contribution Poor gas production due to Wet Section
Statistical Analysis 40% Improvement
Conclusions • Bottom-hole assembly function as per design • Pressure response indicates more surface area was opened • No complication of surface logistics • Horseshoe Canyon CBM production improvement >40% • Spinner logs run on each wells stimulated with the 2 different methods have shown a more consistent production contribution per zone • Full potential of high-energy release system yet to be realized
Maximize Reserves CONTACT Reservoir Effective stimulation Increase production rates